Datasets:

common-pile
/

oercommons

Dataset card Data Studio Files Files and versions Community

Split (1)

train · 9.34k rows

id stringlengths 54 56	text stringlengths 0 1.34M	source stringclasses 1 value	added stringdate 2025-03-18 00:34:10 2025-03-18 00:39:48	created stringlengths 3 51 ⌀	metadata dict
https://oercommons.org/courseware/lesson/108733/overview	Faces and Places of Sustainability in Africa: Inspirations and Innovations Overview The students in CIVE230: Engineering and Sustainable Development go beyond the course content by learning from the world around us and from each other. This e-book has been the project experience that allowed students to explore topics of their choice in cities of their choice, and has become a souvenir from the course! Sustainability lives within the people we know and places we visit The students in CIVE230: Engineering and Sustainable Development go beyond the course content by learning from the world around us and from each other. This e-book has been the project experience that allowed students to explore topics of their choice in cities of their choice, and has become a souvenir from the course! Students in the course were tasked with making a contribution to an e-book. They were creative and innovative in applying course concepts to cities of their choice by exploring sustainability challenges and innovations. Their sustainability project encouraged them to explore solutions including sustainable infrastructure, technologies, policies and initiatives, globally. Students took on the task of connecting these sustainability innovations that make an impact – no matter how small – to relevant Sustainable Development Goals (SDG). They also explored sustainability champions and highlighted their efforts and described their inspiration for choosing them. I am proud of all student contributions. I am proud of the teaching team as well - Mahmoud Badawy, Soukaina Jazouli, and Jide Ogunbanjo - who ensured this course ran efficiently. This e-book serves as a contribution by the class for the class, and for the wider University of Waterloo and engineering community. Please enjoy browsing through!	oercommons	2025-03-18T00:37:13.355450	Student Guide	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/108733/overview", "title": "Faces and Places of Sustainability in Africa: Inspirations and Innovations", "author": "Reading" }
https://oercommons.org/courseware/lesson/122332/overview	MY BODY IS MY OWN Nearly half of women, girls ‘do not own their bodies’, UN says Women’s autonomy in refusing risky sex in sub-Saharan Africa: Evidence from 30 countries Women’s healthcare decision-making and unmet need for contraception in Mali Your Body. My Soul. Overview This lesson aims to give students the opportunity to gain knowledge on the relationship between democracy and women's bodily autonomy in Mali. The topics disccused is formatted to make students think critically about the ways in which democracy may show up differently across the world and how it shows up affects various topics. What is Democracy? Start the lesson off with an interactive activity that will allow students to think answer two questions that they will revisit at the end of the lesson to see what has changed (if anything does change). Give students at least 5 minutes for each question to participate in the activity. Take the time to think about what democracy means to you. What are the first things that come to mind when you hear the word democracy? Scan the QR Code below and share the words and/or phrases that came to mind with the rest of the group. If you are doing this lesson independtly, jot down what comes to mind and keep it close. You will revisit this question toward the end of the lesson. What is Bodily Autonomy? Take the time to think about what comes to mind when you hear the phrase "bodily autonomy." Like you did in the previous section, you can either scan the QR code to share with the rest of the group, or jot down your ideas and save them for later in the lesson. The Foundation Democracy in simple terms can be defined as "government by the people." A more in depth defintion would include the aspect of representation in different parts of government, processes of elections, citizens' rights and freedoms, and ensuring that all groups are being treated equally. However, there is so much to consider when speaking about such a layered concept. Democracy can show up in multiple forms and be implemented differently. The way democracy shows up in the United States can be completely different in other parts of the world like Africa. Cultural, economic, political, external and historical factors play a significant role in determining the ways in which democracy is carried out. Food for Thought: - What does democracy in the United States look like? - What does democracy in Africa look like? Consider these two questions as you navigate through the rest of the lesson. If you want to learn more about democracy, you can watch the YouTube video below. What does democracy look like in Africa? As stated in the previous section, democracy looks different in various parts of the world. But in this lesson, we will be focusing on Africa. Although all countries in Africa do not have a democractic form of government, democracy in Africa is robust and evergrowing throughout the continent. When examining democracy in Africa, it is important to keep the history of the continent in mind. The presence of colonial powers began in the 15th century when European exploration and trade on Africa started. The most notable period of colonization can be linked to "The Scramble for Africa" that occurred in the 19th century, marking the division of African territory among European powers. External parties raced to get a chance at exploiting African countries for personal economic and strategic gains. Governing practices eventually changed to fit the expectations and desires of outside powers, thus resulting in a domino effect for every other aspect of society. Colonial rule within the nations began to disrupt the day-to-day lives of the indigeneous people. The decolonization of Africa occurred in the mid-1950s to 1975. A series of political developments - including violence, revolts, and unrest - led to the countries regaining and in some cases gaining for the first time, their autonomy. The time following post colonial rule was very challenging for most of Africa. The governance structures imposed by colonial powers often disregarded ethnic, cultural, and tribal boundaries. The suppression of traditional governance led to a gap between modern democractic ideals and indigenous practices. Lasting effects of colonial rule also led to slow development, increased lack of education, failing governments, and continuation of certain practices implemented by external parties. Bodily Autonomy in Africa A prominent issue in some countries in Africa is women's lack of bodily autonomy. Unlike other developed countries, developing countries are found to have the highest percentage of women that don't make their own decisions regarding sexual and reproductive health and rights. Quick Facts: - Nearly half of women and adolescent girls in developing countries are denied the right to choose whether the want to have sec with the partners, use contraception, or seek healthcare - In countries Mali, Niger, and Senegal, more than 90% of women are deprived of their bodily autonomy. Activity: Take the time to read the resources attached to this section to learn more about this prevalent issue. The country that we will focus on is Mali. Although Mali is our point of focus, pinpoint other trends that you may notice and make a small note of the countries that pique your interest. A Glimpse Inside Their World Women in Mali face a multitude of challenges regarding their bodily autonomy. 90% of women don't make their own healthcare decisions. The patriarchal ideology can be a prominent factor in regulation by a secondary role. Contraception barriers such as lack of information, gender norms, legal requirements, violence, and/or the healthcare system also play a role. Taking into account that less than half of women in Mali have an education, it isn't surprising that most young women lack the proper information about contraception and health services tailored to meet their needs. Cultural norms encourage fertility and require women to seek authorization from their husbands for certain contraceptive procedures. Thus making it harder for them to make their own decisions. Cultural practices like early marriage, domestic violence, and female genital mutilation are also contributing factors. While onlookers may see these practices as harmful, it is important to think about how the people in Mali see them as normal. There is no set definition for early marriage. So, what the U.S. deems as early, may not be early in other places. It's vital to not let personal opinions overshadow the harsh reality. While looking through the articles attached to this section, consider the following question and take note of what you come up with: - What does this issue have to with democracy? Remember to consider all the democracy encompasses. It's not just a simple concept that can be explained in one sentence. It requires context and one to think about historical implications, culture, and external factors. How does democracy contribute to lack of women’s rights and equality? In the previous section, you were tasked with answering how lack of bodily autonomy and democracy coincide with each other. Below are a few points that you should have thought of when answering the question. It is okay if you missed anything listed because you can just add to what u already have. If you thought of anything that was wasn't listed, please feel free to share with others what else you wrote and why u thought it contributed. Factors: - Government - Form of government - Women's representation in government - If women are elected in official positions, do they represent the greater majority of the women that make up the population? Are their voices and opinions actually heard when they speak out on certain topics? - Education access for women - Citizen freedom and government engagement - Economy, poverty, and development Deep Dive Quick Facts: Government: - Type: Republic - Independence: September 22, 1960 - Constitution - Branches - Excective - president (chief of state and commander in chief of the armed forces) & prime minister (head of government) - Legislative - National Assembly (sole legislative arm) - Judicial - Supreme Court (judicial and administrative powers) - Political parties: Multiparty democracy - Suffrage: Universal at 18 Education: Percent of educated women in Mali compared to the world average of 91.74% - 43.4% (2018) - 38.45% (2020) Poverty: - 49.3% of Malians live below the poverty line - Poverty rates increased from 15.9% (2021) to 19.1% (2022) - Fluctuation in commodity prices has resulted in a low-income economy - Commodity prices: the fluctuating values of goods like natural resources, agricultural products, and metals in the market - Rapic population growth - 5.88 children per woman Activity: I have attached a link to the Afrobarometer website. Please use this resource to do a deeper dive on statistics of Mali. A few things that you should look at are women's representation in government, women's access to education, economic conditions, citizens' involvement in government, and anything else you think can help you better understand the dynamic of women's autonomy over their body. When you see something that you find interesting, don't just take note of it. Ask yourself how you think it contributes to the topic of discussion. Remember that almost everything plays a role, whether that be directly or indirectly. Reflection Now that you have read through the lesson, I want you to return to the two QR codes at the beginning of the lesson. Answer the two of the questions and think of how your answers changed. If they changed, explain why. If they didn't explain why they stayed the same. Democracy is a very intricate concept. There are so many factors that play a part in the way democracy is carried out. Those same factors also influence and are partly responsible for other issues that various countries face. In this lesson, the issue discussed was the lack of bodily autonomy in Mali. Statistics of poverty, education, economic conditions, citizens' involvement in government, etc. served as an explanantion to the high secondary roles having the final say. But due to cultural norms, Malians may not see this as an issue. The ways of the Malians that outsiders deem as "harmful" may be viewed as perfertly normal by the Mali citizens. Activity: In Section 5, you were supposed to write down at least one country that piqued your interest when looking through the MY BODY MY OWN resource. Use the Afrobarometer to do a similar evaluation on how democracy or the lack of democracy is causing the statistics on women's bodily autonomy in the country.	oercommons	2025-03-18T00:37:13.391084	12/02/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/122332/overview", "title": "Your Body. My Soul.", "author": "Khamanie Dorsainrre" }
https://oercommons.org/courseware/lesson/60871/overview	Parenting Styles Demonstrated by Disney Characters Overview This is a blog that compares parenting styles to specific disney characters. Parenting Styles Demonstrated by Disney Characters This is a blog that compares parenting styles to specific disney characters.	oercommons	2025-03-18T00:37:13.407105	12/17/2019	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/60871/overview", "title": "Parenting Styles Demonstrated by Disney Characters", "author": "Jesse Peters" }
https://oercommons.org/courseware/lesson/71888/overview	Sign in to see your Hubs Sign in to see your Groups Create a standalone learning module, lesson, assignment, assessment or activity Submit OER from the web for review by our librarians Please log in to save materials. Log in Ragju Raghu or	oercommons	2025-03-18T00:37:13.432124	08/28/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/71888/overview", "title": "R", "author": "Raghu Panwar" }
https://oercommons.org/courseware/lesson/117294/overview	LiPS Program Overview What are effective ways to increase and keep attention in a structured task/program? There are many different structured programs, so with the research and knowledge I gain about maintaining attention, I will apply it while using the LiPS program. CAT	oercommons	2025-03-18T00:37:13.448008	06/25/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/117294/overview", "title": "LiPS Program", "author": "Jocelyn Umaña" }
https://oercommons.org/courseware/lesson/114234/overview	SHU: IHE Accessibility in OER Reflection Overview This document serves as a reflective piece for faculty and staff who took part in the Accessible OER Academy for Institutions of Higher Education, a freely available program hosted by ISKME and CAST. Participants were equipped with this Open Educational Resource (OER) to conduct a Landscape Analysis, aiming to identify crucial frameworks and aids to steer our efforts in promoting Accessibility in OER. Our team utilizes this document as a platform to exchange ideas within our community, as we advance as an institution towards greater integration and utilization of OER internally, while advocating for accessibility best practices for all. Landscape Analysis for Accessibility in OER in Local Context Part One: Initial Thoughts - Our initial goal was actually a few goals: - Learn more about accessibility as an institution and identify any new strategies or gaps. - Learn about OERs and as a baseline, how to start implementing them at our institution. - Start small and create a plan that prioritizes goals with targeted dates of compliance. Part Two: Introductory probing questions: What does accessibility look like in our organization? How do we measure accessibility Accessibility efforts at SHU are progressing, especially with the recent appointment of a new Accessibility Director. This change is expected to improve accessibility across the board. While some faculty members may need guidance, there's growing awareness within SHU Global about accessibility, though there's room for improvement. We do have a significant number of online instructors facing accessibility challenges, highlighting the need for ongoing support and training. Regarding student involvement, not all students readily self-report or seek Individualized Education Programs (IEPs). What does OER look like in our organization? How do we measure access to OER? We do not have widespread OER adoption, rather we just have select faculty or staff who have some knowledge of it. We have no way of analyzing access to OERs. Part Three: Clarifying questions for accessibility: What are the organizational structures that supports accessibility? At our institution, we have an Accessibility Coordinator. Additionally, we have Canvas ' accessibility checker is good; it is easy to caption videos and create alternative text for images, and it shows areas that aren't accessiblie. Who generates most of the accessibility structures/conversation in our organization? Currently, a lot of the accessibility conversations happen within the Digital Education space. So OLAC, as a committee is focused on accessibility in online courses, and generates a lot of the conversations surrounding accessibility on our campus. Where do most educators get support with accessibility? Educators have a few resources for help when they have accessibility questions. First, the Accessibility Coordinator has a lot of great resources and tools for faculty. Second, the instructional designer acts as a hands-on help with accessibility in instructional materials and courses. Lastly, the Canvas Administrator often reminds and supports faculty with accessibility in their Canvas courses. What content areas might have the largest gaps in access to accessibility? There is not a lot of on-ground support for accessibility, mostly because there is no quality assurance process like there is for online courses. When an online course is inaccessible, it is either caught and addressed when working with the instructional designer or during an OLAC course review. That structure is not in place for on-ground courses, so there is no way of identifying or addressing accessibility gaps. Part Four: Clarifying questions for OER: What is our organizational structure that supports curricular resources? We do not have a defined organizational structure that supports curriculuar resources. Our librarian maintains a database for online articles for faculty to use in their courses, which is always a great starting point. What is our organizational structure that supports OER? There is no organization structure in place to support OER. Many faculty and staff are unsure of where to start to put this in place. Who generates most of the curricular resources in our organization? Faculty generate most of the curriculuar resources. Where do most educators get support with curricular resources? Faculty go to their respective departments for resources. What content areas might have the largest gaps in access to curricular resources/OER? Since our campus does not currently have an OER initiative, we do not have the data or research to identify gaps. Part Five: Clarifying questions for Faculty learning and engagement: What Professional Learning (PL) structures have the best participation rates for our educators? The support structures in place for faculty that gets the best participation is usually Workshop Week or Common Dialogue day, both of which are hybrid events focused on sharing teaching and learning best practices. What PL structures have the best "production" rates for our educators? The PL structures that have the best "production" rates, or best learning outcomes, is the OLAC training course that faculty are required to take prior to teaching online. This is also the case for the Accessibility course. What incentive do we have to offer people for participating in learning and engagement? Unfortunately, there is no tangable learning incentive for those participating in learning and engagement. There is a sense of community at our instituion for those who are "lifelong learners" and several people participate for this reason. Who are the educators that would be most creative with accessibility and OER? Our OLAC committee memebers are already very aware of accessibility in education and implement best practices into their course. They would be very creative given the opportunity to use OERs in their courses. Who are the educators that would benefit the most from accessibility and OER? We believe that all educators would benefit from OER use, especially since many of our instructors are interested in OER use but are unsure where to start. Part Six: Final Probing questions: What is our current goal for Accessibility in OER and why is that our goal? Our current goal for Accessibility in OER is to gain support in getting a baseline for implementation. This includes ongoing resources to help faculty in the "day to day" of OER and Accessibility, rather than just widespread training every year. Who have we not yet included while thinking about this work? In speaking with cohort members, someone mentioned grants and seeking out funding to get OERs and Accessibility support started. If we do explore external funding, it would be benefitial to include our institution's grand writer in that process. What barriers remain when considering this work? The largest barriers to our work in accessibility and OER is time. Many of us in our cohort are doing the work of 1.5 jobs, so dedicating additional time to implementation is difficult. What would genuine change look like for our organization for this work? There would need to be significant structure and organizational changes at our institution for widespread adoption to work. Many faculty and staff are overworked and underappreciated, which needs to be addressed from the top-down. Team Focus Identifying and Describing a Problem of Practice The following questions should help your team ensure that you are focusing your collaboration. What is your Team’s specific goal for this series? You may consider using AEM Quality Indicators for Creating Accessible Materials to help add to or narrow your work. Our initial goal was actually a few goals:- Learn more about accessibility as an institution and identify any new strategies or gaps. - Learn about OERs and as a baseline, how to start implementing them at our institution. - Start small and create a plan that prioritizes goals with targeted dates of compliance What other partners might support this work? We have some support from administration to look into OER and accessibility, particularly identifying gaps. What is your desired timeframe for this work? This is an ongoing project, so there is no definitive timeframe. How will you include diverse voices and experiences in this work? We have involved several faculty members and staff memebers from a wide range of expertise to weigh in. Please create a Focus Question that explains your goal and provides specific topics that you would like feedback on. This is what you will share in your breakout groups for feedback. How do you, as an institution, get started with providing OER resources? What feedback did you receive from another team during the March 14th Implementation Session? Team Work Time and Next Steps Sharing and Next Steps What was your redefined goal for this series? Our redefined goal was to get started, as an instution, using OER resources by providing some training to those who were unable to join this training series. What does your team want to celebrate? We had a lot of faculty and staff participate in this academy! Considering how busy everyone is, it was great that we were able to make time and all come together for this training. What did your team accomplish? Please link to or attach at least one resource you have created/adapted. We have finished this reflection document, which is getting us started thinking and reflecting on OER and accessibility gaps at the institution. What are your team’s next steps? A few of us in this cohort are creating an OER resource training for faculty, and we plan to include some of the topics covered in this training series.	oercommons	2025-03-18T00:37:13.476843	03/14/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/114234/overview", "title": "SHU: IHE Accessibility in OER Reflection", "author": "Ashley Harris" }
https://oercommons.org/courseware/lesson/106231/overview	Emergency Evacuation Procedures Overview This resource provides video recordings and a downloadable Personal Emergency and Evacuation Plan (PEEP) for new therapist to utilize when conducting emergency and evacuation planning for their students. Emergency Evacuation Procedures Emergency planning for our students is essential. The following ECHO recordings go over the PEEP (Personal Emergency and Evacuation Plan) and is important for all new hires to be aware of. 1. The PEEP: A Template for a Student Personal Emergency and Evacuation Plan 2. Evacuation Preparedness and Equipment: When the Drill Becomes Reality? 3. Emergency Evacuation Planning for Students with Disabilities A template of the PEEP is provided as a downloadable document.	oercommons	2025-03-18T00:37:13.496094	07/03/2023	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/106231/overview", "title": "Emergency Evacuation Procedures", "author": "Nathaniel Baniqued" }
https://oercommons.org/courseware/lesson/105468/overview	IHE Accessibility in OER Implementation Guide--MTSU Cohort Overview Our cohort from Middle Tennessee State University conducted a Landscape Analysis to uncover key structures and supports that can guide our work to support accessibility in OER. Section One: Landscape Analysis for Accessibility in OER in Local Context In this section, you and your team will engage in a Landscape Analysis to uncover key structures and supports that can guide your work to support Accessibility in OER. We exnourage to explore some of the questions from each category. You may or may not answer all of these questions, but this is an offering. We ask that you complete Parts One, Two and Six. Part One: Initial Thoughts What are your team's initial goals for this series? - To learn best practices of how to make OER accessible for all learners and to share what we learn with our campus - To consider ways faculty could make (or find) OER goodies that be consumed in a variety of methods (read, listened to, viewed, etc.). - Get OER and accessibility information out there for students and faculty in a universal way. - Promote OER as “not a burden” or extra work for faculty. - Think about how we can encourage levels of accessibility, where at least some minimum standards are met. Part Two: Introductory probing questions: What does accessibility look like in our organization? How do we measure accessibility? Our Office of Institutional Equity and Compliance oversees the compliance portion of campus needs, including the Disability & Access Center (DAC). The DAC provides face to face services for students, supports student registration for accommodation, and informs faculty of a need for accommodation. They also support the Adaptive Technologies Center. ITD, specifically Academic and Instructional Technologies, supports in classroom technology enhancements (Panopto, Zoom, etc.). The Center for Technologies and Training (CTAT) has an accessibility person, workshops are done occasionally on these topics for making documents and such accessible. MTSU Online has instructional designers with specific training and certifications in accessibility. We monitor, adapt, and enhance accessibility and accommodation needs for all certified online courses through the accessibility checks of resources, the promotion and integration of H5P activities, and intentional conversations with all developers about accessibility and inclusion. What does OER look like in our organization? How do we measure access to OER? OER at MTSU is not widespread, but it is slowly growing. A Student Success & Open Education Librarian was recently hired and tasked with developing the OER program. We have an OER Task Force assembled to plan next steps.The university recently identified new OER goals under Strategic Priority 3 of our Quest 2025 that aspire “to expand the use of open educational resources and educate stakeholders" and to “promote the value of OER to faculty and students.” We are starting to track the number of course sections using OER. In Fall 2022, there were 24 courses and 54 sections marked with the OER attribute. For upcoming Fal 2023, there are 35 courses and 163 sections. Part Six: Final Probing questions: What is our current goal for Accessibility in OER and why is that our goal? Create a 1-2 page set of guidelines/tips that can serve as a starting point for faculty thinking about inclusivity, accessibility, and OER Periodically present a series of faculty workshop to promote a positive attitude toward OER Who have we not yet included while thinking about this work? - Provost's office - President's office What barriers remain when considering this work? Time Buy in from other faculty Access to current, updated, quality OER Knowledge or skill in creating derivatives that are accessible Incentives to create this culture e.g., funds What would genuine change look like for our organization for this work? Adoption of OER by a certain percentage of faculty/across courses. Creation and use of engaging, accessible OER resources. Sharing/creating OER in a shared MTSU platform where faculty don’t need to reinvent the wheel for some topics across disciplines Section Two: Team Focus Identifying and Describing a Problem of Practice The following questions should help your team ensure that you are focusing your collaboration. - What is your Team’s specific goal for this series? You may consider using AEM Quality Indicators for Creating Accessible Materials to help add to or narrow your work. We want to create a 1-2 page resource that serves as a starting point for MTSU faculty on the topic of accessibility in open educational resources. It should include general guidelines as well as practical tips to help faculty get started on their journey of creating and adapting accessible OER. We hope this will help raise awareness among stakeholders about the importance of thinking about inclusivity and accessibility in OERs before creation or adoption. - What other partners might support this work? Provost, LT&ITC, SGA, or a unit with funds willing to print/publish resource. - What is your desired timeframe for this work? Infographic or other resources in time for new faculty orientation fair in August – share with departments for start of year information for returning faculty. - How will you include diverse voices and experiences in this work? This is a key point of our conversations, so including diverse voices and experiences is not in addition to our work – it is a key component of our work. Please create a Focus Question that explains your goal and provides specific topics that you would like feedback on. This is what you will share in your breakout groups for feedback. What content should be included and what would be the best format to deliver that content (slide deck, infographic, tutorial video, etc.). What is your university doing to encourage OER? What feedback did you receive from another team during the May 25th Implementation Session? They have been nominated for awards, Communications and Kinesiology (not institutional). They include it in the contracts. They give stipends for workshop attendance.They use Bucks +. Section Three: Team Work Time and Next Steps Sharing and Next Steps What was your redefined goal for this series? Identify and share starting points for faculty to create and curate accessible OER. Share those through an infographic and plan a series of workshops via our teaching and learning center this fall and next spring. What does your team want to celebrate? We've all learned so much about accessibility principles and tools, and we've started building a community around OER and accessiblity! The conversation is just getting started. What did your team accomplish? If you have links to resources, please include them here. We created an infographic (linked in Section 4 below) and are planning future workshops and collaborations. What are your team’s next steps? We will continue collaborating and plan to meet as a group once or twice a month going forward.	oercommons	2025-03-18T00:37:13.519019	Sam Zaza	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/105468/overview", "title": "IHE Accessibility in OER Implementation Guide--MTSU Cohort", "author": "Ginelle Baskin" }
https://oercommons.org/courseware/lesson/72735/overview	SOCIAL IMPACT OF INFORMATION TECHNOLOGY DEVELOPMENT Overview Introduction to the lecture World society has been changed by the impetuous development and diffusion of information and communication technology (ICT) into fields such as economics, business, education, health, agriculture, and so on. The Department of Education, Training, and Employment (Queensland, Australia) states: «To live and work in the technology-enabled world of the 21st Century, high-level skills in the use of information and communication technologies (ICT) are essential for all citizens». (DETE, 2001a, p.5)	oercommons	2025-03-18T00:37:13.531016	09/21/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/72735/overview", "title": "SOCIAL IMPACT OF INFORMATION TECHNOLOGY DEVELOPMENT", "author": "Olena Maiboroda" }
https://oercommons.org/courseware/lesson/79494/overview	French Level 4, Activity 13: Un pitch de film / A Film Pitch (Online) Overview In this activity students will practice talking about French films, and then practice pitching an original film idea of their own. Activity Information Did you know that you can access the complete collection of Pathways Project French activities in our new Let’s Chat! French pressbook? View the book here: https://boisestate.pressbooks.pub/pathwaysfrench Please Note: Many of our activities were created by upper-division students at Boise State University and serve as a foundation that our community of practice can build upon and refine. While they are polished, we welcome and encourage collaboration from language instructors to help modify grammar, syntax, and content where needed. Kindly contact pathwaysproject@boisestate.edu with any suggestions and we will update the content in a timely manner. A Film Pitch / Un pitch de film Description In this activity students will practice talking about French films, and then practice pitching an original film idea of their own. Semantic Topics French films, movies, film ideas, french, films, français, créer une histoire, create a story Products Movies, Films Practices Watching movies Perspectives Directors tend to be more famous than actors in France, and films are usually described first with the director and secondly with the main characters and actors. They are seen as artists! NCSSFL-ACTFL World-Readiness Standards - Standard 1.1: Students engage in conversations or correspondence in French to provide and obtain information, express feelings and emotions, and exchange opinions. - Standard 1.2: Students understand and interpret spoken and written French on a variety of topics. - Standard 3.2: Students acquire information and recognize the distinctive viewpoints that are only available through francophone cultures. - Standard 4.2: Students demonstrate understanding of the concept of culture through comparisons of francophone cultures and their own. Idaho State Content Standards - COMM 1.1: Interact and negotiate meaning (spoken, signed, written conversation) to share information, reactions, feelings, and opinions - COMM 2.1: Understand, interpret, and analyze what is heard, read, or viewed on a variety of topics. - COMM 3.1: Present information, concepts, and ideas to inform, explain, persuade, and narrate on a variety of topics using appropriate media in the target language. - CLTR 2.1: Analyze the significance of a product (art, music, literature, etc...) in a target culture. - CLTR 2.2: Describe the connections of products from the target culture with the practices and perspectives of the culture. NCSSFL-ACTFL Can-Do Statements - I can talk about French films. - I can describe an original film idea in French. - I can share my ideas and opinions with my peers. Materials Needed Warm-Up Warm-Up 1. Begin the activity by opening the Google presentation and introducing the Can-Do statements. 2. Ask the students these questions: - Quel est votre genre de film préféré ? (What is your favorite genre of movie?) - Avez-vous déjà regardé un film français? Lequel/lesquels ? (Have you ever seen a French film? If so, which one(s)?) Main Activity Main Activity 1. Have the students start by watching these two movie trailers (bande-annonce de film): Le Petit Vous allez regarder 2 bande-annonce de film. 2. Here are a few reflection questions for them to think about while watching: Pensez à ces question en regardant les bandes-annonces - Quelle est l'intrigue générale du film ? (What is the general plot of the film?) - Quels éléments rendent ce film intéressant ? (What elements make this film seem interesting?) - Voudriez-vous regarder ce film ? (Would you watch this film?) 3. After watching, students are going to create an original film idea of their own. This can be done with partners via breakout rooms or individually. Maintenant, vous allez créer une idée pour un nouveau film avec un(e) partenaire ou individuellement. Questions to think about: (slide 8) Pensez à ces questions quand vous formulez votre idée : - Quel genre de film est-il ? (What genre of film is it?) - Qui sont les personnages principaux ? (Who are the main characters?) - Qu’est-ce qui se passe pendant le film ? (What happens during the film?) - Pourquoi quelqu'un devrait-il regarder ce film ? (Why should someone watch this film?) 4. After about 7-10 minutes, have the students present their film ideas to the rest of the group. Encourage them to treat this as a type of film pitch. Puis, vous allez la partager avec la classe. Wrap-Up Wrap-Up Ask the following question(s) to finish the activity: - Quelle est votre idée de film préférée de cette activité ? Expliquez pourquoi. (What’s your favorite film idea from this activity? Why?) Cultural Resources The Highest Grossing Films in France French Films to watch on Netflix End of Activity - Can-Do statement check-in… “Where are we?” - Read can-do statements and have students evaluate their confidence. - Encourage students to be honest in their self evaluation - Pay attention, and try to use feedback for future activities! NCSSFL-ACTFL Can-Do Statements - I can talk about French films. - I can describe an original film idea in French. - I can share my ideas and opinions with my peers.	oercommons	2025-03-18T00:37:13.569180	Camille Daw	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/79494/overview", "title": "French Level 4, Activity 13: Un pitch de film / A Film Pitch (Online)", "author": "Mimi Fahnstrom" }
https://oercommons.org/courseware/lesson/113717/overview	Cell Membranes Made EASY! Overview This is a video and worksheet covering the basics of cell membranes (Anatomy and Physiology 2e, Chapter 3). Cell Membranes Video and Worksheet This video and worksheet cover the basic concepts of cell membranes (Human Anatomy and Physiology 2e Chapter 3).	oercommons	2025-03-18T00:37:13.586356	Assessment	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/113717/overview", "title": "Cell Membranes Made EASY!", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/128180/overview	S6 UNIT 14 Overview Key Unit Competence: By the end of the Unit, I should be able to evaluate the impact of multi-purpose river projects on sustainable development of different countries in the world. WORLD MULTIPURPOSE RIVER PROJECTS 14.1. Definition, aim, objectives and importance of multipurpose river Projects This refers to projects that are built on various rivers and are used for different purposes such as providing power, eliminating floods, providing water for agriculture, domestic and industrial use. Aims of multipurpose river projects: The aims of the multipurpose river projects are to increase the economic independence through the sustainable development of various economic sectors, the national wealth and the standards of living of inhabitants. Objectives of multipurpose river development: - To control flood. - To provide water for irrigation, diversify agricultural production. - To check soil erosion. - To provide water for drinking and domestic purposes. - To generate electricity for industries, villages and cities. - To provide inland navigation. - To encourage tourism and recreation. - To preserve wildlife. - To develop fisheries. - To create employment opportunities. - To promote industrialization and urbanization. - Diversify the economy. - Creation of settlements for the landless/surplus population. Hydro-electric power plant (HEP): an hydro-electric power plant is constructed to generate hydro-electricity for industries and homes. As represented on the figure below, a hydro-electric power plant arrangement consists of basic sections such as dam, reservoir, penstock, control gates, turbines, power house which include generator and transformer and power lines. These basic sections are briefly described in the following: Dam: A barrier constructed across a river to hold back water and raise its level, forming a reservoir used to generate electricity or for domestic, irrigation or industrial water supply. Some dams are built also to preventing the flow of water or loose solid materials (such as soil or snow). Reservoir: The part of river where water will be stored is called Reservoir. Penstock: Penstocks are generally made of reinforced concrete or steel to transport water from reservoir to turbine with less friction losses. Control Gate: Also called crane is used to control over the water travelling in penstock. Turbines: Water turbines are used to convert the energy of falling water into mechanical energy and enable generators to produce electrical energy from rotating shaft of turbine. Power House: At the power house generated power from generator will be stepped up and supplied to transmission power lines. Power lines: wires connected to the generators that carry electricity to homes, industries and mines. 14.1.2. Importance of multipurpose river projects for sustainable development The benefits of river dam projects for the sustainable development of countries include: - Provision of cheap and reliable hydro-electric power: Most river dam projects in Africa are used to generate hydro-electric power for both domestic and industrial purposes. - Provision of water: The dams provide water for domestic, industrial and irrigation uses for local inhabitants residing nearby. The water stored behind dams is irrigation reservoir which helps in the growing of crops, especially during the dry season. This has reduced farmers’ dependence on climate. Irrigation farming can be carried out to increase food supply. - River water is renewable source of energy: In contrast of other sources of energy which are non-renewable because they are exhausted with time as they are exploited (e.g. wood, coal, petroleum), multipurpose river projects are mainly built on river water which is long lasting and one of renewable source of energy. - Development of tourism: Some multipurpose river projects can be of tourist interests, thus earning foreign exchange, because river dam projects are associated with features like impressive architectural designs, waterfalls, dams and lakes which may be fascinating to the people that come to visit the places. - Generation of government revenue: This is through taxation of workers’ incomes and earning of electricity and water boards. - Employment opportunities: River dam projects create employment opportunities for several people, especially those engaged in the production of hydro-electric power and supply of water for domestic, industrial and irrigated agriculture developed in the area. Provided employment raises people’s standards of living. - Industrial development: The projects have stimulated the development of industries as there is ample power that is generated. This enabled the boost of textile, brewing, sugar processing and steel rolling industries. - Development of infrastructure: The projects have opened water transport routes or shipping routes (river navigation). Many other infrastructures such as development of towns, schools and hospital facilities among others have developed within the river valley. - Promotion of international relations: There have been joint ventures in the development of river projects that have created co-operation among nations. - Flood control: Dams are used to control flooding in flood-prone areas by regulating the flow of water downstream. - Reduction of importation: There is reduction on costs incurred on the importation of fuel, manufactured products and foodstuffs since these are now produced locally. 14.2. Problems affecting Multipurpose River Projects - Change in river regime - Inadequate funds - Inadequate skills and technology - Deforestation - These projects have led to displacement of people where dams are built. - Construction of dams caused ecological problems like blocking the migration of fish - Siltation of dams - Excessive evaporation which leads to the change of climate conditions 14.3. Solutions to the problems affecting Multipurpose River Projects - Establishment of the project based on accurate environmental conditions such as the characteristics of river regime and seasonal fluctuations, to avoid situation where the project collapses soon after its establishment. - Training people to do the maintenance of the machinery and infrastructures generated by the project. The lack of required home-grown skilled personnel can be addressed if governments plan early enough and invest in the area of human resource development, to improve their human resources capacity and thus reduce dependence on foreign expatriates who are always quite expensive to hire. - Continuous monitoring and evaluation of projects and taking corrective measures are needed. - Continued partnership and cooperation with donors and funding agencies to obtain soft or long-term loans with which to finance the project activities. - Fight and contain the spread of Bilharzia/Schistomiasis over irrigated project areas. - Resettle the landless due to the drawning of agricultural land by the manmade lake resulting from dam construction. In order to maintain the viability of the projects, some of activities to undertake include: - Removing in the waters the invasive species which are dangerous to aquatic lives. - Allow sufficient time and money for extensive public participation to ensure that plans are optimal; that all sections of affected society are considered and; that local institutions are in place to sustain irrigated agriculture, particularly in respect of land and water rights; - Afforestation: The increase of number of trees and vegetation protects the water catchment areas of the rivers feeding the dams. This reduces the fluvial erosion and other types of erosion which could damage the dams; - Provide short-term support and/or skills for an alternative livelihood if irrigation removes existing livelihood. 14.4. Case Studies 14.4.1. The Tennessee Valley Authority (USA) The Tennessee basin in USA was often devastated by floods and its economy depressed because the pioneer settlers and their descendants farmed using inappropriate traditional methods till the region became poverty-stricken. The soils were eroded, hill slopes were treeless, rivers which were filled with silt eroded from the surrounding hills became uncontrollable, causing huge floods on extensive parts of the region and many damages to lives and properties. The Tennessee Valley became one of the poorest parts of USA in terms of economic wellbeing. In 1933, the president Franklin Roosevelt signed the act to establish the Tennessee Valley Authority (TVA). It is found in USA. It was constructed in 1993 to provide navigation, control floods and for purpose of electricity generation. The TVA was formed to solve the problems in several states such as: Tennessee, Kentucky, Virginia, North Carolina, Georgia, Alabama and Mississippi. It was undertaken in Tennessee valley area to revive one of the poorest and badly eroded parts of USA. i. Aims of The Tennessee Valley Authority The Tennessee Valley Authority (TVA) is a corporation formed for large-scale rehabilitation of a vast region which includes parts of seven adjoining states of Tennessee, Kentucky, Virginia, North Carolina, Alabama, Georgia and Mississippi, in the United States of America (USA). The Tennessee Valley Region is drained by the Tennessee River and River Timberland, both tributaries of the Ohio River which is a tributary of Mississippi River. The drained area is about 106,000 km². Due to persistent flooding and soil erosion which marked the Tennessee basin for centuries ii. Problems faced by the region before the creation of TVA - There were flood on river Tennessee and its tributary which caused massive destruction of farmlands, loss of property and human lives. - Poverty had become a major challenge due to lack of employment opportunities and means of livelihood. - Soil erosion especially on the hilly slope of the Appalachian Mountains had become a threat to the farmers and entire region. Famine had become a serious problem. - Diseases like malaria and bilharzia due to floods had become common. - There was rampant unemployment due to lack of industries within the region. - There was a problem of poor transport system because Tennessee river and its tributaries were not navigable. - High government cost iii. Strategies taken by the USA central government to solve the problems Strategies taken to solve the problems in Tennessee region were sequenced in various steps: Step 1: Assignments tasked to the Tennessee Valley Authority The following tasks were assigned to Tennessee Valley Authority when it was created: - Building dams to control flooding of River Tennessee and its tributaries and later generate hydro-electric power. The generated electricity would be exported to other neighboring states thus reaping revenue for the state. - Controlling severe soil erosion by putting in place sustainable conservation measures, and mechanisms for reclaiming badly eroded lands and flooded swamps in the area. - Promotion of forestry through afforestation programs. These programs aimed to reduce flooding and soil erosion in the area. - Improvement of the transport facilities such as roads, railways and water transport whose construction and maintenance were hindered by floods. - Promotion of the industrial development to increase alternative employment opportunities to the people in the area, in the agriculture sector and industrial sector. - Teaching inhabitants better farming methods to improve sustainably agriculture in the region. - Providing enough and sustainable housing to accommodate the rapidly growing population. - Conserving wildlife in the area. - Controlling the spread of diseases such as malaria and Bilharzia that resulted from floods. Step 2: Concrete actions taken to control soil erosion The following are concrete conservation measures taken by TVA to control soil erosion: - Training of farmers: Experts were hired from outside the local area especially from other agriculturally advanced regions of USA like California and Southern USA to educate local farmers on how to improve their farming methods; - Creation of demonstration farms: aimed at giving advice to farmers on modern and better farming methods such as mixed farming and crop rotation; - Re-afforestation programs: These were undertaken to plant young trees on ridges and hills. Their roots would bind the soil particles together and absorb excess water which was previously running off; - Filling the Gullies: gullies were covered with brushwood to cover and trap soils and stones and eventually fill up the gullies; - Terracing: this involved the cutting of a series of wide steps and construction of embankments on hilly slopes to reduce gradient and surface runoff; - Introduction of modern farming methods: farms were mechanized in order to increase the production. The use of fertilizers and manure to maintain soil fertility was also applied. Step 3: Construction of Dams and results - Several dams were constructed: Nine dams were constructed on the main Tennessee River and 23 on its tributaries. The major ones along the Tennessee River include Noris, Cherokee, Fontana, Chickamauga, Willson, Pickwick, Fort Loundon, Douglas, Kentucky, Guntersville, Hirwassee and Walts bar. All the dams can control floods, storing water, assisting navigation and generating hydro-electricity. - The huge reservoirs created by the dams hold back enormous quantities of water: This reduced greatly the flood heights, and since then this water is released for irrigation purpose or holds water for navigation. - Elimination of swamps: The management of swamps resulted in a complete elimination of malaria and bilharzia - Development of tourism: Natural parks and man-made lakes were created. Camping, canoeing and hunting have been promoted. The scenic beauty around dam recreation facilities at wildlife reservations attract more tourists and increase foreign exchange. - Supply of Electricity to industries: The TVA also directs the storage and release of water and generation of power at four dams owned by the Aluminum Company of America (ALCOA). Step 4: Construction of important infrastructures and industries The major infrastructures and industries constructed include: - Electric Power Station and urban development: Constructed power stations stimulated the growth of urban centres, for example, Memphis and Birmingham - in Alabama State, Atlanta in Georgia and many others across the region. By 1953, 80% of homes in the region were electrified, compared with 3% at the beginning of the project in 1933. Today the full-scale rural electrification has been a great achievement for the TVA. - Transport Infrastructures: Roads, air and railway transport networks were constructed in the region. Navigation on created dams on Tennessee and transportation of freights and passengers over a distance of 1.050 km are known to be among the most efficient worldwide. - Educational and research institutions: Various Institutions of learning such as Universities, Colleges and Schools were constructed in Tennessee Region. All research centres were established with linkage to universities and colleges. - Industrial centres: Industries were constructed to generate employment opportunities to the people. Major industries include Aluminum manufacturing, fertilizers industry like phosphates, paper mills, chemicals, pharmaceuticals, automobiles and food processing plants. - Health centres and hospitals: Several health centres and hospitals were constructed to improve the health of states within the Tennessee catchment area. These are able to serve not only the seven states of the region, but the international community as well. Benefits of TVA for sustainable development of the region - The control of floods and soil erosion has been successfully and sustainably mastered. - Cheap hydro-electric power was availed: This attracted diversified industries that offered employment within the Tennessee valley. - Diversified food products: Milled grains, baked foods, confectioneries and beverages and many others are produced in the region. - Local farmers joined the established demonstration farms: Farmers were trained on better farming methods to control soil erosion and increase crop yields. - Diversified and improved transport networks: This encouraged significantly the local and international commerce. - Many and diversified industries in the region process ores and other raw materials: Raw materials that were formerly processed in the North East of USA are now processed in the Tennessee region. - Tourism was greatly promoted: The region covered by TVA earns the government of USA foreign exchange as a tourist attraction destination; - The production of motor vehicles, boats and aircraft parts: Constitute Tennessee’s largest industry in terms of contribution to overall TVA’s states economies. 14.4.2. Akasombo Dam – The Volta River Project (Ghana) i. Location and site of Akasombo Dam The construction of the Akasombo Dam was the first Ghanaian project undertaken by the Volta River Authority (VRA) in 1960. The dam is located on River Volta near the Akasombo town in southern Ghana. The site has been chosen because it was where the river valley was narrowest and surrounded by a rock strong enough to hold the dam Aims and objectives of the project The project aimed at constructing Akasombo Dam and Volta Lake, one of the longest man-made lakes in the world. The dam is 111 m high and 660 m long at the top and 366 m at the bottom. A man-made lake; called Volta Lake, was formed behind the dam covering an area of 8502 sq.km. The Lake extends for 400 km with a shoreline of 7,250 km. ii. The dam was built with the following objectives: - To provide cheap electricity to run the smelter: called Volta Aluminum Company (VALCo) located at the new port of Tema and to increase the Ghana’s domestic and industry supplies of power. - To control and regulate the flows and recurrent flooding of the River Volta. - To promote agriculture through development of irrigated farming but also to provide a major inland waterway. - To construct the Lake Volta to enhance fishing and supplement population in animal proteins. - To create employment opportunities for Ghanaian population to improve the standards of living for the people in the area. iii. Factors favouring the establishment of the Akasombo river project - The heavy and well distributed rainfall provides regular and reliable supply of water in Volta basin. This makes the flows more regular and energy produced relatively constant. - The availability of land. The region around Akasombo is sparsely populated. - The hard basement rocks provided a firm foundation for construction of the dam. - The River Volta crosses a narrow gorge located at Akasombo valley in the south eastern part of Ghana where River Volta cuts through Akwapin hill. - A large market - There is high demand for the power generated for both industrial, especially the Volta Aluminum Company (VALCo) and for domestic use, and high demand for other products from the multipurpose project. - Foreign investors - the foreign investors especially from USA and Britain provided a support in form of skilled labour. - The availability of capital to construct the complex to provide power and set up flood controls, from the World Bank and Britain. - The creation of Volta River Authority (VRA) whose primary task was to manage the development of the Volta basin, which include construction and supervision of the dam, the power station and the power transmission network. - The government policy to develop a large-scale multipurpose project to promote economic development. - Importance of Akasombo Dam - Hydro-electricity production promoted industries, port cities and international co-operation. - The generation of hydro-electric power (HEP) has significantly reduced the expense of importing petroleum oil for thermal power stations thus saving foreign exchange. - Cheap electricity is supplied to VALCo smelter. - Ghana can process much of the bauxite (Aluminum ore) instead of shipping it in raw state which is bulky. - Akasombo dam allowed the development of numerous industries at Tema, Accra, Tokoradi and Kumasi cities. Industrial development has enabled Ghana to become less dependent on import of some food stuff and to process locally some of agriculture products, e.g. cocoa. - It has enabled the development of ports and urban centres. For instance, Tema is an industrial city home of the Aluminum smelter. - The dam supplies electricity to Ghana’s neighbors such as Togo, Benin and Ivory Coast. This has strengthened economic co-operation between Ghana and her neighbours. - Development of transport, fishing and tourism. - Irrigation has promoted agriculture. New farming activities developed along the shorelines of Lake Volta as it became valuable resource for irrigation. It is a potential source for irrigation which enabled Ghana to grow various crops among others such as rice, sugarcane, maize and vegetables. - Farming has greatly improved and diversified. The Akasombo Dam and Lake Volta are great tourist attractions which bring in foreign exchange. - The project has generated employment opportunities to many people, for instance, people involved in the distribution of electricity in the cities of Accra, Tema, Tokoradi and others. - The project has raised the people’s standards of living and has helped in the diversification of the economy from being predominantly agricultural to industrial, mining, fishing and tourism, hence multipurpose development. - Problems associated with the Akasombo dam project - The dam flooded traditional farm land and about 80,000 people were displaced by the rising water of lake Volta. - There is high cost of resettlement and disruption of families - Volta Aluminium Company needed a lot of power for smelting aluminium and it consumed more than half of the power produced, so several areas/ people were deprived of the use of electricity. - The development of industries like aluminium smelter and oil refining at Tema led to environment pollution. - Lake Volta become habitat for disease vectors like water snails and mosquitoes, which are found in stagnant water and that led to spread of bilhazia and malaria respectively. - During the period of drought, there was reduction in lake levels which reduced the power output. - Due to the development of HEP, other power sources lost market, which discourages their producers. - Silting of lake Volta. Solution to the problems - Public education and provision of sanitary facilities are used to maximize avoidance of the risk of bilharzias infection in the vulnerable group. Drug are also used for treating infected members of the community. - Water weeds are controlled - Artificial shrimp farms have been established in the lower Volta using simple and inexpensive methods, hence, fighting poverty. - The 80,000 people who were displaced were settled into 52 resettlement villages. 14.4.3. Aswan High Dam (Egypt) It is located on the River Nile in Egypt near the city of Aswan. The construction of the dam led to the creation of a man-made lake known as Lake Nasser. The reservoir was named after Abdel Nasser, the leader of Egypt at the time. It has the capacity of 2100 MW. The construction of the dam started in 1960 and was completed in 1970. The dam is about 3830 metres long and 111 metres high. Its base is 980 metres wide. i. Aims and objectives of the project The project to construct Aswan High Dam was conceived with aim to develop sustainably the country in various economic sectors The major objectives of the project are: - To prevent recurrent flooding which affects the Nile valley during the rainy season, mostly in August and September. - To control and provide a regular flow of water for irrigation, during both the dry and rainy seasons. - To enable the country to grow enough food to feed the growing population. - To increase the amount of irrigated land. - To generate Hydro-electricity Power for both domestic and industrial purposes. - To create a man-made lake (reservoir) where a fishing industry could be established. ii. Factors favouring the construction of Aswan High Dam - Strong basement rock: The dam was constructed where a strong basement rock to support heavy dam structures existed. This provided a firm foundation for the dam. - The channel was narrowed where the dam was constructed. This made the construction cheaper and easier. - Presence of large capital invested: The construction and the maintenance of the dam were made possible by funds provided by the Soviet Union and Egypt goverments. - Availability of skilled labour: Russian experts and egyptians semi-skilled labour were hired to construct the project. - Advanced technology involved in the general work of dam construction which included strong turbines which produce high power voltage. iii. Importance of Aswan High Dam for the sustainable development of the region - This became a source of government revenues, - creation of employment opportunities for many people. - Flood control: The dam enabled the control of floods and regulated the flow of the River in the Nile valley. People’s lives and properties are safe in the Nile valley. This saved money which was formerly spent on displaced people. The reservoir created provides water in times of droughts. - Production of Hydro-electric power (HEP): Aswan High Dam has an output of about 2100 MW. The production of (H.E.P). has led to the development of diversified industries in the region, such as iron and steel, textiles; mining industries especially oil drilling (Petro-chemical) and sugar refining especially in Cairo and the free zone area of the Nile delta. The establishment of industry has created employment opportunities to the majority of local Egyptians. - Provision of power for domestic purpose: There has been a program of rural electrification, especially along the Nile and in rural villages because of the presence of the Aswan High Dam. - Improvement of agriculture sector: Irrigated land area of Egypt has increased by 25 percent since Aswan High Dam is established. Farmers can now grow several crops in the year, such as maize, wheat, barley vegetables and others. - The water in the region is supplied on regular basis: L. Nasser holds with 80 % of its water going to Egypt and 20 % to Sudan. The water stored is used for irrigation. - Promotion of fishing: Lake L. Nasser has promoted the fishing industry, - Promotion of tourism: The Aswan High Dam and Lake Nasser are tourist attractions. This enables to earn foreign exchange. - Reduction of costs to import fuel: The construction of the dam has resulted into a significant reduction of costs incurred on the importation of fuel petroleum products. iv. Problems associated with the construction of the Aswan High Dam - There was displacement of people and their livestock: 42,000 people who used to live in the region that is now covered by Lake Nasser were evacuated 1,300 km by rail across Nubian Desert to Khasm El Gibra. - A lot of cost for resettling displaced people: Much fund was involved to relocate people since they were given double their foremen hectares of land and the irrigation and electric power had to be provided from the new dam. - Pollution of water, soil and air: this was due to the establishment of industries in the area. - Increase of diseases like bilharzias and malaria: The outbreak of these diseases was caused by stagnant water, this causes great expense to the government economy in treating its people. - High evaporation of water: It is estimated that 25% of water is lost through evaporation because of high temperatures. The high evaporation rates lead to increased saline deposits in the soil which are associated with decreased yield. v. Solutions to the problems associated with Aswan High Dam Some solutions have been put forwards to solve problems caused by the Aswan High Dam. - Regular dredging is carried out to remove waste matter which affect the drainage of the new valleys. - Treatment of waste (recycling) is performed before their disposal. Some environmental laws have been set to regulate dumping in the river. - Construction of levees to control overflow of water that resulted in floods. - Use of ferry and steamers to ease the communication around Lake Nasser. - Spraying to control diseases such as Bilharzia spread by snails from the stagnant water which gives a breeding ground for them. - There is a legislation against brick making along the river bank. - Farmers are sensitized to the use of organic manure as opposed to inorganic fertilizers to reduce salinity and soil pollution. - Sensitization of population for new settlement plans: There has been a general sensitization for new settlement along the river bank against dumping of garbage in the river which is partly responsible for making the river burst its banks. 14.4.4. Huang He River Project (China) i. Location of Huang Ho River Huang He called the Yellow River (formerly known as the Hwang Ho), is located in China. The river originates from the Northern part of mount Bayan Ha of Tibet plateau in Qinghai province and runs Eastwards, a distance of 5,464 km to empty in the Bo-hai Sea at Shantong. The river flows through 9 provinces namely Qinghai, Sachuan, Ganso, Ningxia, Inner Mangolia region, Shanxi, Shaanxi and Shanang. It covers an area of 750,000 km2. The main tributaries of the Huang Ho in its lower riches include Taohe, Jighe, Welhe, Luohe, Fehhe, Yihe and Qinhe. The Huang Ho River is China’s longest and largest river after the Yangtze River, with over 30 tributaries feeding it. ii. Problems faced in Huang Ho Basin The following are some of challenges faced in the Huang He basin: - Several foods along the Huang He River - Severe soil erosion and large silt load - Irregular flow and change of river course - The river faces a threat of drying up - High population growth rate - Problem of pollution iii. Aims and objectives of Huang Ho Basin Development project In 1950 the government of China created a multipurpose project called “Huang Ho Basin Development”. The major aim was to control devastating floods and to sustainably develop areas around the yellow river. The major objectives of the project are meant: - To reduce the risks of flood to lives and properties; - To produce energy and increase the discharge during dry periods; • To retain silt and store water for irrigation; - To provide water for home consumption and industries. iv. Importance of the project - Several dams were built: over 40 dams were built along Huang He and its tributaries to regulate the flows of water and to produce hydro-electric energy. Activities of construction were sequenced between 1960s and 2010s. The most documented hydroelectric power stations of the project include Sanmenxia, Xialangdi, Sanshengong, Qintong Gorge, Luijiiaxia, Lijlaxia Dam, Yuanguoxia, Lianqio, Bapanxia, Da George Dam, Li Geong Dam, Wanjiazhi Dam and Laxiwa Dam. - Development of cities and settlement centres: Several cities were created and greatly expended in the Huang He basin (see the map below). More than 400 million people have settlements in the Huang-Ho river basin. This was possible because of the multi-functional projects focusing on the development of traffic (roads, navigation on Huang-ho River year round), ecology, economic and flood prevention for the cities along the river that attract people to settle in the area for employment opportunities. - Creation of reservoirs: Some dams were created with the main purpose of storing water. For instance Longyang gorge, Liujia Dam, Xialangdi Dam - Floods control: The regulation of rivers’ flow has virtually eliminated floods that regularly submerged the northern china’s plain. - Food production: The crops grown are rice, wheat, maize, soyabeans, potatoes, sweet potatoes and cereals. This uspports a large population living along the river basin. - Remarkable expansion of irrigation: Irrigation of the dry areas of the northern part of China was made possible with the help of the Huang-Ho River. irrigated area increased from 0,8 million hectares in 1950 to 7.5 million hectares in 2000. - Tourist attraction: Many tourist centres along Huang He promote the tourism industry. The touristic features include the Hukou falls in Shaanxi, the caves, stone statues and the Huang-Ho river dams, among others. Tourism is a major foreign exchange earner in China. - Industrial development is facilitated by the Huang-Ho River. A number of industries have developed in the region, such as petrochemical factories and mining industries. The river provides significant amounts of water to industries to cool the machines. v. Challenges faced the project - Increased rate of water demand and use resulting from high population growth and regional economic development caused the drying up of the flow of the river. - Parts of the river especially in mountain area remain frozen in winter season during which water remains frozen, and the water supply from precipitation is limited. - The Yellow river crosses some arid and semi-arid region. Thus precipitation and water sources are limited. - The land surface change from slope land to terraces has involved expansion of irrigation activities which affected the regional hydrology and rive flow. vi. Measures to solve problems related to water shortage There is a water transfer from the South to the North project to channel through the ground canal from River Yangtze where water sources are relatively rich in the South to the Huang Ho where water resources are limited. 14.4.4. Orange River scheme – South Africa Orange River project was developed by South Africa during the apartheid era. The 2,200 km long River has its source from Drankensberg mountain ranges in Lesotho and ends in the Atlantic Ocean. Several dams have been built along the River Orange and its tributaries. The dams built include:Welbedacht Dam, Gariep dam, Vanderkloof dam, Torquay dam, … The major objectives of the Orange River project were: - To create reservoir for storing water for irrigation, to promote agricultural production in the Orange river basin. - To control floods of River Orange. - To generate hydro-electric power. - To supply water in arid areas of Eastern Cape such as the Great Fish and Sundays River valleys. - Contributions of Orange River project - The Orange River project contributed much to the development of south Africa. - The project supplies water to the cities like Bloemfontein, Kimberly, Port Elizabeth and small towns. - It has created an increase in population in the Orange River basin by attracting farm labor of 160,000 people. - River Orange which used to flood the lower areas destroying property and life has been controlled. After dam construction, the floods have become less frequent and less destructive. - The project created employment opportunities to a number of people. - Irrigation farming has flourished in dry areas. - Industries have been established. Gariep dam generates 360 MW while Vanderkloof dam generates 240 MW of HEP. - These boosted the development in the mining industry and manufacturing industries. - Dams constructed in the region led to the development of towns by supplying electricity which runs different activities. - Fishing is carried out in manmade lake (reservoirs) created by the scheme. - Dams have promoted tourism; the county gets foreign exchange	oercommons	2025-03-18T00:37:13.723796	03/06/2025	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/128180/overview", "title": "S6 UNIT 14", "author": "NIYONKURU SELEMAN" }
https://oercommons.org/courseware/lesson/122842/overview	Graphical Information Overview Grapical Information refers to visual reprentations that use not-representation elements .such as shapes,colours,lines and textures - to convey ideas,concepts If you'd like to have an explanation of graphical information overviews without bullet points, here is a narrative version: A graphical information overview is the illustration of data or information through graphics, thus simplifying the understanding of complex ideas. It applies charts, graphs, maps, and other visual aids to describe trends, relationships, and insights. Its primary intention is to make big datasets more accessible to the users to quickly get a grip of the basic details. For example, line charts illustrate trends over time, bar charts compare categories, and pie charts illustrate proportions. Such visualizations are very helpful in decision-making; they bring forth patterns and anomalies that can be tricky to find through raw data formats such as a spreadsheet. The axes, labels, legends, and color scheme provide context and help in clarification. Good design makes the visuals not too cluttered and in a presentation manner that will click with your audience. Modern tools are available that can easily create this overview, such as Tableau or Power BI and programming libraries such as Matplotlib or D3.js. Best practices refer to the right kind of data, making them readable, and maintaining consistencies in the design of the elements. INTRODUCTION Graphical information is any form of data or content represented visually. Charts, graphs, diagrams, images, and other visual elements convey information in ways that are often easier to interpret and understand than raw data or textual explanations. The purpose of using graphical information is primarily to make complex or abstract concepts more accessible, to highlight patterns, trends, relationships, and facilitate quicker decision-making. History of Graphical Information The use of graphical information dates back thousands of years, as human beings have always been concerned with ways to represent data graphically, communicate complex ideas, and make sense of the world around them. The development of various graphical methods over the centuries has been parallel to the development in science, technology, and culture. Here is a chronological overview of the history of graphical information: 1. Prehistoric and Ancient Origins (Before 3000 BCE - 500 CE) Early Visual Communication: - Cave Paintings & Petroglyphs (Prehistoric): The earliest examples of graphical information are found in cave paintings and carvings. These images have animals, hunting scenes, and everyday life, conveying early humans' stories and information. - Egyptian Hieroglyphs (c. 3000 BCE): Ancient Egyptians came up with a system of writing called hieroglyphs, comprising symbolic pictures that represented sounds, ideas, and objects. Early forms of writing in graphical as well as textual format to record history, religious beliefs, and administrative data were employed. - Mesopotamian Cuneiform (c. 3000 BCE): Similarly, the Sumerians in Mesopotamia used cuneiform—a system of wedge-shaped marks made on clay tablets—to record trade, legal codes, and events. Although mostly textual, some cuneiform inscriptions did include simple graphical elements. 2. Renaissance and Early Modern Period (1400 - 1800) Scientific Illustrations and Graphical Advances: - Geometric Diagrams (c. 500 BCE - 1500 CE): Greek and Roman scholars such as Euclid (geometry) and Ptolemy (astronomy) provided the groundwork for the use of diagrams to explain abstract concepts. Euclid's "Elements" is one of the earliest examples of a work that uses diagrams to explain mathematical and geometric principles. - The Printing Press (1440 CE): Johannes Gutenberg's invention of the printing press in the 15th century revolutionized the mass production of books and graphical content. This made books containing elaborate illustrations and diagrams about various scientific fields widely distributed. Scientific Illustrations (16th - 17th Century): - Leonardo da Vinci and Scientific Drawing (c. 1500s): During his work in anatomy, engineering, and mechanics, the drawings, sketches, and diagrams of Leonardo da Vinci were detailed and used visual representations to explain complex inventions and ideas. His own famous anatomical drawings as well as machine designs marked the development of both the art and science. - Andreas Vesalius (1543): In "De humane corporis fabric," Vesalius used detailed anatomical illustrations to correct misunderstandings in human anatomy that had existed for centuries. 3. Age of Exploration and Enlightenment (1600 - 1800) Maps and Charts for Navigation: - Birth of Cartography (16th - 18th Century): The age of exploration led to the development of maps and nautical charts. One of the most famous is Gerardus Mercator's world map in 1569, which introduced the "Mercator projection" that changed the face of cartography and became the norm for maritime navigation. - Scientific Observation Graphs: Representations started coming into existence in early forms of graphical representation in 17th and 18th century scientific studies. Astronomers and mathematicians could finally understand planetary motion, law of physics, and some natural phenomena with the introduction of diagrams and graphs such as Johannes Kepler and Sir Isaac Newton. 4. The 19th Century: The Birth of Modern Graphs and Data Visualization Origin of Statistical Graphs: - William Playfair (1786): Often credited with inventing the first modern statistical graphs, Playfair, a Scottish engineer, introduced the line chart in his book The Commercial and Political Atlas. He also created bar charts and pie charts to represent economic data, particularly trade and production statistics. These were the first true visualizations of data that were meant to convey information more clearly and efficiently than raw numbers. - Florence Nightingale (1850s): As a nurse and statistician, Florence Nightingale used a form of the polar area chart (sometimes called a Nightingale Rose Diagram) to present data on soldier mortality during the Crimean War. Her graphic demonstrated that most deaths were due to preventable diseases, not battle wounds. This innovation in data visualization had a significant impact on healthcare reform. 5. 20th Century: The Digital Revolution and Advanced Visualization Modern Graphical Tools Development: - Early Computers and Graphs (1950s-1960s): The introduction of computers in the mid-20th century opened the gates for more advanced techniques for visualizing data. From the 1950s to the 1960s, researchers began to use computers to plot plots and charts for scientific studies. Among the first of such graphical tools are scatter plots and histograms. - John Tukey and Exploratory Data Analysis (1970s): The statistician John Tukey's work on exploratory data analysis (EDA) promoted the development of graphical techniques for data exploration, including box plots and stem-and-leaf plots. He made it clear that one should visualize data before making conclusions from it. Graphical Software Introduction - Graphing Software (1980s): Graphical software, like Excel in 1985 and Lotus 1-2-3 in 1983, introduced data visualization tools into the hands of non-experts. These programs enabled fast and easy charting, graphing, and table creation without the need to have advanced statistical knowledge. - Advanced Data Visualization (1990s-2000s): With the advent of supercomputer graphics software such as Tableau, Microsoft Power BI, and D3.js, businesses, researchers, and governments could design dynamic and interactive dashboards, data visualizations, and infographics. Graphical information has also had a great contribution from the Internet in distributing visual data all over the world. 6. 21st Century: Interactive and Real-Time Data Visualization Interactive Graphics and Dashboards: - Data Dashboards: The 2000s saw the widespread adoption of interactive data dashboards in business analytics. With tools such as Tableau and Power BI, real-time data can be visualized in various formats, such as bar graphs, pie charts, and geographic maps, enabling businesses to track KPIs and make decisions on live data. - Real-Time Data Visualization: The Internet of Things (IoT) and big data technologies have made real-time data visualization a prominent tool in health care, finance, and urban planning. For instance, live data is used in smart cities to manage traffic, monitor pollution levels, and optimize energy consumption. The Rise of Infographics and Social Media: - Infographics: In the 2010s, infographics emerged as the new medium to represent very complex information in simple ways with visual appeal. Today, infographics are greatly used in journalism, marketing, and education. Such tools as Canva can democratize infographics with little design experience and can have professional-quality visuals. - Social Media Graphics: Graphics are important spaces to share graphical information on platforms such as Instagram, Twitter, and Facebook. Visual content, driven by data, such as charts, memes, and viral infographics, is used for ideation, spreading awareness, and influencing public opinion. 1. Charts & Graphs These are used to represent numerical data visually, helping to understand trends, comparisons, or relationships between variables. - Bar Chart: Useful for comparing quantities across different categories. - Line Chart: Shows trends over time or continuous data. - Pie Chart: Represents proportions or percentages of a whole. - Histogram: Displays the distribution of a dataset (e.g., frequency of data within certain ranges). - Scatter Plot: Shows relationships between two continuous variables. - Area Chart: Similar to a line chart but with the area below the line shaded. 2. Diagrams Diagrams can graphically describe processes, structures, or systems. - Flowchart: For illustrating processes or steps of decision-making - Venn Diagram: To depict logical relationships between different sets - Mind Map: Visualizing hierarchical information, often used in brainstorming - Network Diagram: Illustrates interrelated entities, for example, computer networks, organizational structures 3. Infographics - Infographics are the combination of graphics (such as charts, images, and icons) with text to explain complex information in a simplified, visually appealing manner. They are used in reports, presentations, and online media. 4. Maps Maps are graphical representations of geographic locations or data that has a spatial component. - Geographic Maps: Display physical or political locations. - Heat Map: Represents data through varying color intensity (often used for showing the density of certain events or characteristics). 5. Pictures and Images Images are graphical descriptions that may give detailed information of a topic (for example, pictures, illustrations, and icons). They are very common in: - Scientific Visualization: Visual representation of scientific data for easy understanding. - Medical Imaging: Graphical pictures developed using techniques such as MRI, CT scans, and X-rays. 6. 3D Models and Graphic Representations - 3D Graphs: Data points are plotted in three dimensions and are normally used in mathematical or scientific data with a large number of data points. - CAD (Computer-Aided Design): is used for designing and visualizing 3D models, most often for engineering or architecture. - Virtual Reality (VR) and Augmented Reality (AR): these technologies rely on 3D models and immersive experiences to communicate graphical information. 7. Tables and Grids - Though not really graphical in nature, the use of tables and grids is quite common to place data in rows and columns so that comparison and analysis can easily be done. 8. Data Visualization This is graphical representation of the data in such a way so that the data can easily be understood and proper insights can be gained. It is often supported by tools like Tableau, Power BI, or D3.js. - Heatmaps: The data is presented using colors to represent the intensity or magnitude. - Tree Maps: Hierarchical data is presented as a group of nested rectangles, mainly showing proportions. 9. User Interface (UI) and Web Design Graphics Graphical information within UI/UX design entails the visual structure and components of a website or application: - Wireframes: Basic sketches of web pages or applications. - Icons and Buttons: Visible features that enable users to navigate. 10. Animation and Motion Graphics These are graphics that change with time; they are usually used for the demonstration of processes or concepts that evolve: - GIFs: Short clips that loop to demonstrate sequences or interactions of short times. - Videos: An animated or motion graphics video depicting abstracted data or storyline 11. Data Dashboards Dashboard: An interactive view showing different graphical elements, such as charts and tables, that represent a set of real-time KPIs or key data points. These various graphical types of information will help people digest data and concepts better in a visual format, improving their understanding, interest, and decisions. Let me know if you need more detailed information on any of them!	oercommons	2025-03-18T00:37:13.785162	12/10/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/122842/overview", "title": "Graphical Information", "author": "FIROZ ALI LASKAR" }
https://oercommons.org/courseware/lesson/91193/overview	Using Marketing Information Overview Provided by: Lumen Learning. License: CC BY: Attribution Outcome: Using Marketing Information What you’ll learn to do: use marketing information to inform the marketing strategy After you work through the process of identifying a problem, collecting and analyzing the best marketing information available, you arrive at the moment you’ve been waiting for: You can use this information to guide your decisions about marketing strategy. That strategy is aimed at getting you the results you need. We’ve already described this final part of the overall marketing research process, but in this section you’ll get a chance to see how real-world companies undertake this final, important step. The specific things you’ll learn in this section include: - Explain and provide examples of how marketers can use marketing information to improve the marketing mix Learning Activities The learning activities for this section include the following: - Reading: Using Marketing Information Licenses and Attributions CC licensed content, Original - Outcome: Using Marketing Information. Provided by: Lumen Learning. License: CC BY: Attribution Reading: Using Marketing Information Translating Marketing Information into Action With marketing information and research results collected, it’s now the responsibility of marketers to share this information internally with people who need to understand it. It’s standard practice to hold meetings with appropriate team members to walk through the research findings and brainstorm together about how to apply the results to marketing strategy and operations. It’s also good practice to make the research report available on a company intranet or other central forum, where people who need the information can readily find and access it. The reception to research results may vary from person to person or from team to team. In some cases, where marketers have been waiting on the research results before they move forward, the new information fills a gap in their knowledge. They are likely very eager to take guidance from the research and charge ahead. In other cases, marketers may have a vested interest in continuing to do the things they’ve always done—perhaps because they dislike change or because they think the original course of action is still working. In these situations, if the research suggests that a course change is necessary, there may be significant resistance. Start Conversations About New Customer Insights To help encourage a better reception to what the organization is learning from marketing information, it may be useful to review the original problem the research is trying to solve. Remind team members that the goal of using marketing information is to gain new customer insights that will help make the organization more effective. With this in mind, marketers should think about how the research results can help them better understand customers and translate this understanding into adjustments to the marketing mix to better address customers’ needs. By framing research results around a deeper or broader understanding of the customer, it can help defuse resistance and make people feel more informed and empowered to make good marketing decisions. The following section lists the types of questions marketers can explore as they brainstorm about how marketing information and research results can help them adjust marketing strategy and improve the marketing mix. These questions are a useful jumping-off point for deeper conversations about new customer insights and how to put them into action. Using Marketing Information to Shape Marketing Strategy: Types of Questions to Explore Target Segment(s) What new insights do we have about our target segment(s)? Which problems should we be solving for our customers? Are we targeting the right segments? Product What attracts customers to our products? What improvements would make them even more attractive to our target segments? Promotion What types of messages will make target segments want our products? What types of promotional campaigns will work best for each target segment? Who do our target segments listen to, and what are they saying about us? Price How are we going at providing good value for the price? How does our pricing affect customers’ willingness to buy? How would changes to pricing affect sales? Place Are we offering our products in the places and times that target segments feel the need for them? If not, how can we improve? How can we make it easier for customers to find and buy our products? Are there more efficient ways for us to get our products into customers’ hands? Don’t Forget to Measure Impact As marketers begin to apply the research findings and recommendations, it is essential to track the impact of the new strategy to determine whether the original problem or challenge is being addressed. If the original marketing problem was focused on improving the messaging associated with a product, for example, then the organization should start to see improved lead generation, inquiries, and/or sales once the new messaging is adopted and implemented. If the original marketing problem was focused on which segments to target and how to reach them, organizations should be able to track improvements in interest and sales among these segments after they have begun to implement a market mix focused on these segments. This link between taking action and measuring results is important. It provides a continuing stream of marketing information to help marketers understand if they are on the right path and where to continue to make adjustments. Eventually this process will surface new marketing problems that warrant attention through the marketing research process. In this way, the process of using marketing information to solve problems becomes a continuous cycle. What does this process look like in the real world? Let’s examine two examples. Example: Procter & Gamble Goes to China For decades, the consumer products company Procter & Gamble has been a visible leader when it comes to relying on marketing research and using it to guide marketing strategy decisions. In particular, it has focused on ways of entering new markets and establishing a leading market position. As it explored opportunities for market leadership in China, one standout product category was disposable diapers, a profitable category for P&G in the U.S. and other global markets. In the early 2000s, the company rushed in to launch Pampers in China, its leading disposable diaper brand. The effort flopped. Culturally, Chinese parents did not see the need for the new American disposable diaper product. They were doing fine using cloth diapers and kaidangku, the open-crotch pants used traditionally for infants and young children. Instead of pulling out, P&G turned to marketing research for additional insights about ways of generating demand for Pampers. The research focused on identifying “winning qualities” of disposable diapers that would make Chinese mothers interested in trying the product. It concluded that improving infants’ sleep quality could become a powerful motivator. In 2007, P&G launched campaign called “Golden Sleep” to promote the idea that Pampers disposable diapers can help babies fall asleep faster and sleep with less disruption. Marketing research was directly responsible P&G’s adjustments to product positioning and promotion strategy. The campaign invited parents to upload pictures of their sleeping babies to a Chinese Pampers Web site. This reinforced the link between Pampers products and the message of “better sleep for babies.” The ad campaign also featured research results linked to Pampers and infant sleep such as, “Baby Sleeps with 50 percent Less Disruption,” and “Baby Falls Asleep 30 percent Faster.” “Golden Sleep” was a tremendous success, moving Pampers to a leading market position and creating broad demand for a product category that was previously almost nonexistent in China. P&G attribute this success to the insights generated by a marketing team and research effort focused on better understanding and addressing customer needs.1 Example: Shaking Up the Milkshake A fast-food restaurant chain identified milkshakes as a focus for improving sales. Initial marketing research efforts were focused on creating a “typical” milkshake-drinker profile. The researchers then found people who fit the profile and were willing to help them understand what constituted the ideal milkshake: thick or thin? Which flavors? Smooth or chunky? These effort led the company to tinker with its milkshake products, segmentation, targeting, and promotion strategies, but sales still did not improve. The company hired an outside researcher to help the company understand what they might be missing about milkshakes. This researcher spent time in a restaurant observing and documenting milkshake sales, as well as talking to milkshake buyers about why they had made their product choice. A couple of key insights emerged about milkshake buyers. First and somewhat surprising, 40 percent of milkshake sales took place early in the morning, and the buyers were commuters on their way to work. Second, the ideal milkshake for these customers was thick and substantial but easy to consume during a commute. Third, another key buyer audience was parents purchasing a treat for children, but the ideal milkshake for them was a thinner product children can drink quickly with a straw. Acting on these new insights, the company adjusted its marketing strategy. Instead of focusing on a single “milkshake buyer” profile, it reformulated its milkshake products and promotion strategy to better fit the needs of different types of target milkshake customers. It offered a thicker, chunkier “morning milkshake” to appeal to commuters who wanted a satisfying alternative to a morning donut or bagel. The chain also introduced a different milkshake positioned as a kid treat, which offered the thinner, easier-and-quicker-to drink benefits parents wanted. Persistence and perseverance in the marketing research process led the company to dig deeper to understand customers, their unique needs, and how to adjust marketing strategy in response to this new information.2 - http://www.forbes.com/sites/china/2010/04/27/how-procter-and-gamble-cultivates-customers-in-china/ - http://hbswk.hbs.edu/item/clay-christensens-milkshake-marketing Licenses and Attributions CC licensed content, Original - Reading: Using Marketing Information. Authored by: Lumen Learning. License: CC BY: Attribution CC licensed content, Shared previously - Cake Milkshake Heaven. Authored by: Tina H. Located at: https://www.flickr.com/photos/ohocheese/4963121362/. License: CC BY-NC-ND: Attribution-NonCommercial-NoDerivatives CC licensed content, Specific attribution - Image: Feedback . Authored by: Tumisu. Provided by: Pixabay. Located at: https://pixabay.com/illustrations/feedback-group-communication-2044700/. License: CC0: No Rights Reserved. License Terms: Pixabay License	oercommons	2025-03-18T00:37:13.817986	03/22/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/91193/overview", "title": "Statewide Dual Credit Principles of Marketing, Marketing Information and Research, Using Marketing Information", "author": "Anna McCollum" }
https://oercommons.org/courseware/lesson/128219/overview	S6 UNIT 3 Overview There are several theories of continental drift that were developed at the beginning of the 20th century. The following are the four main theories of continental drift: • Alfred Lothar Wegener’s theory • Maurice Ewing’s theory • Harry Hammond Hess’ theory • Frank Taylor’s theory THE ORIGIN AND DISTRIBUTION OF THE CONTINENTS 3.1. Concept and theories of continental drift The term continental drift refers to the slow movement of the Earth’s continents(landmasses) towards and away from each other. 3.1. 2. Theories of the origin and distribution of the continents and ocean basins There are several theories of continental drift that were developed at the beginning of the 20th century. The following are the four main theories of continental drift: - Alfred Lothar Wegener’s theory - Maurice Ewing’s theory - Harry Hammond Hess’ theory - Frank Taylor’s theory a) Alfred Lothar Wegener’s theory According to Wegener’s theory, there was single super continent block called Pangaea “pan JEE uh”, which means “all land” surrounded by an extensive water mass called pantalassa (pan means all and Thalassa means oceans), that moved apart in a process called continental drift. That movement took place about 200 million years ago. It has been hypothesized that the supercontinent of Pangea broke up to form Laurasia (North America, Greenland and all Eurasia, North of India subcontinent) and Gondwanaland (South America, Africa, Madagascar, India, Arabia, Malaysia, East Indies, Australia and Antarctica). The present shapes and relative positions of the continents are the result of fragmentation of Laurasia and Gondwanaland by rifting and drifting apart of the broken landmasses following the formations of oceans and seas These two blocks were separated by a long shallow inland sea called Tethys sea. However, Wegener’s theory was initially criticized because he could not explain how solid continents have changed their positions. His theory has been revived by other researchers after discovering new evidences. Maurice Ewing confirmed the existence of Mid-Atlantic Ridge which is a mountain range extending the entire length of the ocean bed which is about 1000 km wide and rises 2500 m in height. Also, Ewing’s studies argue that rocks of this range were volcanic and recent in origin. Similar ranges were later discovered on other oceans’floor. C) Harry Hammond Hess’s Theory: Sea-Floor Spreading The Sea-Floor Spreading theory was put forward by an American Geologist, Harry Hess. Sea-floor spreading occurs along mid-ocean-ridge; when the tectonic plates slowly moves away from each other, hot magma from the mantle comes up to the surface. As magma cools by the seawater the rock forms a new part of the crust. d)Taylor’s theory(American) argued that originally there were two big landmasses, namely Laurasia and Gondwanaland. Frank Taylor’s theory states that the original Laurasia was located near the current North Pole, whereas Gondwanaland was located near the South Pole. Both landmasses radially moved to the Equator. Their collision would have resulted in the formation of folded mountains, such as Atlas, Alps mountain ranges and others. He suggested that Laurasia and Gondwanaland were forced to move from their former positions because of the moon’s tidal attraction. According to this theory, the moon came very close to the earth during the cretaceous period. This closeness of the moon to the earth exerted powerful tidal attraction, which pulled the landmasses from their polar position towards the Equator. Where there was resistance to the outward spread of landmasses, the crust usually would fold, raising mountain ranges in front, while resulting in stretches (troughs and basins). He explained that Pangea later split up into two super continents known as Laurasia and Gondwanaland. Taylor’s arguments about continental drift have however been criticized: - The theory doesn’t clearly demonstrate how the causes of the movement of continents from their polar positions ought to have been from within the earth and not outside it. - The theory was rejected because researchers of his time doubted how the moon could ever exert enough force to pull the huge landmasses (continents) as they are known today. - Finally, Taylor doesn’t explain the formation of earlier fold mountains like the Caledonian system of Siluro-Devonian times while explaining the possible formation of the fold mountains Atlas and Alps. 3.2 The evidence of continental drift The following are Wegner’s evidence (indicators) of continental drifting: - The jigsaw fit (Visual fitting) of the southern continents: Observation shows that when Africa and South America are assembled together, a nice and perfect fitting would occur. The west coast of Africa and Eastern coast of south America fit exactly each other. - Similarities of flora (Vegetation) and fauna (animals): Studies have shown that vegetation types and animal species on both the west African and North west American coast are the same. - Positions of climatic zones: It has been observed through time that the positions of climatic zones have fundamentally changed. For example, the presence of temperate climatic features such as glaciated highlands in south America and Africa, conflicts with their location in the tropics where climate is purely tropical. - Also the presence of tropical lateritic soils in North America, Britain, China and Germany, contradicts the location of these countries in the temperate regions whose climate does not favour the formation of laterites. America, Europe and China were enjoying a tropical climate at the equator, which encouraged laterites to form. - The formation of the Mid Atlantic Ridge: The continuous accumulation of new volcanic rock materials at the mid of the Atlantic and Pacific oceans indicate that Africa and South America are drifting apart, molten rock fills the trench between them hence forming a ridge in the middle of the ocean. - The widening Eastern Arm of the East African Rift Valley: Research has shown that the eastern arm of the East African Rift Valley is widening and that Somalia and Arabia are consequently separating at the rate of 2cm per year implying that continents are still drifting. - Geological evidence: Similarities have been noted to exist in the rock structures of Africa, South America and the Indian subcontinent. The strata(layers) of rocks along the coast of South America are found to be similar. - The existence of glacial erosional features: There are hanging valleys and truncated spurs in the tropics and low lying areas of Africa, all suggest that Africa must have been nearer to the southern pole during glaciations. 3.3 Effects of the continental drift on the evolution of the physical features - Pangaea split apart into a southern landmass “GONDWANLAND” and the northern landmass called “LAURASIA”, later the two super continents split again into landmasses that are present day continents. - It has also affected the earth’s climate. The climate of different part of the world has changes throughout the year. - Collision of earth’s crusts the Indian subcontinent and Asian continent created the Himalayan mountain range. - Formation of rift valleys - Continental drift is the major cause of earthquakes, volcanoes, oceanic trenches, mountain range formation and other geologic phenomenon which created the new landscapes on the earth’s surface. 3.4.1. The concept of tectonics plate The concept suggests that earth’s crust and upper mantle (lithosphere) are broken into sections, called plates that are slowly move on the mantle. The upper surface of the earth’s crust (SIAL) is made up six major and twenty other minor blocks called tectonic plates. The whole mechanism of the evolution, nature and motion of plates and resultant reactions is called Plate tectonics. The word tectonic comes from the Greek word “TECTONIKOS” meaning building or construction. Used in this context it refers to the deformation of earth’s crust as a result of internal forces resulting in various structures in the lithosphere. Tectonic processes include Tension when plates diverge and Compression when plates converge. These processes result in deformation of the earth crust. Tension causes fracturing and faulting of the crust while compression produces folds and over thrust faults. 3.4.2. Types of Plate Tectonics There are two types of plate tectonics: continental plate and oceanic plate. - Continental crust is composed of older, lighter rock of granitic type: Silicon and Aluminum (SIAL). - Oceanic crust consists of much younger, denser rock of basaltic composition: Silicon and Magnesium (SIMA). The major differences between the two types of plates are summarized in the table below: Difference between continental plate and oceanic plate Factor \| Continental plate (SIAL) \| Oceanic plate (SIMA) \| Thickness of rock \| 35-40 km on average, reaching 60-70 km under mountain chains \| 6-10 km on average \| Age of rocks \| Very old, \| Very young, \| Weight of rocks \| Lighter, with an average density of 2.6gm/cc \| Heavier, with an average density of 3.0gm/cc \| Nature of rocks \| Light in color, many contain silica and aluminum; numerous types, granite is the most common \| Dark in color; many contain silica and magnesium; few types, mainly basalt \| 3.4.3. Boundaries and movement of tectonic plates i. Tectonic Plate boundaries Boundaries of plate tectonic include the subduction zone, the mid-ocean ridge and the transform boundary. - Divergent boundary (Mid-ocean ridge): It is an underwater mountain range which is formed when forces within earth spread the seafloor apart. It is created when convection currents rise in the mantle beneath where two tectonic plates meet at a divergent boundary, thus forming the oceanic ridge. - Transform boundary (Transform fault): It is a boundary which exists between two plates that are sliding horizontally past one another, thus forming the transform faults (see the figure below). - Convergent boundary (Subduction zone): This is the area where an ocean floor plate collides with a continental plate and the denser oceanic plate sinks under the less dense continental plate, thus forming the oceanic trench. ii. Tectonic plate movements Plate movements include convergence, divergence and way past movement along the transform fault. - Convergence is a movement whereby two crustal plates are colliding or one subsiding beneath the other. The margin where this process occurs is known as a destructive plate boundary. This boundary is a region of active deformation. - Divergence is a movement whereby two crustal plates are moving away from each other. The margin where this process occurs is known as a constructive plate boundary. It initially produces rifts which eventually become rift valleys. - Way past is plates’ movement predominantly horizontal, where crust is neither produced nor destroyed as the plates slide horizontally past each other. The plate movements are characterized by the following: - Due to its relatively low density, continental crust does not sink; but it is the oceanic crust which is denser that can sink. Oceanic crust is then formed and destroyed, continuously; - Continental plates, such as the Eurasian plate, may consist of both continental and oceanic crust; - Continental crust may extend far beyond the margins of the landmass; - Plates cannot overlap. This means that either they must be pushed upwards on impact to form mountains, or one plate must be forced to downwards into the mantle; - No gap may occur on the earth’s surface so, if two plates are moving apart new oceanic crust originating from the mantle is formed; - The Earth is neither expanding nor shrinking in size. Thus, when the new oceanic crust is being formed in one place, older oceanic crust is being destroyed in another; - Plate movement is slow and is usually continuous. Sudden movements are detected as earthquakes; - Most significant landforms (folded mountains, volcanoes, insular arcs deep sea trenches, and batholith intrusion) are found at plate boundaries. Major landforms resulting from plate movements: Plate movement \| Description of changes \| Example of landform \| Divergent \| Spreading: Two plates move away from each other, new oceanic crust appears, forming mid-oceanic ridges with volcanoes \| Mid-Atlantic Ridge formed by American plates, moving away from Eurasian and African plates. \| Convergent \| Subduction: Oceanic crust moves towards continental crust but, being denser, sinks and is destroyed to form deep sea trench and islands arcs with volcanoes, \| Andes fold mountain chain formed by Nazca which sinks under South American Plate Rocky mountain chain formed by Juan de Fuca, sinks under North Americas Plate, Island arcs of the West Indies and Aleutians Examples of trenches: Mariana trench, PeruChile-trench (Pacific ocean), Puerto-Rico trernch in the Atlantic ocean. \| Convergent \| Collision: two continental crust collide and, as neither can sink, are forced up into fold mountains \| Himalayas formed by Indian plate collided with Eurasian Plate, Alp mountains formed by African Plate collided with Eurasian Plate, \| Transform \| Lateral sliding: Two plates move sideways past each other. Land is neither formed nor destroyed \| San Andreas fault in California \| 3.4.4 Characteristics of plate tectonics Tectonic plates are characterized by the construction and destruction of landforms at margins of plates. However, at some boundaries, the construction or destruction may not occur. These are called passive margins or conservative boundaries. i. Constructive landforms Constructive landforms occur where two plates diverge, or move away from each other, and a new crust is created at the boundary. They are formed in the following ways: - This occurs when a continent ruptures and the two new plates move apart and create a new ocean. - The crust is uplifted and stretched apart, causing it to break into blocks that become tilted on faults. Eventually a long narrow rift valley appears. - Magma rises up from the mantle to continually fill the widening crack at the center (The magma solidifies to form new crust in the rift valley floor. - Crustal blocks on either side slip down along a succession of steep faults, creating mountains. - A narrow ocean is formed - The ocean basin can continue to widen until a large ocean has been formed and the continents are widely separated. - The ocean basin widens, while the passive continental margins subside and receive sediments from the continents. - As the plates diverge, molten rock or magma rises from the mantle to fill any possible gaps between them, creating new oceanic crust - Destructive landforms Destructive landforms occur where continental and oceanic plates converge. They are formed in the following ways: - The oceanic plate that is denser is forced to dip downwards at an angle to form a subduction zone with its associated deep-sea trench. - The sunk plate will melt and transformed into magma as the pressure and the temperature rise. - The newly created magma will try to rise to the earth’s surface. Where it does rich surface volcanoes will occur. This process will either create a long chain of fold mountains (e.g. the Andes) or, if the eruptions take place off shore, an Island arc will be created (e.g. Japan, Caribbean). - Passive or conservative margins - The areas which are lacking active plate boundaries at the contact of continental crust with oceanic crust. - The transform faults which are large cracks produced at right-angles to the plate boundary because neither landform is constructed nor destroyed 3.5. Major plates and effects of plate tectonics The following are the major tectonic plates of the world: - The Pacific plate which covers a large part of the basin of Pacific Ocean. - The Eurasian plate located between the northern mid-ocean ridge of the Pacific Ocean and the Pacific and Philippines Plates margins. - The North American plate bordered by the eastern margin of the Pacific plate in the West and mid-ocean ridge of the Atlantic Ocean in the East. iv. The South American Plate located between the subduction zone of Nazca plate in the West and the mid-ocean ridge of the Atlantic Ocean in the East. - The African plate located between the mid-ocean ridge of the Atlantic Ocean in the West and the mid-ocean ridge of Indo-Australian plate in the East. - The Indo-Australian plate extends around the Australian subcontinent, between the Pacific plate and the African Plate. - The Antarctic plate corresponds with the Antarctic continent around the South Pole. - The Nazca Plate which is located between the Pacific plate and the South American plate. However, several minor plates, about 20 have been identified (e.g. Arabian plate, Bismarck plate, Caribbean Plate, Carolina plate, Cocos plate, Juan de Fuca plate, Nazca or East Pacific plate, Philippines plate, Scotia plate among others). 3.5.2. Effects of plate tectonics - Earthquakes - Volcanic eruption and - Tsunamis 3.6. The theory of Isostasy 3.6.1. Meaning of Isostasy The concept of Isostasy comes from “iso” = equal, and “stasis” = equilibrium. It describes how various continental and oceanic crusts, stay in equilibrium over the asthenosphere. The main characteristic of isostasy - By isostasy, the lighter crust must float on the denser underlying mantle. - It explains how different topographic heights can exist on the earth’s surface. - Isostatic equilibrium is an ideal which states where the crust and mantle would settle in equilibrium in absence of disturbing forces. - Isostasy theory is concerned with vertical movements of plates which depend on lithospheric masses. - The loading of crust by ice or sediments may cause the subsidence of lithosphere, whereas the discharge resulting from ice melting or erosion may cause the uplift of lithospheric compartment. - The waxing and waning of ice sheets erosion, sedimentation, and extrusive volcanism are examples of processes that perturb isostasy. - Isostasy controls the regional elevations of continents and ocean floors in accordance with the densities of their underlying rocks. Main theories of Isostasy There are two main theories which have been developed to explain how Isostasy acts to support mountain masses. Pratt’s theory: The theory stipulates that there are lateral changes in rock density across the lithosphere (crust). If the mantle below is uniformly dense, the less dense crustal blocks float higher to become mountains, whereas the denser blocks form basins and lowlands. Airy’s theory: According to Airys’s theory, the rock density across the lithosphere is approximately the same but the crustal blocks have different thicknesses. Therefore, mountains that shoot up higher also extend deeper base into the denser material beneath.	oercommons	2025-03-18T00:37:13.914705	03/07/2025	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/128219/overview", "title": "S6 UNIT 3", "author": "NIYONKURU SELEMAN" }
https://oercommons.org/courseware/lesson/126533/overview	Northwest Open XR Initiative Open Education Resources Submission Guidelines Overview This outlines the guidelines for authors submitting open education resources to the Northwest Open XR Initiative group. About the Northwest Open XR Initiative The Northwest Open XR Initiative (NWXR) project at Bellevue College serves as a resource for higher education institutions, especially community and technical colleges in the Pacific Northwest and beyond, funded by a National Science Foundation grant. Our goal is to create XR curricular resources for educators and learners in the creation of an open-access XR educational archive to disseminate resources and models regionally and nationally. The open education resources (OER) here consist of our work at Bellevue College, and the work of connected institution projects that are funded through our grant to produce OER aligned with our goals. This material is based upon work supported by the National Science Foundation under Award No. 2329587 About These Guidelines These guidelines have been written to help ensure that all OER that are submitted to the NWXR archive reach a range of standards relating to their potential benefit, currency, ease of use and level of professionalism, as well as ensuring that submissions to this group have the greatest possible potential to be approved by the OER Commons review team. About Extended Reality (XR) Technologies For the purposes of this guide, extended reality (XR) technologies are defined as immersive technologies, such as virtual reality (VR), augmented reality (AR), 360° video and online virtual worlds. For our purposes, these technologies should be considered to be broadly defined. Other terms, such as mixed reality and spatial computing are synonymous with augmented reality under a broad definition. Minimum Standards All OER that will be published to the NWXR archive will adhere to the following minimum standards: The resource satisfies all of the required conditions in the OER Commons Submission Guidelines. The resource will be released under a Creative Commons license (and the authors have the right to assign such a license). The resource focuses on material that relates to XR technologies and their application to education. Recommended Standards In addition to the above minimum standards, we also encourage submitting authors to aim to also meet the following recommended standards: The resource satisfies all of the suggested conditions in the OER Commons Submission Guidelines. Additional Resources The following additional resources are likely to be helpful, particularly as you work on publishing your first few projects: Types of OER Deliverables We Accept Types of OER Deliverables We Accept* Prototypes & Interactives These are materials that will often have come out of our network and class activities, where educators and students have created XR applications that can be used to teach specific things within a class context. These will often be prototypes or vertical slices and will often require access to a VR headset, phone, or tablet to use. Workshops These are materials to enable the delivery of a workshop (usually 1-3 hours of in-class delivery). These materials would include a slide deck, instructions for how to run the lesson and potentially some resources for direct distribution to students (such as worksheets). Application Guides/Primers Short 1-2 page guides that introduce particular XR applications that can be used in an educational context. Rather than writing lessons, these would be more like a starting point from which lessons could be developed. Each guide would provide some high-level summary information about an XR application with education potential, along with some ideas for how it might be used in an educational context. Professional Development Materials Resources that have been designed for teachers to use for their own professional development, rather than being used directly in work with students. This might include overviews of various XR applications and how they are used, as well as discussing pros and cons of different tools in an educational context. Full Courses These are full courses that can be downloaded as packs for Canvas and other learning management systems and will enable institutions to run/remix the course as a whole. We don't anticipate doing a lot of these, but there might be 1-2 that come together. *This list is intended to encourage our community of XR educators to think about the types of materials that other educators will find useful. It is not an exhaustive list, so you can also consult the OER Commons Material Types list for other types of materials that can be published as OERs. How to Contact the NWXR Team If you have suggestions for how to improve these guidelines, or if you have questions for the project team, you can contact us by sending an email to xrlab [at] bellevuecollege.edu.	oercommons	2025-03-18T00:37:13.938760	02/25/2025	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/126533/overview", "title": "Northwest Open XR Initiative Open Education Resources Submission Guidelines", "author": "Bellevue College XR Lab" }
https://oercommons.org/courseware/lesson/116968/overview	FAD Syllabus: UNCA POLS320 Overview Syllabus shared by a UNC System faculty member. Sample Syllabus POLS 320: Challenges to American Democracy Fall 2023 Course Description: This course will provide an opportunity for students to study the foundational ideas that informed the creation of the American constitutional system, trace major debates that have arisen in American political life, and discuss the contemporary challenges in maintaining American democracy. In particular, we will examine the extent to which the scope of American democracy has expanded and become more encompassing over time, as well as the shortcomings in that process. We will focus on the role that the diversity in American society has played in challenging status quo interpretations of “democracy” and how under-represented groups have used the promises made in the founding documents of the American tradition to agitate for equal rights and equal treatment. Topics of interest include: religion and religious minorities, slavery and race relations, and women’s rights in the US. Our overarching goals will be to critically examine how democratic the United States is and has been, to discuss the progress and limitations of achieving equality in the US, and to evaluate our national efforts to “form a more perfect Union.” Diversity Intensive: This course has a diversity intensive designation, meaning its content is centered on issues of diversity and the complexity of differences in society. As such, there are 5 primary student learning outcomes for the course: - Students will understand the socially constructed nature of identities. - Students will understand the significance of individuals’ differing relationships to power. - Students will understand how individuals, organizations, and institutions create, per- petuate, or challenge inequality. - Students will understand how multiple identities intersect. - Students will be better equipped to reevaluate their ideas about diversity and difference. Readings: All required readings will be available on the course Moodle site. Reading assign- ments should be completed prior to the class period for which they are assigned. Students should come to class prepared to discuss the assigned readings and/or with questions about the material. Please note that the reading load may vary slightly across class periods. If I find that students are not consistently and evenly completing the assigned readings and that discussion is lacking, I reserve the right to administer pop quizzes. Though, I’d like to avoid doing so! Class Structure: In terms of the day-to-day of the course, there may be mini-lectures on occasion, but it will be a primarily discussion-based class. As such, I expect students to come to class prepared to discuss the course readings. This does not mean that you have to understand all material that was assigned perfectly, but it does mean that you should have read the material, reflected upon it, and prepared questions (should you have any). Regular participation in class discussions is expected of all students and is part of the course grade, as reflected below. We will also begin each class period by briefly discussing political news. Office Hours and Communication: The best way to contact me is via email (FACULTY MEMBER EMAIL ADDRESS). I check my email regularly, and I will do my best to respond to you within 24-hours (it may be longer on the weekend). In addition, I will host office hours twice a week: in-person on Mondays from 2-3 PM and on Tuesdays via Zoom from 10:30 to 11:30 AM. You are also welcome to schedule a meeting with me outside those times. I will also ask that you regularly check your email for class updates and changes. As we all know, things can change quickly, so please make sure to stay on top of your inbox in case a development affects our class. Response Papers: Students will be asked to complete three response papers through- out the course of the semester. These papers are meant to be critical/analytic papers, rather than summary pieces. I will ask students to engage with course readings, make connections between/across the ideas and themes of the course, and to take their analysis outside the scope of this particular class and its assigned readings (students can connect readings to current events, readings from other courses, etc). I will be looking for students to show creativity, critical thinking, and engagement with the big ideas of the course. I will provide general guidelines/suggestions for avenues to explore in the response papers, but students are asked and expected to make these papers their own. Students may choose when to sub- mit each of their response papers with three caveats: 1) There are intermittent deadlines for each of the papers, to break up when you write them. However, you are always welcome to submit well before those deadlines; 2) Response papers are due before class on the day for which we discuss a particular set of assigned readings; and 3) I will not accept more than one response paper from a particular student in a single week. Formal Assignments: There are so many important topics that I was forced to leave off the syllabus, due to the time constraints of a single semester. To correct for this unfor- tunate reality, I have decided to ask each student to, in a sense, help write the course. The final project will require each student to choose a topic that they feel belongs/fits with the current topics covered in the course, identify reading assignments that they believe would capture the nuance and larger themes covered in the course, and weave those topics into a cohesive narrative and defense. Students will also be asked to present part of their unit to the rest of the class at the end of the semester. To break up the process and ensure that students are on the right track for the final project, I have broken the process up into distinct assignments. The component parts include several smaller assignments (a pre-proposal, a formal proposal, and an annotated bibliography), on top of the final paper/presentation. Prompts will be given for each assignment. Grading: You will be graded upon the following: Response Papers (30%–10% each); Pre- Proposal (5%); Proposal (10%); Annotated Bibliography (10%); Final Paper (15%); Final Presentation (10%); Participation (20%). The grading scale for this course is as follows: A: 92-100; A-: 90-91; B+: 88-89; B: 82- 87; B-: 80-81; C+: 78-79; C: 72-77; C-: 70-71; D+: 68-69; D: 60-67; F: anything below 60. Please note that late work will be penalized 10 points per 24 hour period and will not be accepted after 48 hours of the due date/time. Late work will not be accepted for response papers, however. Attendance: Attendance is mandatory in this course and will be considered in the par- ticipation grade (as will tardiness). Students may have two unexcused absences without penalty. Any student that accrues 6 or more unexcused absences will automatically receive a failing grade in the course. One thing to note is that, while the pandemic may be over, COVID-19 is still very much a part of our lives, and some of us are more susceptible than others. As such, if you sus- pect you may have COVID-19, I ask that you get yourself tested and do not attend class. COVID- related absences will be excused. Student Accommodations: UNC Asheville values the diversity of our student body as a strength and a critical component of our dynamic community. Students with disabilities or temporary injuries/conditions may require accommodations due to barriers in the structure of facilities, course design, technology used for curricular purposes, or other campus resources. Students who experience a barrier to full access to this class should let the professor know, and/or make an appointment to meet with the Office of Academic Accessibility as soon as possible. To make an appointment, call 828.232.5050 or email academicaccess@unca.edu. Learn more about the process of registering, and the services available through the Office of Academic Accessibility here: https://accessibility.unca.edu/. While students may disclose disability at any point in the semester, students who receive Letters of Accommodation are strongly encouraged to request, obtain and present these to their professors as early in the semester as possible so that accommodations can be made in a timely manner. It is the student’s responsibility to follow this process each semester. Honor Code: All written work for this course is to be completed strictly in accordance with the University’s policy for Academic Honesty. If you are unsure of what the policy requires in regard to a particular assignment, do not hesitate to contact the instructor. Any violations of the Honor Code will result in a failing grade on the assignment and will be reported to university administration. Course Outline (please note that schedule is subject to change) August 21–Course Introduction Syllabus, Q&A - Philosophical Foundations of the American Republic August 23–Defining Democracy Class Activity No readings August 25–The Political Form Aristotle, selection from The Politics Montesquieu, selections from Spirit of the Laws Discussion Questions: What are the different kinds of regimes in Montesquieu’s classifi- cation scheme? How does his scheme differ from Aristotle’s? What is a democracy? A republic? August 28—The Grounds for Revolution John Locke, selections from Second Treatise of Government James Otis, “The Rights of the British Colonies Asserted and Proved,” 1764 John Dickinson, “Letters from a Farmer in Pennsylvania,” Letter VII, 1768 Discussion Questions: What do these authors mean by a state of nature/natural rights? How does Locke’s view of the origins of government affect his opinion of what governments can and cannot do? On what basis does Dickinson equate British taxation with slavery? August 30—Independence Declaration of Independence Alexander Hamilton, “The Farmer Refuted,” 1775 Thomas Jefferson, Letter to Henry Lee, 1825 Jefferson, Letter to Roger Weightman, 1826 Discussion Questions: What were the grounds for declaring independence? What does the Declaration mean by a natural right to liberty? How was it influenced by Locke? September 1–No Class (APSA Conference) September 4–No Class (Labor Day) September 6—The Constitution and Its Opponents U.S. Constitution, (read over Articles I-IV) Brutus, “No. 1” 1787; Centinel, “No. 1,” 1787 Herbert Storing, selection from What the Anti-Federalists Were For Discussion Questions: What were the main objections to the Constitution? Are they still relevant? September 8—The Constitution and Its Defense Federalist Papers, Nos. 10, 14, 51 (last paragraph only of No. 14) Discussion Questions: To what extent was the “extended republic” of the Constitution an innovation? According to Madison, what problem can only be controlled by a large, diverse republic? Are these concerns relevant to politics today? - Religion, Religious Minorities, and American Politics September 11—Puritan Roots Tocqueville, Democracy in America, 1835, pp. 27-44 Mayflower Compact, 1620 John Winthrop, “On Liberty,” 1645 Discussion Questions: How did the Puritans understand the role of religion in politics? What problems can emerge when religious law is the direct foundation of political law? September 13—The Founders and Religion Patrick Henry, “A Bill Establishing a Provision for Teachers of the Christian Religion” James Madison, “Memorial and Remonstrance against Religious Assessments” Thomas Jefferson, Notes on the State of Virginia, Q.17 Jefferson, “Letter to Danbury Baptist’s Association” George Washington, “Letter to Touro Synagogue” Washington, “Letter to Quakers” Washington, “Thanksgiving Day Proclamation” Discussion Questions: What was the Founders’ view of the proper relation of religion and politics? What explains the differential treatment of atheists and Quakers, in their view? September 15—The First Amendment First Amendment to the U.S. Constitution Lee v. Weisman (1992) Discussion Questions: Does the First Amendment require neutrality between religions or dictate a stance with regard to religion vs. non-religion? September 18—The First Amendment, Reprised Kennedy v. Bremerton School District (2022), excerpts Discussion Questions: How does this case (re)define the religious protections of the First Amendment? September 20—Guest Lecture Karen Brinson Bell, Executive Director NC State Board of Elections September 22–A City Upon A Hill John Winthrop, “A Model of Christian Charity”, 1630 Ronald Reagan, “Farewell Address,” 1989 Possible additional readings TBD Discussion Questions: What did Winthrop mean when he referred to Massachusetts Bay as a “city upon a hill”? How have more contemporary politicians adapted the phrase to serve their purposes? Has their usage been consistent with Winthrop’s? September 25—Religion in the Post-9/11 Era Bush-Gore Second Presidential Debate, 2000 (excerpts) “Islam is Peace,” Remarks by George W. Bush, September 2001 George W. Bush Address to Muslims in Aftermath of 9/11 attacks, September 2001 Discussion Questions: What was the political rhetoric around the religion of Islam and Muslims in America in the immediate aftermath of the 9/11 attacks? Did the rhetoric match subsequent government and military actions? September 27—Religion in the Contemporary US Obama, Address to the Nation on Keeping the American People Safe, Dec 2015 Trump, Address on Terrorism, Immigration, and National Security, June 2016 Readings are subject to change and/or be added upon Discussion Questions: How much has the political rhetoric towards the Muslim population changed in the US? With the threat of ISIS and the Syrian refugee crisis in recent memory, what stance should politicians take toward religious equality and religious minorities within (and outside) US borders? Do we have a responsibility to be a “city upon a hill?” - Slavery, Race, and Civil Rights in the US September 29—Slavery in the Early Republic *Deadline for Response Paper 1* Benjamin Franklin, “An Address to the Public from the Pennsylvania Society for Promoting the Abolition of Slavery” Alexander Hamilton, “Letter to John Jay” Slavery provisions in the U.S. Constitution: Art. 1 Sec. 2, Clause 3; Art. 1, Sec. 9, Clause 1; Art. 4, Sec. 2, Clause 3(c) Herbert Storing, “Slavery and the Moral Foundations of the American Republic” (selection) John C. Calhoun, Speech on the Oregon Bill, 1848 Alexander Stephens, “Cornerstone Speech,” 1861 Discussion Questions: What were some of the early plans to advance abolitionism? What status did slavery hold in the Constitution? How did Calhoun and Stephens deal with the claims of the Declaration? October 2—Lincoln-Douglas Debates *Pre-Proposal Due by 9:30 AM EST* Thomas Jefferson, “Letter to John Holmes,” 1820 Abraham Lincoln, “Speech on the Repeal of the Missouri Compromise,” 1854 Lincoln, Selections from first, fifth, sixth, and seventh of the Lincoln-Douglas debates, 1858 Stephen Douglas, Selections from the Lincoln-Douglas debates, 1858 Lincoln, “Speech at Chicago,” 1858 Discussion Questions: What were the different positions of Lincoln and Douglas on the 1850s crisis? Which is closer to Jefferson’s on the Missouri Compromise? What were the dif- ferent views of Lincoln and Douglas on the meaning of the Declaration and the Constitution? October 4—Emancipation Lincoln, Emancipation Proclamation, 1863 Abraham Lincoln, “Gettysburg Address,” 1863 Lincoln, Letter to Albert Hodges, April 4, 1864 Abraham Lincoln, Second Inaugural Address, 1865 Thirteenth Amendment Discussion Questions: To what extent has executive power been the constitutional force that has changed race relations in the United States? What role has the military power facilitated these changes? How did Lincoln’s views on slavery evolve, if at all? October 6—Slavery and the Constitution Frederick Douglass, Selections from Narrative of the Life of Frederick Douglass, 1845 William Lloyd Garrison, “On the Constitution and the Union” 1832 Frederick Douglass, “The Constitution of the U.S.: Is It Pro-Slavery or Anti-Slavery?” 1860 Discussion Questions: How did Frederick Douglass view the Declaration and the Consti- tution? How did Douglass’ view of the Constitution differ from that of Garrison? October 9—No Class (Fall Break) October 11—Washington-DuBois Divide Booker T. Washington, “The Atlanta Exposition Address”, 1895 W.E.B. DuBois, Selections from Souls of Black Folk, 1903 Plessy v. Ferguson, 1896 Discussion Questions: How did the views of Washington and DuBois differ on how to achieve racial equality? What are the grounds of Justice Harlan’s dissent in Plessy v. Ferguson? October 13—King-Malcolm X Divide? Martin Luther King, Jr., “I Have a Dream” Speech, 1963 Malcolm X, “The Ballot or the Bullet”, 1964 Barack Obama, “Philadelphia Address on Race”, 2008 (skim) Discussion Questions: How do the views of King and Malcolm X differ on how to ad- vance racial equality? How does Obama’s address draw on elements of King’s tradition and philosophy? Malcolm X’s? October 16—King’s Legacy Martin Luther King, Jr., Letter from Birmingham Jail, 1963 Discussion Questions: Is there a tension between the two King speeches we read? Are there biases in how we remember Civil Rights activists like Dr. King? October 18—Voting Rights, A History 15th amendment Fannie Lou Hamer, Testimony Before the Credentials Committee, DNC, 1964 Lyndon B. Johnson, Speech Before Congress on Voting Rights, 1965 Shelby v. Holder, 2013 Discussion Questions: In what ways did the US fail to live up to the 15th amendment during the Jim Crow period? Are there still echoes of this today? October 20—Voting Rights, Today Blake, “North Carolina Governor Signs Extensive Voter ID” Liptak and Wines, “Strict NC Voter ID Law Thwarted After Supreme Court Rejects Case” Alexander, The New Jim Crow (excerpts) Discussion Questions: Has the contemporary US lived up to the promises that LBJ made in the 1960s? How and where do we still fall short? To what extent is the fight for voting rights a fight for our democracy? October 23—Class Cancelled *Proposal Due at 9:30 AM EST* October 25—Race Relations Today: The Reparations Debate Coates, “The Case for Reparations”, excerpts Discussion Questions: What are reparations? What is Coates’ argument for reparations? October 27—Race Relations Today: The Reparations Debate, continued Stolberg, “At Historic Hearing, House Panel Explores Reparations” Asheville Reparations Resolution Discussion Questions: What is the state of reparations policy in the US today? In Asheville? October 30—Catch Up Day - Women, Women’s Rights, and American Democracy November 1—The Early Struggle for Suffrage Declaration of Sentiments, Seneca Falls Convention, 1848 Mott, “Discourse on Women,” 1849 Susan B. Anthony, Women’s Right to the Suffrage Speech, 1873 Discussion Questions: To what extent did the the participants at Seneca Falls draw on the American tradition to call for women’s rights? To what extent did they reject the tradi- tion? What were the early arguments for women’s suffrage in the US? To what extent were these early efforts successful? November 3—“Outsiders” & the Fight for Women’s Suffrage *Deadline for Response Paper 2* Sojourner Truth, “Ain’t I a Woman?” speech (both versions), 1851 (and 1863) Staples, “How the Suffrage Movement Betrayed Black Women,” 2018 Frederick Douglass, Speech to the International Council on Women, 1888 Pankhurst, “Freedom or Death,” 1913 Discussion Questions: To what extent was the women’s suffrage movement in the US en- couraged by the political activism of women themselves? Did men play a vital role in the movement? Black men? What place did Black women hold in the movement? To what extent do “outsiders” in US politics band together to agitate for communal rights? November 6— The Fight and Victory for Suffrage Shaw, “The Fundamental Principle of a Republic,” 1915 Catt, “The Crisis,” 1916 (skim) Catt, Address to Congress, 1917 (skim) Woodrow Wilson, Speech on Women’s Suffage, 1918 19th amendment Discussion Questions: How did women eventually gain the right to vote in the US? What role did the states, the president, and Congress play in the process? Who was excluded? November 8 & 10— The Equal Rights Amendment Equal Rights Amendment Betty Friedan, The Feminine Mystique (excerpts) Chisholm, “For the Equal Rights Amendment,” 1970 Phyllis Schafly, “What’s Wrong with Equal Rights for Women?,” 1972 Discussion Questions: What was the equal rights amendment, and why was it so con- troversial, especially among women themselves? Why did the amendment fail? November 13— The Debate over Birth Control *Annotated Bibliography due via Moodle at 9:30 AM EST* Sanger, “The Morality of Birth Control,” 1921 Sanger, Russell, and Shaw vs Roosevelt, Debate on Birth Control, excerpts, 1921 Discussion Questions: To what extent has the woman’s body become politicized in the United States? Is/was the debate really about reproduction or about something else? November 15— The Debate over Abortion I Planned Parenthood v. Casey Roe v. Wade Discussion Questions: Is there a right to privacy protected in the Constitution? Why is abortion one of the hot button political issues still today? November 17— The Debate over Abortion II Hubbard, “45 States Have Enacted Abortion-Related Laws in Recent Years” Dobbs v. Jackson Women’s Health Organization (2022), excerpts Discussion Questions: How has the idea of a fundamental right to abortion changed in the US? What does this mean for women’s rights generally in the US? November 20— Women and Human Rights *Deadline for Response Paper 3* Roosevelt, “The Struggle for Human Rights,” 1948 Hillary Clinton, Speech at the UN 4th World Conference on Women, 1995 “Hillary Clinton’s Beijing Speech Resonates 20 Years Later” (NYT) Kamala Harris, Remarks to Commission on the Status of Women, 2021 Discussion Questions: To what extent can and should the struggle for women’s rights be seen as a wider struggle for human rights and civil rights? Are women’s rights a human rights issue? November 22-24—Thanksgiving Break (No Class) *Reading for Presentation due Nov. 24th by 12:00 PM EST* November 27-December 4— Class Presentations December 4—Wrapping Up (Finish presentations) MLK Jr., “Remaining Awake Through a Great Revolution,” 1959 Toqueville, Democracy in America, 1835, V. 2, Part 4, Ch. 6 *Final Paper due Monday, Dec. 11th by 10:30 AM via Moodle*	oercommons	2025-03-18T00:37:14.029370	06/18/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/116968/overview", "title": "FAD Syllabus: UNCA POLS320", "author": "UNC System" }
https://oercommons.org/courseware/lesson/128140/overview	Be Real. Be Ready: Sex Trafficking Prevention (High School Lesson Information) Overview This information page outlines a lesson on Sex Trafficking Prevention from the Be Real. Be Ready. curriculum created by the Adolescent Health Working Group (AHWG), San Francisco Unified School District teachers, and the San Francisco Department of Public Health. The lesson aims to educate students on separating myths from facts about human trafficking, understanding its impact on individuals and communities, and learning how to be allies and support other students. Be Real. Be Ready. \| Adolescent Health Working Group Sex Trafficking Prevention Lesson (High School) “Be Real. Be Ready.” is a comprehensive relationship and sexuality curriculum for high school students. The full curriculum is made up of 26 lessons. Educators can select which lessons best serve the needs of their students. In this lesson on Sex Trafficking Prevention, students will be able to: - Separate myths from facts in regards to human trafficking - Understand how human trafficking affects the people involved and others in the community - Understand how to be an ally and support other students Lesson activities include adressing common misconceptions, watching the "America's Daughters" video clip, a group activity on resisting trafficking, and a post-survey on sex trafficking prevention. If "America's Daughters" is not available, videos from the Polaris Project may be substituted after previewing. Information about Developer of Be Real. Be Ready. Instructional Materials Adolescent Health Working Group (AHWG) improves health equity to ensure that all youth ages 11 to 24 in California and beyond have unimpeded access to comprehensive, youth-centered, and culturally based healthcare. AHWG is a coalition of youth-serving providers, young people, and caregivers advocating for harm reduction and policy improvements in the areas of sexual health, mental health, and substance use. Instructional Material Review Review Detail and Comments from Reviewers The 2024 Comprehensive Sexual Health Education Instructional Materials Review of selected instructional materials was a joint project of the Washington Office of Superintendent of Public Instruction (OSPI) and the Washington Department of Health (DOH). The review was conducted by OSPI’s Sexual Health Education Instructional Materials Review Panel. This title was found to be consistent with Washington requirements for comprehensive sexual health education. Comments Digital lessons can be downloaded and printed from the Adolescent Health Working Group website. An email address is required to download the materials. These materials are not under an open license; however, they are intended for free educational use.	oercommons	2025-03-18T00:37:14.053492	Washington OSPI OER Project	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/128140/overview", "title": "Be Real. Be Ready: Sex Trafficking Prevention (High School Lesson Information)", "author": "Lesson Plan" }
https://oercommons.org/courseware/lesson/114058/overview	Google Generative AI Resources Overview List of Google Online Educational Resources on Generative AI Google Cloud Generative AI Resources Google Cloud Generative AI Resources: Introduction to Generative AI - This is an introductory level microlearning course aimed at explaining what Generative AI is, how it is used, and how it differs from traditional machine learning methods. It also covers Google Tools to help you develop your own Gen AI apps. Introduction to Large Language Models - This is an introductory-level micro-learning course that explores what large language models (LLM) are, the use cases where they can be utilized, and how you can use prompt tuning to enhance LLM performance. It also covers Google tools to help you develop your own Gen AI apps. Introduction to Responsible AI - This is an introductory-level microlearning course aimed at explaining what responsible AI is, why it's important, and how Google implements responsible AI in their products. It also introduces Google's 7 AI principles. Generative AI Fundamentals - Earn a skill badge by completing the Introduction to Generative AI, Introduction to Large Language Models, and Introduction to Responsible AI courses. By passing the final quiz, you'll demonstrate your understanding of foundational concepts in generative AI. Responsible AI: Applying AI Principles with Google Cloud - In this course, you will learn how Google Cloud does this today, together with best practices and lessons learned, to serve as a framework for you to build your own responsible AI approach.	oercommons	2025-03-18T00:37:14.066011	03/09/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/114058/overview", "title": "Google Generative AI Resources", "author": "John Verber" }
https://oercommons.org/courseware/lesson/94649/overview	Washington State Department of Licensing: Data Stewardship Overview The Washington State Department of Licensing contracted with the University of Washington to create an educational resource to provide an introduction to data stewardship principles. The course breaks down key concepts to familiarize individuals that are new to data stewardship and for those that wish to learn to think of data as an asset. Author Note & Copyright Statement Author Note Nic Weber, Information School, University of Washington Kathleen M. Hart, Data Stewardship Program, Washington State Department of Licensing Jessica Christie, Data Stewardship Program, Washington State Department of Licensing Correspondence concerning this e-book should be emailed to datastewards@dol.wa.gov. Copyright Statement Except where otherwise noted, Data Stewardship: Washington State Department of Licensing, is available under the CC-BY 4.0 license. All logos and trademarks are property of their respective owners. Sections used under fair use doctrine (17 U.S.C. § 107) are marked. This resource may contain links to websites operated by third parties. These links are provided for your convenience only and do not constitute or imply any endorsement or monitoring by the Department of Licensing. Please confirm the license status of any third-party resources and understand their terms of use before reusing them. Introduction Data is a relational concept. It can mean different things to different stakeholders in different contexts. In the context of the Washington State Department of Licensing (DOL) this relational aspect of data, and the challenges of data management, was succinctly described as follows: DOL has a diverse collection of applications to support its operational needs. There are many common data elements across these applications that are currently being defined and used separately and inconsistently. While this usually has no impact on the operation of the individual applications, it creates problems when trying to match and accumulate data from multiple systems for analysis and forecasting. The solution to this problem is to centrally define and manage this data so it is referenced and used consistently by all applications [1] The goal of this course is to both introduce terminology and techniques for working with data, as well as foreground principles in effective data stewardship. In doing so, we will try to help reduce the complexity of managing and providing services for data across DOL. Structure of course The book is structured around three chapters: Data Stewardship - Fundamental Concepts: In this chapter a working definition of data is introduced. We will discuss how data and collections of data can be differentiated by types and roles. We will also cover metadata and the process of organizing and structuring documentation to make data more accessible and useful to stakeholders. We will conclude with an overview of data governance (and where a data steward fits into governance at DOL) as well as data ethics. Data Stewardship - In Practice: The second chapter covers best practices in data management and records management and disposal, and how to apply concepts of data quality. We will also cover the selection and use of standards related to data and metadata, and how to serve stakeholders of data at DOL through data interviews. Data Stewardship - Applications: In the final chapter we will discuss data infrastructures including repositories for storing and preserving data, how to select and apply standards to data (and metadata), techniques for cleaning or tidying data, and some general applications for managing databases, understanding emerging technologies like artificial intelligence, and principles of visualizing data. Each chapter has a set of Intended Learning Outcomes (ILOs), in other words what you should be able to take away from and understand upon reading the chapter; suggested readings where you can dive deeper into a topic of interest; as well as general working definitions that you can use for future reference. [1] Quest Information Systems, Inc. (2008). Data Acquisition and Management Practices Study: Project Summary Report. Washington State Department of Licensing. Data Stewardship - Fundamental Concepts This first chapter introduces basic concepts related to data stewardship and working with data more broadly in the context of the public sector. We begin by first unpacking the concept of data and explaining how to approach various contextual ambiguities about what constitutes data. We then review some basic concepts related to data stewardship such as management of data and data quality. We wrap up this introduction by discussing the concept of data governance and data ethics. Defining Data The Department of Licensing defines data as: Numbers and facts that have not been grouped or analyzed. (Data that is grouped becomes statistics. Data that is analyzed becomes data analysis.) This includes numbers and facts in electronic records, paper records, emails, text messages, recordings, and images.[1] This working definition clarifies what the Department of Licensing considers data and how data is to be successfully managed over time. This definition also draws a clear distinction between a type of information object (e.g., electronic records, paper records, text messages, etc.) and the role that the information object is supposed to play (e.g., grouped numbers become statistical data, analyzed information objects become data analysis, etc.). The point is that data need to have an application to become meaningful to a customer, but in the abstract data are simply information objects with potential for use in many different contexts. It is often overwhelming to think of all the different ways that data may be used. Instead, it is more helpful to think about data as having type and role distinctions—A type is rigid (such as a format) and a role is fluid (it can change given a context). A simple example outside the context of data will help make this clear: - Jay Inslee is a person. This is a type. - Jay Inslee is the Governor of Washington State. This is a role. He will play this role for a fixed amount of time. After his term as governor expires, he will cease to play this role. But he will still be a person regardless of whether he is the Governor of Washington State. Data have similar types and roles—A tabular dataset such as a comma separated values (CSV) or Excel document will have a type of structure (rows, columns, and values). Unless we take some purposeful action to transform this data it will remain tabular as a type of data. This tabular data (type) might be evidence of some real-world example—it might be a set of species occurrence records, the precipitation and temperature of a particular place, the number of vehicles that pass through a certain point at a certain time, or even a vehicle registration number. These are different roles that data can play. Without context these are just numbers or files (information objects) that are waiting to be used as evidence by a data stakeholder (such as the definition offered by DOL above). This evidential role of data can shift and change depending on who is using the data, and for what purpose. Thinking about data as having roles and types helps us as data stewards to think about what exactly a stakeholder wants and needs. If we understand what role the data is supposed to play, we can better find the right type of data for a customer or stakeholder. Types: Structured vs Unstructured Data Structure is often a helpful distinction in identifying types of data. Structured data means that there is a predetermined form or logic to how information is arranged and presented to a user. A spreadsheet is an example of structured data—it has rows, columns and values This structure communicates to a user how the data values should be interpreted. Unstructured data means that is no predetermined way in which data are supposed to be presented and used by a customer. Unstructured data for example can be emails, text messages, other formal documents, videos, or even audio recordings. As with much of data stewardship, real world data rarely falls exactly in one category or the other. Often data are semi-structured, which is when a set of data has a file format (such as XML or JSON) but no predefined form or scheme that explains, for example, what a column of data should be. Below is a helpful figure—we can think about data as being structured or unstructured, as well as having semi-structures (such as XML or JSON). We will discuss these types of data as well as metadata in the next section of the course. Figure 1 Data roles vs types. “Data Types” by Nic Weber (of UW), CC BY 4.0. Roles: Entity vs Reference Data The Department of Licensing, like any complex organization, has a variety of data that it collects and manages over time to execute business functions. DOL data can serve a variety of purposes, and these “data roles” vary by not just the type of data that are collected and managed, but how they are used. This is described succinctly by DOL in the following way: DOL has a diverse collection of applications to support its operational needs. There are many common data elements across these applications that are currently being defined and used separately and inconsistently. While this usually has no impact on the operation of the individual applications, it creates problems when trying to match and accumulate data from multiple systems for analysis and forecasting. [2] A helpful way to think about the roles that data plays at DOL is that they can be either as reference data or entity data. Reference Data: This is the most straightforward type of data. It is comprised of simple lists which are directly defined at the enterprise level for use in all applications. This includes items like States, Counties, Fee Types, etc. These lists tend to be defined by outside sources and change very infrequently. Entity Data: This is the more complex type of data. It is comprised of data that is common across applications, but instead of being centrally defined, is entered or generated and updated within multiple applications. The classic example of this is customer data. This data tends to be complex in structure and change very frequently. Both reference and entity data in DOL are roles that different information objects can play. This relational nature of the data helps us to understand when it is appropriate to, for example, apply a broad standard for editing or cleaning data, applying a data quality checklist, or even recommending a data source to a customer. Reference data should depend upon external sources for validation and reliability (components of data quality that we will review in the next chapter). Entity data, as described above, can have a more relational or real time application that can shift or change given a context. A breakdown of what we’ve covered in this section so far: Data have types and roles that impact how it is used as evidence. Data types are distinguished by the structure or format of the data, and data roles are distinguished by how the data might be used (as reference data or as entity data). Categories of Data Thus far, we’ve described data by types and roles that are pre-established based on some aspect of the data or its use. Another way to differentiate the roles that data might play within an organization is by categorizing data with respect to its content. DOL has helpful developed a four-part categorization that includes the following types of data content: Category \| Explanation \| Category 1: Public Information \| Information the Agency can or currently releases to the public. It does not need protection from unauthorized disclosure, but does need integrity and availability protection controls. Examples of Category 1: Agency information available on the internet, through brochures and other publications. \| Category 2: Sensitive Information \| Information the Agency doesn’t generally release to the public unless specifically requested and allowable by law. Examples of Category 2: Internal business procedures, policies, and standards. \| Category 3: Confidential Information \| Information specifically protected from disclosure by law. This may include: a. Personal information. b. Information concerning Employee personnel records. c. Information regarding Information Technology infrastructure and security of computer and telecommunication systems. Examples of Category 3: Driver license numbers, driver license photos, Employee personnel files, and computer or network passwords. \| Category 4: Confidential Information requiring special handling \| Information specifically protected from disclosure by law and with: a. Especially strict handling requirements dictated by statutes, regulations, or agreements. b. Serious consequences that can arise from unauthorized disclosure, such as threats to health and safety, or legal sanctions. Examples of Category 4: Social Security numbers, bank account or debit card numbers, tort claim or lawsuit files, medical or disability information, firearm serial numbers. \| Table 1 DOL Data Classification and Handling Standards Note. This categorization comes from the following publications OCIO 141.10[3] and DOL policy 1.7.11[4]. These categories are essential to understanding not only how data should be governed (discussed in depth below), but also for identifying the role that data might appropriately play. For example, if a customer requests Category 4 data, as a steward of DOL, we would need to ensure that the customer has proper credentials to accept this data and verify that the data is transferred to the customer in a secure and reliable manner. Data Collections Another helpful distinction to draw is whether data are standalone products, or collections of multiple data sources that are of value to a stakeholder. For example, the WA State Department of Transportation collects traffic data from each route or highway in the state. Individually a data source may be just about one specific Highway, but in total all data about all Highways in Washington constitute a collection of data. The National Science Board provides a helpful distinction between three types of data collections: - General Data Collections: These data have minimal processing or quality checks and may not conform to standards for format and structure—if such standards exist at all. These collections usually are developed by and for a specific internal DOL client and may not be preserved beyond the end of a project. Many thousands of these collections likely exist throughout the department—stored on shared drives or even personal desktops. - Community Data Collections: These collections may follow standards for a community of potential clients, whether by adoption of existing standards or by developing new standards. Resource data collections may receive some direct funding from DOL or be created to comply with a particular records management requirement for making data accessible to the public. - Reference Data Collections: Are those that serve large communities, conform to robust standards, and are sustained indefinitely. These collections have large budgets, diverse and distributed stakeholders, and clients that depend on these data as well as established governance structures.[5] FAIR Data An emerging shorthand description for open data—that is applicable to any sector— is the concept of F.A.I.R. FAIR data should be Findable, Accessible, Interoperable, and Reusable. We will discuss this concept in a bit more depth throughout this course. But, having this shorthand definition of what we try to achieve in doing data stewardship is a helpful reminder for the steps needed to make data truly accessible over the long term. Data Stewardship As a data steward our job will include a variety of department specific tasks, but more generally stewardship is used to describe “accountability and responsibility for data and processes that ensure effective control and use of data assets. Stewardship can be formalized through job titles and descriptions, or it can be a less formal function driven by people trying to help an organization get value from its data.[6] Some general tasks that might be included in data stewardship: - Creating and managing metadata. - Documenting rules and standards. - Managing data quality issues. - Executing operational data governance activities. - Setting and managing guidelines around data access. Data Quality From the ISO 8000 definition we assume data quality are “…the degree to which a set of characteristics of data fulfills stated requirements.”[7] In simpler terms data quality is the degree to which a set of data or metadata are fit for use. Examples of data quality characteristics include completeness, validity, accuracy, consistency, availability, and timeliness. In the final chapter of this book, we will discuss strategies and techniques for applying data quality standards to DOL data. Data Governance Data Governance is a collection of practices and processes which help to ensure the formal management of data assets within an organization. Data governance includes not just rules or regulations, but also clear definitions about what data management means in a specific organizational context and how data quality, security, and preservation should be carried out (e.g., through stewardship). While not exhaustive most data governance models will include some combination of the following elements: - Authority and Control - Who will make decisions, and where are decision making processes documented, for planning, monitoring, and enforcing data management? - Security - What are the requirements for secure, trusted, authentic data and access regulations in an organization? This includes identity management, as well as the following: - Planning - How is security described across the organizational assets under management? - Monitoring - How often are security plans and responsibilities updated, what will constitute a necessary revision of security plans? - Evaluating - How are security plans and monitoring evaluated and by whom? - Accountability - If planning, monitoring, or security is not followed, what are the consequences and to whom does responsibility for enforcement ultimately lie with? - Quality - What constitutes quality assurance and who is responsible for carrying out either evaluation of quality or updating of data quality standards? In future chapters we will discuss data storage and data infrastructures, but it helps to foreground those discussions with a simple model depicting the central role of data governance. Data governance includes decisions about not just data, but also the hardware, software, and implementation of policies throughout a data lifecycle. A good data governance model will specify how each of these different aspects of data management should be carried and will be the basis for creating policies that govern individual data stewardship work. Data Governance in Washington State: The One Washington[8] project is the largest data and technology project is recent memory for the State of Washington. Between 2021 and 2027 it will restructure and replace almost all administrative systems with an Enterprise Resource Planning tool and will reorder all the data those various systems contain. The project has published a Data Governance Strategy document[9] that provides some insight into data governance in practice for the state of Washington. Data Ethics Ethics can be practically framed as “the study of the general nature of morals and of the specific moral judgments or choices to be made by a person” (Burns, 2012).[10] This definition situates ethics as a matter of individual choice, but of course the choices we make as individuals have broad impacts on the communities we are part of, serve, and wish to see flourish. That is, ethics is often practically framed as the result of individual choices and actions, but ethics also encompasses the implicit and explicit values of an institution, community of practice, or even group of data stakeholders. The relationship between individual choice and collective action is particularly relevant for data stewardship where you will need to collaboratively work to provide regular and unfettered access to resources needed to conduct research, develop guidelines or regulations that govern ethical behavior, and practically implement standards that encode or formalize these rules in a data governance model. It is important to acknowledge at the outset that data ethics, morals, and judgements, whether individual or collective, don’t arise from the ether—they are grounded in beliefs about what is right, just, or serves the greater good given an alternative set of choices. The ethical dilemmas faced by a community of practitioners are often about deciding what is right, how is justice enacted and preserved, or what choices we make can produce the greatest good for the communities on whose behalf we work. Data ethics can generally include any and all of the following aspects of data: - Ownership - Who is the responsible party that can make a claim of data—this is often based on licenses, rights of individuals who own data about themselves, or even state and federal regulations about data access. - Transparency - What do data contain, and how are data about individuals or institutions clearly and coherently documented for potential use? This should include any restrictions of the quality or validity of data. - Consent - If data contains information about people or groups of people then there must be some documented consent that the data is able to be used for a specific purpose. Consent often goes beyond a license— because it entails not just that the data can be accessed and used, but whether or not the data subjects have given their permission to do so. - Privacy - If data contains information that may be traceable to an individual or institution then there should be guidance or regulation on how the privacy of those stakeholders can be preserved, and who has access to data at what level of privacy preservation. - Openness - Data access often falls on a spectrum from freely accessible to anyone with an internet connection to accessible only through a data sharing agreement, or even through a formal data records request. While these are not the only issues that you may face as a data steward working at DOL— it is often helpful to refer to these different ethical questions to determine what ethics are at stake when making a decision about how to prepare data, how to decide upon data access controls, and what stakeholder privacy means in the context of data release. DOL’s Policy 1.7.12[11] addresses data ethics directly. The initial statements of the policy emphasize the trust relationship between a government agency and the people of the state as the basis for data ethics in the agency. Here is an excerpt: - Customer Trust: As the steward of customers’ data, the Agency has an obligation to ethically handle data in a manner that builds and maintains trust. - Respecting the Person Behind the Data: The Agency respects customers’ right to privacy and will only collect the minimum personal information required by law to fulfill business purposes. - Transparency in the Collection and Use of Data: Customers have the right to know how the Agency and others use their data. The Agency will be transparent about: What data we collect; How we use it; and Who we share it with and for what purposes. Summary In this chapter we have introduced several important concepts for data stewardship including how data might be differentiated based on its type or its role— types of data are based on structure, and these types are usually fixed and unchanging whereas the role of data, such as entity data or reference data, can vary given the application or context of how data are used. We also covered four broad categories used to describe data that are managed in DOL— these include public information, sensitive information, confidential information, and confidential information requiring specific handling. These categories help to further differentiate data by the role they might play for analysis by a customer, or in data governance that attempts to systematically create rules for data access. We also discussed some principles that govern ethical handling of data, including ownership of data, privacy, and consent. Further Reading - Borgman, C. L. (2015). What are Data? In Big data, little data, no data: Scholarship in the networked world. MIT press. - Washington State Department of Licensing. (2020). Data Stewardship Framework. https://www.dol.wa.gov/privacy/docs/data-stewardship-framework.pdf - Washington Consolidated Technology Services Agency (WaTech). (2021). Washington State Privacy Principles. (https://watech.wa.gov/sites/default/files/public/privacy/WSAPP.pdf) Example 1 Throughout the first chapter of this book we've discussed the idea that data are fundamentally relational— they mean different things to different customers at different points in time. To understand this relational nature of data it can be helpful to look at an example of how the same data are displayed to customers in different settings. These settings drive the stewardship of data, given the needs of a customer that may vary over time. Below is a screenshot of the Washington Department of Transportation's Traffic GeoData Portal. This map displays real-time traffic count data from routes and interstates throughout Washington. Figure 2 Washington Department of Transportation's Traffic GeoData Portal[12] This traffic map is interactive— it allows a customer to select a route, or even a point on a route, where data traffic is collected and see the real-time estimates of things like "How many single unit trucks are on this route in the last hour". This view of the data is useful for getting a quick overview of what the state of traffic is at any one moment in time. But let's assume that instead of a quick overview of the real-time data an analyst at DOL wants access to the data that is powering this visualization. They may want this data for a variety of reasons—they may want to map all the single use trucks on the road for June 1, 2021 and determine what percentage of single use trucks are licensed in the state of the WA. The WSDOT traffic geodata portal allows us to view this data by selecting a polygon and "printing" the data. If we choose to do this, then we get an easy to manipulate data table that looks like the following: Obj. ID \| RT. ID \| Location ID \| Direction of Travel \| Sngl Unit Trk% \| Dbl. Unit Trk % \| 1220 \| 410 \| At Milepost 116.26 A: PERMANENT TRAFFIC RECORDER S818 WEST \| Bothways \| 9.87 \| 2.14 \| 3624 \| 12 \| At Milepost 185.62 A: PERMANENT TRAFFIC RECORDER S818 EAST \| Bothways \| 4.93 \| 4.31 \| 2005 \| 12 \| Before Milepost 185.44 A: RIGHT WYE CONNECTION SR 12 \| Bothways \| - \| - \| 3809 \| 12 \| At Milepost 185.25 A: PERMANENT TRAFFIC RECORDER S818 SOUTH \| Bothways \| 7.45 \| 7.18 \| 2759 \| 12 \| After Milepost 185.48 A: RIGHT WYE CONNECTION SR 12 \| Bothways \| - \| - \| 4329 \| 12 \| From Milepost 188.65 A to Milepost 189.87 A \| - \| - \| - \| 2163 \| 12 \| From Milepost 185.48 A to -~Milepost 188.65 A \| - \| - \| - \| 2323 \| 410 \| From Milepost 114.40 A to Milepost 116.37 A \| - \| - \| - \| 4299 \| 12 \| From Milepost 178.86 A to Milepost 183.45 A \| - \| - \| - \| 1434 \| 12 \| From Milepost 183.45 A to Milepost 185.48 A \| - \| - \| - \| Table 2 Polygon printing of WSDOT traffic geodata portal data. Note. This table is much more informative and useful for analysis than a map. It gives us variables (such as Object ID, Route ID, Location). It also gives us observations of things like the number of single use trucks on Route 410 at milepost 116.2 on June 1, 2021 at 12:00pm. Questions: - In the example above from WSDOT—is this entity data or reference data? - Is the map an example of structured, unstructured, or semi-structured data? Why? - According to the DOL data categories, what kind of data is this table? [1] Department of Licensing. (2017). Structured Data Collection, Storage, and Retention (Administrative Policy 1.7.7). Inside Licensing: Internal Department of Licensing Intranet. [2] Quest Information Systems, Inc. (2008). Data Acquisition and Management Practices Study. Washington State Department of Licensing. [3] Office of the Chief Information Officer (OCIO). (2017). Securing Information Technology Assets Standards (Policy 141.10). https://ocio.wa.gov/policy/securing-information-technology-assets-standards [4] Department of Licensing. (2020). Data Security: Employee’s Data Security Requirements (Administrative Policy 1.7.11). Inside Licensing: Internal Department of Licensing Intranet. [5] National Science Board. (2005). Long Lived Digital Data Collections: Enabling research and education in the 21st Century. National Science Foundation. https://www.nsf.gov/geo/geo-data-policies/nsb-0540-1.pdf [6] DAMA International. (2017). DAMA-DMBOK: Data Management Body of Knowledge (2nd Edition). New Baskin, NJ: Technics Publications. [7] International Organization for Standardization (ISO). (2011). Data Quality: Part 1 – Overview. https://www.iso.org/standard/50798.html [8] Office of Financial Management. (2022). One Washington. https://one.wa.gov/ [9] Data Governance Advisory Committee. (2020). One Washington Data Governance Strategy. https://ofm.wa.gov/sites/default/files/public/onewa/OneWa_Data_Governance.pdf [10] Burns, S. A. (2012). Evolutionary pragmatism, A discourse on a modern philosophy for the 21stCentury. [11] Department of Licensing. (2020). Data Ethics (Administrative Policy 1.7.12). Inside Licensing: Internal Department of Licensing Intranet. [12] Washington Department of Transportation. (2022). Traffic Count Data: Geospatial Open Data Portal. https://wsdot.wa.gov/about/transportation-data/travel-data/traffic-count-data Data Stewardship - In Practice Introduction Library and Information Science (LIS) is a field that is concerned primarily with organizing, providing access to, and structuring information for effective use. In some cases this will mean working directly with people seeking information, and in other cases it will involve applying standards for the efficient discovery of information. As a data steward working in the public sector it will be helpful to first gain a working knowledge of these concepts from LIS, and then how to apply these in a public sector data context. We will first review metadata and knowledge organization practices more generally. Then, we will look at the concept of a data management plan (DMP) and how these DMPs can be useful in a public sector setting. Then, we'll discuss the concept of a data interview that can be used to meaningfully interact with customers that are seeking data. Metadata Metadata is often described as “data about data”—in some ways this is true, but this simple definition tends to obscure as much as it reveals about the important of data documentation. Metadata is most simply a set of standardized attribute-value pairs that provide contextual information about an object or artifact playing the role of data. In the following sections we will try to unpack concepts like attributes and values, and how they relate to descriptions of data. Perhaps the best way to do this is introducing some features of metadata as it is typically used to organize, describe, and provide supplementary information about data. These features (such as: class, sub-class, attribute, or instance) can apply to data at various levels of "granularity" or the level of specificity that goes from general (e.g., a type of data) to concrete example (e.g., a dataset that lives on your hard drive and has the exact tittle `mydata101.csv`). Here are features that are consistent across most metadata applications: - Classes are the broadest concept in metadata applications. A class is used to categorize or identify features that can be used for a domain of objects. Domain here means something like an area of application, a group of users, or even a set of intended customers. For example, a class of alcoholic drinks might be wine. Classes can be further refined by sub-classes, which are made up of instances, properties, and values (or attributes of an instance). - Sub-classes refine a class. A sub-class can be a more specific example of a class. Returning to our wine example, a sub-class of wines might be red, white, or rosé. Another sub-class could divide wines into sparkling or non-sparkling. Another sub-class could refine wine by their vintage, country of origin, or even the blend of grapes used to make a wine (Cabernet, Sauvignon Blanc, Malbec, etc.) The point is that a sub-class provides some way to divide or simplify the class that belongs to a domain. In the context of data stewardship, sub-classes aren't necessarily correct or incorrect—they simply help structure metadata about digital objects so that they can be more easily and accurately described. We judge class and sub-classes of metadata based not on their correctness but based on their utility—How well they help describe, simplify, and retrieve data. For example, if we have class of data called "Customer" and a sub-class called "Female Customers" we've likely created some distinction based on gender identity. Will this be a useful way to retrieve data for customers? Maybe, but the retrieval of data based on gender is likely too narrow of a use to be a reliable way to create a sub-class for all Customer data. Instead, we might create sub-classes like "Customer-Demographics" which is more general and likely solves use cases where any kind of analysis can make use of customer identities (e.g., height, weight, education, gender identity, religion, reported race, etc.). - Instances are observations or concrete examples of a class or sub-class. Returning to our wine, the class of Red Wine has a sub-class called Malbec. An instance of Malbec would be a bottle that was available for purchase—such as a Catena Malbec. A class or sub-class instance also has attributes or properties that further refine the object and specify why it is a member of that class or sub-class. - Attributes are defining features of a class or sub-class and refer to instances. An instance is a member of a class if it has all the attributes of that class. For example, a mammal has certain features (reproductive organs, respiratory system, etc.) that define its base or necessary attributes for class membership. Canines as a sub-class have a more specific set of attributes that define membership in that sub-class. Returning to our wine example, a Catena Malbec is a Malbec, and a red wine if and only if it has all the attributes that are used to define a Malbec AND red wine hold true. - Relations are the ways that we relate different instances and classes to one another. An instance or a class can be related in one or many ways. These different features of metadata are known as semantic features. That is, classes and attributes define the meaning of, and relationships between, data as individual items or records and collections of items and records. Another distinction in metadata is known as syntax or the features that structure or govern a particular application of semantic metadata features. The simplest way to understand metadata syntax is, like data, through how a metadata record is structured (or unstructured) and how the metadata conforms to a standard. Metadata Structures The structure of a particular metadata record will often be either formal or informal and this means that, like data, we can think of there being structured metadata and unstructured metadata syntaxes. Structured metadata is quite literally a structure of attribute and value pairs that are defined by a scheme. Most often, structured metadata is encoded in a machine-readable format like XML or JSON. Crucially, structured metadata is compliant with and adheres to a standard that has defined attributes—such as Dublin Core, EML, DDI. Metadata schemas are used in structured metadata to define semantics, such as attributes (e.g., what do you mean by “creator” in ecology?); suggest controls of values (e.g., dates = MM-DD-YYYY); define requirements for being “well-formed” (e.g., what fields are required for an implementation of the standard); and provide example use cases that are satisfied by the standard. Structured metadata is, typically, differentiated by its documentation role. - Descriptive Metadata: Tells us about objects, their creation, and the context in which they were created (e.g., title, author, date). - Technical Metadata: Tells us about the context of the data collection (e.g., the instrument, computer, algorithm, or some other tool that was used in the processing or collection of the data). - Administrative Metadata: Tells us about the management of that data (e.g., rights statements, licenses, copyrights, institutions charged with preservation, etc.). Unstructured metadata is meant to provide contextual information that is human readable. Unstructured metadata often takes the form of contextual information that records and makes clear how data were generated, how data were coded by creators, and relevant concerns that should be acknowledged in reusing these digital objects. Unstructured metadata includes things like codebooks, README files, or even an informal data dictionary. A further important distinction about metadata is that it can be applied to both individual items, or collections, or groups of related items. This is known as the difference between item level or collection level metadata. Metadata Standards Metadata standards are based on broad community agreement about what is essential to record and communicate to stakeholders about a set of data. A metadata standard includes clear and unambiguous definitions of what attributes are, and what the accepted values are for any attribute. The total collection of attributes that make up a standard are often called a “schema” or “core elements”. For example, one of the most broadly used metadata standards for image resources is ExIF or the Extensible Interchange Format[1]—If you have ever taken a picture with your phone and later uploaded it to a computer the metadata captured by your phone’s camera is based on ExIF this allows any device to see attributes such as the date, time, camera model, or geolocation of where an image was taken. ExIF includes a mix of both descriptive and technical metadata attributes. Dublin Core is another metadata standard that is used broadly for describing images, web-resources, documents, and other multimedia, including data. The Dublin Core is made up of 15 essential attributes that must be recorded and stored alongside any object. Each attribute (or term) in Dublin Core[2] is defined by a standards making body that provides guidance on how attributes are to be used in describing a resource. An example of the attributes of a metadata record following the Dublin Core standard can be found below: Attribute \| Definition \| Example \| Title \| A name given to the resource, either supplied by the individual assigning metadata or from the object \| Example: "A Pilot's Guide to Aircraft Insurance" \| Creator \| Entity responsible for making the resource. \| Example: "Duncan, P. A." \| Subject \| The topic of the resource, typically represented using keywords. \| Example: "Colonial medicine" \| Description \| An account of the resource. \| Example: "Illustrated guide to airport markings and lighting signals for airports with low visibility conditions." \| Publisher \| An entity responsible for making the resource available. \| Example: "The University of Texas Press" \| Contributor \| An entity responsible for making contributions to the resource (e.g. editor, transcriber, illustrator). \| Example: "Austin Citizen Photograph" \| Coverage \| The spatial or temporal topic of the resource. \| Example: "Austin, TX" \| Date \| A point or period of time associated with the resource. \| Example: "1998-02-16" \| Type \| The nature or genre of the resource. For a list of possible types, visit the DCMI Type Vocabulary. \| Example: “Image” \| Format \| The file format, physical medium, or dimensions of the resource. \| "[128] p. : ill. ; 15 cm." \| Rights \| Information about rights held over the resource. \| Example: "This electronic resource is made available by the University of Texas Libraries solely for the purposes of research, teaching and private study." \| Source \| A related resource from which the described resource is derived. \| Example: "ZA 3075 Y69 2007" \| Language \| Language(s) of the resource. \| Example: "Spanish" \| Relation \| A related resource. For a list of possible relations, visit the Summary Refinement and Scheme Table. \| Example: "HasVersion 13th Edition" \| Identifier \| A unique reference to the resource. \| Example: "doi: 10.15781/T2251FN91" \| Table 3 Dublin Core Metadata Standard attributes[3] There are thousands of metadata standards that have been developed to record descriptive, technical, and administrative information about data. Each of these standards differs based on the type of data that is being described, and the organizational context of data customers. Choosing or selecting the right metadata standard is typically a data governance issue rather than an individual choice. However, there are some general guidelines that can be helpful for selecting and applying a metadata standard where one does not yet exist: - Purpose: Will the metadata be used to record descriptive, technical, or administrative information about data? (It could include all three.) - Creation: At what point in the data lifecycle will metadata be created? This decision will also drive who is responsible for creating the metadata. If a data collector is also charged with creating metadata then as a data steward your role might be to validate or confirm that metadata standards are applied correctly (the next chapter provides guidance for checking metadata quality). - Data types and role: Determining the type of data that is being collected can be the first and often most important aspect of selecting a metadata standard. Image, text, or numeric data all have different controlled standards that might be relevant to selecting a standard. Recording the roles and types of data in advance of choosing a standard will usually help reduce the decision. - Consult a metadata catalog: Lists of metadata standards can be found across the web—these will help to narrow the selection of a particular standard to meet the needs of data types and roles. An example of a metadata catalog include The Research Data Alliance’s Metadata Standards Catalog.[4] Data Documentation In addition to metadata there are a number of other forms of ‘documentation’ that can be valuable for stakeholders of data or a data collection. These include data dictionaries, readme files, and codebooks. README files provide narrative explanation of what a dataset contains, how it was produced, and how it can or should be used. README files are simply a narrative for the data—they provide a way for data to be described informally for stakeholders. Below are some examples and resources for creating a README file for data documentation. - A standard for README files (https://github.com/RichardLitt/standard-readme) - Some advice on creating README files for data and data collections (https://data.research.cornell.edu/content/readme) - A template for creating README files for data (https://drive.google.com/file/d/1OXQYDoGMB1xE2ocs98hS1cCTLLzK0ZvQ/view) Data Dictionaries define the variables and values of a dataset (and constraints on the values of those variables). Most often this takes the form of a table—where data values are explained with a clear definition and the value that data should take (e.g., a number, text string, etc.). Data dictionaries typically contain four elements: - Variable labels - this provides the name of the variable as it appears in the dataset that a client or stakeholder will download. - Variable definitions - this explains what the variable is meant to record or measure. The definition should use plain language—informing the client what the data is meant to represent. Often this is hard to determine—so, if you are creating a new data dictionary you may have to guess what exactly the variable means. - Variable value types - this can typically be a description such as date, a number (or integer), or a text string. The point of defining a variable value is to tell a potential user what type of data they should expect to see in a dataset. - Allowed values - this could include the type of value (e.g., string, dateTime) or the control on that value (e.g., postal codes from the USPS). Value constraints—or allowed values—are extremely important to document because they help a user understand why 05-21-2021 is not just a random assortment of numbers, but in fact follows a standard convention for representing a date (MM-DD-YYYY). Data dictionaries can be a little overwhelming to think about initially, but there are a number of valuable resources to consult when getting started with this form of data documentation: - Introduction to creating data dictionaries (https://help.osf.io/article/217-how-to-make-a-data-dictionary) - Example of a simple data dictionary (https://missing-pieces.s3.amazonaws.com/missing_pieces_data_dict_11-20-2017.pdf) CodeBooks are more formal documentation that is often created for statistical or quantitative data. A codebook defines how data were coded, and how those codes were created in order to analyze or summarize a dataset. Codebooks are often very helpful if a dataset contains a number of non-standard data values or variables. - Introduction to the concept of a codebook (https://www.icpsr.umich.edu/icpsrweb/content/shared/ICPSR/faqs/what-is-a-codebook.html) - Example of a codebook that follows best practices described in the link above (https://www.icpsr.umich.edu/web/pages/instructors/setups/codebook/) Data Management and Data Management Plans Data management is simply defined as the active and ongoing stewardship of data throughout a lifecycle of use, including its reuse in unanticipated contexts. A lifecycle of data can include the planning for data collection, the collecting of data, the creation of documentation about data, the storage of data, the services that help clients find and use data, and the long-term preservation of data. Data management is active—that is, it requires purposeful interactions with both data creators and data users, as well as stewardship of the data itself (cleaning, applying standards, updating data, etc.). Simply, we can think of data in an organizational context as having three layers: The data itself, the documentation (which we discussed above), and its storage. We will discuss storage in depth in the final chapter of this book. For now, it’s good to have a working mental model of what data management applies to—all three layers of the organizational context in which data are collected, described, and stored. In the definition of data management, I referred to what might seem like a complex “lifecycle” of data. A lifecycle model is meant to be a conceptual model that spells out, broadly, the different stages that data might go through and the various people that will be involved in each stage. A lifecycle model doesn’t necessarily have a clear start or finishing point—the idea is that data might move through, or “cycle” through, each of these stages. As data stewards there is an important role to play each stage of the lifecycle—At the point of collection all the way through to the preservation or destruction of data. Below is a helpful depiction of the most basic stages of a data management lifecycle. Figure 3 Data Lifecycle Management. Image “Data Management Lifecycle” by Will Saunders (of DOL), CC BY 4.0. Data Management Plan A data management plan (DMP) is a written document that describes how data will be managed at each stage of a data lifecycle. As a data steward serving internal DOL stakeholders this might include asking a client: “How do you expect to acquire or generate during the course of a project?”, “How will you manage, describe, analyze, and store those data during the project?”, and “What mechanisms will you use at the end of your project to share and preserve your data?” DMPs are created by data producers with consultation of data stewards. Ideally a DMP is created before data collection begins, but oftentimes it is necessary to develop data management plans during or even at the conclusion of a project. Although an ideal data management plan documents each stage in the lifecycle above, it must include at least four elements: - Data Types: What types of data are being created, collected, and how should they be preserved - Data Roles: Who might use the data, and how might those needs change over time? - Data Documentation: What types of metadata standards are appropriate? What kinds of other documentation might also be useful? - Data Quality: Should data be cleaned and / or the quality be checked before being stored? There is a wealth of support for data management planning on the web: - DMPTool provides interactive templates for creating standards compliant DMPs (https://dmptool.org/) - Stanford University's Library has a very thorough overview of DMPs for research and public use (https://library.stanford.edu/research/data-management-services/data-management-plans) - USGS guide on federal agency DMPs (https://www.usgs.gov/data-management/data-management-plans) Data Interviews Traditional to LIS is the idea of an information (or data) interview—that is, when people seek information what kinds of mental models do they use to structure a question, how do they translate that question into a query for information in a database, and what types of techniques are helpful for reformulating a query to actually answer their question (not just what the information system returns from a query)? Behind all information interviews—whether it is between people or between people and an information system—are “mental models.” A mental model is a simple working assumption about how a domain should work. For example, we have a simple working model of a vending machine—we enter money, we select an item, and the machine delivers our selected item. This mental model breaks down if what we expect is not what is returned. If we put in a dollar, select ‘Diet Coke’, and receive a Sprite—something went wrong. Did we press the wrong button? Was the Diet Coke mislabeled? When our mental model doesn’t match reality, we often have to diagnose the problem to understand what went wrong. Data interviews are not so different than a vending machine in terms of the basic steps used to retrieve an item (input and delivery), but our satisfaction with retrieved items is often much more complicated. In data interviews—where a user is seeking a piece of structured information about a topic—the mental model we often use is related to information retrieval. We pose a query to an information system and expect to get results back that are relevant to that query. The relevance of a query might be judged either by recall or precision. - Recall is related to the total amount of information returned—Did we retrieve all the information or data that a system had relevant to our query? - Precision is about the accuracy of the returned results—Did the information system give us back a subset of the relevant information that is most useful to our query? (See, Figure 4 for a visual example.) Figure 4 Representation of the values precision and recall in search query results. Image “Precision and Recall” by Walber, CC BY-SA 4.0. Recall and precision are both useful for a data interview. Sometimes what we desire, especially in exploratory searching, is to cast a broad net and find all the information that might exist about a topic. In this case, recall will be a helpful mental model to judge relevancy. If, however, we want to retrieve a particular type of information (sometimes called a ‘known item’ search) then precision will be a much better model to judge whether or not an information system retrieved the item we were seeking. Knowing in advance what kind of search is being conducted, and then building a search strategy with the correct mental model in place is the key to successful data interviews. As a data steward, it will be rare that you encounter a user who has not already done some searching and come up empty. It is much more likely that a user will come to you having been frustrated by not finding an answer to their question, or the data they expect to already exist. In a library setting these types of interviews are often called a “reference interview” and helpfully the field has evolved some of the traditional techniques to be applicable to data users or customers. The existing resources on “data reference interviews” can range from very formal—such as a worksheet used for scientific data to more simple and straightforward models for general data users. All of these approaches share some basic things in common: helping a user understand the question they are trying to answer, asking questions about what resources might accessible and what might be useful, and then following up with the user to ensure that they have a match between expectation and reality. Below is a breakdown of this process into just four simple steps to follow during a data interview with a customer: The first two steps in a data interview should be identifying the type of question being asked, and the relevancy of the expected results: What question is the user trying to answer? (In other words, why does the customer want data?) - Exploratory - Locating what resources might be available and what might be useful for a project (for example). - Known Item - There is a clear and distinguishable right answer, and the data likely exist somewhere in the institution. The customer is simply trying to find the right data to answer their question. What mental model will be used to judge the relevance of data? (In other words, what model will the user apply to the data they receive?) - Recall - Most likely an exploratory search is interested in finding everything that might be relevant to their search—so, recall is almost always the mental model to have in mind when guiding exploratory questions. - Precision - For a customer that knows that a resource exists but cannot locate it. When interacting with a customer executing these two steps will help clarify what data is most relevant, and how that data’s relevance will be judged by the user. The next two steps are focused on locating data and ensuring that the data meets the customer’s needs. It's helpful to think of these steps as being about a data query and evaluation. Query: What data sources are available and what is optimal query for those sources? (In other words—what are the search terms and facets for browsing that will likely yield a relevant dataset?) - A query or search strategy will always require iteration to learn and experiment with a search interface to retrieve relevant data. This is often helpful to do, initially, with a customer. For example, going to a database, looking at the available holdings and then executing some searches alongside the user to make sure the types of results match their expectations. - Once the customer understands how to best formulate searches—it is often best to let them continue experimenting and trying to find the best data source. Evaluation: After getting a customer on the right path to finding data set up a time to check-in and make sure they found what they were looking for, and if not, what the next steps might be in their search process. Next steps might include, designing a project to collect new data, filing a records request to get information that might not be publicly available, or even directly contacting other people in the organization to help with their search. Throughout this process it can be helpful to create a log of the data interview. This could simply record the time, the question being asked, and the search strategy you helped devise. The log plays two important roles: - Check-in: The log can help be an external reminder about when to re-contact a user to help evaluate their search process. - Record of searches: The log can also help to document for yourself and other data stewards the kinds of searches that customers are executing. Over time this log will be useful in understanding changes that are necessary to a database, to data description standards, or even coming up with documentation or guidance that can answer repeated questions from customers. A template for a basic data log might look like this simple spreadsheet. Data Licensing and Copyright Most jurisdictions throughout the world have some provision for intellectual property rights that govern how and under what conditions information objects can be shared and reused. In the United States, most data that are considered factual information cannot be subject to a copyright claim—for example, I could not claim that information about a highway is my property and anyone who references or uses information about highways is subject to legal action based on copyright infringement (this was enshrined in law through a famous case, Feist Publications vs Rural Telephone Service Company[5]). However, when data is arranged or organized in a specific way (e.g., a database) then data collectors do have some copyright protection for the intellectual effort that went into arranging and organizing the data. The copyright protections that are afforded to database creators is limited and varies (slightly) by state and municipality in the US. Regardless of whether data can (or should) be subject to copyright protections, most federal, state, and municipal agencies are subject to open government or public records legislation that requires transparency and access to government information (in Washington this is codified under the Washington Public Records Act[6]). For data, and particularly what is deemed to be non-proprietary and non-confidential data, most government agencies have been motivated to make structured information “as open as possible and as closed as is necessary”. Washington state has long been a leader in open government, and its longstanding open data program has been successfully organized around principles of transparency and accountability. Regardless of the success of open government, in order to truly achieve the goals of an open data program data needs to be specifically licensed for use and redistribution. When data are published to an openly accessible location on the web a license acts a declaration or reference to an existing legal document that specifies how data should be accessed, used, and any limitations on redistribution. At the federal level, open data license requirements are described in the Foundations for Evidence-Based Policymaking Act of 2018[7]. These requirements are interpreted as follows: Agencies must apply open licenses, in consultation with the best practices found in Project Open Data, to information as it is collected or created so that if data are made public there are no restrictions on copying, publishing, distributing, transmitting, adapting, or otherwise using the information for non-commercial or for commercial purposes. Common licenses used for open data include the following: - Open Data Commons Attribution License (ODC-By) v1.0 (https://opendatacommons.org/licenses/by/1-0/) - Open Data Commons Public Domain Dedication and License (PDDL) (https://opendatacommons.org/licenses/pddl/1-0/) - Creative Commons Zero Public Domain Dedication (CC0), e.g., "license" (https://creativecommons.org/publicdomain/zero/1.0/) - Creative Commons Attribution (CC BY), e.g., "license" (https://creativecommons.org/licenses/by/4.0/) - Creative Commons Attribution-ShareAlike (CC BY-SA), e.g., "license" (https://creativecommons.org/licenses/by-sa/4.0/) - GNU Free Documentation License, e.g., "license" (http://www.gnu.org/licenses/fdl-1.3.en.html All that is required for a license to be applied to data is that there is a clear and unambiguous label that states which license and version is applicable to the data (or collection of data) and where possible provides a link to the text explaining limitations implied. Despite the importance of and simplicity in licensing open data these conventions are rarely followed. Examples of licenses (and lack of licenses) in the wa.data.gov portal Public Domain license - Healthcare Provider Credential Data (https://data.wa.gov/Health/Health-Care-Provider-Credential-Data/qxh8-f4bd) No License - WA Tax Exemptions - Potential Eligibility by Make/Model Excluding Vehicle Price Criteria (https://data.wa.gov/Transportation/WA-Tax-Exemptions-Potential-Eligibility-by-Make-Mo/aug9-4a7g) - Vehicle Battery Registration (https://data.wa.gov/Natural-Resources-Environment/Vehicle-Battery-Registration/we9k-a58y) Reproducibility and Replication through Open Data Open data is most often lauded as a democratic principle that enables government transparency and accountability. While simply publishing and licensing data so that it is openly accessible and reusable guarantees some amount of transparency there is, almost always, a significant gap between data being accessible and data being meaningfully reusable. This gap—between access and meaningful use—is one of the significant challenges of data stewardship. When data are used for analysis or policymaking (i.e., they are transformed from raw inputs to some data role) there is an assumption that by having access and license to reuse data one could reasonably arrive at the same conclusions. This is, broadly speaking, an assumption that open data facilitates reproducibility, replication, or verification. And while these terms are often used interchangeably, they have slightly different meanings. “Reproducibility” refers to instances in which the original data and computer codes are used to regenerate the results. Reproducibility in this sense should be a guarantee that if data and analytic steps are made accessible then anyone with reasonable skills could arrive at the same conclusions as the original analyst. If a customer wants to verify a report by DOL that the number of Antique Automotive transfers in 2021 was greater than 1000, then reproducibility of this claim should be as easy as pointing to a DOL Vehicle Registration dataset.[8] However, reproducibility is often more complicated than simply pointing at numbers in a dataset. Reproducibility often requires transparency in the form of openly accessible and well documented data, clear and unambiguous analytic steps, and any software or tools used to transform a raw number into a textual claim. “Replicability” refers to instances in which an individual collects new data to arrive at the same findings as a previous study or report. Replicability implies that if one were to have a different method of data collection then the result or claim of an analysis should hold true (regardless of the data that are used). For example, if a report claims that over 60% of all highway traffic in the state of Washington is by commercial vehicles then regardless of which data we use we should be able to verify that the number of vehicles on the road are commercially licensed—and that number should be approximately 60% of all vehicles.[9] The differences between replication and reproducibility are subtle but important. Reproducibility implies that a specific result can be regenerated. Replicability implies that a broad finding or claim should have veracity—that is, it should be able to be “rediscovered” or hold true if the same type of data are collected and analyzed a second time. A simple way that I think about this is through cooking: - If I follow a recipe for making chocolate chip cookies, then I should be able to use the same ingredients and the same oven settings to create multiple sheets of the same exact cookie. That is, I can reproduce a cookie many times. - If I attend a holiday party, taste an excellent chocolate chip cookie, and ask my friend for the recipe–then (using similar ingredients and similar oven settings) I should be able to recreate the original cookie. That is, I should be able to replicate (in proximate fashion) the original cookie that I tasted. Reproducibility and replication are often goals of stakeholders or customers that are served by government agencies. When a report or analysis is made public then there is an assumption that we can either reproduce the exact findings, or in the future replicate the claims made using new data. Many times, through a reference interview, it will become clear that the goals of a customer are to verify something they believe to be true or maybe are skeptical about the result holding up over time. Determining first if the customer goal is to regenerate or reproduce a finding, or if the customer wants to replicate a previous study can often guide the resources that are suggested, and the steps taken to serving a customer effectively. Further Reading - National Conference of State Legislatures. (2022). State Open Data Laws and Policies. https://www.ncsl.org/research/telecommunications-and-information-technology/state-open-data-laws-and-policies.aspx - Federal Enterprise Data Resources. (2022). Open Licenses. data.gov. https://resources.data.gov/open-licenses/ - Data.world. (2022). Common Dataset License Types. Data.world. https://data.world/license-help - Creative Commons. (2022). Open Data. Creative Commons. https://creativecommons.org/about/program-areas/open-data/ - Open Knowledge Foundation. (2022). Guide to Open Data Licensing. Open Knowledge Foundation. https://opendefinition.org/guide/data/ On Metadata - Data Management. (2001). Metadata Creation. United States Geological Survey (USGS). https://www.usgs.gov/data-management/metadata-creation - Horsburgh, J. etal. (2022). Identify and use relevant metadata standards. DataONE. https://old.dataone.org/best-practices/identify-and-use-relevant-metadata-standards - Federal Enterprise Data Resources. (2014). DCAT-US Schema v1.1 (Project Open Data Metadata Schema). Data.gov. https://resources.data.gov/resources/dcat-us/ - W3C. (2020). Data Catalog Vocabulary (DCAT) - Version 2. Data.gov. https://www.w3.org/TR/vocab-dcat/ On Curating / Preparing Data for Reproducibility: On Reproducible Research and Replicable Results (using open science principles) - Psomopoulos, F. (2017). Open Science Tools, Data & Technologies for Efficient Ecological & Evolutionary Research: Transparent, Reproducible and Open Research. https://reproducible-analysis-workshop.readthedocs.io/en/latest/2.Transparent-Open-Research.html - German National Library of Science and Technology. (2019). Reproducible Research and Data Analysis. Open Science Training Handbook. https://open-science-training-handbook.gitbook.io/book/open-science-basics/reproducible-research-and-data-analysis The Turing Way Community. (2021). Guide for Reproducible Research. https://the-turing-way.netlify.app/reproducible-research/reproducible-research.html [1] Extensible Interchange Format (ExIF). (2022). Wikipedia: ExIF. https://en.wikipedia.org/wiki/Exif [2] Dublin Core Metadata Initiative (DCMI). (2020). DCMI Metadata Terms. https://www.dublincore.org/specifications/dublin-core/dcmi-terms/ [3] Ibid. [4] Research Data Alliance. (2022). Metadata Standards Catalog. https://rd-alliance.github.io/metadata-directory/ [5] Feist Publications, Inc., Petitioner v. Rural Telephone Service Company, Inc. 499 U.S. 340. (1991). https://www.law.cornell.edu/supremecourt/text/499/340 [6] Washington State Legislature. Chapter 42.56 Public Records Act. https://app.leg.wa.gov/RCW/default.aspx?cite=42.56 [7] Foundations for Evidence-Based Policymaking Act. HR 4174. (2018). https://www.congress.gov/bill/115th-congress/house-bill/4174 [8] Department of Licensing. (May 2021). Vehicle and Vessel Fee Distribution Reports. https://fortress.wa.gov/dol/vsd/vsdFeeDistribution/DisplayReport.aspx?rpt=2021M05-57.csv&countBit=1 [9] Barba, L.A. (2018). Terminologies for Reproducible Research. arXiv preprint. arXiv, 1802.03311. Data Stewardship - Applications In this chapter we will discuss applications of concepts to data stewardship. This will extend concepts covered in previous sections (e.g., data cleaning) and will focus on practical ways to implement these concepts at DOL. The goal of this chapter is to understand how to apply and use existing best practices in data stewardship and where possible resources for further learning. The topics we will cover include: - Data Quality - Data Cleaning - AI and Machine Learning - Data Visualization - Databases Data & Metadata Quality Data Quality In the 'Fundamentals of Data Stewardship' section we defined data quality through the International Standards Organization[1] as “…the degree to which a set of characteristics of data fulfills stated requirements.” An ISO standard is developed by experts in consultation with various stakeholders to agree upon a broad definition that can be applied in any setting. ISO standards can be a great starting point for understanding a broad definition or authoritative way to describe a concept like data quality. Additional work has gone into defining internal and external indicators of data quality—these include the following: Internal Indicators - Validity - Data should clearly and adequately represent the intended result. - Reliability - Data should accurately represent what it purports. - Timeliness - Data should be recorded at frequency, and with regularity, to be reliable. - Precision - Data should be free of errors. External Indicators - Integrity - Data should be verified for being accurate and should have safeguards in place to control data editing so that accuracy can be guaranteed over time. - Documentation - Information about how data were collected, analyzed, and the context of appropriate use should be accessible alongside data itself. - Format - Data should be stored in a format that is regularly checked for preservation. Judging data quality within a particular institution is often a matter of adjusting or refining these indicators. For example, the United States Agency for International Development (USAID) has developed a checklist for conducting data quality assessments. Each time a data steward recommends a data source for use a data quality assessment is conducted to guarantee that the data are “fit for purpose”—that is, the recommended data meet the strict quality standards that are expected of USAID research and policy making. Some examples of the USAID approach to data quality: - Data Quality Assessment Checklist and Recommended Procedures (https://www.usaid.gov/sites/default/files/documents/1865/Data_Quality_20Assessment_Checklist.pdf) - Data Quality Assessment Checklist—Additional Help (https://www.usaid.gov/sites/default/files/documents/1868/597sad.pdf) As a data steward, understanding and even recommending data quality indicators will be largely dependent upon the rules and regulations of a data governance program. Thus, a good place to start might be finding out where, or even if, data quality is defined by your organization, and where, if possible, there are examples of how master data have been transformed to meet these standards. Metadata Quality Metadata quality is, as it sounds, extremely similar in spirit to data quality, but includes some refined indicators that can be useful to documentation that provides a description, rules of access, or rights for data use. There is no ISO or even broadly agreed upon definition of metadata quality (in part because many organizations think of metadata as a sub-class of data). However, there are some broadly agreed upon indicators that can be helpful in evaluating the quality of structured and unstructured documentation that plays the role of metadata. These include: - Completeness - All necessary descriptive, technical, or administrative attributes are included in a metadata record. - Accuracy - Information is correct both semantically and syntactically. Meaning that the proper standards for representing information are identified and used (e.g., representing a ‘Date’ the ISO standard 8601 is followed, such as `DD-MM-YYYY` or `01-01-2000` to represent `January 01, 2000`). - Accessibility - Metadata can be accessed and read by both humans and machines. This is a critical indicator for many business applications because metadata will often play multiple roles—machine-readable metadata will drive data discovery systems, and human-readable metadata will be used to evaluate and judge relevancy. Both forms of metadata govern who can and should access data. - Conformance to expectations - Values (that is, what the attribute of a metadata record describes) adhere to the expectations of your defined user communities (both internal and external). A good example of this is an attribute like “location”—for some metadata records location might be a plain language description like “Whatcom County” while other records require a more specific locale like the latitude and longitude of the county (e.g., 48.8787° N, 121.9719° W). - Consistency - Semantic and structural values and attributes are represented in a consistent manner across records. Values remain consistent within a record or type of records, and attributes are defined clearly with an existing schema. As we talked about in previous chapters, having a schema that can be clearly identified and interpreted is the key to metadata consistency across an organization. - Timeliness - When the resource changes, the metadata is updated accordingly. When additional metadata becomes available or when metadata standards change, the metadata associated with the resource is also consistently updated. - Provenance - Information about the source of the metadata or data are recorded and captured in the record, and metadata transformations or changes can be traced back to the original record. Like data quality, metadata quality has a number of specific institutional applications to ensure that this documentation meets the expectations of data customers. Data and Metadata Quality in Practice Applying quality standards can happen informally and formally. Informally, the criteria described above can be used heuristically to guide the creation or editing of data to ensure that it meets a customer’s expectations. It is my experience in data curation that informal quality assessments are part of daily work in identifying data for customers and helping stakeholders to assess whether data are being collected with the right level of sophistication or accuracy. Often this informal process of metadata quality assessment will reveal shortcomings or inaccuracies of quality that should be fixed by a data owner. The repair or improvement of data is a matter of contacting the owner and helping them understand where there is a gap between best and current practices. More formally, data quality assessments can be conducted as part of an inventory process that attempts to systematically evaluate the readiness of data to meet customer needs. A data inventory, like all of data stewardship, can vary based on the needs of an organization and is oftentimes a necessary exercise in establishing data governance. The general steps to performing a data inventory (also called a data audit) are: - Establishing an oversight committee. - Determining the scope and plan of the inventory. - Choosing which indicators of data or metadata quality will be assessed (and often refining the indicator definitions to meet a particular assessment need). - Cataloging data assets in accordance with the inventory plan and identified data quality indicators. - Documenting the inventory for a data governance committee which can then prioritize or guide next steps in improving data quality. Recommended resources for developing and executing a data inventory: - GovEx is a non-profit that works with government agencies at the state and municipal level has established an excellent guide to designing and executing data inventories. This guide includes numerous examples of checklists and data quality indicators used by agencies throughout the US. (https://labs.centerforgov.org/data-governance/data-inventory/) - The US Department of Transportation has developed a sophisticated model for executing data inventories (https://www.transportation.gov/sites/dot.gov/files/docs/DOT%20-%20OpenData%20-%20Data%20Inventory%20Approach.pdf) Data inventories are a part of good data governance, but they are also increasingly a component of data privacy legislation. For example, the General Data Protection Regulation (GRPR) established by the EU includes an article (30) that requires any entity collecting personally identifiable information (PII) to conduct an inventory of data security and quality.[2] Similarly, the state of Washington has flirted with the idea of enacting data privacy legislation that is similar to the California Privacy Rights Act (CPRA). Understanding the requirements of a data inventory in these legislative contexts can often lead to more useful and meaningful data quality indicators. - A helpful review and resources for GDPR Data Inventories (https://www.thomashelbing.com/en/info/records-data-processing-activities-data-mapping-data-inventory) - CPRA explainer and data inventory minimal standards (https://www.natlawreview.com/article/businesses-should-begin-assessing-their-data-practices-order-to-meet-california) Data and Metadata Cleaning There is a concept from data science known as 'tidy data' that establishes some general principles for the structure and representation of data. These principles should be applicable across all kinds of data tables that have variables, values, and various kinds of observations. The simplest formulation of tidy data is: - Each variable is a column - Each observation is a row - Each type of observational unit is a table[3] Metadata should have some similar principles. That is, there should be general rules that we can follow to develop to describe attributes, values, and their corresponding relationship to instances of a class. Here are the principles I will put for tidy metadata as it applies to tables of data. The properties of a dataset are expressed as an attribute-value pair that conforms to a schema: - Attributes are declared by a namespace. - Values are, where possible, constrained by a controlled vocabulary. - Schemas are published to the web. Let's unpack each of these statements so that it makes sense in the context of data stewardship. - Schemas are published to the web - A metadata schema establishes and defines data elements (attributes) and the rules governing the use of data elements to describe a resource.[4] Schemas are, in plain language, the rules of engagement for creating metadata. That is, they govern what are the valid and invalid use of an attribute-value pair to describe a dataset. Schemas then must be public in order to be validated. Publishing a schema to the web means that the schema must be at a resolvable web address (a URL) and should be encoded in a machine-readable language (e.g., XML or JSON). Schemas should, where possible, use definitions of elements (attributes) as a unique namespace. - Attributes are declared by a namespace - In publishing a schema to the web, we should also take care to define the use of an attribute such that each attribute has a unique location where the definition and explanation of its use is publicly accessible and identifiable in a schema. The attribute namespace has a subtle, but important relationship to a schema. A schema can be made up multiple namespaces, each namespace can be a part of a different schema. - Values are, where possible, constrained by a controlled vocabulary - Recall that in our chapter on tidy data, we discussed the appeal to authority control for standard units of measurement. In metadata we want to rely upon this authority control in a similar way—this helps to standardize what types of values an attribute can have and provide clear guidance for how these values should be constrained. Data Repositories A data repository is both a digital archive for storing and preserving data, as well as the practical infrastructure, that carries out the policies and governance for data management. - Software and Hardware - For ingesting, curating, and preserving data. - Management Policies - Establish mission, goals, levels of preservation, types of data accepted, cost of deposit, etc. - Governance - How the repository will be managed, by whom, and through what budgets, and with what level of security. The last 20 years have seen data increasingly published to the web as structured information free for sharing and reuse. We have, thus far, discussed multiple innovations that have made this increase in data collection and publishing possible, including how data are practically stored, retrieved, and packaged for reuse. Early efforts at increasing data access focused specifically on how to embed data in electronic publishing environments[5] and how to provide programmatic access to data that were stored on remote servers.[6] Over the last decade technologies have been developed to better connect different components of the data publication lifecycle starting from a small number of hard to use proprietary repositories to a diverse range of (slightly easier to use) open-source options. These repositories depend on an “architecture” that is a complex and highly coordinated integration of software, hardware, and human services. Layers of a Data Repository Data repositories are simply a series of technical “layers” or a “stack” of technologies—each layer consists of a set of services and interfaces that allow data to be reliably preserved and published for reuse. The layers of a repository are described below. Figure 5 Representation of hardware layer of a repository. “Repository Levels” by Kathleen Hart (of DOL), CC BY 4.0. Hardware: The hardware layer of a repository consists of technologies that practically store and serve data to a software layer. The hardware layer of a repository practically, at minimum, consists of a set of servers (hosting databases, websites, etc.) and a set of backup storage environments such as spinning disks or tape-based storage. The hardware layer is closest to what we described in the Introduction chapter as the “physical” layer of a computing system (hence the “hard” in hardware). Figure 6 Representation of hardware and software layers of a repository. “Repository Levels” by Kathleen Hart (of DOL), CC BY 4.0. Software: The software layer of a repository consists of code that practically runs a web-interface and provides APIs that connect different servers to one another so that data can be reliably retrieved and served to end-users. The software layer presents a graphic user interface to “customers” of the data repository and allows for ease of access. This software layer also provides a graphic user interface for curators who manage deposits to a data repository and allows for metadata and other descriptive elements to be attached to data before it is ingested into a long-term storage environment. Often the software layer of a repository is described as a “repository framework” (e.g., Dataverse, CKAN, or DSpace)—meaning the different software components that are particularly configured for data access and preservation (more on this below). The software and hardware layer practically carry out preservation and long-term storage of data. Figure 7 Representation of hardware, software, and policy layers of a repository. “Repository Levels” by Kathleen Hart (of DOL), CC BY 4.0. Policy: The policy layer of a repository consists of curation services such as deposit, ingest, metadata creation, and publication of data to the web. The policy layer provides specific rules for how these services are to be carried out and specifies who is in charge of what practical functions of data publication and preservation. Figure 8 Representation of hardware, software, policy, and governance layers of a repository. “Repository Levels” by Kathleen Hart (of DOL), CC BY 4.0. Governance: The governance layer of a repository consists of institutional guidelines that specify how data should be managed over the long term, the rights of data producers and consumers, and the intellectual property claims that can be made by any institutional actor (as we discussed in chapter 1). Putting these layers together we can begin to understand how a generic term like "repository" or "data portal" is actually a much more complex sociotechnical arrangement of software, hardware, policy, and governance. Each of these layers necessarily supports the others and are necessary for a well-functioning and sustainable digital storage environment where data can be discovered, accessed, and contributed. In thinking about the different repositories that will be accessible to and used in a data stewardship role, this simply layered model can help unpack the people, the rules, and the resources that make up any one data repository. Note. The following sections focus on applications that are related to data analysis and data reuse. These sections are meant to provide an introduction to and grounding in applications that will be tangentially related to stewarding data, but in understanding the basic principles that are behind these applications the task of evaluating vendor products and helping customers in data acquisition and reuse will be much easier. Artificial Intelligence Artificial Intelligence, or AI, is a field of computer science that uses formal logic to develop models that mimic human reasoning (hence, the term ‘artificial’ intelligence). AI is almost always aimed at tasks related to prediction, classification, or regression (i.e., estimating the relationships between a dependent variable and one or more independent variables). AI’s most basic goal in mimicking human reasoning is to automate tasks by turning data (examples) into models (recipes). In this sense, artificial intelligence models are algorithms—that is, models are algorithmic recipes that automate some task by using data to make a prediction, regression, or classification. In the past AI has struggled to make much progress on task automation for two reasons: - insufficient data to train a model, and - insufficient computational power to run a model that can realistically mimic human reasoning. Increasingly AI researchers have access to large amounts of well-structured data that can be used to train a model to classify or predict certain outcomes (e.g., the web contains lots of images of cats and dogs and this data can be used to build a classifier to determine whether an image contains a dog or a cat). The cost of high-performance computing has come down, so there is also the opportunity to run models over very large datasets that can accurately make classifications or predictions. AI is increasingly described as anything that includes data and a prediction or decision-making algorithm. While there is great potential for AI applications in automating repetitive tasks, there is a long way to go before these applications can realistically mimic human decision making or complex decision making. For example, if a person is walking a bike along the road an AI powering a driverless vehicle has a hard time determining whether the object is a bicycle or a person. This confusion can delay the decision-making process that tells the car that it should swerve in order to miss the object (whether or not it is a person or a vehicle). This example resulted in the first known death at the hands of AI.[7] Machine Learning Machine learning is a field of AI that contains all the elements described above: data, tasks, and models. What machine learning attempts to do is optimize the automation of a task based on input data that is purposefully curated. To understand this process, it is helpful to first understand the broad difference between supervised vs unsupervised machine learning. In the broadest sense, these two forms of machine learning place emphasis on different aspects of an AI—supervised learning is teaching a machine to make decisions by example (the emphasis is on data), and unsupervised learning is teaching a machine to make decisions by developing a sophisticated pattern making model (the emphasis on an algorithm). - Supervised machine learning - uses pre-labeled data that humans purposefully collect and categorize in order to train a model to perform a specific task. In some sense we can think of supervised learning as the flash card model of learning—By showing a machine thousands of examples of an image that is labeled as either a cat or a dog the machine can learn intricate features that distinguish cats from dogs. With enough examples (data) the machine can then look at a new image and make an accurate classification—that is, whether the features of the image resemble what the machine “knows” about a cat or a dog. - Unsupervised machine learning - uses data, but instead of having thousands of diverse examples of labeled data a researcher will optimize a machine learning algorithm to learn patterns. Drawing on the example above about cats and dogs, an unsupervised machine learning application could be shown 100 example images of cats, dogs, monkeys, horses, and elephants. The machine would then learn features that distinguish these animals from one another, but in a shallow way. For example, if an image of a cat lacks pointy ears, then the unsupervised machine learning application will likely mislabel the image as a dog. But, what the unsupervised machine learning approach lacks in accuracy it makes up for in diversity. Unsupervised machine learning can build complex patterns between data. This makes the unsupervised approach to machine learning very useful when labeled data isn’t easy or economical to use. AI, and by extension machine learning, are complex topics of data analysis, but understanding generally how these techniques work is valuable to data stewardship in the following ways: - Increasingly, vendors advertise or attempt to sell AI applications that are heavily dependent upon models. These models are, as described above, only as useful as the quality of the labeled data that is used for training. Understanding how well a model can be used by an organization is therefore dependent upon how much work it will take to clean or prepare labeled data. - Machine learning is often described as a way to automate repetitive tasks in data analysis or even data cleaning. And, while machine learning can perform exceptionally well at these tasks it is important to recognize which kind of machine learning approach will be taken, and what data are required to successfully train a machine learning model. This can help a data steward identify and recommend data that is useful to model development, or even identify opportunities for restructuring existing data to meet machine learning needs. Data Visualization Just as good writing depends on colorful examples, tone, correct grammar, and a logical progression of ideas so too does data analysis. Often data analysis results in not just a neat tidy number, but a set of results that need to be both explained in text and visually communicated through graphs, charts, or plots. The value of data visualization (plots, charts, and graphs) is not simply to show off the results of an analysis through pretty pictures, but to economically communicate about data using a set of principles. This brief introduction to principles of data visualization is meant to guide future work, but it is by no means comprehensive. At the end of this section, I provide a number of resources for further consultation. We will cover four principles in total: selecting variables to visualize data, determining the scale and relationship of variables for visualization, and mapping these variables to a visualization style or “aesthetic”. Principles of Data Visualization 1. Select Variables - Data that are easy to visualize often contain a variable, an observation, and value. Each of these components of our data inform what is the best method of data visualization. Most frequently we want to depict a relationship between two or more variables in a set of data by showing how values change between observations. For example, if we want to communicate with a policymaker about the rate of traffic fatalities over time then we would identify a variable like traffic accidents in young drivers and select some observations that occur during a bounded period of time (e.g., 2005-2016). By showing how the values for these observations change we can demonstrate that there is a rise in traffic accidents, a decline, or maybe there is no steady trend at all. The point is that we identify in our data what relationship we want to depict, and then determine what variables can be used to demonstrate a relationship. Most often an independent variable (that is a variable that will occur regardless of any external event) is placed on the X axis and a dependent variable is placed on the Y axis. In the example above, the independent variable is time and the dependent variable is traffic accidents. The relationship would then be depicted as follows: Figure 9 Washington Traffic Safety Commission: Number of Drivers Ages 20 and Younger Involved in Fatal Crashes[8] 2. Determine Scale of Values - Data can be differentiated by many types and roles (as we’ve discussed throughout the curriculum). For data visualization often the first decision to make is whether the values of an observation are discrete or continuous. - Discrete values are whole or complete numbers that represent some real-world phenomenon without an intermediary. In the example above, fatal crashes (the dependent variable) is a discrete value. There can’t be a partial fatality (either a driver died as the result of an accident or they did not). - Continuous values are numbers that can be partial, or divisible by some intermediary. In the example above, the X axis depicts time by year. But, time is a continuous value—we could choose to represent time by hours, days, months, or years. Data may also contain categories or classifications that are neither discrete nor continuous. For example, if we were visualizing data related to traffic accidents, we might have categories such as: - Head-on Collisions - Highway Construction Accidents - Intersection Accidents - Interstate Accidents - Rear-End Accidents - Side-Impact Accidents These are distinctions in the type of accident—they don’t have discrete or continuous values that can be easily visualized. Thus, it may be useful to use the categorical values together with discrete and continuous variable data values (e.g., image below). Figure 10 Motorcycle Riders Involved in Fatal Crashes by Age Group and Speeding[9] Note: This chart provides an example of visual categorization of data. 3. Determine Type of Variable Relationship - If data visualization, at its core, is about clearly communicating relationships between variables in our data then it is worth knowing the types of common relationships that might occur, and what types of visualizations are best for communicating with each type. The three most common types of variable relationships that will be visualized are: - Amount - Distribution - Proportion There are several other relationship types that fall into and between these visualizations, including: - Correlation - how one variable relates to another (such as the number of times an accident occurs because of distraction). - Ranking - Time Series - Deviation - Distribution - Proportion / Part-Whole Relationship 4. Map Elements to Aesthetics - Finally, the graphical elements we choose to construct a visualization can feel overwhelming, but often they break down into three categories of visual aesthetics: - Position - All data visualizations are rendered in some form of spatial analysis—data for example can be visualized in two-dimension position (with an X and Y axis), or data could have a more complex coordinate system that makes use of multiple dimensions (such as latitude, longitude, and depth on a map). Regardless of what dimensions are being depicted all visualizations must have a fixed position. - Shape, size, and color - All visualizations make use of shape, size, and color to communicate differences between variables, observations, and values. Data points can take different shapes (circles, triangles, or squares) that communicate a different variable, or size (small, medium, or large) that communicates effect size. Most often though, data visualization makes use of color (such as blue vs red) to depict differences in variables or observations that are being depicted. These three simple elements (shape, size, and color) are the essential building blocks of all visual grammars that allow for communicating differences between a variable, an observation, or a value being depicted. - Lines (or trends) - Visualizations often make use of lines to demonstrate a trend or a pattern (in our example above a downward trend was communicated with a sloping solid black line). Lines can be emphasized by their thickness, and lines can be differentiated by their type (e.g., solid, dashed, pointed lines). Often it is helpful to reduce the number of trend or shape lines to effectively communicate. Summary This chapter has introduced and refined some major applications of data stewardship, including data and metadata quality, data cleaning, and the relationship between software, hardware, and digital objects (data). We also reviewed the emerging uses of labeled data in AI applications, focusing specifically on machine learning techniques. Finally, we discussed some aspects of data visualization that can be used to determine, or help customers determine, what type of data is appropriate for which types of visualization styles. Through the everyday work of data stewardship, we begin to translate some of the foundational concepts covered in earlier chapters into actual practice. These practices will be highly contextual, and most of the “best practices” described will take time to learn and apply correctly in a specific organizational setting like the Department of Licensing. In this sense, the value of the chapter can be as a reference guide to existing resources that can be helpful, for example with data quality, in choosing a specific set of indicators and then putting those indicators into practice at DOL. Further Reading On Data and Metadata Quality - CURATE steps from the Data Curation Network - these include Checking, Understanding, Requesting, Augmenting, Transforming, and Evaluating metadata records. (https://openscholarship.wustl.edu/cgi/viewcontent.cgi?article=1008&context=data-curation-workshop-2017) On Machine Learning and AI - IBM Primer on Machine Learning (https://www.ibm.com/cloud/learn/machine-learning) - Classification, Regression, and Prediction (https://towardsdatascience.com/classification-regression-and-prediction-whats-the-difference-5423d9efe4ec) - AI in the public sector (https://www.mckinsey.com/industries/public-and-social-sector/our-insights/when-governments-turn-to-ai-algorithms-trade-offs-and-trust) On Data Visualization - Fundamentals of Data Visualization (https://clauswilke.com/dataviz/) - Data Visualization with R and GGPlot2 (https://datavizs21.classes.andrewheiss.com/) - Contrast, Repetition, Alignment, and Proximity (CRAP) visualizations (https://www.presentationzen.com/chapter6_spread.pdf) [1] International Organization for Standardization (ISO). (2019). Data Quality—Part 63 – Data quality management: Process measurement. https://www.iso.org/standard/65344.html [2] European Union. Art 30. (2016). General Data Protection Regulation (GRPR): Records of processing activities. https://gdpr-info.eu/art-30-gdpr/. [3] Wickham, Hadley. (2014). Tidy Data. Journal of Statistical Software. 59, (1): 1–23. doi:10.18637/jss.v059.i10. [4] Zhang, A. B., & Gourley, D. (2009). Creating digital collections. Elsevier. [5] Abiteboul, S., Buneman, P., & Suciu, D. (2000). Data on the web: from relations to semistructured data and XML. Morgan Kaufmann. [6] Richardson, A. D., Klosterman, S., & Toomey, M. (2013). Near-surface sensor-derived phenology. In Phenology: An integrative environmental science (pp. 413-430). Springer. [7] Krisher, T. and Dazio, S. (2022, Jan. 18). Felony charges are 1st in a fatal crash involving Autopilot. Associated Press: Detroit. https://apnews.com/article/tesla-autopilot-fatal-crash-charges-91b4a0341e07244f3f03051b5c2462ae [8] Washington Traffic Safety Commission (WTSC). (2021). Young Drivers. WTSC. https://wtsc.wa.gov/programs-priorities/young-drivers/ [9] National Highway Traffic Safety Administration (NHTSA). (2022). Motorcycle Riders Involved in Fatal Crashes by Age Group and Speeding. Data Visualization – Fatality Analysis Reporting System. https://cdan.dot.gov/DataVisualization/DataVisualization.htm#	oercommons	2025-03-18T00:37:14.328982	Matt Lewin	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/94649/overview", "title": "Washington State Department of Licensing: Data Stewardship", "author": "Textbook" }
https://oercommons.org/courseware/lesson/78332/overview	- - Choice Boards - wa-early-learning - wa-families - wa-math - wa-supporting-youngest-learners - License: - Creative Commons Attribution - Language: - English Education Standards Learning Domain: Counting and Cardinality Standard: Understand the relationship between numbers and quantities; connect counting to cardinality. Learning Domain: Counting and Cardinality Standard: Count to 100 by ones and by tens. Learning Domain: Counting and Cardinality Standard: Count backwards by ones from 20. Learning Domain: Operations and Algebraic Thinking Standard: Relate counting to addition and subtraction using strategies, such as, by counting on and back. Learning Domain: Counting and Cardinality Standard: Understand the relationship between numbers and quantities; connect counting to cardinality. Learning Domain: Counting and Cardinality Standard: Count to answer how many?ť questions about as many as 20 things arranged in a line, a rectangular array, or a circle, or as many as 10 things in a scattered configuration; given a number from 1-20, count out that many objects. Learning Domain: Counting and Cardinality Standard: Count to 100 by ones and by tens. Learning Domain: Measurement and Data Standard: Directly compare two objects with a measurable attribute in common, to see which object has "more of"ť/"less of"ť the attribute, and describe the difference. For example, directly compare the heights of two children and describe one child as taller/shorter. Learning Domain: Measurement and Data Standard: Classify objects into given categories; count the numbers of objects in each category and sort the categories by count. (Limit category counts to be less than or equal to 10.) Learning Domain: Measurement and Data Standard: Describe measurable attributes of objects, such as length or weight. Describe several measurable attributes of a single object. Learning Domain: Geometry Standard: Correctly name shapes regardless of their orientations or overall size. Learning Domain: Geometry Standard: Describe objects in the environment using names of shapes, and describe the relative positions of these objects using terms such as above, below, beside, in front of, behind, and next to. Learning Domain: Operations and Algebraic Thinking Standard: Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem. Learning Domain: Operations and Algebraic Thinking Standard: Represent addition and subtraction with objects, fingers, mental images, drawings (drawings need not show details, but should show the mathematics in the problem), sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations. Learning Domain: Number and Operations in Base Ten Standard: Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <. Learning Domain: Geometry Standard: Distinguish between defining attributes (e.g., triangles are closed and three-sided) versus non-defining attributes (e.g., color, orientation, overall size); for a wide variety of shapes; build and draw shapes to possess defining attributes. Learning Domain: Operations and Algebraic Thinking Standard: Relate counting to addition and subtraction (e.g., by counting on 2 to add 2). Learning Domain: Measurement and Data Standard: Organize, represent, and interpret data with up to three categories; ask and answer questions about the total number of data points, how many in each category, and how many more or less are in one category than in another. Learning Domain: Mathematical Practices Standard: Reason abstractly and quantitatively. Mathematically proficient students make sense of the quantities and their relationships in problem situations. Students bring two complementary abilities to bear on problems involving quantitative relationships: the ability to decontextualize"Óto abstract a given situation and represent it symbolically and manipulate the representing symbols as if they have a life of their own, without necessarily attending to their referents"Óand the ability to contextualize, to pause as needed during the manipulation process in order to probe into the referents for the symbols involved. Quantitative reasoning entails habits of creating a coherent representation of the problem at hand; considering the units involved; attending to the meaning of quantities, not just how to compute them; and knowing and flexibly using different properties of operations and objects. Learning Domain: Mathematical Practices Standard: Construct viable arguments and critique the reasoning of others. Mathematically proficient students understand and use stated assumptions, definitions, and previously established results in constructing arguments. They make conjectures and build a logical progression of statements to explore the truth of their conjectures. They are able to analyze situations by breaking them into cases, and can recognize and use counterexamples. They justify their conclusions, communicate them to others, and respond to the arguments of others. They reason inductively about data, making plausible arguments that take into account the context from which the data arose. Mathematically proficient students are also able to compare the effectiveness of two plausible arguments, distinguish correct logic or reasoning from that which is flawed, and"Óif there is a flaw in an argument"Óexplain what it is. Elementary students can construct arguments using concrete referents such as objects, drawings, diagrams, and actions. Such arguments can make sense and be correct, even though they are not generalized or made formal until later grades. Later, students learn to determine domains to which an argument applies. Students at all grades can listen or read the arguments of others, decide whether they make sense, and ask useful questions to clarify or improve the arguments. Learning Domain: Mathematical Practices Standard: Model with mathematics. Mathematically proficient students can apply the mathematics they know to solve problems arising in everyday life, society, and the workplace. In early grades, this might be as simple as writing an addition equation to describe a situation. In middle grades, a student might apply proportional reasoning to plan a school event or analyze a problem in the community. By high school, a student might use geometry to solve a design problem or use a function to describe how one quantity of interest depends on another. Mathematically proficient students who can apply what they know are comfortable making assumptions and approximations to simplify a complicated situation, realizing that these may need revision later. They are able to identify important quantities in a practical situation and map their relationships using such tools as diagrams, two-way tables, graphs, flowcharts and formulas. They can analyze those relationships mathematically to draw conclusions. They routinely interpret their mathematical results in the context of the situation and reflect on whether the results make sense, possibly improving the model if it has not served its purpose. Learning Domain: Mathematical Practices Standard: Use appropriate tools strategically. Mathematically proficient students consider the available tools when solving a mathematical problem. These tools might include pencil and paper, concrete models, a ruler, a protractor, a calculator, a spreadsheet, a computer algebra system, a statistical package, or dynamic geometry software. Proficient students are sufficiently familiar with tools appropriate for their grade or course to make sound decisions about when each of these tools might be helpful, recognizing both the insight to be gained and their limitations. For example, mathematically proficient high school students analyze graphs of functions and solutions generated using a graphing calculator. They detect possible errors by strategically using estimation and other mathematical knowledge. When making mathematical models, they know that technology can enable them to visualize the results of varying assumptions, explore consequences, and compare predictions with data. Mathematically proficient students at various grade levels are able to identify relevant external mathematical resources, such as digital content located on a website, and use them to pose or solve problems. They are able to use technological tools to explore and deepen their understanding of concepts. Learning Domain: Mathematical Practices Standard: Attend to precision. Mathematically proficient students try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning. They state the meaning of the symbols they choose, including using the equal sign consistently and appropriately. They are careful about specifying units of measure, and labeling axes to clarify the correspondence with quantities in a problem. They calculate accurately and efficiently, express numerical answers with a degree of precision appropriate for the problem context. In the elementary grades, students give carefully formulated explanations to each other. By the time they reach high school they have learned to examine claims and make explicit use of definitions. Cluster: Count to tell the number of objects Standard: Understand the relationship between numbers and quantities; connect counting to cardinality. Cluster: Count to tell the number of objects Standard: Count to answer “how many?” questions about as many as 20 things arranged in a line, a rectangular array, or a circle, or as many as 10 things in a scattered configuration; given a number from 1-20, count out that many objects. Cluster: Know number names and the count sequence Standard: Count to 100 by ones and by tens. Cluster: Describe and compare measurable attributes Standard: Directly compare two objects with a measurable attribute in common, to see which object has “more of”/“less of” the attribute, and describe the difference. For example, directly compare the heights of two children and describe one child as taller/shorter. Cluster: Classify objects and count the number of objects in each category Standard: Classify objects into given categories; count the numbers of objects in each category and sort the categories by count. (Limit category counts to be less than or equal to 10.) Cluster: Describe and compare measurable attributes Standard: Describe measurable attributes of objects, such as length or weight. Describe several measurable attributes of a single object. Cluster: Identify and describe shapes (squares, circles, triangles, rectangles, hexagons, cubes, cones, cylinders, and spheres) Standard: Correctly name shapes regardless of their orientations or overall size. Cluster: Identify and describe shapes (squares, circles, triangles, rectangles, hexagons, cubes, cones, cylinders, and spheres) Standard: Describe objects in the environment using names of shapes, and describe the relative positions of these objects using terms such as above, below, beside, in front of, behind, and next to. Cluster: Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from Standard: Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem. Cluster: Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from Standard: Represent addition and subtraction with objects, fingers, mental images, drawings (drawings need not show details, but should show the mathematics in the problem), sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations. Cluster: Extend the counting sequence Standard: Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <. Cluster: Reason with shapes and their attributes Standard: Distinguish between defining attributes (e.g., triangles are closed and three-sided) versus non-defining attributes (e.g., color, orientation, overall size); for a wide variety of shapes; build and draw shapes to possess defining attributes. Cluster: Add and subtract within 20 Standard: Relate counting to addition and subtraction (e.g., by counting on 2 to add 2). Cluster: Represent and interpret data Standard: Organize, represent, and interpret data with up to three categories; ask and answer questions about the total number of data points, how many in each category, and how many more or less are in one category than in another. Common Core State Standards Math Cluster: Mathematical practices Standard: Reason abstractly and quantitatively. Mathematically proficient students make sense of the quantities and their relationships in problem situations. Students bring two complementary abilities to bear on problems involving quantitative relationships: the ability to decontextualize—to abstract a given situation and represent it symbolically and manipulate the representing symbols as if they have a life of their own, without necessarily attending to their referents—and the ability to contextualize, to pause as needed during the manipulation process in order to probe into the referents for the symbols involved. Quantitative reasoning entails habits of creating a coherent representation of the problem at hand; considering the units involved; attending to the meaning of quantities, not just how to compute them; and knowing and flexibly using different properties of operations and objects. Common Core State Standards Math Cluster: Mathematical practices Standard: Construct viable arguments and critique the reasoning of others. Mathematically proficient students understand and use stated assumptions, definitions, and previously established results in constructing arguments. They make conjectures and build a logical progression of statements to explore the truth of their conjectures. They are able to analyze situations by breaking them into cases, and can recognize and use counterexamples. They justify their conclusions, communicate them to others, and respond to the arguments of others. They reason inductively about data, making plausible arguments that take into account the context from which the data arose. Mathematically proficient students are also able to compare the effectiveness of two plausible arguments, distinguish correct logic or reasoning from that which is flawed, and—if there is a flaw in an argument—explain what it is. Elementary students can construct arguments using concrete referents such as objects, drawings, diagrams, and actions. Such arguments can make sense and be correct, even though they are not generalized or made formal until later grades. Later, students learn to determine domains to which an argument applies. Students at all grades can listen or read the arguments of others, decide whether they make sense, and ask useful questions to clarify or improve the arguments. Common Core State Standards Math Cluster: Mathematical practices Standard: Model with mathematics. Mathematically proficient students can apply the mathematics they know to solve problems arising in everyday life, society, and the workplace. In early grades, this might be as simple as writing an addition equation to describe a situation. In middle grades, a student might apply proportional reasoning to plan a school event or analyze a problem in the community. By high school, a student might use geometry to solve a design problem or use a function to describe how one quantity of interest depends on another. Mathematically proficient students who can apply what they know are comfortable making assumptions and approximations to simplify a complicated situation, realizing that these may need revision later. They are able to identify important quantities in a practical situation and map their relationships using such tools as diagrams, two-way tables, graphs, flowcharts and formulas. They can analyze those relationships mathematically to draw conclusions. They routinely interpret their mathematical results in the context of the situation and reflect on whether the results make sense, possibly improving the model if it has not served its purpose. Common Core State Standards Math Cluster: Mathematical practices Standard: Use appropriate tools strategically. Mathematically proficient students consider the available tools when solving a mathematical problem. These tools might include pencil and paper, concrete models, a ruler, a protractor, a calculator, a spreadsheet, a computer algebra system, a statistical package, or dynamic geometry software. Proficient students are sufficiently familiar with tools appropriate for their grade or course to make sound decisions about when each of these tools might be helpful, recognizing both the insight to be gained and their limitations. For example, mathematically proficient high school students analyze graphs of functions and solutions generated using a graphing calculator. They detect possible errors by strategically using estimation and other mathematical knowledge. When making mathematical models, they know that technology can enable them to visualize the results of varying assumptions, explore consequences, and compare predictions with data. Mathematically proficient students at various grade levels are able to identify relevant external mathematical resources, such as digital content located on a website, and use them to pose or solve problems. They are able to use technological tools to explore and deepen their understanding of concepts. Common Core State Standards Math Cluster: Mathematical practices Standard: Attend to precision. Mathematically proficient students try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning. They state the meaning of the symbols they choose, including using the equal sign consistently and appropriately. They are careful about specifying units of measure, and labeling axes to clarify the correspondence with quantities in a problem. They calculate accurately and efficiently, express numerical answers with a degree of precision appropriate for the problem context. In the elementary grades, students give carefully formulated explanations to each other. By the time they reach high school they have learned to examine claims and make explicit use of definitions. Math Choice Board: PreK-1st Grade (Spring Edition) Overview Explore the Mathematics Student Choice Boards for PreK-1st grade created by the Washington Office of Superintendent of Public Instruction. Background Information Explore the OSPI-created Choice Boards for PreK-1st grade. So often we get locked into the idea that math has to be taught by sitting down at a table and completing worksheets. We want to challenge that idea by providing you with some choice boards. These grids are filled with fun activities you can do at home while playing with your kids. We like choice boards because they give children choice while still setting specific parameters designed to encourage developmentally appropriate math skills. We have set up the choice boards by grade bands. Each column focuses on a different math concept, and the activities dive deeper into the skill as you work your way down the board. This gives you the freedom to enter the board at a place that best suits your child, and provides additional activities to continue working on the skill.	oercommons	2025-03-18T00:37:14.415564	Washington OSPI Mathematics Department	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/78332/overview", "title": "Math Choice Board: PreK-1st Grade (Spring Edition)", "author": "Interactive" }
https://oercommons.org/courseware/lesson/83322/overview	Education Standards Intro to Early Childhood Education- ECED&105 Overview Introduction to Early Childhood Education Open Education Resources Textbook for common course ECED& 105 Introduction to Early Childhood Education was produced with support from funding secured through the Carl D. Perkins Act. Intro to Early Childhood Education- ECED&105 Overview to this Textbook Welcome to Introduction to Early Childhood Education. This textbook will cover the following topics: An overview of the field of early learning Historical roots of early learning Professionalism, values and ethics required for working in the field Philosophers and theorists that have contributed to early learning Brain development and the importance of executive function Developmentally appropriate practice Developmental theory: how children grow and develop The value of play for young children Environments both indoors and outdoors and the contribution both make to the developing child Family connections and support for all families Issues and trends within the field of early learning Beyond behaviors: guiding children’s behavior Adverse Childhood Trauma and building resiliency Diversity and equity within the field of early learning The beginning of each chapter includes a brief biography of the author and peer reviewer for the chapter along with a side note containing an overview of the topics discussed within the chapter. Student Learning Outcomes ECED& 105 Introduction to Early Childhood Education is found in the common course inventory in Washington State. It is one of the first courses found in the ECE Initial Certificate and holds a set of common student learning outcomes that are aligned with Washington State Core Competencies as published by the Department of Children Youth and Families www.dcyf.wa.gov as well as the national organization: National Association for the Education of Young Children www.naeyc.org Noted at the beginning of each chapter is the student learning outcome(s) that best aligns with content written in the chapter. The table that follows notes the alignment of the student learning outcomes at most Washington State Community and Technical Colleges. It should be noted that some colleges have additional outcomes.	oercommons	2025-03-18T00:37:14.441366	07/08/2021	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/83322/overview", "title": "Intro to Early Childhood Education- ECED&105", "author": "Gayle Julian" }
https://oercommons.org/courseware/lesson/119182/overview	what ai can do? What AI Can Do? Overview It describes the basic character of AI in the term of STA (Sense, Think, Act) AI Can do It describes basic character of artificial intelligence	oercommons	2025-03-18T00:37:14.459842	Lesson	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/119182/overview", "title": "What AI Can Do?", "author": "Educational Technology" }
https://oercommons.org/courseware/lesson/96772/overview	My Family House – A Free ESL Lesson Plan Overview Learn more about your students with this fun speaking lesson! This ESL lesson plan teaches students to use the present simple to talk about a family house. With lots of picture prompts and new vocabulary, this interactive lesson will help increase your student's confidence. You can also access 150+ more free lessons like this with a free Off2Class account! Off2Class The lesson is designed for Level B1 (pre-intermediate). When should you teach the My Family House lesson? One of the best ways to personalize your ESL lessons is to encourage students to talk about themselves. This lesson is perfect for group or individual ESL lessons, and will create conversations about different types of houses. The lesson is suitable for pre-intermediate students (B1 on the CEFR scale), and can be taught to children, teenagers and adults. How to teach this lesson about My Family House To help students speak about their houses, this lesson includes many photos and new terms. First, the student sees a slide with images only. The next slide then shows the same images with suggested vocabulary. We recommend that for each set, you encourage the student to talk about each image, and then offer the vocabulary, without asking the student to memorize it. We included images and vocabulary to encourage the student, rather than force them to learn new lexical items here. You can access full teacher notes for this lesson plan by signing up for a free Off2Class account.	oercommons	2025-03-18T00:37:14.478806	Lesson Plan	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/96772/overview", "title": "My Family House – A Free ESL Lesson Plan", "author": "Speaking and Listening" }
https://oercommons.org/courseware/lesson/90360/overview	My Family: A Free ESL Speaking Lesson Plan Overview This speaking lesson will help you gauge your students’ vocabulary skills when discussing family. You should encourage students to use the present simple tense to talk about family structure and relationships. You can use this lesson plan to review how to talk about age too. You can also access 150+ more free lessons like this with a free Off2Class account! Off2Class Primary objectives: to use the present simple to talk about family structure and relationships (e.g., brother, father, mother, sister), with a focus on immediate family members Remember to ask your student information questions: - Who...? - What...? - Where...? - How...? - Why...? - How much...? And personalize the situation: - Did you...? - Have you ever...? You can access full teacher notes for this lesson plan by signing up for a free Off2Class account.	oercommons	2025-03-18T00:37:14.496981	Christine Chan	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/90360/overview", "title": "My Family: A Free ESL Speaking Lesson Plan", "author": "Lesson Plan" }
https://oercommons.org/courseware/lesson/79173/overview	Education Standards Riddle Me This Reading Library Call Numbers Overview This activity was created to assist students in identifying various locations in the library by reading library call numbers. Understanding is demonstrated by investing the library organization and creation of their own riddle search with answer key utilizing Google Doc or Sheets. Library Riddle Scavenger Hunt The lesson is created for new to middle school, 6th grade students. This Riddle Search is designed to help students read call numbers, identify and locate various sections of their new library. This lesson will need to be remixed to fit the organization of your school library. It is recommended to create a call number placement key to keep track where the letters have been placed around the library. Example: A PB FIC FIC FIC SAG ZIN AVI B YA FIC FIC E JON DES HOP C Classic FIC FIC GRA KON etc. Riddle Answer Sheet Why didn't the thief burgle the library? Because he was afraid the judge would give him a long sentence. How come the librarian slipped and fell in the library? Because she strayed into the non-friction section What did one book say to the other one? I just wanted to see if we are on the same page What do you do if pet starts eating your library book? Take the words right out of their mouth. Why did the vampire check out a drawing book? He wanted to learn how to draw blood. Why does an elephant use his trunk as a bookmark? That way he always nose where he stopped reading. What did the detective do when he didn't believe the librarian's story? He booked her! Where does a librarian sleep? Between the covers. What do planets like to read? Comet books. What do you get when you cross an elephant with a computer? A lot of memory. What part of a computer does an astronaut like best? The space bar. When the cold wind blows, what does a book do? It puts on a book jacket. When a librarian goes fishing, what goes on her hook? A bookworm, of course. What does the mummy do when he goes to the library? He gets all wrapped up in a good book. Work through the PowerPoint below called Riddle Me This. Write your name on the printed riddle document or make a copy for yourself on the computer. Quietly search the library for the answer(letters) to the call number clues! See how many you can quietly get done. Turn in finished riddles to your teacher. Create your own riddle search. Complete the following Library Riddles. Additional riddles can be found in the attached word document. Why didn't the thief burgle the library? Because he was afraid the judge would give him a …… E YA 974.8 PB FIC 081 PB FIC GN PB Classic FIC YOL FIC MAR FIC HUG BUR FIC NAY 741.5 FIC FIC WES STE DUA HAR SHA HAR GRA How come the librarian slipped and fell in the library? Because she strayed into the ______________ section. PB 921 974.8 FIC 998.9 GN FIC FIC PB FIC 974.8 FIC EAR MAR ORC BIL 741.5 KON NAY FIC VOI MAR HAR PET PAT What did one book say to the other one? I just wanted to see if we are on the… PB FIC 497 PB FIC FIC PB FIC FIC ZIN COU FIC BYA SAG FIC WES MAC WEI DUA What do you do if pet starts eating your library book? Take the _____________ right out of their _____________. FIC 897 FIC 970.03 PB 497 FIC 358 FIC FIC. RIO SNE DEV BLE FIC COU VOI HIB NAY CHR MAC Why did the vampire check out a drawing book? He wanted to learn how to… FIC FIC FIC FIC FIC E 921 YA 970.03 MCN DEV ZIN RIO JON YOL EAR FIC BLE STE Why does an elephant use his trunk as a bookmark? That way he always __________ where he stopped _______________. 974.8 FIC PB FIC FIC 081 FIC FIC GN PB PB. MAR VOI FIC WES DEV BUR ZIN MCN 741.5 FIC FIC MAC PET HAR DUA	oercommons	2025-03-18T00:37:14.538318	Shelley Rath	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/79173/overview", "title": "Reading Library Call Numbers", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/94894/overview	https://www.stayingcoolinthelibrary.us/teaching-book-care-rules-activities-and/ https://youtu.be/oes1PE58WQE LibraryNinjasBookCarePowerPoint Library Book Care Overview We are going to talk about how to take care of our library books. Library Book Care	oercommons	2025-03-18T00:37:14.557812	07/05/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/94894/overview", "title": "Library Book Care", "author": "Lisa Henson" }
https://oercommons.org/courseware/lesson/115010/overview	Chapter 2-Supervised Learning Chapter2-Supervised Learning-Part 2 Chapter 3- Unsupervised Learning Chapter 4- introduction to Neural Network Chapter 5-Model Evaluation Lab Session-Data Preprocessing Practical Session-Classification Practical Session-Clustering Practical Session- Introduction to Python Programming Practical Session- Introduction to Python Programming Practical Session-Neural Network Practical Session-Regression Introduction to Machine Learning Overview Course Description Machine Learning is the study of how to build computer systems that learn from experience. This course will explain how to build systems that learn and adapt using real-world applications. Some of the topics to be covered include concept learning, neural networks, genetic algorithms, reinforcement learning, instance-based learning, and so forth. The course will be project-oriented, with emphasis placed on writing software implementations of learning algorithms applied to real-world problems. Course Outline Course objectives At the end of the course, students should: - Know about the fundamental concepts in machine learning, the different classes of machine learning algorithms, and ways to choose and apply different basic machine learning algorithms. - Learn about ways to evaluate the performance of learning systems. - Be able to prepare data and apply machine learning methods to achieve a learning goal within an intelligent system. - Be able to judge the suitability of a machine learning paradigm for a given problem and the available data, have an understanding of the capabilities and limitations of the considered machine learning algorithms, and is able to identify problems or misleading results. Course outline Chapter 1: Introduction - What is machine learning? - History and relationships to other fields - Essential math and statistics for machine learning - Applications of machine learning - Types of machine learning techniques Chapter 2: Supervised learning - Introduction - Linear model - Regression - Understand the operation regression - Linear regression - Polynomial regression - Regularization techniques - Understand the metrics used to evaluate regression - A case study in regression - Classification - Understand the operation of classifiers - KNN - Naïve Bayes - Logistic regression - Decision trees - Random forest - Support vector machines - A case study in classification - Understand the metrics used to evaluate classifiers - How to improve supervised models - Parametric models for classification and regression - Understand the problems of over-parameterization and the curse of dimensionality - Use regularization on over-parameterized models Chapter 3: Unsupervised learning - Introduction - Understand the principles of unsupervised learning models - Clustering approaches - K-Means - K nearest neighbors - Hierarchical clustering - Correctly apply and evaluate clustering models - Association rule learning - Apriori algorithm - Reinforcement learning - Markov decision - Monte Carlo prediction - Case study Chapter 4: Neural Network - Introduction - Understanding the brain - Neural networks as a paradigm for parallel processing - The Perceptron - Training a Perceptron - Artificial neural network - Multilayer Perceptron - Back propagation algorithm - Nonlinear Regression - Two-Class Discrimination - Multiclass Discrimination - Multiple Hidden Layers - Training procedures - Improving convergence - Overtraining - Structuring the network - Tuning the network size - A case study in neural network - Introduction Chapter 5: Model Evaluation - Data processing - Data cleaning and transforming - Feature selection and visualization - Model selection and tuning - Methods of dimensional reduction - Principal component analysis (PCA) - Singular value decomposition (SVD) - T-distributed Stochastic Neighbor Embedding (t-SNE) - Optimize the performance of the model - Control model complexity - Over-fitting and Under-fitting - Cross-Validation and Re-sampling methods - K-Fold Cross-Validation - 5 ×2 Cross-Validation - Bootstrapping - Gradient descent (batch, stochastic) - Bias, variance - Performance evaluation methods Introduction This chapter serves as an introduction to the fundamental aspects of machine learning, covering key concepts such as its definition, historical development, and intricate connections with other fields. Furthermore, it explores the indispensable mathematical and statistical foundations essential for a comprehensive understanding of machine learning. The chapter also covers diverse applications of machine learning across various domains, and sheds light on the different types of learning in this dynamic field. Supervised Learning In this chapter, our goal is to introduce the foundational principles of supervised learning. As we progress, we place particular emphasis on both regression and classification techniques, offering learners a more comprehensive perspective on the practical application of these methodologies in real-world scenarios. By the end of this chapter, learners will not only possess a robust understanding of the core principles but will also be armed with valuable insights into the tangible applications of supervised learning. This knowledge empowers them to skillfully navigate and leverage the full potential of this influential paradigm within the vast expanse of machine learning. Unsupervised Learning This chapter discusses unsupervised learning techniques, with a particular emphasis on two popular approaches: clustering and association rule learning. The chapter extensively covers two key clustering algorithms: K-means and hierarchical clustering. Learners gain a comprehensive understanding of how these algorithms work, including their strengths and applications in grouping data points based on inherent patterns. The chapter also covers association rule learning, which involves discovering meaningful associations with datasets, focusing on two prominent algorithms: Apriori and FP-Growth. By engaging in in-depth discussions, learners gain a better grasp of how these algorithms enable the extraction of relevant rules from complex datasets. In a nutshell, this chapter equips learners with a solid foundation in unsupervised learning, providing them with practical insights into clustering and association rule learning through in-depth discussions of K-means, hierarchical clustering, Apriori, and FP-Growth algorithms. Introduction to Neural Network This chapter provides a comprehensive exploration of the principles underlying neural networks, offering a detailed introduction to this groundbreaking field. We begin by examining the core principles that govern neural networks, drawing parallels to the complicated workings of the human brain. Furthermore, the chapter presents an extensive explanation of perceptrons, which form the foundational building blocks of neural networks. Progressing forward, the chapter navigates through the complexities of multilayer perceptrons, demonstrating their capabilities through practical examples and problem-solving scenarios. Through this exploration of multilayer perceptrons, students gain invaluable insights into how neural networks can be structured to tackle real-world challenges effectively. In essence, this chapter serves as a crucial stepping stone in comprehending neural networks, equipping students with the knowledge and skills necessary to navigate this dynamic and rapidly evolving field with confidence and proficiency. Model Evaluation This chapter, i.e., organized into two sections, introduces the key concepts of model evaluation in machine learning. The first section provides an overview of key terminology, model evaluation metrics tailored to various tasks, and introduce the concepts of the bias-variance tradeoff. The following section covers important data preprocessing techniques such as data cleansing, transformation, and reduction.	oercommons	2025-03-18T00:37:14.599786	Lecture	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/115010/overview", "title": "Introduction to Machine Learning", "author": "Homework/Assignment" }
https://oercommons.org/courseware/lesson/105289/overview	2.3.2 Functions of Management 2.3.3 Firm Vision or Mission Agribusiness Functions of Management Overview Qualities of a Successful Business Manager Learning Objective 6a Discuss qualities of a successful agribusiness manager. Being a Manager Managers are in constant action. Virtually every study of managers in action has found that they “switch frequently from task to task, changing their focus of attention to respond to issues as they arise, and engaging in a large volume of tasks of short duration.” Managers, in fact, spend very little time by themselves. Contrary to the image offered by management textbooks, they are rarely alone drawing up plans or worrying about important decisions. Instead, they spend most of their time interacting with others—both inside and outside the organization. If casual interactions in hallways, phone conversations, one-on-one meetings, and larger group meetings are included, managers spend about two-thirds of their time with other people. Henry Mintzberg observed CEOs on the job to get some idea of what they do and how they spend their time. He found, for instance, that they averaged 36 written and 16 verbal contacts per day, almost every one of them dealing with a distinct or different issue. Most of these activities were brief, lasting less than nine minutes. In the same vein, Lee Sproull’s study revealed that, during the course of a day, managers engaged in 58 different activities with an average duration of just nine minutes. John Kotter’s study found that the average manager spent just 25% of his time working alone, and that time was spent largely at home, on airplanes, or commuting. Kotter’s study reveals that successful general managers spend most of their time with others, including subordinates, their bosses, and numerous people from outside the organization. Few of them spent less than 70% of their time with others, and some spent up to 90% of their working time this way. Kotter also found that the breadth of topics in manager’s discussions with others was extremely wide, with unimportant or irrelevant issues taking time alongside important business matters. His study revealed that managers rarely make “big decisions” during these conversations and rarely give orders in a traditional sense. They often react to others’ initiatives and spend substantial amounts of time on unplanned activities that aren’t pre-scheduled. He found that managers will spend most of their time with others in short, disjointed conversations: “It is not at all unusual for a general manager to cover ten unrelated topics in a five-minute conversation.” Interruptions also appear to be a natural part of the job. Rosemary Stewart found that the managers she studied were working uninterrupted for half an hour only nine times during the four weeks she studied them. As Mintzberg has pointed out, “Unlike other workers, the manager does not leave the telephone or the meeting to get back to work. Rather, these contacts are his work.” The interactive nature of management means that most management work is conversational. Managers spend about two-thirds to three-quarters of their time in verbal activity. These verbal conversations, according to Robert Eccles and Nitin Nohria, are the means by which managers gather information, stay on top of things, identify problems, negotiate shared meanings, develop plans, put things in motion, give orders, assert authority, develop relationships, and spread gossip. In short, they are what the manager’s daily practice is all about. When managers are in action, they are talking and listening. The 3 Core Management Roles In Mintzberg’s seminal study of managers and their jobs, he found there are three core management roles: interpersonal, informational, and decisional. Interpersonal Roles Managers are required to interact with a substantial number of people in the course of a workweek. They host receptions; take clients and customers to dinner; meet with business prospects and partners; conduct hiring and performance interviews; and form alliances, friendships, and personal relationships with many others. Numerous studies have shown that such relationships are the richest source of information for managers because of their immediate and personal nature. The interpersonal role of managers arises directly from formal authority and involves basic interpersonal relationships. Managers fill the figurehead role. Managers are responsible for the work of the people in their unit, and their actions in this regard are directly related to their role as a leader. The influence of managers is most clearly seen, according to Mintzberg, in the leader role. Formal authority vests them with great potential power. Leadership determines, in large part, how much power they will realize. Additionally, as the head of an organizational unit, every manager must perform some ceremonial duties. In Mintzberg’s study, chief executives spent 12% of their contact time on ceremonial duties and 17% of their incoming mail dealt with acknowledgments and requests related to their status. For instance, a company president who deals with charity or philanthropic requests is engaging in the ceremonial duties that come with being a figurehead. The impact of a leadership role of managers can be seen in some famous examples of managers who had huge impacts on business success. When Lee Iacocca took over Chrysler Corporation (now DaimlerChrysler) in the 1980s, the once-great auto manufacturer was in bankruptcy, teetering on the verge of extinction. Iacocca formed new relationships with the United Auto Workers, reorganized the senior management of the company, and—perhaps most importantly—convinced the U.S. federal government to guarantee a series of bank loans that would make the company solvent again. The loan guarantees, the union response, and the reaction of the marketplace were due in large measure to Iacocca’s leadership style and personal charisma. More recent examples include the return of Starbucks founder Howard Schultz to re-energize and steer his company, and Amazon CEO Jeff Bezos’s ability to innovate during a downturn in the economy. Managers also fill the liaison role, which falls under the larger interpersonal umbrella. Popular management literature has had little to say about the liaison role until recently. This role, in which managers establish and maintain contacts outside the vertical chain of command, becomes especially important in view of the finding of virtually every study of managerial work that managers spend as much time with peers and other people outside of their units as they do with their own subordinates. Surprisingly, they spend little time with their own superiors. In Rosemary Stewart’s study, 160 British middle and top managers spent 47% of their time with peers, 41% of their time with people inside their unit, and only 12% of their time with superiors. Informational Roles Managers are required to gather, collate, analyze, store, and disseminate many kinds of information. As monitors, managers are constantly scanning the environment for information, talking with liaison contacts and subordinates, and receiving unsolicited information, much of it as a result of their network of personal contacts. A good portion of this information arrives in verbal form, often as gossip, hearsay, and speculation. In doing so, they become information resource centers, often storing huge amounts of information in their own heads, moving quickly from the role of gatherer to the role of disseminator in minutes. Although many business organizations install large, expensive management information systems to perform many of those functions, nothing can match the speed and intuitive power of a well-trained manager’s brain for information processing. Not surprisingly, most managers prefer it that way. In the disseminator role, managers pass privileged information directly to subordinates, who might otherwise have no access to it. Managers must not only decide who should receive such information, but how much of it, how often, and in what form. Increasingly, managers are being asked to decide whether subordinates, peers, customers, business partners, and others should have direct access to information 24 hours a day without having to contact the manager directly. In the spokesperson role, managers send information to people outside of their organizations. An example of fulfilling a spokesperson role is when an executive makes a speech to lobby for an organizational cause, or a supervisor suggests a product modification to a supplier. Increasingly, managers are also being asked to deal with representatives of the news media, providing both factual and opinion-based responses that will be printed or broadcast to vast unseen audiences, often directly or with little editing. The risks in such circumstances are enormous, but so too are the potential rewards in terms of brand recognition, public image, and organizational visibility. Decisional Roles Ultimately, managers are charged with the responsibility of making decisions on behalf of both the organization and the stakeholders with an interest in it. Such decisions are often made under circumstances of high ambiguity and with inadequate information. Often, the other two managerial roles—interpersonal and informational—will assist a manager in making difficult decisions in which outcomes are not clear and interests are often conflicting. In the role of entrepreneur, managers seek to improve their businesses: adapt to changing market conditions and react to opportunities as they present themselves. Managers who take a longer-term view of their responsibilities are among the first to realize that they will need to reinvent themselves, their product and service lines, their marketing strategies, and their ways of doing business as older methods become obsolete and competitors gain advantage. While the entrepreneur role describes managers who initiate change, the disturbance or crisis handler role depicts managers who must involuntarily react to conditions. Crises can arise because bad managers let circumstances deteriorate or spin out of control, but just as often good managers find themselves in the midst of a crisis that they could not have anticipated but must react to just the same. The decisional role of resource allocator involves managers making decisions about who gets what, how much, when, and why. Resources, including funding, equipment, human labor, office or production space, and even the boss’s time are all limited, and demand inevitably outstrips supply. Managers must make sensible decisions about such matters while still retaining, motivating, and developing the best of their employees. Managers spend considerable amounts of time in the role of negotiator. Negotiations happen over budget allocations, labor and collective bargaining agreements, and other formal dispute resolutions. In the course of a week, managers will often make dozens of decisions that are the result of brief but important negotiations between and among employees, customers and clients, suppliers, and others with whom managers must deal. Increased Emphasis on Leader and Entrepreneurial Roles The entrepreneur role is gaining importance. Managers must increasingly be aware of threats and opportunities in their environment. Threats include technological breakthroughs on the part of competitors, obsolescence in a manager’s organization, and dramatically shortened product cycles. Opportunities might include product or service niches that are underserved, out-of-cycle hiring opportunities, mergers, purchases, or upgrades in equipment, space, or other assets. Managers who are carefully attuned to the marketplace and competitive environment will look for opportunities to gain an advantage. The leader role is also more prominent these days. Managers must be more sophisticated as strategists and mentors. A manager’s job involves much more than simple caretaking in a division of a large organization. Unless organizations are able to attract, train, motivate, retain, and promote good people, they cannot possibly hope to gain advantage over the competition. Thus, as leaders, managers must constantly act as mentors to those in the organization with promise and potential. When organizations lose a highly capable worker, all else in their world will come to a halt until they can replace that worker. Even if they find someone ideally suited and superbly qualified for a vacant position, they must still train, motivate, and inspire that new recruit, and live with the knowledge that productivity levels will be lower for a while than they were with their previous employee. Role Recap A visual recap of all the roles discussed in this section is illustrated in Figure 2.3.1c. Attributions Title Image: " Farmland seen from the air" by Mrwrite at English Wikipedia, Wikimedia Commons is in the Public Domain Description: Public Domain Farmland seen from an airliner. The circles you can see are irrigated crops being grown, they are called pivots. Center-pivot irrigation (sometimes called central pivot irrigation), also called circle irrigation, is a method of crop irrigation in which equipment rotates around a pivot. A circular area centered on the pivot is irrigated, often creating a circular pattern in crops when viewed from above. "Principles of Management" by David S. Bright, Anastasia H. Cortes, OpenStax is licensed under CC BY 4.0 Access for free at https://openstax.org/books/principles-management/pages/1-1-what-do-managers-do Functions of Management Learning Objectives 6b Discuss the four functions of management. Efficiency and Management A manager’s time is fragmented. Managers have acknowledged from antiquity that they never seem to have enough time to get all those things done that need to be done. In the latter years of the twentieth century, however, a new phenomenon arose: demand for time from those in leadership roles increased, while the number of hours in a day remained constant. And their work is not always easily delegated to others. This results in small allotments of time for each task they must complete and each role they must fill. Values compete and the various roles are in tension. Managers clearly cannot satisfy everyone. Employees want more time to do their jobs; customers want products and services delivered quickly and at high-quality levels. Supervisors want more money to spend on equipment, training, and product development; shareholders want returns on investment maximized. A manager caught in the middle cannot deliver to each of these people what each most wants; decisions are often based on the urgency of the need and the proximity of the problem. Managers take on heavy loads. In recent years, many North American and global businesses were reorganized to make them more efficient, nimble, and competitive. For the most part, this reorganization meant decentralizing many processes along with the wholesale elimination of middle management layers. Many managers who survived such downsizing found that their number of direct reports had doubled. Classical management theory suggests that seven is the maximum number of direct reports a manager can reasonably handle. Today, high-speed information technology and remarkably efficient telecommunication systems mean that many managers have as many as 20 or 30 people reporting to them directly. Efficiency is essential. With less time than they need, with time fragmented into increasingly smaller units during the workday, with the workplace following many managers out the door and even on vacation, and with many more responsibilities loaded onto managers in downsized, flatter organizations, efficiency has become the core management skill of the twenty-first century. 4 Functions of Managers:Plan, Organize, Direct, and Control What responsibilities do managers have in organizations? According to our definition, managers are involved in planning, organizing, directing, and controlling. Managers have described their responsibilities that can be aggregated into nine major types of activity. These include: - Long-range planning. Managers occupying executive positions are frequently involved in strategic planning and development. - Controlling. Managers evaluate and take corrective action concerning the allocation and use of human, financial, and material resources. - Environmental scanning. Managers must continually watch for changes in the business environment and monitor business indicators, such as returns on equity or investment, economic indicators, business cycles, and so forth. - Supervision. Managers continually oversee the work of their subordinates. - Coordinating. Managers often must coordinate the work of others both inside the work unit and outside. - Customer relations and marketing. Certain managers are involved in direct contact with customers and potential customers. - Community relations. Contact must be maintained and nurtured with representatives from various constituencies outside the company, including state and federal agencies, local civic groups, and suppliers. - Internal consulting. Some managers make use of their technical expertise to solve internal problems, acting as inside consultants for organizational change and development. - Monitoring products and services. Managers get involved in planning, scheduling, and monitoring the design, development, production, and delivery of the organization’s products and services. Not every manager engages in all of these activities. Rather, different managers serve different roles and carry different responsibilities, depending upon where they are in the organizational hierarchy. Variations in Mangerial Work Although each manager may have a diverse set of responsibilities, including those mentioned above, the amount of time spent on each activity and the importance of that activity will vary considerably. The two most salient perceptions of a manager are (1) the manager’s level in the organizational hierarchy and (2) the type of department or function for which he/she/they is responsible. Let us briefly consider each of these. Management by Level We can distinguish three general levels of management: executive management, middle management, and first-line management: - Executive managers are at the top of the hierarchy and are responsible for the entire organization, especially its strategic direction. - Middle managers, who are at the middle of the hierarchy, are responsible for major departments and may supervise other lower-level managers. - First-line managers supervise rank-and-file employees and carry out day-to-day activities within departments. Figure 2.3.2a shows the differences in managerial activities by hierarchical level. Senior executives will devote more of their time to conceptual issues, while front-line managers will concentrate their efforts on technical issues. For example, top managers rate high on such activities as long-range planning, monitoring business indicators, coordinating, and internal consulting. Lower-level managers, by contrast, rate high on supervising because their responsibility is to accomplish tasks through rank-and-file employees. Middle managers rate near the middle for all activities. Managerial Skills We can distinguish three types of managerial skills: technical, human relations, conceptual. - Technical skills. Managers must have the ability to use the tools, procedures, and techniques of their special areas. An accountant must have expertise in accounting principles; whereas, a production manager must know operations management. These skills are the mechanics of the job. - Human relations skills. Human relations skills involve the ability to work with people and understand employee motivation and group processes. These skills allow the manager to become involved with and lead his group. - Conceptual skills. These skills represent a manager’s ability to organize and analyze information in order to improve organizational performance. They include the ability to see the organization as a whole and to understand how various parts fit together to work as an integrated unit. These skills are required to coordinate the departments and divisions successfully so that the entire organization can pull together. As shown in Figure 2.3.2b, different levels of these skills are required at different stages of the managerial hierarchy. That is, success in executive positions requires far more conceptual skill and less use of technical skills in most (but not all) situations; whereas, first-line managers generally require more technical skills and fewer conceptual skills. Note, however, that human relations skills, or people skills, remain important for success at all three levels in the hierarchy. Management by Department or Function In addition to level in the hierarchy, managerial responsibilities also differ with respect to the type of department or function. There are differences found for quality assurance, manufacturing, marketing, accounting and finance, and human resource management departments. For instance, manufacturing department managers will concentrate their efforts on products and services, controlling, and supervising. Marketing managers, in comparison, focus less on planning, coordinating, and consulting and more on customer relations and external contact. Managers in both accounting and human resource management departments rate high on long-range planning, but they will spend less time on the organization’s products and service offerings. Managers in accounting and finance are also concerned with controlling and monitoring performance indicators, while human resource managers provide consulting expertise, coordination, and external contacts. The emphasis on and intensity of managerial activities varies considerably by the department the manager is assigned to. At a personal level, knowing that the mix of conceptual, human, and technical skills changes over time and that different functional areas require different levels of specific management activities can serve at least two important functions. First, if you choose to become a manager, knowing that the mix of skills changes over time can help you avoid a common complaint that often young employees want to think and act like a CEO before they have mastered being a first-line supervisor. Second, knowing the different mix of management activities by functional area can facilitate your selection of an area or areas that best match your skills and interests. In many firms, managers are rotated through departments as they move up in the hierarchy. In this way they obtain a well-rounded perspective on the responsibilities of the various departments. In their day-to-day tasks they must emphasize the right activities for their departments and their managerial levels. Knowing what types of activity to emphasize is at the core of the manager’s job. Attributions "Principles of Management" by David S. Bright, Anastasia H. Cortes, OpenStax is licensed under CC BY 4.0 Access for free at: https://openstax.org/books/principles-management/pages/1-3-major-characteristics-of-the-managers-job Firm Vision or Mission? Learning Objectives 6e Define and distinguish firm vision and mission. Conveying the Purpose of a Business The first step in the process of developing a successful strategic position should be part of the founding of the firm itself. When entrepreneurs decide to start a business, they usually have a reason for starting it, a reason that answers the question “What is the point of this business?” Even if an entrepreneur initially thinks of starting a business in order to be their own boss, they must also have an idea about what their business will do. And that idea about what a business will do should be conveyed through a vision and a mission, but these two things do slightly differ. Vision Statement A vision statement is an expression of what a business’s founders want that business to accomplish. The vision statement is usually very broad, and it does not even have to mention a product or service. The vision statement does not describe the strategy a firm will use to follow its vision—it is simply a sentence or two that states why the business exists. Mission Statement While a firm’s vision statement is a general statement about its values, a firm’s mission statement is more specific. The mission statement takes the why of a vision statement and gives a broad description of how the firm will try to make its vision a reality. A mission statement is still not exactly a strategy, but it focuses on describing the products a firm plans to offer or the target markets it plans to serve. Clearing Up Confusion An interesting thing to note about vision and mission statements is that many companies confuse them, calling a very broad statement their mission. For example, Microsoft says that its mission is “to help people around the world realize their full potential.” By the description above, this would be a good vision statement. However, Microsoft’s official vision statement is to “empower people through great software anytime, anyplace, and on any device.” Although the second statement is also quite broad, it does say how Microsoft wants to achieve the first statement, which makes it a better mission statement than their vision statement. Figure 2.3.3a gives examples of vision and mission statements for the Walt Disney Company and for Ikea. Notice that in both cases, the vision statement is very broad and is not something a business could use as a strategy because there’s simply not enough information to explain what kind of business each might be. The mission statements, on the other hand, describe the products and services each company plans to offer and the customers each company plans to serve in order to fulfill their vision. Why are vision and mission statements important to a firm’s strategy for developing a competitive advantage? To put it simply, you can’t make a plan or strategy unless you know what you want to accomplish. Vision and mission statements together are the first building blocks in defining why a firm exists and in developing a plan to accomplish what the firm wants to accomplish. Attributions "Principles of Management" by David S. Bright, Anastasia H. Cortes, OpenStax is licensed under CC BY 4.0 https://openstax.org/books/principles-management/pages/9-2-firm-vision-and-mission	oercommons	2025-03-18T00:37:14.682032	Erin Krier	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/105289/overview", "title": "Agribusiness Functions of Management", "author": "Lesson" }
https://oercommons.org/courseware/lesson/66273/overview	Demographic Composition of the Texas State Legislature Overview Demographic Composition of the Texas State Legislature Learning Objective At the end of this section, you will be able to: - Discuss the demographic composition of the Texas House of Representatives and the Texas Senate Introduction This section describes the demgraphic composition of the Texas House of Representatives and the Texas Senate General Description: Pale, Male, and Stale It’s often been said the Texas State Legislature is “pale, male, and stale.” This may not be quite as accurate as in the past, but the Texas State Legislature is predominantly white, male, and middle-aged, making it far less diverse than Texas as a whole. Descriptive data on the composition of the Texas State Legislature is available at the Legislative Reference Library. Partisan Makeup The Republican Party controls both the Texas State House of Representatives and the Texas State Senate: The Texas State House of Representatives currently has 83 Republicans and 67 Democrats. The Texas State Senate currently has 18 Republicans and 13 Democrats. Gender Makeup The Texas State Legislature is predominantly male. Although their overall count is growing, women remain incredibly outnumbered in the 87th Texas Legislature— just 48 of 181 seats in the House and Senate are currently held by women. Approximately 25% of the Texas State House of Representatives is female (112 males, 38 females) Approximately 32% of the Texas State Senate is female (21 males, 10 females) Taken together, only 27% of the total membership of the Texas State Legislature is female (48 of 181 total members). Notably, with the addition of Democrats Julie Johnson, Jessica González, and Erin Zwiener to the 86th Legislature in 2019, the number of legislators who identify as members of the LGBT community increased from two to five. Age Distribution Description \| House Members \| Senate Members \| Total \| Under 30 \| 0 \| 0 \| 0 \| 30 - 39 \| 16 \| 0 \| 16 \| 40 - 49 \| 43 \| 1 \| 44 \| 50 - 59 \| 44 \| 15 \| 59 \| 60 - 69 \| 29 \| 7 \| 36 \| 70 and over \| 17 \| 8 \| 2 \| Licenses and Attributions CC LICENSED CONTENT, ORIGINAL Revision and Adaptation. Authored by: Kris S. Seago. License: CC BY: Attribution Revision and Adaptation: Composition of Texas Legislature. Authored by: John Osterman. License: CC BY: Attribution	oercommons	2025-03-18T00:37:14.715634	05/05/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/66273/overview", "title": "Texas Government 2.0, The Texas Legislature, Demographic Composition of the Texas State Legislature", "author": "Kris Seago" }
https://oercommons.org/courseware/lesson/124433/overview	Vital Signs Theory Micro-credential - 2024- Common Cartridge(Blackboard) V1.2 Vital Signs Theory Micro-credential Course Files Vital Signs Theory Micro-credential Overview This resource contains the full course content for the Vital Signs Theory Micro-credential for healthcare and nursing students. This foundational level micro-credential takes 2-3 hours to complete and includes content formats such as powerpoint lectures, videos, articles, links, and images, assessments, as well as some interactive content. All content was created in collaboration with healthcare employers and SMEs in the healthcare field. Within this resource you will find: all course files, IMSCC file for embedding into Blackboard LMS, and resources and guidance documents for implementation. Vital Signs Theory Micro-credential Course content and Resources Course Description This micro-credential provides an in-depth understanding of vital signs, essential for healthcare professionals in monitoring and assessing patient health. Learners will build on their clinical skills by studying the theory around the four primary vital signs: temperature, pulse rate, respiratory rate, and blood pressure. Learners will understand the physiological mechanisms underlying each vital sign, enhancing comprehension of their importance in clinical practice. Normal ranges for vital signs across different age groups and conditions will be discussed, as well as the ability to identify when readings deviate from these norms. Potential causes of abnormal vital signs and determining appropriate next steps in patient care, including when to escalate concerns will be presented. The importance of maintaining patient safety during assessments and documentation of results will be emphasized. Skills: Blood Pressure \| Temperature \| Respirations \| Pulse \| Vital Signs \| Vital Signs Documentation \| Clinical Skills \| Patient Care \| Patient Safety About: The micro-credential is intended to be taken online independently. It should take between 2-3 hours to complete. It is a foundational level micro-credential, and has been developed with healthcare industry professionals from large healthcare employers in the state of CT. Course Files (ZIP Folder): This folder contains all course files, including PowerPoint presentations, images, and external documents. It also includes a course roadmap, which outlines the intended sequence for building the course from scratch. The embedded links document provides all resource links used within the micro-credential. SCORM File: This Common Cartridge file is designed to directly embed the entire course and its content into a compatible Learning Management System (LMS). It was used in Blackboard Ultra and is formatted to SCORM 1.2. Resources and Guidance Documents (ZIP Folder): This folder contains instructional resources and guidance for instructors on how to effectively use the provided materials. This content was created as part of the CT SHIP grant, lead by CT State Community College - Norwalk. https://ctstate.edu/workforce-development/microcredentials The total cost of CT Statewide Healthcare Industry Pathway project (CT SHIP) was $6.9M. $3.4M (49%) was funded through a U.S. Department of Labor – Employment and Training Administration grant and another $3.5M (51%) was committed through non-federal state and local resources. The Workforce product was funded by the grant awarded by the U.S Department of Labor's Employment and Training Administration. The product was created by the grantee and does not necessarily reflect the official position of the U.S Department of Labor. The U.S Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on any linked sites and include, but not limited to, the accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.	oercommons	2025-03-18T00:37:14.739073	02/06/2025	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/124433/overview", "title": "Vital Signs Theory Micro-credential", "author": "Renee Dunbar" }
https://oercommons.org/courseware/lesson/96129/overview	Calculus of Parametric Curves: Calculus 3 project by Briana Yang Overview This Project has been completed as part of a standard 10 weeks Calculus 3 asynhronous online course with optional WebEx office hours during Summer 2022 semester at MassBay Community College, Wellesley Hills, MA. Summary Author: Briana Yang Instructor: Igor V Baryakhtar Subject: Calculus 3 Course number: MA 202-700 Course type: Asynhronous online Semester: Summer 2022, 10 weeks College: MassBay Comminity College, MA Tags: Calculus, Project Based Learning, Active Learning Language: English Media Format: pdf License: CC-BY 4.0 All project content created by Briana Yang Content added to OER Commons by Igor V Baryakhtar	oercommons	2025-03-18T00:37:14.757781	Homework/Assignment	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/96129/overview", "title": "Calculus of Parametric Curves: Calculus 3 project by Briana Yang", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/99500/overview	Gender inequalities #2 Gender Inequalities Overview Gender Inequalities and the our experinces as a research team. Ant 100 FY12 Arthur and Sahaja. Gender Inequalities and Its Negative Effect on the World. After our long journey of research, we put into the topic of empowerment of women and gender inequalties. Our team included me (Arthur Movsesyan) and my partner Sahaja. We worked on ways we could limit gender inequalaties and ways we can educate others so it stops. We saw some patterns of bias and agenda such as logical fallacies because a lot of the men we came up to during our research believed that all genders were treated equally. Some people don't know how it feels to be treated like crap because they aren't getting treated like this. Furthermore, this is why my team focused on educating others because we think a lack of education is the cause of this issue. Anthropology plays a big connection with our topic as it shows how unstable our country is with these inequalities. As all our research supported that the equality of all genders would play a big impact in our society by bettering women's resources and making both genders better connected. This goes to show how colonialism, sustainability, and anthropology are all related because all of them show how the world would be a better place by educating each other on whats wrong and humans taking control of their minds to find ways to make this world a better place. Its important to show growth within the economy and us as people overall. This relationship relates to our project as this is our resolution to limiting gender inequalities and finally ending it one day. We wanted to target everyone we can so, people can understand the hardships of women and together we can make a difference. Although this project was rough since, it was an online group project. Our team managed to do a successful job but, next time we need to work on our communication and set up more meetings with our professor to be on track within our work. We should have also met up more in person as we all split up in our own separate ways.	oercommons	2025-03-18T00:37:14.774734	12/17/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/99500/overview", "title": "Gender Inequalities", "author": "Arthur Movsesyan" }
https://oercommons.org/courseware/lesson/66278/overview	Introduction: Texas' Governor and Executive Branch Overview Introduction: Texas' Governor and Executive Branch Learning Objective By the end of this chapter, you will be able to: - Explain the structure and function of the executive branch of the Texas government Introduction In its 2019 session, the Texas Legislature failed to pass a “Sunset” bill that would have continued the existence of the Texas State Board of Plumbing Examiners. The bill had stalled amid controversy over whether or not to phase out this small agency and combine its functions into the larger Texas Department of Licensing and Regulation. Without passage of S.B. 621, Texas faced an interesting problem. With no law requiring plumbers to be licensed and no agency to license them, anybody with a pipe wrench could now go into the plumbing business, performing jobs from replacing a kitchen faucet to complex medical gas piping in a hospital with no license and no training. Shortly after the session, legislators realized what they had done. Some legislators, plumbers, city plumbing inspectors and others began calling for a special legislative session to fix the problem. Instead, Texas Governor Greg Abbott simply issued an executive order extending the existence of the state board through the next regular legislative session. How? "A qualified workforce of licensed plumbers throughout the state, including from areas not directly affected by Hurricane Harvey, will be essential as those funds are being invested in crucial infrastructure, medical facilities, living facilities, and other construction projects,” he said in his order. By extending the board through the next legislative session or until “disaster needs subside,” the governor was able to tap into sweeping powers given to his office to deal with natural disasters. How can a governor in a “weak governor” state sidestep the legislature and resurrect an agency despite legislation to the contrary? In this chapter, we’ll look at the executive branch of state government in Texas. Licensing and Attribution CC LICENSED CONTENT, ORIGINAL The Executive Department and the Office of the Governor of Texas: Introduction. Authored by: Andrew Teas. License: CC BY: Attribution	oercommons	2025-03-18T00:37:14.791692	05/05/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/66278/overview", "title": "Texas Government 2.0, The Executive Department and the Office of the Governor of Texas, Introduction: Texas' Governor and Executive Branch", "author": "Kris Seago" }
https://oercommons.org/courseware/lesson/66284/overview	Glossary Overview Glossary Glossary: Texas' Governor and Executive Branch appointment: the power of the chief executive, whether the president of the United States or the governor of the state, to appoint persons to office. attorney general: an elected state official that serves as the state's chief civil lawyer bureaucracy: the complex structure of offices, tasks, rules, and principles of organization that is employed by all large-scale institutions to coordinate the work of their personnel. comptroller: an elected state official who directs the collection of taxes and other revenues, and estimates revenues for the budgeting process. executive budget: the state budget prepared and submitted by the governor of the legislature, which indicates the governor's spending priorities. land commissioner: an elected state official that acts as the manager of the most publicly-owned lands. lieutenant governor: the second-highest elected official in the state and president of the state senate line-item veto power: enables the governor to veto individual components (or lines) of an appropriations bill. plural executive: a group of officers or major officials that functions in making current decisions or in giving routine orders typically the responsibility of an individual executive officer or official. In Texas, the power of the Governor is limited and distributed amongst other government officials. secretary of state: the state official, appointed by the governor, whose primary responsibility is administering elections veto: the governor's power to turn down legislation; can be overridden by a two-thirds vote of both the House and Senate Licenses and Attributions CC LICENSED CONTENT, ORIGINAL The Executive Department and the Office of the Governor of Texas: Glossary Authored by: Andrew Teas. License: CC BY: Attribution	oercommons	2025-03-18T00:37:14.808208	05/05/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/66284/overview", "title": "Texas Government 2.0, The Executive Department and the Office of the Governor of Texas, Glossary", "author": "Kris Seago" }
https://oercommons.org/courseware/lesson/87991/overview	Rise of Totalitarian Regimes Overview Totalitarianism One of the most disturbing developments of the Interwar Period, between the two world wars, was the rise of totalitarian regimes across the world. Totalitarianism emerged because of widespread dissatisfaction over the outcome and aftermath of the First World War, in conjunction with the exploitation of the impulse toward political democratization occurring across the world totalitarian leaders. These leaders seized control of countries around the world, playing to popular dissatisfaction, toward the end of pursuing their agendas of national and personal aggrandizement. The rise of such regimes, particularly in Italy, Japan, and Germany, led to disastrous consequences for humanity, first and foremost being the Second World War and the Holocaust. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts totalitarianism: an approach to government defined by a central authority exercising complete control over a society Benito Mussolini: fascist leader of World War II Italy and early fascist leader of post-WWI Europe Adolf Hitler: Nazi leader of World War II Germany, responsible for the Holocaust Totalitarianism After World War I totalitarianism emerged as an approach to government in nations across Eurasia. It was a reaction to the dissatisfaction felt by many citizens in nations where it took hold, including most notably Germany, Italy, and Japan. Totalitarianism is distinct from the absolutist governments of early modern Europe and is defined by the executive branch of a national government, usually the monarchy, enjoying complete control over the government, but not the society. Totalitarianism is also marked by a number of different characteristics, including authoritarianism, national and/or ethnic chauvinism, personality cults, and an industrialized approach to governance. The political developments and organizational and technological advances growing out of the Industrial Revolution made totalitarianism possible. Ironically, the most significant political development that contributed to the rise of totalitarian was the grant of nominal universal male suffrage. Totalitarian leaders such as Benito Mussolini and Adolf Hitler exploited this development, arguing that each had the mandate of his people. Before these developments and advances, during the early modern era, absolutist rulers such as Louis XIV of France could not conceive of totalitarian control over their countries. During the Interwar period totalitarianism took a number of different forms, including fascism and statism, in a range of attitudes toward the governed, from benign to malignant. Fascism Fascism is a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, characterized by one-party totalitarian regimes, which were run by charismatic dictators, as well as involved glorification of violence, and racist ideology. The first fascist movements emerged in Italy during World War I, then spread to other European countries. Opposed to liberalism, communism, and anarchism, fascism is usually placed on the far-right within the traditional left–right spectrum. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts fascism: a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, which holds that liberal democracy is obsolete and that the complete mobilization of society under a totalitarian one-party state is necessary to prepare a nation for armed conflict and to respond effectively to economic difficulties. liberalism - ideology based on the concept of equality of opportunity which emerged in early modern Europe, developed by participants in the Enlightenment, This ideology has become one of the principle ideologies in political and economic discourse, along with a basis for a number of national political parties. communism: a political, social, and economic movement and philosophy in which there are ideally no economic or social classes or private property and resources are owned equally by the people. Karl Marx developed this ideology, with Friedrich Engels, during the mid-nineteenth century in response to the Industrial Revolution. totalitarianism: an approach to government defined by a central authority exercising complete control over a society autarky: the economic and political concept of self-sufficiency Benito Mussolini: fascist leader of World War II Italy and early fascist leader of post-WWI Europe Factors and Developments underlying the Emergence of Totalitarian Regimes A number of factors and developments in the aftermath of World War I fueled the emergence of totalitarian regimes during the twenties and thirties. First, those countries which did succumb to totalitarianism, on both sides, were disappointed in the ending this conflict from them. Second, many, if not most supporters, sought simple and easy solutions to complex problems. Third, totalitarian rulers possessed charisma, even if it appealed to negative emotions. Fascist Ideologies Fascists saw World War I as a revolution that brought massive changes to the nature of war, society, the state, and technology. The advent of total war and the total mass mobilization of belligerent societies had broken down the distinction between civilians and combatants. A “military citizenship” arose in which all citizens were involved with the military in some manner during the war. The war resulted in the rise of a powerful state capable of mobilizing millions of people to serve on the front lines and providing economic production and logistics to support them, as well as having unprecedented authority to intervene in the lives of citizens. In the early twentieth century fascists believed that liberal democracy was obsolete, and they regarded the complete mobilization of society under a totalitarian one-party state as necessary to prepare a nation for armed conflict and respond effectively to economic difficulties. Such a state had to be led by a strong leader—such as a dictator and a martial government composed of the members of the governing fascist party—to forge national unity and maintain a stable and orderly society. Fascism rejected assertions that violence was automatically negative in nature; on the other hand, it viewed political violence, war, and imperialism as means that could achieve national rejuvenation. Fascists advocated a mixed economy with the principal goal of achieving autarky (self-sufficiency) through protectionist and interventionist economic policies. Reaching its apex during the twenties and thirties, fascism was repudiated by the end of the Second World War because of its association with the Axis Powers. Since the end of World War II in 1945, few parties have openly described themselves as fascist, and the term is instead now usually used pejoratively by political opponents. The terms neo-fascist or post-fascist are sometimes applied more formally to describe parties of the far right with ideologies similar to or rooted in 20th century fascist movements. Early History of Fascism The historian Zeev Sternhell has traced the ideological roots of fascism back to the 1880s, and in particular to the fin-de-siècle (French for “end of the century”) theme of that time. This ideology was based on a revolt against materialism, rationalism, positivism, bourgeois society, and democracy. The fin-de-siècle generation supported emotionalism, irrationalism, subjectivism, and vitalism. The fin-de-siècle mindset saw civilization as being in a crisis that required a massive and total solution. Its intellectual school considered the individual only one part of the larger collectivity, which should not be viewed as an atomized numerical sum of individuals. They condemned the rationalistic individualism of liberal society and the dissolution of social links in bourgeois society. The term fascist comes from the Italian word fascismo, derived from fascio meaning a bundle of rods, ultimately from the Latin word fasces. This was the name given to political organizations in Italy known as fasci—groups similar to guilds or syndicates. At first, it was applied mainly to organizations on the political left. The Fascists came to associate the term with the ancient Roman fasces or fascio littorio—a bundle of rods tied around an axe, an ancient Roman symbol of the authority of the civic magistrate carried by his lictors, which could be used for corporal and capital punishment at his command. The symbolism of the fasces suggested strength through unity: a single rod is easily broken, while the bundle is difficult to break. After the end of the World War I, fascism rose out of relative obscurity into international prominence, with fascist regimes forming most notably in Italy, Germany, and Japan, the three of which would be allied in World War II. Fascist Benito Mussolini seized power in Italy in 1922, and Adolf Hitler had successfully consolidated his power in Germany by 1933. Rise of Fascism in Italy After the First World War Italy became the first major European power to embrace fascism, with Benito Mussolini leading the way. Italy was one of a number of nations around the world which came under the control of various forms of totalitarian governments. Italy foreshadowed the emergence of fascism in other countries, and Mussolini became a model for other totalitarian leaders in Europe, including General Francisco Franco in Spain and Adolf Hitler in Germany. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts Benito Mussolini: fascist leader of World War II Italy and early fascist leader of post-WWI Europe Francisco Franco: a Spanish general who ruled over Spain as a dictator for 36 years from 1939 until his death (He took control of Spain from the government of the Second Spanish Republic after winning the Civil War, and was in power 1978, when the Spanish Constitution of 1978 went into effect.) Adolf Hitler: Nazi leader of World War II Germany, responsible for the Holocaust fascism: a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, which holds that liberal democracy is obsolete and that the complete mobilization of society under a totalitarian one-party state is necessary to prepare a nation for armed conflict and to respond effectively to economic difficulties. At the outbreak of World War I in August 1914, the Italian political left split over the war. While the Italian Socialist Party (PSI) opposed the war, a number of Italian revolutionary syndicalists supported war against Germany and Austria-Hungary on the grounds that their reactionary regimes had to be defeated to ensure the success of socialism. Angelo Oliviero Olivetti formed a pro-interventionist fascio called the Fasci of International Action in October 1914. Benito Mussolini, upon expulsion from his position as chief editor of the PSI’s newspaper Avanti! for his anti-German stance, joined the interventionist cause in a separate fascio. The fascists and the Italian political right held common ground: both held Marxism in contempt, discounted class consciousness, and believed in the rule of elites. Italian fascists began to accommodate themselves to Italian conservatives by making major alterations to its political agenda—abandoning its previous populism, republicanism, and anticlericalism, while adopting policies in support of free enterprise, and accepting the Roman Catholic Church and the monarchy as institutions in Italy. Fascists identified their primary opponents as the majority of socialists on the left who had opposed intervention in World War I. The first meeting of the Fasci of Revolutionary Action was held on January 24, 1915 and was led by Benito Mussolini. This group first used the term “fascism.” During the first meeting of this group in January 1915, Mussolini declared that it was necessary for Europe to resolve its national problems—including national borders of Italy and elsewhere—“for the ideals of justice and liberty for which oppressed peoples must acquire the right to belong to those national communities from which they descended.” Attempts to hold mass meetings were ineffective, and the organization was regularly harassed by government authorities and socialists. In the next few years, the relatively small group took various political actions. To appeal to Italian conservatives, fascism adopted policies such as promoting family values, including policies designed to reduce the number of women in the workforce by limiting the woman’s role to that of a mother. The fascists banned literature on birth control and increased penalties for abortion in 1926, declaring both crimes against the state. Though fascism adopted a number of positions designed to appeal to reactionaries, the Fascists sought to maintain fascism’s revolutionary character, with Angelo Oliviero Olivetti saying “Fascism would like to be conservative, but it will [be] by being revolutionary.” The Fascists supported revolutionary action and committed to secure law and order to appeal to both conservatives and syndicalists. Mussolini and Fascist Italy Prior to fascism’s accommodation of the political right, Fascism had been a small, urban, northern Italian movement that had about a thousand members. After aligning itself with Italian conservatives, the fascist party rose to prominence using violence and intimidation. In 1919, Benito Mussolini founded the Fasci Italiani di Combattimento in Milan, which became the Partito Nazionale Fascista (National Fascist Party) two years later. In 1920, militant strike activity by industrial workers reached its peak in Italy. Mussolini and the Fascists took advantage of the situation by allying with industrial businesses and attacking workers and peasants in the name of preserving order and internal peace in Italy. The Fascist movement’s membership soared to approximately 250,000 by 1921, with the New National Fascist Party (PNF) Mussolini organized in 1921. Italian fascism, under Mussolini’s control, was rooted in Italian nationalism and the desire to restore and expand Italian territories. Italian fascists deemed such territorial expansion necessary for a nation to assert its superiority and strength, as well as to avoid succumbing to decay. They claimed that modern Italy is the heir to ancient Rome and its legacy, and historically they supported the creation of an Italian Empire to provide spazio vitale (“living space”) for colonization by Italian settlers and to establish control over the Mediterranean Sea. Domestically Italian Fascism promoted a corporatist economic system, whereby employer and employee syndicates were linked together in associations to collectively represent the nation’s economic producers and work alongside the state to set national economic policy. This economic system intended to resolve class conflict through collaboration between the classes. Fascists Under Mussolini Seize Power Mussolini’s Fascist movement took control of the Italian government in 1922, ruling Italy until 1943. Fascist paramilitaries first struck at political opponents in a wave of strikes against socialist offices, along with the homes of socialist leaders. Included in their targets were the headquarters of socialist and Catholic labor unions in Cremona. The Fascists then escalated their strategy by violently occupying a number of northern Italian cities. Along with occupation, the Fascists imposed Italianization upon German-speaking people in Trent and Bolzano. After seizing these cities, the Fascists made plans to take Rome. The Fascists met little serious resistance from authorities in these strikes and occupations, which emboldened them in their next step to take control of Rome. On October 24, 1922, the Fascist party held its annual congress in Naples, where Mussolini ordered Blackshirts to take control of public buildings and trains, as well as converge on three points around Rome. The Fascists managed to seize control of several post offices and trains in northern Italy while the Italian government, led by a left-wing coalition, was internally divided and unable to respond to the Fascist advances. King Victor Emmanuel III of Italy thought the risk of bloodshed in Rome to disperse the Fascists was too high. Victor Emmanuel III decided to appoint Mussolini as Prime Minister of Italy. Mussolini arrived in Rome on October 30 to accept the appointment. Fascist propaganda aggrandized this event, known as “March on Rome,” as a “seizure” of power because of Fascists’ heroic exploits. Mussolini in Power Upon becoming Prime Minister of Italy, Mussolini had to form a coalition government, because the Fascists did not have control over the Italian parliament. Consequently, little drastic change in government policy occurred initially. Repressive police actions were limited at the beginning of Mussolini’s tenure as well. In addition, Mussolini’s coalition government pursued economically liberal policies under the direction of liberal finance minister Alberto De Stefani, a member of the Center Party, including balancing the budget through deep cuts to the civil service. The Fascists’ first attempt to entrench Fascism in Italy began with the Acerbo Law, which guaranteed a plurality of the seats in parliament to any party or coalition list in an election that received 25% or more of the vote. Through considerable Fascist violence and intimidation, the list won a majority of the vote, allowing many seats to go to the Fascists. In the aftermath of the election, a crisis and political scandal erupted after Socialist Party deputy Giacomo Matteoti was kidnapped and murdered by a Fascist. The liberals and the leftist minority in parliament walked out in protest in what became known as the Aventine Secession. During the latter half of the twenties Mussolini progressively solidified his totalitarian control over the government and the country. On January 3, 1925, Mussolini addressed the Fascist-dominated Italian parliament and declared that he was personally responsible for what happened, but insisted that he had done nothing wrong. He proclaimed himself dictator of Italy, assuming full responsibility over the government and announcing the dismissal of parliament. From 1925 to 1929, Mussolini’s fascists further solidified their control over the government and the country by denying opposition deputies access to Parliament and expanding censorship. In a December 1925 decree it was announced that Mussolini was responsible solely to the King. Between 1925 and 1927, Mussolini progressively dismantled virtually all constitutional and conventional restraints on his power, thereby solidifying his control over the government and the country. A law passed on Christmas Eve 1925 changed Mussolini’s formal title from “president of the Council of Ministers” to “head of the government” (though he was still called “Prime Minister” by most non-Italian outlets). Thereafter, he began styling himself as Il Duce (the leader). He was no longer responsible to Parliament and could be removed only by the king. While the Italian constitution stated that ministers were responsible only to the sovereign, in practice it had become all but impossible to govern against the express will of Parliament. The Christmas Eve law ended this practice and made Mussolini the only person competent to determine the body’s agenda. This law transformed Mussolini’s government into a de facto legal dictatorship. Local autonomy was abolished, and podestàs appointed by the Italian Senate replaced elected mayors and councils. Mussolini also extended his control over education, the press, and unions in Italy. All teachers in schools and universities had to swear an oath to defend the fascist regime. Newspaper editors were all personally chosen by Mussolini and no one without a certificate of approval from the fascist party could practice journalism. These certificates were issued in secret; Mussolini thus skillfully created the illusion of a “free press.” The trade unions were also deprived of independence and integrated into what was called the “corporative” system. The aim, although never completely achieved, was inspired by medieval guilds and was meant to place all Italians in various professional organizations or corporations under clandestine governmental control. Totalitarianism in Japan During the 1920s and the 1930s, a growing number of Japanese embraced political totalitarianism, ultranationalism, and militarism, in a mixture resembling fascism, culminating in militaristic leaders of the Army and Navy taking control of the Japanese government. As part of this process the Japanese government embarked upon an ambitious and aggressive effort to expand the Japanese empire westward across east Asia and eastward across the Pacific Ocean. Ultimately, this led to Japan’s defeat in the Second World War, the dismantling of the Japanese empire, and the end of Japan’s authoritarian government. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts totalitarianism: an approach to government defined by a central authority exercising complete control over a society militarism: the belief or the desire of a government or people for a country to maintain a strong military capability and be prepared to use it aggressively to defend or promote national interests; the glorification of the military; the ideals of a professional military class; the “predominance of the armed forces in the administration or policy of the state" statism: the belief that the state should control either economic or social policy or both, sometimes taking the form of totalitarianism, but not necessarily. It is effectively the opposite of anarchism Showa era: period in Japanese history corresponding to the reign of Emperor Showa (Hirohito) from 1926 to 1989 Treaty of Versailles: the most important of the peace treaties that ended World War I, which was signed on June 28, 1919, exactly five years after the assassination of Archduke Franz Ferdinand fascism: a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, which holds that liberal democracy is obsolete and that the complete mobilization of society under a totalitarian one-party state is necessary to prepare a nation for armed conflict and to respond effectively to economic difficulties. League of Nations: an intergovernmental organization founded on January 10, 1920, as a result of the Paris Peace Conference that ended the First World War; the first international organization whose principal mission was to maintain world peace. Its primary goals as stated in its Covenant included preventing wars through collective security and disarmament and settling international disputes through negotiation and arbitration. Statism in Japan Statism in Japan was a totalitarian political ideology which developed from the Meiji Restoration of 1868 into the 1930s. It is sometimes also referred to as Japanese fascism or Shōwa nationalism, after Japanese Emperor Showa (or Hirohito), who reigned as the emperor of Japan from 1926 to 1989. The period of Hirohito’s reign is also known as the Showa era. This statist movement dominated Japanese politics during the first part of the Shōwa period. It is characterized by a mixture of ideas including chauvinistic Japanese nationalism, militarism, and “state capitalism.”. Contemporary Japanese political philosophers and thinkers developed and advanced these ideas as part of their vision for Japan as an authoritarian and homogenous society with an empire that would stretch across the eastern half of Asia and the Pacific Ocean, making Japan one of the world’s leading powers. Development of Statist Ideology One of the catalysts for the development of statist ideology in Japan after World War I was the discriminatory treatment of Japan by Western Allied Powers. The 1919 Treaty of Versailles that ended World War I did not recognize the Empire of Japan’s territorial claims to the same extent that it did British and French imperial territorial claims. Subsequent international naval treaties between Western powers and the Empire of Japan, signed in Washington, D.C. in 1921 and in London in 1930, imposed prejudicial limitations on Japanese naval shipbuilding that put the Imperial Japanese Navy at a disadvantage vis-a-vis the British, the French, and the U.S. Navies. These measures were correctly considered by many in Japan as refusal by the Western powers to consider Japan an equal partner, as well as a part of a pattern of prejudicial treatment that Japan had had to endure at the hands of the Western power in its efforts to secure recognition as a world power since the 1868 Meiji Restoration. These treaties provoked a surge of nationalism among many Japanese, who saw the discriminatory provisions as a threat to Japanese interests. Consequently, ultranationalist leaders pushed for an end to Japanese participation in such conciliatory diplomacy that put the Japanese empire at a disadvantage. During the 1920s a growing number of Japanese came to reject economic, strategic, military, and diplomatic cooperation with the U.S. and European powers as prejudicial to Japanese interests. By 1931 many in Japan had come to accept military dictatorship and aggressive territorial expansion as the best ways to protect Japan. In the 1920s and 1930s, the supporters of Japanese statism used the slogan Showa Restoration, which implied that a new resolution was needed to replace the existing political order dominated by corrupt politicians and capitalists, with one which (in their eyes), would fulfill the original goals of the Meiji Restoration of direct Imperial rule via military proxies. Early Shōwa statism is sometimes given the retrospective label “fascism,” but this was not a self-appellation and it is not entirely clear that the comparison is accurate. When authoritarian tools of the state such as the Kempeitai were put into use in the early Shōwa period, they were employed to protect the rule of law under the Meiji Constitution from perceived enemies on both the left and the right. This included the Ministry of Home Affairs arresting left-wing political dissidents beginning in 1930. From 1930 through 1933 the Ministry made over 30,000 such arrests. Nationalist Politics during the Shōwa Period Left-wing groups had been subject to violent suppression by the end of the Taishō period, and radical right-wing groups, inspired by fascism and Japanese nationalism, rapidly grew in popularity. The extreme right became influential throughout the Japanese government and society, notably within the Kwantung Army, a Japanese army stationed in China along the Japanese-owned South Manchuria Railroad. During the Manchurian Incident of 1931, radical army officers bombed a small portion of the South Manchuria Railroad and, falsely attributing the attack to the Chinese, invaded Manchuria. The Kwantung Army conquered Manchuria and set up the puppet government of Manchukuo there without permission from the Japanese government. International criticism of Japan following the invasion led to Japan withdrawing from the League of Nations. The withdrawal from the League of Nations meant that Japan was politically isolated. Japan had no strong allies and its actions had been internationally condemned, while internally popular nationalism was booming. Local leaders such as mayors, teachers, and Shinto priests were recruited by the various movements to indoctrinate the populace with ultra-nationalist ideals. They had little time for the pragmatic ideas of the business elite and party politicians. Their loyalty lay to the emperor and the military. In March 1932 the “League of Blood” assassination plot and the chaos surrounding the trial of its conspirators further eroded the rule of democratic law in Shōwa Japan. In May of the same year, a group of right-wing Army and Navy officers succeeded in assassinating Prime Minister Inukai Tsuyoshi. The plot fell short of staging a complete coup d’état, but effectively ended rule by political parties in Japan. Japan’s expansionist vision grew increasingly bold. Many of Japan’s political elite aspired to have Japan acquire new territory for resource extraction and settlement of surplus population. These ambitions led to the outbreak of the Second Sino-Japanese War in 1937. After their victory in the Chinese capital, the Japanese military committed the infamous Nanking Massacre. The Japanese military failed to defeat the Chinese government led by Chiang Kai-shek and the war descended into a bloody stalemate that lasted until 1945. Japan’s stated war aim was to establish the Greater East Asia Co-Prosperity Sphere, a vast pan-Asian union under Japanese domination. Hirohito’s role in Japan’s foreign wars remains a subject of controversy, with various historians portraying him as either a powerless figurehead or an enabler and supporter of Japanese militarism. The United States opposed Japan’s invasion of China and responded with increasingly stringent economic sanctions intended to deprive Japan of the resources to continue its war in China. Japan reacted by forging an alliance with Germany and Italy in 1940, known as the Tripartite Pact, which worsened its relations with the U.S. In July 1941, the United States, Great Britain, and the Netherlands froze all Japanese assets when Japan completed its invasion of French Indochina by occupying the southern half of the country, further increasing tension in the Pacific. Decline of Democracy in Europe between the World Wars The development of fascism in Italy, Germany, and Spain occurred in the larger context of the decline of democracy in Europe. The conditions of economic hardship caused by the Great Depression brought about significant social unrest around the world, leading to a major surge of fascism and in many cases, the collapse of democratic governments in Europe. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts fascism: a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, which holds that liberal democracy is obsolete and that the complete mobilization of society under a totalitarian one-party state is necessary to prepare a nation for armed conflict and to respond effectively to economic difficulties. Beer Hall Putsch: a failed coup attempt by the Nazi Party leader Adolf Hitler to seize power in Munich, Bavaria, during November 8 – 9, 1923 (About two thousand men marched to the center of Munich where they confronted the police, resulting in the death of 16 Nazis and four policemen.) Adolf Hitler: Nazi leader of World War II Germany, responsible for the Holocaust Initial Surge of Fascism The March on Rome, through which Mussolini became Prime Minister of Italy, brought Fascism international attention. One early admirer of the Italian Fascists was Adolf Hitler, who, less than a month after the March, had begun to model himself and the Nazi Party upon Mussolini and the Fascists. The Nazis, led by Hitler and the German war hero Erich Ludendorff, attempted a “March on Berlin” modeled upon the March on Rome, which resulted in the failed Beer Hall Putsch in Munich in November 1923. The Nazis briefly captured Bavarian Minister President Gustav Ritter von Kahr and announced the creation of a new German government to be led by a triumvirate of von Kahr, Hitler, and Ludendorff. The Beer Hall Putsch was crushed by Bavarian police, and Hitler and other leading Nazis were arrested and detained until 1925. Another early admirer of Italian Fascism was Gyula Gömbös—leader of the Hungarian National Defence Association (known by its acronym MOVE) and a self-defined “national socialist.” In 1919 Gömbös spoke of the need for major changes in property and in 1923 stated the need for a “March on Budapest.” Though it was opposed to the Italian government due to Yugoslav border disputes with Italy, Yugoslavia briefly had a significant fascist movement: the Organization of Yugoslav Nationalists (ORJUNA). ORJUNA supported Yugoslavism and the creation of a corporatist economy, as well as opposed democracy and took part in violent attacks on communists. ORJUNA was dissolved in 1929 when the King of Yugoslavia banned political parties and created a royal dictatorship, though ORJUNA supported the King’s decision. Amid a political crisis in Spain involving increased strike activity and rising support for anarchism, Spanish army commander Miguel Primo de Rivera engaged in a successful coup against the Spanish government in 1923 and installed himself as a dictator as head of a conservative military junta that dismantled the established party system of government. Upon achieving power, Primo de Rivera sought to resolve the economic crisis by presenting himself as a compromise arbitrator figure between workers and bosses, and his regime created a corporatist economic system based on the Italian Fascist model. A variety of para-fascist governments that borrowed elements from fascism were formed during the Great Depression, including those of Greece, Lithuania, Poland, and Yugoslavia. In Lithuania in 1926, Antanas Smetona rose to power and founded a fascist regime under his Lithuanian Nationalist Union. The Great Depression and the Spread of Fascism The events of the Great Depression resulted in an international surge of fascism and the creation of several fascist regimes and regimes that adopted fascist policies. According to historian Philip Morgan, “the onset of the Great Depression…was the greatest stimulus yet to the diffusion and expansion of fascism outside Italy.” Fascist propaganda blamed the problems of the long depression of the 1930s on minorities and scapegoats: “Judeo-Masonic-bolshevik” conspiracies, left-wing internationalism, and the presence of immigrants.” In Germany, it contributed to the rise of the National Socialist German Workers’ Party, which resulted in the demise of the Weimar Republic and the establishment of the fascist regime under the leadership of Adolf Hitler: Nazi Germany. With the rise of Hitler and the Nazis to power in 1933, liberal democracy was dissolved in Germany, and the Nazis mobilized the country for war, with expansionist territorial aims against several countries. In the 1930s the Nazis implemented racial laws that deliberately discriminated against, disenfranchised, and persecuted Jews and other racial and minority groups. The Great Depression contributed to the growth of fascist movements elsewhere in Europe. Hungarian fascist Gyula Gömbös rose to power as Prime Minister of Hungary in 1932 and attempted to entrench his Party of National Unity throughout the country; he created an eight-hour workday and a 48-hour work week in industry, sought to entrench a corporatist economy, and pursued irredentist claims on Hungary’s neighbors. The fascist Iron Guard movement in Romania soared in political support after 1933, gaining representation in the Romanian government. An Iron Guard member assassinated Romanian prime minister Ion Duca. During the February 6, 1934 crisis, France faced the greatest domestic political turmoil since the Dreyfus Affair when the fascist Francist Movement and multiple far-right movements rioted en masse in Paris against the French government, resulting in major political violence. Totalitarianism beyond Europe Fascism also expanded its influence outside Europe, especially in East Asia, the Middle East, and South America. In China, Wang Jingwei’s Kai-tsu p’ai (Reorganization) faction of the Kuomintang (Nationalist Party of China) supported Nazism in the late 1930s. In Japan, a Nazi movement called the Tōhōkai was formed by Seigō Nakano. The Al-Muthanna Club of Iraq was a pan-Arab movement that supported Nazism and exercised its influence in the Iraqi government through cabinet minister Saib Shawkat, who formed a paramilitary youth movement. Learning Outcomes - Explain the global challenge to liberalism by totalitarianism through the movements of communism, fascism, and National Socialism. - Evaluate the factors that led to the global depression in the 1930s. - Compare and contrast the reactions of nations worldwide to this global depression. Key Terms / Key Concepts fascism: a form of radical authoritarian nationalism that came to prominence in early 20th-century Europe, which holds that liberal democracy is obsolete and that the complete mobilization of society under a totalitarian one-party state is necessary to prepare a nation for armed conflict and to respond effectively to economic difficulties. National Socialism: fascist and totalitarian ideology associated with Adolf Hitler, also known as Nazism, characterized by antisemitism, anticommunism, and scientific racism Several, mostly short-lived fascist governments and prominent fascist movements were formed in South America during this period. Argentine President General José Félix Uriburu proposed that Argentina be reorganized along corporatist and fascist lines. Peruvian president Luis Miguel Sánchez Cerro founded the Revolutionary Union in 1931 as the state party for his dictatorship; it was later taken over by Raúl Ferrero Rebagliati who sought to mobilize mass support for the group’s nationalism in a manner akin to fascism. Ferrero even started a paramilitary Blackshirts arm as a copy of the Italian group, although the Union lost heavily in the 1936 elections and faded into obscurity. In Paraguay in 1940, Paraguayan President General Higinio Morínigo began his rule as a dictator with the support of pro-fascist military officers, appealed to the masses, exiled opposition leaders, and only abandoned his pro-fascist policies after the end of World War II. The Brazilian Integralists, led by Plínio Salgado, claimed as many as 200,000 members, although following coup attempts it faced a crackdown from the Estado Novo of Getúlio Vargas in 1937. In the 1930s, the National Socialist Movement of Chile gained seats in Chile’s parliament and attempted a coup d’état that resulted in the Seguro Obrero massacre of 1938. Fascism in its Epoch Fascism in its Epoch is a 1963 book by historian and philosopher Ernst Nolte, widely regarded as his magnum opus and a seminal work on the history of fascism. The book, translated into English in 1965 as The Three Faces of Fascism, argues that fascism arose as a form of resistance to and a reaction against modernity. Nolte subjected German Nazism, Italian Fascism, and the French Action Française movements to a comparative analysis. Nolte’s conclusion was that fascism was the great anti-movement: it was anti-liberal, anti-communist, anti-capitalist, and anti-bourgeois. In Nolte’s view, fascism was the rejection of everything the modern world had to offer and was an essentially negative phenomenon. Nolte argued that fascism functioned at three levels: in the world of politics as a form of opposition to Marxism, at the sociological level in opposition to bourgeois values, and in the “metapolitical” world as “resistance to transcendence” (“transcendence” in German can be translated as the “spirit of modernity”). In regard to the Holocaust, Nolte contended that because Adolf Hitler identified Jews with modernity, the basic thrust of Nazi policies towards Jews had always aimed at genocide: “Auschwitz was contained in the principles of Nazi racist theory like the seed in the fruit.” Nolte believed that for Hitler, Jews represented “the historical process itself.” Attributions Images courtesy of Wikimedia Commons Title Image - Nürnberg, Reichsparteitag, SA- und SS-Appell, September 1934. Attribution: Bundesarchiv, Bild 102-04062A / Georg Pahl / CC-BY-SA 3.0, CC BY-SA 3.0 DE <https://creativecommons.org/licenses/by-sa/3.0/de/deed.en>, via Wikimedia Commons. Provided by: Wikipedia Location: https://commons.wikimedia.org/wiki/File:Bundesarchiv_Bild_102-04062A,_N%C3%BCrnberg,_Reichsparteitag,_SA-_und_SS-Appell.jpg License: CC BY-SA: Attribution-ShareAlike Boundless World History "The Rise of Fascism" Adapted from https://courses.lumenlearning.com/boundless-worldhistory/chapter/the-rise-of-fascism/ CC LICENSED CONTENT, SHARED PREVIOUSLY Curation and Revision. Provided by: Boundless.com. License: CC BY-SA: Attribution-ShareAlike CC LICENSED CONTENT, SPECIFIC ATTRIBUTION Italian Fascism. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Italian_Fascism. License: CC BY-SA: Attribution-ShareAlike Fascism. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism. License: CC BY-SA: Attribution-ShareAlike March_on_Rome.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:March_on_Rome.jpg. License: CC BY-SA: Attribution-ShareAlike Fascism. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism. License: CC BY-SA: Attribution-ShareAlike Fin de siu00e8cle. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fin_de_siecle. License: CC BY-SA: Attribution-ShareAlike March_on_Rome.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:March_on_Rome.jpg. License: CC BY-SA: Attribution-ShareAlike Hitlermusso2_edit.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:Hitlermusso2_edit.jpg. License: CC BY-SA: Attribution-ShareAlike Statism in Shu014dwa Japan. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Statism_in_Showa_Japan. License: CC BY-SA: Attribution-ShareAlike Shu014dwa period. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Showa_period. License: CC BY-SA: Attribution-ShareAlike History of Japan. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/History_of_Japan. License: CC BY-SA: Attribution-ShareAlike March_on_Rome.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:March_on_Rome.jpg. License: CC BY-SA: Attribution-ShareAlike Hitlermusso2_edit.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:Hitlermusso2_edit.jpg. License: CC BY-SA: Attribution-ShareAlike 400px-Emperor_Shu014dwa_Army_1938-1-8.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Showa_period#/media/File:Emperor_Showa_Army_1938-1-8.jpg. License: CC BY-SA: Attribution-ShareAlike Francoist Spain. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Francoist_Spain. License: CC BY-SA: Attribution-ShareAlike Francisco Franco. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Francisco_Franco. License: CC BY-SA: Attribution-ShareAlike Falangism. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Falangism. License: CC BY-SA: Attribution-ShareAlike March_on_Rome.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:March_on_Rome.jpg. License: CC BY-SA: Attribution-ShareAlike Hitlermusso2_edit.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:Hitlermusso2_edit.jpg. License: CC BY-SA: Attribution-ShareAlike 400px-Emperor_Shu014dwa_Army_1938-1-8.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Showa_period#/media/File:Emperor_Showa_Army_1938-1-8.jpg. License: CC BY-SA: Attribution-ShareAlike Francisco_Franco_en_1964.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Francisco_Franco#/media/File:Francisco_Franco_en_1964.jpg. License: CC BY-SA: Attribution-ShareAlike Fascism. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism. License: CC BY-SA: Attribution-ShareAlike Fascism and ideology. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism_and_ideology. License: CC BY-SA: Attribution-ShareAlike Fascism In Its Epoch. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism_In_Its_Epoch. License: CC BY-SA: Attribution-ShareAlike March_on_Rome.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:March_on_Rome.jpg. License: CC BY-SA: Attribution-ShareAlike Hitlermusso2_edit.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:Hitlermusso2_edit.jpg. License: CC BY-SA: Attribution-ShareAlike 400px-Emperor_Shu014dwa_Army_1938-1-8.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Showa_period#/media/File:Emperor_Showa_Army_1938-1-8.jpg. License: CC BY-SA: Attribution-ShareAlike Francisco_Franco_en_1964.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Francisco_Franco#/media/File:Francisco_Franco_en_1964.jpg. License: CC BY-SA: Attribution-ShareAlike Bundesarchiv_Bild_119-1486,_Hitler-Putsch,_Mu00fcnchen,_Marienplatz.jpg. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Fascism#/media/File:Bundesarchiv_Bild_119-1486,_Hitler-Putsch,_Munchen,_Marienplatz.jpg. License: CC BY-SA: Attribution-ShareAlike	oercommons	2025-03-18T00:37:14.860171	Neil Greenwood	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/87991/overview", "title": "Statewide Dual Credit World History, The Catastrophe of the Modern Era: 1919-Present CE, Chapter 13: Post WWI, Rise of Totalitarian Regimes", "author": "Anna McCollum" }
https://oercommons.org/courseware/lesson/87984/overview	The Russian Revolution, the Russian Civil War, and the Formation of the Soviet Union Overview The Russian Revolution: October 1917 On October 25, 1917, Bolshevik leader Vladimir Lenin led his leftist revolutionaries in a successful revolt against the ineffective Provisional Government, an event known as the October Revolution. The Revolution resulted not only in the dissolution of Russia’s Provisional Government but also the execution of Tsar Nicholas II and members of the royal family. The monarchy was then replaced with a communist government that ruled with an intolerant, and often violent, fist for over seventy years. This event remains the seminal turning point in Russian history and for much of Eastern Europe in the twentieth century. Learning Objectives - Explain the key events and people of the Russian Revolution of October 1917 - Examine the long-term consequences and legacies of the Russian Revolution Key Terms / Key Concepts Vladimir Lenin: lead revolutionary and head of the Bolshevik party during the October Russian Revolution in 1917 Leon Trotsky: head of the Petrograd Soviet; an intellectual socialist and eventual righthand man to Lenin soviets: small, locally-elected councils of men with ties to socialist ideas supporting workers, soldiers, and peasantry Bolsheviks: political party of Vladimir Lenin that was considered extreme, and later became the basis of the Russian communist party July Days: four to five days in mid-July 1917 when soldiers, sailors, and workers held armed protests against the Provisional Government “Peace, Land, Bread!”: Lenin’s famous slogan that won the heart and support of the Russian peasantry during his “April Theses” speech in April 1917 October Revolution: successful Russian Revolution that overthrew the democratic Provisional Government and established the Bolsheviks as a military dictatorship Execution of the royal family: plan hatched by Lenin and the Bolsheviks to eliminate any chance of a restoration of the imperial family in Russia Ipatiev House: site where the tsar and his family were executed by the Bolsheviks Background: Vladimir Lenin Vladimir Ilyich Ulyanov, forever remembered by his pseudonym, Lenin, was born some four-hundred miles southeast of Moscow in 1870 in the city of Simbirsk (now Ulyanovsk), Russia. Lenin grew up in a middle-class home and excelled in school. Before reaching adulthood, though, his comfortable lifestyle endured two personal catastrophes that, perhaps, shaped his future career. His father died unexpectedly from a brain bleed when Lenin was a teenager. Not long after, Lenin’s older brother, Alexander, was arrested and later executed for conspiring to assassinate the Tsar. Historians often cite these events as decisive turning points in young Lenin’s life. Ones that inspired the increasing revolutionary attitude that materialized during his time at Kazan University. Exceedingly intelligent, Lenin eventually attended law school. His passion, however, resided in the words of communism’s founder, Karl Marx. Lenin’s revolutionary activity began in earnest around the turn of the century. He moved to Saint Petersburg, married a Marxist schoolteacher, and began writing anti-monarchist, Marxist pieces. Notably, he wrote for the Marxist paper, Iskra (Spark in English). During his time writing for Iskra he adopted the pseudonym, “N. Lenin.” His activities ultimately resulted in several temporary exiles, notably to Zurich, Switzerland. But by the time of his exile, Lenin had recruited a strong group of supporters in Russia. One that would continue throughout his exile, and grow stronger during World War I. The February Revolution In many ways, February Revolution of 1917 was the opening act in the larger Russian Revolution that would occur in October 1917. For over two years, Russian urban populations had suffered from reduced to meager food and fuel rations because of Russian participation in World War I. In February 1917, women in Saint Petersburg led a protest for increased rations and government reform. The protests quickly gained momentum as people from all walks of life joined the revolt. Saint Petersburg’s streets filled with demonstrators. With the tsar at the front, Tsarina Alexandra was left to handle the growing crisis. Instead of confronting or comforting the crowd, Alexandra remained inside her palace with her children. Enormous strikes of hundreds of thousands of workers erupted across the city. From afar, Nicholas attempted to send his guards and policemen to quell the rebellion. Instead, most of his forces sided with the peasants. On March 15, 1917, Nicholas II abdicated. By doing so, the power in Russia fell from the hands of an imperial dynasty to a shaky Provisional Government. Importantly, while the Provisional Government under Alexander Kerensky initially acted as the governing body responsible for foreign affairs, a smaller group was gaining momentum in Russia: the soviets. These groups were small, usually local councils comprised of elected officials. These officials were characterized as anti-monarchal socialists who represented the goals of the people. Notably, Saint Petersburg was home to the Petrograd Soviet. At its head was a man who later became a close ally of Lenin—Leon Trotsky. As the Revolution gained momentum, so too did the power and popularity of the Soviets, as well as the most radical of the socialist movements, which was led by the Bolsheviks and headed by Vladimir Lenin. Vladimir Lenin’s return to Russia from his exile in Zurich, Switzerland is one of legend. News of the February Revolution had reached him, and he deemed it the right moment for a socialist state to take hold in Russia. But the question remained: how could he return to Russia from Switzerland? After several failed efforts, Lenin found an unlikely solution in the form of the German government. Eager to see Russia knocked out of the war and correctly believing that Lenin could help churn up the revolution in Russia, the Germans proposed a deal. They offered him safe passage from Zurich through Germany in a sealed train car that carried other Russian revolutionaries. The train passed into Sweden and Finland. Then Lenin slipped back into Russia in disguise. The German gamble would soon pay off as Lenin and his associates stirred up far more discontent and rebellion than the thousands of mutinying Russian soldiers at the front. On April 16, 1917, Lenin delivered a speech from Finland Station in Saint Petersburg titled the “April Theses.” In this speech, he highlighted the goals for his political party, the Bolsheviks. Among his demands was the claim that all power be handed over to the Soviets. He emerged as a champion of the workers, farmers, sailors, and soldiers by declaring, “Peace, Land, and Bread!" Neither he, nor his party, supported Russian war efforts. Instead, they supported peace, a redistribution of land among the working class, and improved diets for Russia’s suffering population. Unsurprisingly, as support for Lenin’s party grew, the popularity of the Provisional Government quickly diminished. The July Days The summer of 1917 proved far more challenging for Russia than anyone expected. With the tsar’s abdication, three-hundred years of imperial rule had ended overnight. The shaky Provisional Government made attempts to implement democratic rule, but they also chose to remain a committed ally in World War I. This decision likely caused their ultimate downfall. Russians across the country were exhausted and tired of the costs of World War I. Historians have since estimated that nearly two million Russian soldiers were killed in the war, while nearly five million were wounded. Combined these figures suggest that over half of Russia’s army was a casualty in World War I—a far higher figure than any other army in the war. Moreover, the war had exhausted Russia’s natural resources. In July, mobs of sailors, soldiers, and workers banded together to protest the Provisional Government’s decision to remain in the war. These armed demonstrations were known later as the July Days. The goal of demonstrators was to overthrow the Provisional Government—which the working class feared would still put too much government power in the hands of a few, educated elites. But due to disorganization among political factions, the coup failed. Lenin, the head of the Bolshevik Party, was temporarily forced to flee over the border into Finland. The October Revolution By the fall of 1917, Russian food and fuel scarcity ravaged St. Petersburg. Exhaustion and anger permeated every walk of society. For Lenin and the Bolsheviks, it was a perfect recipe for a revolution. Lenin slipped across the border from Finland and met with the man who would become his righthand—Leon Trotsky. As head of the Petrograd Soviet, Trotsky knew more about the city and its people than Lenin did. Together, they organized the foundation of the Russian Revolution. On October 25, 1917, the Bolsheviks organized forces and led an attack on the Provisional Government. Alexander Kerensky tried to organize forces to counter the attack but failed to find enough soldiers. Confronted by superior numbers, Kerensky was forced to flee for his life. The Provisional Government collapsed. Bolshevik forces stormed the tsar’s former residence, the Winter Palace, and seized innumerable priceless treasures, while simultaneously destroying all symbols associated with the imperial rule of the Romanovs. In a climactic moment, Lenin delivered a speech to a crowd that “all rule had passed to the Soviets.” Almost overnight, Russia had transformed from a fledgling democracy to a communist, military dictatorship unseen before (or since) in history. This dictatorship would later be revealed to the world as the Soviet Union. On October 26, the Bolsheviks presented The Decree on Land. It allowed peasants to seize private land from the nobility and redistribute it among themselves. The Bolsheviks viewed themselves as representing an alliance of workers and peasants and memorialized that understanding with the hammer and sickle on the red flag of the Soviet Union. Other decrees resulted in the following: - All private property was seized by the state. - All Russian banks were nationalized. - Private bank accounts were confiscated. - The Church’s properties (including bank accounts) were seized. - All foreign debts were repudiated. - Control of the factories was given to the Soviets. - Wages were fixed at higher rates than during the war, and a shorter, eight-hour working day was introduced. The success of the October Revolution transformed the Russian state into a soviet republic. A coalition of anti-Bolshevik groups attempted to unseat the new government in the Russian Civil War from 1918 to 1922, but they would prove horribly unsuccessful. The Last Days of the Romanovs In March 1917, the last Romanov tsar, Nicholas II, abdicated not only on behalf of himself, but also on behalf of his ailing, hemophiliac son, Alexei. His younger brother, Michael, also quickly refused the throne and was later murdered by Bolshevik supporters in the woods outside of Perm, near the Ural Mountains. Nicholas remained under house arrest with his wife, children, and a handful of servants at their home—Tsarskoe Selo—for six months. In August 1917, Alexander Kerensky decided to move the family to a more secure location, far removed from the capital city. With effort, the Romanovs were transported to a former governor’s palace in Tobolsk, Siberia. For nearly nine months, the family enjoyed relative peace. The tsar and his children enjoyed short walks, reading, music, and even such menial chores as sawing wood. However, conditions for the royal family took a turn for the worse in late 1917 after the Bolsheviks seized power in Saint Petersburg. Throughout all of this, the royal family remained steadfast in their Orthodox faith. Believing that their prayers would be answered and help would soon arrive. Their hopes were destined to be ill-founded. In April 1918, a seasoned Bolshevik guard prepared the family for a final relocation. This time, they would be moved right into the heart of Bolshevik territory. Though they did not know it, plans were made for the execution of the royal family. In April 1918, the family arrived at what would be their final location, the Ipatiev House in Yekaterinburg, Russia. Secretly nicknamed the “House of Special Purpose,” the grandiose home was designated as the future execution site of the royal family. Indeed, the final days of the Romanov family were, as one historian described, a “living Hell.” Bolshevik guards painted over the family’s windows, restricting their view to the outside world. Walks were limited to half-an-hour in a courtyard, once a day. Dinners were served to the royal family after they’d been spat into. And lewd drawings and innuendos were presented to the Romanov daughters. Moreover, the family remained under the constant guard of their Bolshevik captors who restricted their every action. In the early hours of July 17, 1918, Yakov Yurovsky, the chief Bolshevik guard, awoke the family and ordered them to get dressed. To quell their fears, he said the family was being transferred to a new location for their safety. The family was then led into the house cellar. Alexei, unable to walk due to a previous, severe hemophilia bleed, was carried by his father. The seven Romanovs then sat or stood with their servants and waited for instructions. Nearly an hour passed before the Bolshevik guards returned. This time, armed. Yakov Yurovsky said, “Your friends have tried to save you. They have failed you. We now must shoot you.” Reports indicate that the tsar, naïve to the end of his life, had only time to exclaim, “What? What?” before numerous shots were fired upon him. Nicholas and Alexandra died instantly. However, many of the untrained Bolshevik guards, little more than thugs, were uncomfortable executing the tsar’s children. An almost mystical charm initially seemed to protect the daughters. Reports of the events indicate that bullets ricocheted off their dresses, and the executioners resorted to using bayonets and the butt-ends of their rifles to attempt to murder Olga, Tatiana, Marie, and Anastasia. When that failed, Yurovsky and his lieutenant shot the daughters in the back of the head. Later, the executioners discovered the young women had sewn jewels into their dresses in such numbers that they had acted as bullet-proof vests. Yurovsky saw too, that amazingly Alexei had survived the execution. He walked to the “heir of all the Russias,” who still lay in his father’s arms, and savagely kicked the boy before shooting him twice in the back of the head. Similarly, each of the servants were brutally beaten and shot to death. The execution of the royal family had lasted far longer than planned. And the subsequent destruction and burial of the bodies in the Ural Mountains proved disorganized. Almost immediately, rumors circulated that one of the children, likely Anastasia, had survived the massacre and escaped. The rumors escalated in 1988 when the remains of the tsar, his wife, and three of their daughters were excavated and positively identified through DNA analysis. In 2007, though, the rumors were definitively quashed when the remains of Alexei, and his sister (likely Marie) were discovered and positively identified through DNA analysis. In recognition for their devout faith, the Russian Orthodox Church has proclaimed the seven Romanovs, “passion bearers” or members of the faith who remain devout in the hour of their death. This was based on accounts of the family trying to make the sign of the cross as they met their brutal deaths. Impact The Russian Revolution is a pivotal event in modern history. It not only extinguished imperial rule in Russia but also experiments in democracy. The Bolshevik party would reorganize themselves and become the backbone of Soviet communism during the 1920s. Today, the legacies of the Russian Revolution remained mixed. While the rights of workers and the lower classes were touted as the future backbone of Russia, enacting those measures proved difficult. The country erupted into a violent civil war at the end of World War I, as well as engaged in equally brutal wars across parts of Eastern Europe, notably Poland and Ukraine. Moreover, the largest communist and military dictatorship in history would emerge in the shape of the Soviet Union. The Russian Civil War and the Formation of the Soviet Union The Russian Civil War, which erupted 1918 shortly after the October Revolution, was fought mainly between the “Reds,” led by the Bolsheviks, and the “Whites,” a politically diverse coalition of anti-Bolsheviks. An excessively brutal and bloody conflict, it ended in a Bolshevik victory in 1921. By the end of 1922, a pair of treaties had been signed between Russia and territories from present-day Ukraine, Belarus, and Georgia. Thus, the Soviet Union was born. Learning Objectives - Understand the course of the Russian Civil War and its legacies. - Examine the reasons for the formation of the Soviet Union. - Evaluate the pros and cons of the building of the Soviet Union. Key Terms / Key Concepts Red Army: fighting force that supported Lenin, the Russian Revolution, and Bolshevism during the Russian Civil War White Army: fighting force that did not support the Russian Revolution, Lenin, or Bolshevism during the Russian Civil War Russian Civil War: excessively bloody civil war in Russia (1918 – 1921) between the Bolshevik Red Army and the anti-Bolshevik forces, known as the White Army The Red Terror: brutal campaign of elimination and suppression carried out by the Bolsheviks against political enemies during the Russian Civil War The White Terror: brutal campaign of elimination of Bolshevik forces during the Russian Civil War by the White Army, which included mass-murders Soviet Union (USSR): formed in 1922, the union of the communist Russian state with territory from present-day Ukraine, Belarus, and Georgia, that expanded through the subsequent decades Communism: a political, social, and economic movement and philosophy in which there are ideally no economic or social classes or private property and resources are owned equally by the people Cheka: secret police of the Soviet Union that was infamous for its use of violence in the suppression of dissenters and political enemies during the Russian Civil War and after New Economic Plan (NEP): Soviet economic program in which the Russian state would control all significant industry and financial agencies, while individuals could own small plots of land and engage in low-level trade for personal benefit Kulaks: Russian peasant farmers who were considered “wealthy” by the Bolsheviks and targeted as enemies of the communist state war communism: Bolshevik economic practice in the Civil War that allowed the state to seize grain and crop yields to feed the Red Army The Russian Civil War The Russian Civil War (1917 – 1922) was a multi-party war in the former Russian Empire fought immediately after the Russian Revolution of 1917 during which many groups vied to determine Russia’s future. The two largest combatant groups were the Red Army, fighting for the Bolshevik form of socialism, and the loosely allied forces known as the White Army, which included groups with diverse interests. Some favored monarchism, while others favored capitalism or alternative forms of socialism. The White Army had support from Great Britain, France, the U.S., and Japan, while the Red Army possessed internal support, which ultimately proved much more effective. Background In 1917, Russia was a massive, multi-ethnic country that struggled to prosper under tsarist rule; additionally, it suffered enormously in World War I. It is perhaps, no wonder that the country would quickly dissolve into civil war following the chaos of the October Revolution, as agendas and vying viewpoints clashed. Lenin won support of the workers and small-time farmers by declaring, “Peace, Land, Bread!” And in 1918, Russia signed the Treaty of Brest-Litovsk which ceded significant Russian territory over to Germany, including the Baltic states. Many Russians who had supported the Revolution of 1917 turned against the Bolsheviks following the ratification of the Treaty of Brest-Litovsk. This division sparked the Russian Civil War. For Lenin and his associates, “civil war” was an inevitable step in constructing a communist state, just as class-conflict was a critical step of Marxist theory. For Lenin and the Bolsheviks, it was a step that would inflict mass suffering and casualties, but one that was essential in securing their state. In Bolshevik theory, civil war would root-out the “enemies of the people,” such as monarchists, foreigners, and capitalists. When the war ended, only true people of the communist state would remain. Only then could the state operate in harmony. At the heart of their conflict was the war on the kulaks—Russian farmers who were considered “wealthy” because the had larger farms than their neighbors. Many of Lenin’s inner circle believed the kulaks should be eradicated. To the Bolsheviks, these were people who triumphed over their neighbors for personal profit and supported capitalism. In reality, the kulaks typically were not much better off than many of their neighbors. While most Russian farmers worked on a farm for survival and subsistence, the kulaks might own their own farm of ten or twelve acres and have a few more cows or pigs than the average peasant. But that did not stop the Bolsheviks from waging war on them. War on the Battlefield War erupted in Russia between the “Reds” and “Whites” almost immediately following the October Revolution and escalated after the ratification of the Treaty of Brest-Litovsk. Each side had specific advantages. For the White Army, their strongest advantage was the (limited) support from abroad. Western nations such as England and the United States were democratic and anxious that the Bolshevik’s communist revolution could spread across Europe if it proved successful in Russia. Possibly, it could even spread to the United States were socialism had a small but strong following, thus upending democratic and capitalist values. American, English, and Japanese troops fought on the side of the White Army along Russia’s periphery borders, most notably in far eastern Russia near Vladivostok. But while well-intentioned, the Allies were exhausted from fighting the Germans in World War I. As a result, their military efforts were minimal and had the ultimate effect of leaving the White Army to fight on its own. The Red Army, by contrast, had limited outside support. However, under the careful Organization of Leon Trotsky, the Red Army was exceedingly disciplined and organized. Moreover, it largely was supported by the Russian peasantry. Volunteers and conscripted soldiers swelled the size of the Red Army to over five million at the end of the war. For over three years, the two sides clashed across the Russian landscape, notably in present-day Ukraine and Belarus, the Baltic states, Georgia, and far-eastern Russia. Mass casualties resulted among soldiers and civilians alike as the rules of warfare dissolved and terror raged on both sides. The Red Terror Civil war engulfed Russia immediately following the October Revolution. The two dominant sides of the war were the Red and White Armies. But Lenin had to worry about more than winning a war against a rival army on the battlefield. He also worried about political dissenters among the civilians. Internal, political enemies constituted a significant threat for him. To combat this threat, Lenin created secret police—the Cheka. In August 1918, Lenin narrowly escaped an assassination attempt. This close call gave him the pretext he needed to increase the power of the Cheka. In fact, the agency operated with almost unlimited power. Lenin advocated openly for the agency to use terror and violence to destroy enemies of Bolshevism indiscriminately. His telegram to fellow Bolshevik leaders instructed, “Hang no fewer than one-hundred well-known kulaks, rich-bags, blood-suckers (and make sure the hanging takes place in full view of the people).” By the end of 1918 alone, the Cheka officially reported the execution of nearly 13,000 people. Historians suspect the number to be significantly higher, possibly in the hundreds of thousands. Headed by Lenin’s close associate, Felix Dzerzhinsky, the Cheka acted with brutal force. Not restricted to simply identifying anti-Bolsheviks, the organization waged war against all “enemies of the people.” This included enemies on and off the battlefield. They carried out mass executions, arrests, and imprisonments. Anyone who could potentially be classified as anti-Bolshevik (or anti-communism) was targeted, including intellectuals, church clergy, the middle class, and monarchists. The agency increased its activity and persecution of the opposition as the Russian Civil War continued. The White Terror While the “Red Terror” is remembered because of the Bolshevik victory in the Civil War, there was also a “White Terror” on the battlefield. The “White Terror” were wartime atrocities perpetrated by soldiers in the White Army against the Red Army, civilians, socialists, and revolutionaries; particularly in Eastern Russia. Estimates vary widely on the casualties inflicted on Red Army soldiers and civilians during the White Terror. Some figures suggest twenty-thousand perished, while other numbers suggest the casualties were in the hundreds of thousands. Most of these deaths resulted from mass executions and indiscriminate killings. Notably, the White Army targeted Jews as part of the White Terror. Seen as the natural allies of the Bolsheviks because of communist ideology, the White Army carried out mass executions and killings of Jews in the regions of present-day Ukraine and Georgia. The Effects of "War Communism" In 1917, Lenin and the Bolsheviks introduced a method for sustaining their war effort known as “war communism.” This allowed the Bolsheviks to seize grain and farm yields to feed the Red Army. But it had the unintended, negative effect of forcing urban workers to the countryside to help farm and feed the growing army. As a result, production of industrial goods decreased dramatically. And while the Red Army remained fed, Russian and Ukrainian civilians and farmers starved. In 1921, a massive famine broke out and killed an estimated five million people, mostly civilians. It would not be the last famine wrought by Soviet economic planning. Resistance emerged among the working class, but with his powerful Cheka at his beckoning call, Lenin brutally suppressed all dissent. By the end of the Civil War, between 7 and 12 million people had perished due to the fighting and famine. And the casualties were mostly civilians. Conclusion of the Civil War The Red Army defeated the White Armed Forces of South Russia in Ukraine in 1919. The remains of the White forces were beaten at the island of Crimea in the Black Sea and evacuated in late 1920. Lesser battles of the war continued for two more years. Minor skirmishes with the remnants of the White forces in the Far East continued into 1923. Formation of the Soviet Union The government of the Soviet Union was formed in 1922 with the unification of the Russian, Transcaucasian, Ukrainian, and Byelorussian republics. It was based on the one-party rule of the Communist Party (Bolsheviks), who increasingly developed a totalitarian regime, especially during the reign of Joseph Stalin (1924 – 1953). Creation of the USSR and Early Years On December 29, 1922, a conference of delegations from Russia, Transcaucasia, Ukraine, and Byelorussia (Belarus) approved the Treaty on the Creation of the USSR and the Declaration of the Creation of the USSR, forming the Union of Soviet Socialist Republics (USSR). On February 1, 1924, the USSR was recognized by the British Empire. The same year, a Soviet Constitution was approved, legitimizing the union. An intensive restructuring of the economy, industry, and politics of the country began in the early days of Soviet power in 1917. A large part of this was done according to the Bolshevik Initial Decrees—government documents signed by Vladimir Lenin. One of the most prominent breakthroughs was a plan that envisioned a major restructuring of the Soviet economy based on total electrification of the country. The plan was developed in 1920 and covered a 10- to 15-year period. It included the construction of a network of 30 regional power stations, including ten large hydroelectric power plants and numerous electric-powered large industrial enterprises. The plan became the prototype for subsequent Five-Year Plans and was fulfilled by 1931. In 1921, the Bolsheviks had abandoned their war communism economic plan. In its place emerged the New Economic Policy (NEP). The peasants were freed from wholesale levies of grain and allowed to sell their surplus produce in the open market. Commerce was stimulated by permitting private retail trading. However, the state continued to be responsible for all major business ventures, including banking, transportation, heavy industry, and public utilities. Although the left opposition among the Communists criticized the rich peasants, or kulaks, who benefited from the NEP, the program proved highly beneficial, reviving the economy. The NEP would later come under increasing opposition from within the party following Lenin’s death in early 1924. Significance From 1917 – 1922, Russia was in complete turmoil. The tsarist regime was forever destroyed, exercises in democracy eliminated, and strongman Vladimir Lenin became the face of the Bolshevik effort to establish a communist nation. The Russian Civil War erupted and produced excessive and extreme violence wherever the Red and White Armies waged war; and civilians bore the brunt of the violence on both sides of the conflict. The war marked an ominous start for a new government that claimed to be representing the interests of the peasants. For Lenin and his inner circle though, excessive violence was a necessary step to secure a true, communist nation. While Lenin is responsible for many of the agencies and policies that perpetrated such violence, the Soviet Union would experience a far more ruthless military dictator under Lenin’s successor—Joseph Stalin. Attributions All images from Wikimedia Commons Cole, Joshua and Carol Symes. Western Civilizations: Their History and Their Culture. 3rd Ed. W.W. Norton & Company, New York: 2020. 862-4; 879-881. Service, Robert. A History of Modern Russia: From Nicholas II to Vladimir Putin. Harvard University Press, Cambridge: 2003. 101-122. Boundless World History, “The Russian Revolution” https://courses.lumenlearning.com/boundless-worldhistory/chapter/the-russian-revolution/ https://creativecommons.org/licenses/by-sa/4.0/	oercommons	2025-03-18T00:37:14.926431	Neil Greenwood	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/87984/overview", "title": "Statewide Dual Credit World History, The Catastrophe of the Modern Era: 1919-Present CE, Chapter 13: Post WWI, The Russian Revolution, the Russian Civil War, and the Formation of the Soviet Union", "author": "Anna McCollum" }
https://oercommons.org/courseware/lesson/109847/overview	OpenStax Anatomy and Physiology textbook, 2nd edition Overview I have been teaching Human Anatomy and Physiology at Central Arziona College (CAC) for 25 years. About 3 years ago, the Dean of Academics expressed concern over the cost of the text and lab book for our 2 semester A&P classes. I volunteered to lead an appointed committee to look into OER for anantomy and physiology. The Openstax textbook quickly became the choice of the committee members. After teaching a pilot class with the Openstax textbook, all CAC 2 semester A&P classes switched over to it. We have been using it for all our A& P classes, both on campus and online, for about 1.5 years. Student feedback has been very positive. I have been teaching Human Anatomy and Physiology at Central Arziona College (CAC) for 25 years. About 3 years ago, the Dean of Academics expressed concern over the cost of the text and lab book for our 2 semester A&P classes. I volunteered to lead an appointed committee to look into OER for anantomy and physiology. The Openstax textbook quickly became the choice of the committee members. After teaching a pilot class with the Openstax textbook, all CAC 2 semester A&P classes switched over to it. We have been using it for all our A& P classes, both on campus and online, for about 1.5 years. Student feedback has been very positive.	oercommons	2025-03-18T00:37:14.941480	Textbook	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/109847/overview", "title": "OpenStax Anatomy and Physiology textbook, 2nd edition", "author": "Homework/Assignment" }
https://oercommons.org/courseware/lesson/56352/overview	The Chemical Level of Organization Introduction Figure 2.1 Human DNA Human DNA is described as a double helix that resembles a molecular spiral staircase. In humans the DNA is organized into 46 chromosomes. CHAPTER OBJECTIVES After studying this chapter, you will be able to: - Describe the fundamental composition of matter - Identify the three subatomic particles - Identify the four most abundant elements in the body - Explain the relationship between an atom’s number of electrons and its relative stability - Distinguish between ionic bonds, covalent bonds, and hydrogen bonds - Explain how energy is invested, stored, and released via chemical reactions, particularly those reactions that are critical to life - Explain the importance of the inorganic compounds that contribute to life, such as water, salts, acids, and bases - Compare and contrast the four important classes of organic (carbon-based) compounds—proteins, carbohydrates, lipids and nucleic acids—according to their composition and functional importance to human life The smallest, most fundamental material components of the human body are basic chemical elements. In fact, chemicals called nucleotide bases are the foundation of the genetic code with the instructions on how to build and maintain the human body from conception through old age. There are about three billion of these base pairs in human DNA. Human chemistry includes organic molecules (carbon-based) and biochemicals (those produced by the body). Human chemistry also includes elements. In fact, life cannot exist without many of the elements that are part of the earth. All of the elements that contribute to chemical reactions, to the transformation of energy, and to electrical activity and muscle contraction—elements that include phosphorus, carbon, sodium, and calcium, to name a few—originated in stars. These elements, in turn, can form both the inorganic and organic chemical compounds important to life, including, for example, water, glucose, and proteins. This chapter begins by examining elements and how the structures of atoms, the basic units of matter, determine the characteristics of elements by the number of protons, neutrons, and electrons in the atoms. The chapter then builds the framework of life from there. Elements and Atoms: The Building Blocks of Matter - Discuss the relationships between matter, mass, elements, compounds, atoms, and subatomic particles - Distinguish between atomic number and mass number - Identify the key distinction between isotopes of the same element - Explain how electrons occupy electron shells and their contribution to an atom’s relative stability The substance of the universe—from a grain of sand to a star—is called matter. Scientists define matter as anything that occupies space and has mass. An object’s mass and its weight are related concepts, but not quite the same. An object’s mass is the amount of matter contained in the object, and the object’s mass is the same whether that object is on Earth or in the zero-gravity environment of outer space. An object’s weight, on the other hand, is its mass as affected by the pull of gravity. Where gravity strongly pulls on an object’s mass its weight is greater than it is where gravity is less strong. An object of a certain mass weighs less on the moon, for example, than it does on Earth because the gravity of the moon is less than that of Earth. In other words, weight is variable, and is influenced by gravity. A piece of cheese that weighs a pound on Earth weighs only a few ounces on the moon. Elements and Compounds All matter in the natural world is composed of one or more of the 92 fundamental substances called elements. An element is a pure substance that is distinguished from all other matter by the fact that it cannot be created or broken down by ordinary chemical means. While your body can assemble many of the chemical compounds needed for life from their constituent elements, it cannot make elements. They must come from the environment. A familiar example of an element that you must take in is calcium (Ca++). Calcium is essential to the human body; it is absorbed and used for a number of processes, including strengthening bones. When you consume dairy products your digestive system breaks down the food into components small enough to cross into the bloodstream. Among these is calcium, which, because it is an element, cannot be broken down further. The elemental calcium in cheese, therefore, is the same as the calcium that forms your bones. Some other elements you might be familiar with are oxygen, sodium, and iron. The elements in the human body are shown in Figure 2.2, beginning with the most abundant: oxygen (O), carbon (C), hydrogen (H), and nitrogen (N). Each element’s name can be replaced by a one- or two-letter symbol; you will become familiar with some of these during this course. All the elements in your body are derived from the foods you eat and the air you breathe. Figure 2.2 Elements of the Human Body The main elements that compose the human body are shown from most abundant to least abundant. In nature, elements rarely occur alone. Instead, they combine to form compounds. A compound is a substance composed of two or more elements joined by chemical bonds. For example, the compound glucose is an important body fuel. It is always composed of the same three elements: carbon, hydrogen, and oxygen. Moreover, the elements that make up any given compound always occur in the same relative amounts. In glucose, there are always six carbon and six oxygen units for every twelve hydrogen units. But what, exactly, are these “units” of elements? Atoms and Subatomic Particles An atom is the smallest quantity of an element that retains the unique properties of that element. In other words, an atom of hydrogen is a unit of hydrogen—the smallest amount of hydrogen that can exist. As you might guess, atoms are almost unfathomably small. The period at the end of this sentence is millions of atoms wide. Atomic Structure and Energy Atoms are made up of even smaller subatomic particles, three types of which are important: the proton, neutron, and electron. The number of positively-charged protons and non-charged (“neutral”) neutrons, gives mass to the atom, and the number of each in the nucleus of the atom determine the element. The number of negatively-charged electrons that “spin” around the nucleus at close to the speed of light equals the number of protons. An electron has about 1/2000th the mass of a proton or neutron. Figure 2.3 shows two models that can help you imagine the structure of an atom—in this case, helium (He). In the planetary model, helium’s two electrons are shown circling the nucleus in a fixed orbit depicted as a ring. Although this model is helpful in visualizing atomic structure, in reality, electrons do not travel in fixed orbits, but whiz around the nucleus erratically in a so-called electron cloud. Figure 2.3 Two Models of Atomic Structure (a) In the planetary model, the electrons of helium are shown in fixed orbits, depicted as rings, at a precise distance from the nucleus, somewhat like planets orbiting the sun. (b) In the electron cloud model, the electrons of carbon are shown in the variety of locations they would have at different distances from the nucleus over time. An atom’s protons and electrons carry electrical charges. Protons, with their positive charge, are designated p+. Electrons, which have a negative charge, are designated e–. An atom’s neutrons have no charge: they are electrically neutral. Just as a magnet sticks to a steel refrigerator because their opposite charges attract, the positively charged protons attract the negatively charged electrons. This mutual attraction gives the atom some structural stability. The attraction by the positively charged nucleus helps keep electrons from straying far. The number of protons and electrons within a neutral atom are equal, thus, the atom’s overall charge is balanced. Atomic Number and Mass Number An atom of carbon is unique to carbon, but a proton of carbon is not. One proton is the same as another, whether it is found in an atom of carbon, sodium (Na), or iron (Fe). The same is true for neutrons and electrons. So, what gives an element its distinctive properties—what makes carbon so different from sodium or iron? The answer is the unique quantity of protons each contains. Carbon by definition is an element whose atoms contain six protons. No other element has exactly six protons in its atoms. Moreover, all atoms of carbon, whether found in your liver or in a lump of coal, contain six protons. Thus, the atomic number, which is the number of protons in the nucleus of the atom, identifies the element. Because an atom usually has the same number of electrons as protons, the atomic number identifies the usual number of electrons as well. In their most common form, many elements also contain the same number of neutrons as protons. The most common form of carbon, for example, has six neutrons as well as six protons, for a total of 12 subatomic particles in its nucleus. An element’s mass number is the sum of the number of protons and neutrons in its nucleus. So the most common form of carbon’s mass number is 12. (Electrons have so little mass that they do not appreciably contribute to the mass of an atom.) Carbon is a relatively light element. Uranium (U), in contrast, has a mass number of 238 and is referred to as a heavy metal. Its atomic number is 92 (it has 92 protons) but it contains 146 neutrons; it has the most mass of all the naturally occurring elements. The periodic table of the elements, shown in Figure 2.4, is a chart identifying the 92 elements found in nature, as well as several larger, unstable elements discovered experimentally. The elements are arranged in order of their atomic number, with hydrogen and helium at the top of the table, and the more massive elements below. The periodic table is a useful device because for each element, it identifies the chemical symbol, the atomic number, and the mass number, while organizing elements according to their propensity to react with other elements. The number of protons and electrons in an element are equal. The number of protons and neutrons may be equal for some elements, but are not equal for all. Figure 2.4 The Periodic Table of the Elements (credit: R.A. Dragoset, A. Musgrove, C.W. Clark, W.C. Martin) INTERACTIVE LINK Visit this website to view the periodic table. In the periodic table of the elements, elements in a single column have the same number of electrons that can participate in a chemical reaction. These electrons are known as “valence electrons.” For example, the elements in the first column all have a single valence electron, an electron that can be “donated” in a chemical reaction with another atom. What is the meaning of a mass number shown in parentheses? Isotopes Although each element has a unique number of protons, it can exist as different isotopes. An isotope is one of the different forms of an element, distinguished from one another by different numbers of neutrons. The standard isotope of carbon is 12C, commonly called carbon twelve. 12C has six protons and six neutrons, for a mass number of twelve. All of the isotopes of carbon have the same number of protons; therefore, 13C has seven neutrons, and 14C has eight neutrons. The different isotopes of an element can also be indicated with the mass number hyphenated (for example, C-12 instead of 12C). Hydrogen has three common isotopes, shown in Figure 2.5. Figure 2.5 Isotopes of Hydrogen Protium, designated 1H, has one proton and no neutrons. It is by far the most abundant isotope of hydrogen in nature. Deuterium, designated 2H, has one proton and one neutron. Tritium, designated 3H, has two neutrons. An isotope that contains more than the usual number of neutrons is referred to as a heavy isotope. An example is 14C. Heavy isotopes tend to be unstable, and unstable isotopes are radioactive. A radioactive isotope is an isotope whose nucleus readily decays, giving off subatomic particles and electromagnetic energy. Different radioactive isotopes (also called radioisotopes) differ in their half-life, the time it takes for half of any size sample of an isotope to decay. For example, the half-life of tritium—a radioisotope of hydrogen—is about 12 years, indicating it takes 12 years for half of the tritium nuclei in a sample to decay. Excessive exposure to radioactive isotopes can damage human cells and even cause cancer and birth defects, but when exposure is controlled, some radioactive isotopes can be useful in medicine. For more information, see the Career Connections. CAREER CONNECTION Interventional Radiologist The controlled use of radioisotopes has advanced medical diagnosis and treatment of disease. Interventional radiologists are physicians who treat disease by using minimally invasive techniques involving radiation. Many conditions that could once only be treated with a lengthy and traumatic operation can now be treated non-surgically, reducing the cost, pain, length of hospital stay, and recovery time for patients. For example, in the past, the only options for a patient with one or more tumors in the liver were surgery and chemotherapy (the administration of drugs to treat cancer). Some liver tumors, however, are difficult to access surgically, and others could require the surgeon to remove too much of the liver. Moreover, chemotherapy is highly toxic to the liver, and certain tumors do not respond well to it anyway. In some such cases, an interventional radiologist can treat the tumors by disrupting their blood supply, which they need if they are to continue to grow. In this procedure, called radioembolization, the radiologist accesses the liver with a fine needle, threaded through one of the patient’s blood vessels. The radiologist then inserts tiny radioactive “seeds” into the blood vessels that supply the tumors. In the days and weeks following the procedure, the radiation emitted from the seeds destroys the vessels and directly kills the tumor cells in the vicinity of the treatment. Radioisotopes emit subatomic particles that can be detected and tracked by imaging technologies. One of the most advanced uses of radioisotopes in medicine is the positron emission tomography (PET) scanner, which detects the activity in the body of a very small injection of radioactive glucose, the simple sugar that cells use for energy. The PET camera reveals to the medical team which of the patient’s tissues are taking up the most glucose. Thus, the most metabolically active tissues show up as bright “hot spots” on the images (Figure 2.6). PET can reveal some cancerous masses because cancer cells consume glucose at a high rate to fuel their rapid reproduction. Figure 2.6 PET Scan PET highlights areas in the body where there is relatively high glucose use, which is characteristic of cancerous tissue. This PET scan shows sites of the spread of a large primary tumor to other sites. The Behavior of Electrons In the human body, atoms do not exist as independent entities. Rather, they are constantly reacting with other atoms to form and to break down more complex substances. To fully understand anatomy and physiology you must grasp how atoms participate in such reactions. The key is understanding the behavior of electrons. Although electrons do not follow rigid orbits a set distance away from the atom’s nucleus, they do tend to stay within certain regions of space called electron shells. An electron shell is a layer of electrons that encircle the nucleus at a distinct energy level. The atoms of the elements found in the human body have from one to five electron shells, and all electron shells hold eight electrons except the first shell, which can only hold two. This configuration of electron shells is the same for all atoms. The precise number of shells depends on the number of electrons in the atom. Hydrogen and helium have just one and two electrons, respectively. If you take a look at the periodic table of the elements, you will notice that hydrogen and helium are placed alone on either sides of the top row; they are the only elements that have just one electron shell (Figure 2.7). A second shell is necessary to hold the electrons in all elements larger than hydrogen and helium. Lithium (Li), whose atomic number is 3, has three electrons. Two of these fill the first electron shell, and the third spills over into a second shell. The second electron shell can accommodate as many as eight electrons. Carbon, with its six electrons, entirely fills its first shell, and half-fills its second. With ten electrons, neon (Ne) entirely fills its two electron shells. Again, a look at the periodic table reveals that all of the elements in the second row, from lithium to neon, have just two electron shells. Atoms with more than ten electrons require more than two shells. These elements occupy the third and subsequent rows of the periodic table. Figure 2.7 Electron Shells Electrons orbit the atomic nucleus at distinct levels of energy called electron shells. (a) With one electron, hydrogen only half-fills its electron shell. Helium also has a single shell, but its two electrons completely fill it. (b) The electrons of carbon completely fill its first electron shell, but only half-fills its second. (c) Neon, an element that does not occur in the body, has 10 electrons, filling both of its electron shells. The factor that most strongly governs the tendency of an atom to participate in chemical reactions is the number of electrons in its valence shell. A valence shell is an atom’s outermost electron shell. If the valence shell is full, the atom is stable; meaning its electrons are unlikely to be pulled away from the nucleus by the electrical charge of other atoms. If the valence shell is not full, the atom is reactive; meaning it will tend to react with other atoms in ways that make the valence shell full. Consider hydrogen, with its one electron only half-filling its valence shell. This single electron is likely to be drawn into relationships with the atoms of other elements, so that hydrogen’s single valence shell can be stabilized. All atoms (except hydrogen and helium with their single electron shells) are most stable when there are exactly eight electrons in their valence shell. This principle is referred to as the octet rule, and it states that an atom will give up, gain, or share electrons with another atom so that it ends up with eight electrons in its own valence shell. For example, oxygen, with six electrons in its valence shell, is likely to react with other atoms in a way that results in the addition of two electrons to oxygen’s valence shell, bringing the number to eight. When two hydrogen atoms each share their single electron with oxygen, covalent bonds are formed, resulting in a molecule of water, H2O. In nature, atoms of one element tend to join with atoms of other elements in characteristic ways. For example, carbon commonly fills its valence shell by linking up with four atoms of hydrogen. In so doing, the two elements form the simplest of organic molecules, methane, which also is one of the most abundant and stable carbon-containing compounds on Earth. As stated above, another example is water; oxygen needs two electrons to fill its valence shell. It commonly interacts with two atoms of hydrogen, forming H2O. Incidentally, the name “hydrogen” reflects its contribution to water (hydro- = “water”; -gen = “maker”). Thus, hydrogen is the “water maker.” Chemical Bonds - Explain the relationship between molecules and compounds - Distinguish between ions, cations, and anions - Identify the key difference between ionic and covalent bonds - Distinguish between nonpolar and polar covalent bonds - Explain how water molecules link via hydrogen bonds Atoms separated by a great distance cannot link; rather, they must come close enough for the electrons in their valence shells to interact. But do atoms ever actually touch one another? Most physicists would say no, because the negatively charged electrons in their valence shells repel one another. No force within the human body—or anywhere in the natural world—is strong enough to overcome this electrical repulsion. So when you read about atoms linking together or colliding, bear in mind that the atoms are not merging in a physical sense. Instead, atoms link by forming a chemical bond. A bond is a weak or strong electrical attraction that holds atoms in the same vicinity. The new grouping is typically more stable—less likely to react again—than its component atoms were when they were separate. A more or less stable grouping of two or more atoms held together by chemical bonds is called a molecule. The bonded atoms may be of the same element, as in the case of H2, which is called molecular hydrogen or hydrogen gas. When a molecule is made up of two or more atoms of different elements, it is called a chemical compound. Thus, a unit of water, or H2O, is a compound, as is a single molecule of the gas methane, or CH4. Three types of chemical bonds are important in human physiology, because they hold together substances that are used by the body for critical aspects of homeostasis, signaling, and energy production, to name just a few important processes. These are ionic bonds, covalent bonds, and hydrogen bonds. Ions and Ionic Bonds Recall that an atom typically has the same number of positively charged protons and negatively charged electrons. As long as this situation remains, the atom is electrically neutral. But when an atom participates in a chemical reaction that results in the donation or acceptance of one or more electrons, the atom will then become positively or negatively charged. This happens frequently for most atoms in order to have a full valence shell, as described previously. This can happen either by gaining electrons to fill a shell that is more than half-full, or by giving away electrons to empty a shell that is less than half-full, thereby leaving the next smaller electron shell as the new, full, valence shell. An atom that has an electrical charge—whether positive or negative—is an ion. INTERACTIVE LINK Visit this website to learn about electrical energy and the attraction/repulsion of charges. What happens to the charged electroscope when a conductor is moved between its plastic sheets, and why? Potassium (K), for instance, is an important element in all body cells. Its atomic number is 19. It has just one electron in its valence shell. This characteristic makes potassium highly likely to participate in chemical reactions in which it donates one electron. (It is easier for potassium to donate one electron than to gain seven electrons.) The loss will cause the positive charge of potassium’s protons to be more influential than the negative charge of potassium’s electrons. In other words, the resulting potassium ion will be slightly positive. A potassium ion is written K+, indicating that it has lost a single electron. A positively charged ion is known as a cation. Now consider fluorine (F), a component of bones and teeth. Its atomic number is nine, and it has seven electrons in its valence shell. Thus, it is highly likely to bond with other atoms in such a way that fluorine accepts one electron (it is easier for fluorine to gain one electron than to donate seven electrons). When it does, its electrons will outnumber its protons by one, and it will have an overall negative charge. The ionized form of fluorine is called fluoride, and is written as F–. A negatively charged ion is known as an anion. Atoms that have more than one electron to donate or accept will end up with stronger positive or negative charges. A cation that has donated two electrons has a net charge of +2. Using magnesium (Mg) as an example, this can be written Mg++ or Mg2+. An anion that has accepted two electrons has a net charge of –2. The ionic form of selenium (Se), for example, is typically written Se2–. The opposite charges of cations and anions exert a moderately strong mutual attraction that keeps the atoms in close proximity forming an ionic bond. An ionic bond is an ongoing, close association between ions of opposite charge. The table salt you sprinkle on your food owes its existence to ionic bonding. As shown in Figure 2.8, sodium commonly donates an electron to chlorine, becoming the cation Na+. When chlorine accepts the electron, it becomes the chloride anion, Cl–. With their opposing charges, these two ions strongly attract each other. Figure 2.8 Ionic Bonding (a) Sodium readily donates the solitary electron in its valence shell to chlorine, which needs only one electron to have a full valence shell. (b) The opposite electrical charges of the resulting sodium cation and chloride anion result in the formation of a bond of attraction called an ionic bond. (c) The attraction of many sodium and chloride ions results in the formation of large groupings called crystals. Water is an essential component of life because it is able to break the ionic bonds in salts to free the ions. In fact, in biological fluids, most individual atoms exist as ions. These dissolved ions produce electrical charges within the body. The behavior of these ions produces the tracings of heart and brain function observed as waves on an electrocardiogram (EKG or ECG) or an electroencephalogram (EEG). The electrical activity that derives from the interactions of the charged ions is why they are also called electrolytes. Covalent Bonds Unlike ionic bonds formed by the attraction between a cation’s positive charge and an anion’s negative charge, molecules formed by a covalent bond share electrons in a mutually stabilizing relationship. Like next-door neighbors whose kids hang out first at one home and then at the other, the atoms do not lose or gain electrons permanently. Instead, the electrons move back and forth between the elements. Because of the close sharing of pairs of electrons (one electron from each of two atoms), covalent bonds are stronger than ionic bonds. Nonpolar Covalent Bonds Figure 2.9 shows several common types of covalent bonds. Notice that the two covalently bonded atoms typically share just one or two electron pairs, though larger sharings are possible. The important concept to take from this is that in covalent bonds, electrons in the outermost valence shell are shared to fill the valence shells of both atoms, ultimately stabilizing both of the atoms involved. In a single covalent bond, a single electron is shared between two atoms, while in a double covalent bond, two pairs of electrons are shared between two atoms. There even are triple covalent bonds, where three atoms are shared. Figure 2.9 Covalent Bonding You can see that the covalent bonds shown in Figure 2.9 are balanced. The sharing of the negative electrons is relatively equal, as is the electrical pull of the positive protons in the nucleus of the atoms involved. This is why covalently bonded molecules that are electrically balanced in this way are described as nonpolar; that is, no region of the molecule is either more positive or more negative than any other. Polar Covalent Bonds Groups of legislators with completely opposite views on a particular issue are often described as “polarized” by news writers. In chemistry, a polar molecule is a molecule that contains regions that have opposite electrical charges. Polar molecules occur when atoms share electrons unequally, in polar covalent bonds. The most familiar example of a polar molecule is water (Figure 2.10). The molecule has three parts: one atom of oxygen, the nucleus of which contains eight protons, and two hydrogen atoms, whose nuclei each contain only one proton. Because every proton exerts an identical positive charge, a nucleus that contains eight protons exerts a charge eight times greater than a nucleus that contains one proton. This means that the negatively charged electrons present in the water molecule are more strongly attracted to the oxygen nucleus than to the hydrogen nuclei. Each hydrogen atom’s single negative electron therefore migrates toward the oxygen atom, making the oxygen end of their bond slightly more negative than the hydrogen end of their bond. Figure 2.10 Polar Covalent Bonds in a Water Molecule What is true for the bonds is true for the water molecule as a whole; that is, the oxygen region has a slightly negative charge and the regions of the hydrogen atoms have a slightly positive charge. These charges are often referred to as “partial charges” because the strength of the charge is less than one full electron, as would occur in an ionic bond. As shown in Figure 2.10, regions of weak polarity are indicated with the Greek letter delta (δ) and a plus (+) or minus (–) sign. Even though a single water molecule is unimaginably tiny, it has mass, and the opposing electrical charges on the molecule pull that mass in such a way that it creates a shape somewhat like a triangular tent (see Figure 2.10b). This dipole, with the positive charges at one end formed by the hydrogen atoms at the “bottom” of the tent and the negative charge at the opposite end (the oxygen atom at the “top” of the tent) makes the charged regions highly likely to interact with charged regions of other polar molecules. For human physiology, the resulting bond is one of the most important formed by water—the hydrogen bond. Hydrogen Bonds A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another molecule. In other words, hydrogen bonds always include hydrogen that is already part of a polar molecule. The most common example of hydrogen bonding in the natural world occurs between molecules of water. It happens before your eyes whenever two raindrops merge into a larger bead, or a creek spills into a river. Hydrogen bonding occurs because the weakly negative oxygen atom in one water molecule is attracted to the weakly positive hydrogen atoms of two other water molecules (Figure 2.11). Figure 2.11 Hydrogen Bonds between Water Molecules Notice that the bonds occur between the weakly positive charge on the hydrogen atoms and the weakly negative charge on the oxygen atoms. Hydrogen bonds are relatively weak, and therefore are indicated with a dotted (rather than a solid) line. Water molecules also strongly attract other types of charged molecules as well as ions. This explains why “table salt,” for example, actually is a molecule called a “salt” in chemistry, which consists of equal numbers of positively-charged sodium (Na+) and negatively-charged chloride (Cl–), dissolves so readily in water, in this case forming dipole-ion bonds between the water and the electrically-charged ions (electrolytes). Water molecules also repel molecules with nonpolar covalent bonds, like fats, lipids, and oils. You can demonstrate this with a simple kitchen experiment: pour a teaspoon of vegetable oil, a compound formed by nonpolar covalent bonds, into a glass of water. Instead of instantly dissolving in the water, the oil forms a distinct bead because the polar water molecules repel the nonpolar oil. Chemical Reactions - Distinguish between kinetic and potential energy, and between exergonic and endergonic chemical reactions - Identify four forms of energy important in human functioning - Describe the three basic types of chemical reactions - Identify several factors influencing the rate of chemical reactions One characteristic of a living organism is metabolism, which is the sum total of all of the chemical reactions that go on to maintain that organism’s health and life. The bonding processes you have learned thus far are anabolic chemical reactions; that is, they form larger molecules from smaller molecules or atoms. But recall that metabolism can proceed in another direction: in catabolic chemical reactions, bonds between components of larger molecules break, releasing smaller molecules or atoms. Both types of reaction involve exchanges not only of matter, but of energy. The Role of Energy in Chemical Reactions Chemical reactions require a sufficient amount of energy to cause the matter to collide with enough precision and force that old chemical bonds can be broken and new ones formed. In general, kinetic energy is the form of energy powering any type of matter in motion. Imagine you are building a brick wall. The energy it takes to lift and place one brick atop another is kinetic energy—the energy matter possesses because of its motion. Once the wall is in place, it stores potential energy. Potential energy is the energy of position, or the energy matter possesses because of the positioning or structure of its components. If the brick wall collapses, the stored potential energy is released as kinetic energy as the bricks fall. In the human body, potential energy is stored in the bonds between atoms and molecules. Chemical energy is the form of potential energy in which energy is stored in chemical bonds. When those bonds are formed, chemical energy is invested, and when they break, chemical energy is released. Notice that chemical energy, like all energy, is neither created nor destroyed; rather, it is converted from one form to another. When you eat an energy bar before heading out the door for a hike, the honey, nuts, and other foods the bar contains are broken down and rearranged by your body into molecules that your muscle cells convert to kinetic energy. Chemical reactions that release more energy than they absorb are characterized as exergonic. The catabolism of the foods in your energy bar is an example. Some of the chemical energy stored in the bar is absorbed into molecules your body uses for fuel, but some of it is released—for example, as heat. In contrast, chemical reactions that absorb more energy than they release are endergonic. These reactions require energy input, and the resulting molecule stores not only the chemical energy in the original components, but also the energy that fueled the reaction. Because energy is neither created nor destroyed, where does the energy needed for endergonic reactions come from? In many cases, it comes from exergonic reactions. Forms of Energy Important in Human Functioning You have already learned that chemical energy is absorbed, stored, and released by chemical bonds. In addition to chemical energy, mechanical, radiant, and electrical energy are important in human functioning. - Mechanical energy, which is stored in physical systems such as machines, engines, or the human body, directly powers the movement of matter. When you lift a brick into place on a wall, your muscles provide the mechanical energy that moves the brick. - Radiant energy is energy emitted and transmitted as waves rather than matter. These waves vary in length from long radio waves and microwaves to short gamma waves emitted from decaying atomic nuclei. The full spectrum of radiant energy is referred to as the electromagnetic spectrum. The body uses the ultraviolet energy of sunlight to convert a compound in skin cells to vitamin D, which is essential to human functioning. The human eye evolved to see the wavelengths that comprise the colors of the rainbow, from red to violet, so that range in the spectrum is called “visible light.” - Electrical energy, supplied by electrolytes in cells and body fluids, contributes to the voltage changes that help transmit impulses in nerve and muscle cells. Characteristics of Chemical Reactions All chemical reactions begin with a reactant, the general term for the one or more substances that enter into the reaction. Sodium and chloride ions, for example, are the reactants in the production of table salt. The one or more substances produced by a chemical reaction are called the product. In chemical reactions, the components of the reactants—the elements involved and the number of atoms of each—are all present in the product(s). Similarly, there is nothing present in the products that are not present in the reactants. This is because chemical reactions are governed by the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Just as you can express mathematical calculations in equations such as 2 + 7 = 9, you can use chemical equations to show how reactants become products. As in math, chemical equations proceed from left to right, but instead of an equal sign, they employ an arrow or arrows indicating the direction in which the chemical reaction proceeds. For example, the chemical reaction in which one atom of nitrogen and three atoms of hydrogen produce ammonia would be written as N + 3H→NH3N + 3H→NH3 NH3→N + 3H.NH3→N + 3H. Notice that, in the first example, a nitrogen (N) atom and three hydrogen (H) atoms bond to form a compound. This anabolic reaction requires energy, which is then stored within the compound’s bonds. Such reactions are referred to as synthesis reactions. A synthesis reaction is a chemical reaction that results in the synthesis (joining) of components that were formerly separate (Figure 2.12a). Again, nitrogen and hydrogen are reactants in a synthesis reaction that yields ammonia as the product. The general equation for a synthesis reaction is A + B→AB.A + B→AB. Figure 2.12 The Three Fundamental Chemical Reactions The atoms and molecules involved in the three fundamental chemical reactions can be imagined as words. In the second example, ammonia is catabolized into its smaller components, and the potential energy that had been stored in its bonds is released. Such reactions are referred to as decomposition reactions. A decomposition reaction is a chemical reaction that breaks down or “de-composes” something larger into its constituent parts (see Figure 2.12b). The general equation for a decomposition reaction is: AB→A+BAB→A+B An exchange reaction is a chemical reaction in which both synthesis and decomposition occur, chemical bonds are both formed and broken, and chemical energy is absorbed, stored, and released (see Figure 2.12c). The simplest form of an exchange reaction might be: A+BC→AB+CA+BC→AB+CAB+CD→AC+BDAB+CD→AC+BD AB+CD→AD+BCAB+CD→AD+BC In theory, any chemical reaction can proceed in either direction under the right conditions. Reactants may synthesize into a product that is later decomposed. Reversibility is also a quality of exchange reactions. For instance, A+BC→AB+CA+BC→AB+C AB+C→A+BCAB+C→A+BC A+BC⇄AB+CA+BC⇄AB+C Factors Influencing the Rate of Chemical Reactions If you pour vinegar into baking soda, the reaction is instantaneous; the concoction will bubble and fizz. But many chemical reactions take time. A variety of factors influence the rate of chemical reactions. This section, however, will consider only the most important in human functioning. Properties of the Reactants If chemical reactions are to occur quickly, the atoms in the reactants have to have easy access to one another. Thus, the greater the surface area of the reactants, the more readily they will interact. When you pop a cube of cheese into your mouth, you chew it before you swallow it. Among other things, chewing increases the surface area of the food so that digestive chemicals can more easily get at it. As a general rule, gases tend to react faster than liquids or solids, again because it takes energy to separate particles of a substance, and gases by definition already have space between their particles. Similarly, the larger the molecule, the greater the number of total bonds, so reactions involving smaller molecules, with fewer total bonds, would be expected to proceed faster. In addition, recall that some elements are more reactive than others. Reactions that involve highly reactive elements like hydrogen proceed more quickly than reactions that involve less reactive elements. Reactions involving stable elements like helium are not likely to happen at all. Temperature Nearly all chemical reactions occur at a faster rate at higher temperatures. Recall that kinetic energy is the energy of matter in motion. The kinetic energy of subatomic particles increases in response to increases in thermal energy. The higher the temperature, the faster the particles move, and the more likely they are to come in contact and react. Concentration and Pressure If just a few people are dancing at a club, they are unlikely to step on each other’s toes. But as more and more people get up to dance—especially if the music is fast—collisions are likely to occur. It is the same with chemical reactions: the more particles present within a given space, the more likely those particles are to bump into one another. This means that chemists can speed up chemical reactions not only by increasing the concentration of particles—the number of particles in the space—but also by decreasing the volume of the space, which would correspondingly increase the pressure. If there were 100 dancers in that club, and the manager abruptly moved the party to a room half the size, the concentration of the dancers would double in the new space, and the likelihood of collisions would increase accordingly. Enzymes and Other Catalysts For two chemicals in nature to react with each other they first have to come into contact, and this occurs through random collisions. Because heat helps increase the kinetic energy of atoms, ions, and molecules, it promotes their collision. But in the body, extremely high heat—such as a very high fever—can damage body cells and be life-threatening. On the other hand, normal body temperature is not high enough to promote the chemical reactions that sustain life. That is where catalysts come in. In chemistry, a catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any change. You can think of a catalyst as a chemical change agent. They help increase the rate and force at which atoms, ions, and molecules collide, thereby increasing the probability that their valence shell electrons will interact. The most important catalysts in the human body are enzymes. An enzyme is a catalyst composed of protein or ribonucleic acid (RNA), both of which will be discussed later in this chapter. Like all catalysts, enzymes work by lowering the level of energy that needs to be invested in a chemical reaction. A chemical reaction’s activation energy is the “threshold” level of energy needed to break the bonds in the reactants. Once those bonds are broken, new arrangements can form. Without an enzyme to act as a catalyst, a much larger investment of energy is needed to ignite a chemical reaction (Figure 2.13). Figure 2.13 Enzymes Enzymes decrease the activation energy required for a given chemical reaction to occur. (a) Without an enzyme, the energy input needed for a reaction to begin is high. (b) With the help of an enzyme, less energy is needed for a reaction to begin. Enzymes are critical to the body’s healthy functioning. They assist, for example, with the breakdown of food and its conversion to energy. In fact, most of the chemical reactions in the body are facilitated by enzymes. Inorganic Compounds Essential to Human Functioning - Compare and contrast inorganic and organic compounds - Identify the properties of water that make it essential to life - Explain the role of salts in body functioning - Distinguish between acids and bases, and explain their role in pH - Discuss the role of buffers in helping the body maintain pH homeostasis The concepts you have learned so far in this chapter govern all forms of matter, and would work as a foundation for geology as well as biology. This section of the chapter narrows the focus to the chemistry of human life; that is, the compounds important for the body’s structure and function. In general, these compounds are either inorganic or organic. - An inorganic compound is a substance that does not contain both carbon and hydrogen. A great many inorganic compounds do contain hydrogen atoms, such as water (H2O) and the hydrochloric acid (HCl) produced by your stomach. In contrast, only a handful of inorganic compounds contain carbon atoms. Carbon dioxide (CO2) is one of the few examples. - An organic compound, then, is a substance that contains both carbon and hydrogen. Organic compounds are synthesized via covalent bonds within living organisms, including the human body. Recall that carbon and hydrogen are the second and third most abundant elements in your body. You will soon discover how these two elements combine in the foods you eat, in the compounds that make up your body structure, and in the chemicals that fuel your functioning. The following section examines the three groups of inorganic compounds essential to life: water, salts, acids, and bases. Organic compounds are covered later in the chapter. Water As much as 70 percent of an adult’s body weight is water. This water is contained both within the cells and between the cells that make up tissues and organs. Its several roles make water indispensable to human functioning. Water as a Lubricant and Cushion Water is a major component of many of the body’s lubricating fluids. Just as oil lubricates the hinge on a door, water in synovial fluid lubricates the actions of body joints, and water in pleural fluid helps the lungs expand and recoil with breathing. Watery fluids help keep food flowing through the digestive tract, and ensure that the movement of adjacent abdominal organs is friction free. Water also protects cells and organs from physical trauma, cushioning the brain within the skull, for example, and protecting the delicate nerve tissue of the eyes. Water cushions a developing fetus in the mother’s womb as well. Water as a Heat Sink A heat sink is a substance or object that absorbs and dissipates heat but does not experience a corresponding increase in temperature. In the body, water absorbs the heat generated by chemical reactions without greatly increasing in temperature. Moreover, when the environmental temperature soars, the water stored in the body helps keep the body cool. This cooling effect happens as warm blood from the body’s core flows to the blood vessels just under the skin and is transferred to the environment. At the same time, sweat glands release warm water in sweat. As the water evaporates into the air, it carries away heat, and then the cooler blood from the periphery circulates back to the body core. Water as a Component of Liquid Mixtures A mixture is a combination of two or more substances, each of which maintains its own chemical identity. In other words, the constituent substances are not chemically bonded into a new, larger chemical compound. The concept is easy to imagine if you think of powdery substances such as flour and sugar; when you stir them together in a bowl, they obviously do not bond to form a new compound. The room air you breathe is a gaseous mixture, containing three discrete elements—nitrogen, oxygen, and argon—and one compound, carbon dioxide. There are three types of liquid mixtures, all of which contain water as a key component. These are solutions, colloids, and suspensions. For cells in the body to survive, they must be kept moist in a water-based liquid called a solution. In chemistry, a liquid solution consists of a solvent that dissolves a substance called a solute. An important characteristic of solutions is that they are homogeneous; that is, the solute molecules are distributed evenly throughout the solution. If you were to stir a teaspoon of sugar into a glass of water, the sugar would dissolve into sugar molecules separated by water molecules. The ratio of sugar to water in the left side of the glass would be the same as the ratio of sugar to water in the right side of the glass. If you were to add more sugar, the ratio of sugar to water would change, but the distribution—provided you had stirred well—would still be even. Water is considered the “universal solvent” and it is believed that life cannot exist without water because of this. Water is certainly the most abundant solvent in the body; essentially all of the body’s chemical reactions occur among compounds dissolved in water. Because water molecules are polar, with regions of positive and negative electrical charge, water readily dissolves ionic compounds and polar covalent compounds. Such compounds are referred to as hydrophilic, or “water-loving.” As mentioned above, sugar dissolves well in water. This is because sugar molecules contain regions of hydrogen-oxygen polar bonds, making it hydrophilic. Nonpolar molecules, which do not readily dissolve in water, are called hydrophobic, or “water-fearing.” Concentrations of Solutes Various mixtures of solutes and water are described in chemistry. The concentration of a given solute is the number of particles of that solute in a given space (oxygen makes up about 21 percent of atmospheric air). In the bloodstream of humans, glucose concentration is usually measured in milligram (mg) per deciliter (dL), and in a healthy adult averages about 100 mg/dL. Another method of measuring the concentration of a solute is by its molarilty—which is moles (M) of the molecules per liter (L). The mole of an element is its atomic weight, while a mole of a compound is the sum of the atomic weights of its components, called the molecular weight. An often-used example is calculating a mole of glucose, with the chemical formula C6H12O6. Using the periodic table, the atomic weight of carbon (C) is 12.011 grams (g), and there are six carbons in glucose, for a total atomic weight of 72.066 g. Doing the same calculations for hydrogen (H) and oxygen (O), the molecular weight equals 180.156g (the “gram molecular weight” of glucose). When water is added to make one liter of solution, you have one mole (1M) of glucose. This is particularly useful in chemistry because of the relationship of moles to “Avogadro’s number.” A mole of any solution has the same number of particles in it: 6.02 × 1023. Many substances in the bloodstream and other tissue of the body are measured in thousandths of a mole, or millimoles (mM). A colloid is a mixture that is somewhat like a heavy solution. The solute particles consist of tiny clumps of molecules large enough to make the liquid mixture opaque (because the particles are large enough to scatter light). Familiar examples of colloids are milk and cream. In the thyroid glands, the thyroid hormone is stored as a thick protein mixture also called a colloid. A suspension is a liquid mixture in which a heavier substance is suspended temporarily in a liquid, but over time, settles out. This separation of particles from a suspension is called sedimentation. An example of sedimentation occurs in the blood test that establishes sedimentation rate, or sed rate. The test measures how quickly red blood cells in a test tube settle out of the watery portion of blood (known as plasma) over a set period of time. Rapid sedimentation of blood cells does not normally happen in the healthy body, but aspects of certain diseases can cause blood cells to clump together, and these heavy clumps of blood cells settle to the bottom of the test tube more quickly than do normal blood cells. The Role of Water in Chemical Reactions Two types of chemical reactions involve the creation or the consumption of water: dehydration synthesis and hydrolysis. - In dehydration synthesis, one reactant gives up an atom of hydrogen and another reactant gives up a hydroxyl group (OH) in the synthesis of a new product. In the formation of their covalent bond, a molecule of water is released as a byproduct (Figure 2.14). This is also sometimes referred to as a condensation reaction. - In hydrolysis, a molecule of water disrupts a compound, breaking its bonds. The water is itself split into H and OH. One portion of the severed compound then bonds with the hydrogen atom, and the other portion bonds with the hydroxyl group. These reactions are reversible, and play an important role in the chemistry of organic compounds (which will be discussed shortly). Figure 2.14 Dehydration Synthesis and Hydrolysis Monomers, the basic units for building larger molecules, form polymers (two or more chemically-bonded monomers). (a) In dehydration synthesis, two monomers are covalently bonded in a reaction in which one gives up a hydroxyl group and the other a hydrogen atom. A molecule of water is released as a byproduct during dehydration reactions. (b) In hydrolysis, the covalent bond between two monomers is split by the addition of a hydrogen atom to one and a hydroxyl group to the other, which requires the contribution of one molecule of water. Salts Recall that salts are formed when ions form ionic bonds. In these reactions, one atom gives up one or more electrons, and thus becomes positively charged, whereas the other accepts one or more electrons and becomes negatively charged. You can now define a salt as a substance that, when dissolved in water, dissociates into ions other than H+ or OH–. This fact is important in distinguishing salts from acids and bases, discussed next. A typical salt, NaCl, dissociates completely in water (Figure 2.15). The positive and negative regions on the water molecule (the hydrogen and oxygen ends respectively) attract the negative chloride and positive sodium ions, pulling them away from each other. Again, whereas nonpolar and polar covalently bonded compounds break apart into molecules in solution, salts dissociate into ions. These ions are electrolytes; they are capable of conducting an electrical current in solution. This property is critical to the function of ions in transmitting nerve impulses and prompting muscle contraction. Figure 2.15 Dissociation of Sodium Chloride in Water Notice that the crystals of sodium chloride dissociate not into molecules of NaCl, but into Na+ cations and Cl–anions, each completely surrounded by water molecules. Many other salts are important in the body. For example, bile salts produced by the liver help break apart dietary fats, and calcium phosphate salts form the mineral portion of teeth and bones. Acids and Bases Acids and bases, like salts, dissociate in water into electrolytes. Acids and bases can very much change the properties of the solutions in which they are dissolved. Acids An acid is a substance that releases hydrogen ions (H+) in solution (Figure 2.16a). Because an atom of hydrogen has just one proton and one electron, a positively charged hydrogen ion is simply a proton. This solitary proton is highly likely to participate in chemical reactions. Strong acids are compounds that release all of their H+ in solution; that is, they ionize completely. Hydrochloric acid (HCl), which is released from cells in the lining of the stomach, is a strong acid because it releases all of its H+ in the stomach’s watery environment. This strong acid aids in digestion and kills ingested microbes. Weak acids do not ionize completely; that is, some of their hydrogen ions remain bonded within a compound in solution. An example of a weak acid is vinegar, or acetic acid; it is called acetate after it gives up a proton. Figure 2.16 Acids and Bases (a) In aqueous solution, an acid dissociates into hydrogen ions (H+) and anions. Nearly every molecule of a strong acid dissociates, producing a high concentration of H+. (b) In aqueous solution, a base dissociates into hydroxyl ions (OH–) and cations. Nearly every molecule of a strong base dissociates, producing a high concentration of OH–. Bases A base is a substance that releases hydroxyl ions (OH–) in solution, or one that accepts H+ already present in solution (see Figure 2.16b). The hydroxyl ions (also known as hydroxide ions) or other basic substances combine with H+ present to form a water molecule, thereby removing H+ and reducing the solution’s acidity. Strong bases release most or all of their hydroxyl ions; weak bases release only some hydroxyl ions or absorb only a few H+. Food mixed with hydrochloric acid from the stomach would burn the small intestine, the next portion of the digestive tract after the stomach, if it were not for the release of bicarbonate (HCO3–), a weak base that attracts H+. Bicarbonate accepts some of the H+ protons, thereby reducing the acidity of the solution. The Concept of pH The relative acidity or alkalinity of a solution can be indicated by its pH. A solution’s pH is the negative, base-10 logarithm of the hydrogen ion (H+) concentration of the solution. As an example, a pH 4 solution has an H+ concentration that is ten times greater than that of a pH 5 solution. That is, a solution with a pH of 4 is ten times more acidic than a solution with a pH of 5. The concept of pH will begin to make more sense when you study the pH scale, like that shown in Figure 2.17. The scale consists of a series of increments ranging from 0 to 14. A solution with a pH of 7 is considered neutral—neither acidic nor basic. Pure water has a pH of 7. The lower the number below 7, the more acidic the solution, or the greater the concentration of H+. The concentration of hydrogen ions at each pH value is 10 times different than the next pH. For instance, a pH value of 4 corresponds to a proton concentration of 10–4 M, or 0.0001M, while a pH value of 5 corresponds to a proton concentration of 10–5 M, or 0.00001M. The higher the number above 7, the more basic (alkaline) the solution, or the lower the concentration of H+. Human urine, for example, is ten times more acidic than pure water, and HCl is 10,000,000 times more acidic than water. Figure 2.17 The pH Scale Buffers The pH of human blood normally ranges from 7.35 to 7.45, although it is typically identified as pH 7.4. At this slightly basic pH, blood can reduce the acidity resulting from the carbon dioxide (CO2) constantly being released into the bloodstream by the trillions of cells in the body. Homeostatic mechanisms (along with exhaling CO2 while breathing) normally keep the pH of blood within this narrow range. This is critical, because fluctuations—either too acidic or too alkaline—can lead to life-threatening disorders. All cells of the body depend on homeostatic regulation of acid–base balance at a pH of approximately 7.4. The body therefore has several mechanisms for this regulation, involving breathing, the excretion of chemicals in urine, and the internal release of chemicals collectively called buffers into body fluids. A buffer is a solution of a weak acid and its conjugate base. A buffer can neutralize small amounts of acids or bases in body fluids. For example, if there is even a slight decrease below 7.35 in the pH of a bodily fluid, the buffer in the fluid—in this case, acting as a weak base—will bind the excess hydrogen ions. In contrast, if pH rises above 7.45, the buffer will act as a weak acid and contribute hydrogen ions. HOMEOSTATIC IMBALANCES Acids and Bases Excessive acidity of the blood and other body fluids is known as acidosis. Common causes of acidosis are situations and disorders that reduce the effectiveness of breathing, especially the person’s ability to exhale fully, which causes a buildup of CO2 (and H+) in the bloodstream. Acidosis can also be caused by metabolic problems that reduce the level or function of buffers that act as bases, or that promote the production of acids. For instance, with severe diarrhea, too much bicarbonate can be lost from the body, allowing acids to build up in body fluids. In people with poorly managed diabetes (ineffective regulation of blood sugar), acids called ketones are produced as a form of body fuel. These can build up in the blood, causing a serious condition called diabetic ketoacidosis. Kidney failure, liver failure, heart failure, cancer, and other disorders also can prompt metabolic acidosis. In contrast, alkalosis is a condition in which the blood and other body fluids are too alkaline (basic). As with acidosis, respiratory disorders are a major cause; however, in respiratory alkalosis, carbon dioxide levels fall too low. Lung disease, aspirin overdose, shock, and ordinary anxiety can cause respiratory alkalosis, which reduces the normal concentration of H+. Metabolic alkalosis often results from prolonged, severe vomiting, which causes a loss of hydrogen and chloride ions (as components of HCl). Medications also can prompt alkalosis. These include diuretics that cause the body to lose potassium ions, as well as antacids when taken in excessive amounts, for instance by someone with persistent heartburn or an ulcer. Organic Compounds Essential to Human Functioning - Identify four types of organic molecules essential to human functioning - Explain the chemistry behind carbon’s affinity for covalently bonding in organic compounds - Provide examples of three types of carbohydrates, and identify the primary functions of carbohydrates in the body - Discuss four types of lipids important in human functioning - Describe the structure of proteins, and discuss their importance to human functioning - Identify the building blocks of nucleic acids, and the roles of DNA, RNA, and ATP in human functioning Organic compounds typically consist of groups of carbon atoms covalently bonded to hydrogen, usually oxygen, and often other elements as well. Created by living things, they are found throughout the world, in soils and seas, commercial products, and every cell of the human body. The four types most important to human structure and function are carbohydrates, lipids, proteins, and nucleotides. Before exploring these compounds, you need to first understand the chemistry of carbon. The Chemistry of Carbon What makes organic compounds ubiquitous is the chemistry of their carbon core. Recall that carbon atoms have four electrons in their valence shell, and that the octet rule dictates that atoms tend to react in such a way as to complete their valence shell with eight electrons. Carbon atoms do not complete their valence shells by donating or accepting four electrons. Instead, they readily share electrons via covalent bonds. Commonly, carbon atoms share with other carbon atoms, often forming a long carbon chain referred to as a carbon skeleton. When they do share, however, they do not share all their electrons exclusively with each other. Rather, carbon atoms tend to share electrons with a variety of other elements, one of which is always hydrogen. Carbon and hydrogen groupings are called hydrocarbons. If you study the figures of organic compounds in the remainder of this chapter, you will see several with chains of hydrocarbons in one region of the compound. Many combinations are possible to fill carbon’s four “vacancies.” Carbon may share electrons with oxygen or nitrogen or other atoms in a particular region of an organic compound. Moreover, the atoms to which carbon atoms bond may also be part of a functional group. A functional group is a group of atoms linked by strong covalent bonds and tending to function in chemical reactions as a single unit. You can think of functional groups as tightly knit “cliques” whose members are unlikely to be parted. Five functional groups are important in human physiology; these are the hydroxyl, carboxyl, amino, methyl and phosphate groups (Table 2.1). Carbon’s affinity for covalent bonding means that many distinct and relatively stable organic molecules nevertheless readily form larger, more complex molecules. Any large molecule is referred to as macromolecule (macro- = “large”), and the organic compounds in this section all fit this description. However, some macromolecules are made up of several “copies” of single units called monomer (mono- = “one”; -mer = “part”). Like beads in a long necklace, these monomers link by covalent bonds to form long polymers (poly- = “many”). There are many examples of monomers and polymers among the organic compounds. Monomers form polymers by engaging in dehydration synthesis (see Figure 2.14). As was noted earlier, this reaction results in the release of a molecule of water. Each monomer contributes: One gives up a hydrogen atom and the other gives up a hydroxyl group. Polymers are split into monomers by hydrolysis (-lysis = “rupture”). The bonds between their monomers are broken, via the donation of a molecule of water, which contributes a hydrogen atom to one monomer and a hydroxyl group to the other. Carbohydrates The term carbohydrate means “hydrated carbon.” Recall that the root hydro- indicates water. A carbohydrate is a molecule composed of carbon, hydrogen, and oxygen; in most carbohydrates, hydrogen and oxygen are found in the same two-to-one relative proportions they have in water. In fact, the chemical formula for a “generic” molecule of carbohydrate is (CH2O)n. Carbohydrates are referred to as saccharides, a word meaning “sugars.” Three forms are important in the body. Monosaccharides are the monomers of carbohydrates. Disaccharides (di- = “two”) are made up of two monomers. Polysaccharides are the polymers, and can consist of hundreds to thousands of monomers. Monosaccharides A monosaccharide is a monomer of carbohydrates. Five monosaccharides are important in the body. Three of these are the hexose sugars, so called because they each contain six atoms of carbon. These are glucose, fructose, and galactose, shown in Figure 2.18a. The remaining monosaccharides are the two pentose sugars, each of which contains five atoms of carbon. They are ribose and deoxyribose, shown in Figure 2.18b. Figure 2.18 Five Important Monosaccharides Disaccharides A disaccharide is a pair of monosaccharides. Disaccharides are formed via dehydration synthesis, and the bond linking them is referred to as a glycosidic bond (glyco- = “sugar”). Three disaccharides (shown in Figure 2.19) are important to humans. These are sucrose, commonly referred to as table sugar; lactose, or milk sugar; and maltose, or malt sugar. As you can tell from their common names, you consume these in your diet; however, your body cannot use them directly. Instead, in the digestive tract, they are split into their component monosaccharides via hydrolysis. Figure 2.19 Three Important Disaccharides All three important disaccharides form by dehydration synthesis. INTERACTIVE LINK Watch this video to observe the formation of a disaccharide. What happens when water encounters a glycosidic bond? Polysaccharides Polysaccharides can contain a few to a thousand or more monosaccharides. Three are important to the body (Figure 2.20): - Starches are polymers of glucose. They occur in long chains called amylose or branched chains called amylopectin, both of which are stored in plant-based foods and are relatively easy to digest. - Glycogen is also a polymer of glucose, but it is stored in the tissues of animals, especially in the muscles and liver. It is not considered a dietary carbohydrate because very little glycogen remains in animal tissues after slaughter; however, the human body stores excess glucose as glycogen, again, in the muscles and liver. - Cellulose, a polysaccharide that is the primary component of the cell wall of green plants, is the component of plant food referred to as “fiber”. In humans, cellulose/fiber is not digestible; however, dietary fiber has many health benefits. It helps you feel full so you eat less, it promotes a healthy digestive tract, and a diet high in fiber is thought to reduce the risk of heart disease and possibly some forms of cancer. Figure 2.20 Three Important Polysaccharides Three important polysaccharides are starches, glycogen, and fiber. Functions of Carbohydrates The body obtains carbohydrates from plant-based foods. Grains, fruits, and legumes and other vegetables provide most of the carbohydrate in the human diet, although lactose is found in dairy products. Although most body cells can break down other organic compounds for fuel, all body cells can use glucose. Moreover, nerve cells (neurons) in the brain, spinal cord, and through the peripheral nervous system, as well as red blood cells, can use only glucose for fuel. In the breakdown of glucose for energy, molecules of adenosine triphosphate, better known as ATP, are produced. Adenosine triphosphate (ATP) is composed of a ribose sugar, an adenine base, and three phosphate groups. ATP releases free energy when its phosphate bonds are broken, and thus supplies ready energy to the cell. More ATP is produced in the presence of oxygen (O2) than in pathways that do not use oxygen. The overall reaction for the conversion of the energy in glucose to energy stored in ATP can be written: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATPC6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATPIn addition to being a critical fuel source, carbohydrates are present in very small amounts in cells’ structure. For instance, some carbohydrate molecules bind with proteins to produce glycoproteins, and others combine with lipids to produce glycolipids, both of which are found in the membrane that encloses the contents of body cells. Lipids A lipid is one of a highly diverse group of compounds made up mostly of hydrocarbons. The few oxygen atoms they contain are often at the periphery of the molecule. Their nonpolar hydrocarbons make all lipids hydrophobic. In water, lipids do not form a true solution, but they may form an emulsion, which is the term for a mixture of solutions that do not mix well. Triglycerides A triglyceride is one of the most common dietary lipid groups, and the type found most abundantly in body tissues. This compound, which is commonly referred to as a fat, is formed from the synthesis of two types of molecules (Figure 2.21): - A glycerol backbone at the core of triglycerides, consists of three carbon atoms. - Three fatty acids, long chains of hydrocarbons with a carboxyl group and a methyl group at opposite ends, extend from each of the carbons of the glycerol. Figure 2.21 Triglycerides Triglycerides are composed of glycerol attached to three fatty acids via dehydration synthesis. Notice that glycerol gives up a hydrogen atom, and the carboxyl groups on the fatty acids each give up a hydroxyl group. Triglycerides form via dehydration synthesis. Glycerol gives up hydrogen atoms from its hydroxyl groups at each bond, and the carboxyl group on each fatty acid chain gives up a hydroxyl group. A total of three water molecules are thereby released. Fatty acid chains that have no double carbon bonds anywhere along their length and therefore contain the maximum number of hydrogen atoms are called saturated fatty acids. These straight, rigid chains pack tightly together and are solid or semi-solid at room temperature (Figure 2.22a). Butter and lard are examples, as is the fat found on a steak or in your own body. In contrast, fatty acids with one double carbon bond are kinked at that bond (Figure 2.22b). These monounsaturated fatty acids are therefore unable to pack together tightly, and are liquid at room temperature. Polyunsaturated fatty acids contain two or more double carbon bonds, and are also liquid at room temperature. Plant oils such as olive oil typically contain both mono- and polyunsaturated fatty acids. Figure 2.22 Fatty Acid Shapes The level of saturation of a fatty acid affects its shape. (a) Saturated fatty acid chains are straight. (b) Unsaturated fatty acid chains are kinked. Whereas a diet high in saturated fatty acids increases the risk of heart disease, a diet high in unsaturated fatty acids is thought to reduce the risk. This is especially true for the omega-3 unsaturated fatty acids found in cold-water fish such as salmon. These fatty acids have their first double carbon bond at the third hydrocarbon from the methyl group (referred to as the omega end of the molecule). Finally, trans fatty acids found in some processed foods, including some stick and tub margarines, are thought to be even more harmful to the heart and blood vessels than saturated fatty acids. Trans fats are created from unsaturated fatty acids (such as corn oil) when chemically treated to produce partially hydrogenated fats. As a group, triglycerides are a major fuel source for the body. When you are resting or asleep, a majority of the energy used to keep you alive is derived from triglycerides stored in your fat (adipose) tissues. Triglycerides also fuel long, slow physical activity such as gardening or hiking, and contribute a modest percentage of energy for vigorous physical activity. Dietary fat also assists the absorption and transport of the nonpolar fat-soluble vitamins A, D, E, and K. Additionally, stored body fat protects and cushions the body’s bones and internal organs, and acts as insulation to retain body heat. Fatty acids are also components of glycolipids, which are sugar-fat compounds found in the cell membrane. Lipoproteins are compounds in which the hydrophobic triglycerides are packaged in protein envelopes for transport in body fluids. Phospholipids As its name suggests, a phospholipid is a bond between the glycerol component of a lipid and a phosphorous molecule. In fact, phospholipids are similar in structure to triglycerides. However, instead of having three fatty acids, a phospholipid is generated from a diglyceride, a glycerol with just two fatty acid chains (Figure 2.23). The third binding site on the glycerol is taken up by the phosphate group, which in turn is attached to a polar “head” region of the molecule. Recall that triglycerides are nonpolar and hydrophobic. This still holds for the fatty acid portion of a phospholipid compound. However, the head of a phospholipid contains charges on the phosphate groups, as well as on the nitrogen atom. These charges make the phospholipid head hydrophilic. Therefore, phospholipids are said to have hydrophobic tails, containing the neutral fatty acids, and hydrophilic heads, containing the charged phosphate groups and nitrogen atom. Figure 2.23 Other Important Lipids (a) Phospholipids are composed of two fatty acids, glycerol, and a phosphate group. (b) Sterols are ring-shaped lipids. Shown here is cholesterol. (c) Prostaglandins are derived from unsaturated fatty acids. Prostaglandin E2 (PGE2) includes hydroxyl and carboxyl groups. Steroids A steroid compound (referred to as a sterol) has as its foundation a set of four hydrocarbon rings bonded to a variety of other atoms and molecules (see Figure 2.23b). Although both plants and animals synthesize sterols, the type that makes the most important contribution to human structure and function is cholesterol, which is synthesized by the liver in humans and animals and is also present in most animal-based foods. Like other lipids, cholesterol’s hydrocarbons make it hydrophobic; however, it has a polar hydroxyl head that is hydrophilic. Cholesterol is an important component of bile acids, compounds that help emulsify dietary fats. In fact, the word root chole- refers to bile. Cholesterol is also a building block of many hormones, signaling molecules that the body releases to regulate processes at distant sites. Finally, like phospholipids, cholesterol molecules are found in the cell membrane, where their hydrophobic and hydrophilic regions help regulate the flow of substances into and out of the cell. Prostaglandins Like a hormone, a prostaglandin is one of a group of signaling molecules, but prostaglandins are derived from unsaturated fatty acids (see Figure 2.23c). One reason that the omega-3 fatty acids found in fish are beneficial is that they stimulate the production of certain prostaglandins that help regulate aspects of blood pressure and inflammation, and thereby reduce the risk for heart disease. Prostaglandins also sensitize nerves to pain. One class of pain-relieving medications called nonsteroidal anti-inflammatory drugs (NSAIDs) works by reducing the effects of prostaglandins. Proteins You might associate proteins with muscle tissue, but in fact, proteins are critical components of all tissues and organs. A protein is an organic molecule composed of amino acids linked by peptide bonds. Proteins include the keratin in the epidermis of skin that protects underlying tissues, the collagen found in the dermis of skin, in bones, and in the meninges that cover the brain and spinal cord. Proteins are also components of many of the body’s functional chemicals, including digestive enzymes in the digestive tract, antibodies, the neurotransmitters that neurons use to communicate with other cells, and the peptide-based hormones that regulate certain body functions (for instance, growth hormone). While carbohydrates and lipids are composed of hydrocarbons and oxygen, all proteins also contain nitrogen (N), and many contain sulfur (S), in addition to carbon, hydrogen, and oxygen. Microstructure of Proteins Proteins are polymers made up of nitrogen-containing monomers called amino acids. An amino acid is a molecule composed of an amino group and a carboxyl group, together with a variable side chain. Just 20 different amino acids contribute to nearly all of the thousands of different proteins important in human structure and function. Body proteins contain a unique combination of a few dozen to a few hundred of these 20 amino acid monomers. All 20 of these amino acids share a similar structure (Figure 2.24). All consist of a central carbon atom to which the following are bonded: - a hydrogen atom - an alkaline (basic) amino group NH2 (see Table 2.1) - an acidic carboxyl group COOH (see Table 2.1) - a variable group Figure 2.24 Structure of an Amino Acid Notice that all amino acids contain both an acid (the carboxyl group) and a base (the amino group) (amine = “nitrogen-containing”). For this reason, they make excellent buffers, helping the body regulate acid–base balance. What distinguishes the 20 amino acids from one another is their variable group, which is referred to as a side chain or an R-group. This group can vary in size and can be polar or nonpolar, giving each amino acid its unique characteristics. For example, the side chains of two amino acids—cysteine and methionine—contain sulfur. Sulfur does not readily participate in hydrogen bonds, whereas all other amino acids do. This variation influences the way that proteins containing cysteine and methionine are assembled. Amino acids join via dehydration synthesis to form protein polymers (Figure 2.25). The unique bond holding amino acids together is called a peptide bond. A peptide bond is a covalent bond between two amino acids that forms by dehydration synthesis. A peptide, in fact, is a very short chain of amino acids. Strands containing fewer than about 100 amino acids are generally referred to as polypeptides rather than proteins. Figure 2.25 Peptide Bond Different amino acids join together to form peptides, polypeptides, or proteins via dehydration synthesis. The bonds between the amino acids are peptide bonds. The body is able to synthesize most of the amino acids from components of other molecules; however, nine cannot be synthesized and have to be consumed in the diet. These are known as the essential amino acids. Free amino acids available for protein construction are said to reside in the amino acid pool within cells. Structures within cells use these amino acids when assembling proteins. If a particular essential amino acid is not available in sufficient quantities in the amino acid pool, however, synthesis of proteins containing it can slow or even cease. Shape of Proteins Just as a fork cannot be used to eat soup and a spoon cannot be used to spear meat, a protein’s shape is essential to its function. A protein’s shape is determined, most fundamentally, by the sequence of amino acids of which it is made (Figure 2.26a). The sequence is called the primary structure of the protein. Figure 2.26 The Shape of Proteins (a) The primary structure is the sequence of amino acids that make up the polypeptide chain. (b) The secondary structure, which can take the form of an alpha-helix or a beta-pleated sheet, is maintained by hydrogen bonds between amino acids in different regions of the original polypeptide strand. (c) The tertiary structure occurs as a result of further folding and bonding of the secondary structure. (d) The quaternary structure occurs as a result of interactions between two or more tertiary subunits. The example shown here is hemoglobin, a protein in red blood cells which transports oxygen to body tissues. Although some polypeptides exist as linear chains, most are twisted or folded into more complex secondary structures that form when bonding occurs between amino acids with different properties at different regions of the polypeptide. The most common secondary structure is a spiral called an alpha-helix. If you were to take a length of string and simply twist it into a spiral, it would not hold the shape. Similarly, a strand of amino acids could not maintain a stable spiral shape without the help of hydrogen bonds, which create bridges between different regions of the same strand (see Figure 2.26b). Less commonly, a polypeptide chain can form a beta-pleated sheet, in which hydrogen bonds form bridges between different regions of a single polypeptide that has folded back upon itself, or between two or more adjacent polypeptide chains. The secondary structure of proteins further folds into a compact three-dimensional shape, referred to as the protein’s tertiary structure (see Figure 2.26c). In this configuration, amino acids that had been very distant in the primary chain can be brought quite close via hydrogen bonds or, in proteins containing cysteine, via disulfide bonds. A disulfide bond is a covalent bond between sulfur atoms in a polypeptide. Often, two or more separate polypeptides bond to form an even larger protein with a quaternary structure (see Figure 2.26d). The polypeptide subunits forming a quaternary structure can be identical or different. For instance, hemoglobin, the protein found in red blood cells is composed of four tertiary polypeptides, two of which are called alpha chains and two of which are called beta chains. When they are exposed to extreme heat, acids, bases, and certain other substances, proteins will denature. Denaturation is a change in the structure of a molecule through physical or chemical means. Denatured proteins lose their functional shape and are no longer able to carry out their jobs. An everyday example of protein denaturation is the curdling of milk when acidic lemon juice is added. The contribution of the shape of a protein to its function can hardly be exaggerated. For example, the long, slender shape of protein strands that make up muscle tissue is essential to their ability to contract (shorten) and relax (lengthen). As another example, bones contain long threads of a protein called collagen that acts as scaffolding upon which bone minerals are deposited. These elongated proteins, called fibrous proteins, are strong and durable and typically hydrophobic. In contrast, globular proteins are globes or spheres that tend to be highly reactive and are hydrophilic. The hemoglobin proteins packed into red blood cells are an example (see Figure 2.26d); however, globular proteins are abundant throughout the body, playing critical roles in most body functions. Enzymes, introduced earlier as protein catalysts, are examples of this. The next section takes a closer look at the action of enzymes. Proteins Function as Enzymes If you were trying to type a paper, and every time you hit a key on your laptop there was a delay of six or seven minutes before you got a response, you would probably get a new laptop. In a similar way, without enzymes to catalyze chemical reactions, the human body would be nonfunctional. It functions only because enzymes function. Enzymatic reactions—chemical reactions catalyzed by enzymes—begin when substrates bind to the enzyme. A substrate is a reactant in an enzymatic reaction. This occurs on regions of the enzyme known as active sites (Figure 2.27). Any given enzyme catalyzes just one type of chemical reaction. This characteristic, called specificity, is due to the fact that a substrate with a particular shape and electrical charge can bind only to an active site corresponding to that substrate. Due to this jigsaw puzzle-like match between an enzyme and its substrates, enzymes are known for their specificity. In fact, as an enzyme binds to its substrate(s), the enzyme structure changes slightly to find the best fit between the transition state (a structural intermediate between the substrate and product) and the active site, just as a rubber glove molds to a hand inserted into it. This active-site modification in the presence of substrate, along with the simultaneous formation of the transition state, is called induced fit. Overall, there is a specifically matched enzyme for each substrate and, thus, for each chemical reaction; however, there is some flexibility as well. Some enzymes have the ability to act on several different structurally related substrates. Figure 2.27 Steps in an Enzymatic Reaction According to the induced-fit model, the active site of the enzyme undergoes conformational changes upon binding with the substrate.(a) Substrates approach active sites on enzyme. (b) Substrates bind to active sites, producing an enzyme–substrate complex. (c) Changes internal to the enzyme–substrate complex facilitate interaction of the substrates. (d) Products are released and the enzyme returns to its original form, ready to facilitate another enzymatic reaction. Binding of a substrate produces an enzyme–substrate complex. It is likely that enzymes speed up chemical reactions in part because the enzyme–substrate complex undergoes a set of temporary and reversible changes that cause the substrates to be oriented toward each other in an optimal position to facilitate their interaction. This promotes increased reaction speed. The enzyme then releases the product(s), and resumes its original shape. The enzyme is then free to engage in the process again, and will do so as long as substrate remains. Other Functions of Proteins Advertisements for protein bars, powders, and shakes all say that protein is important in building, repairing, and maintaining muscle tissue, but the truth is that proteins contribute to all body tissues, from the skin to the brain cells. Also, certain proteins act as hormones, chemical messengers that help regulate body functions, For example, growth hormone is important for skeletal growth, among other roles. As was noted earlier, the basic and acidic components enable proteins to function as buffers in maintaining acid–base balance, but they also help regulate fluid–electrolyte balance. Proteins attract fluid, and a healthy concentration of proteins in the blood, the cells, and the spaces between cells helps ensure a balance of fluids in these various “compartments.” Moreover, proteins in the cell membrane help to transport electrolytes in and out of the cell, keeping these ions in a healthy balance. Like lipids, proteins can bind with carbohydrates. They can thereby produce glycoproteins or proteoglycans, both of which have many functions in the body. The body can use proteins for energy when carbohydrate and fat intake is inadequate, and stores of glycogen and adipose tissue become depleted. However, since there is no storage site for protein except functional tissues, using protein for energy causes tissue breakdown, and results in body wasting. Nucleotides The fourth type of organic compound important to human structure and function are the nucleotides (Figure 2.28). A nucleotide is one of a class of organic compounds composed of three subunits: - one or more phosphate groups - a pentose sugar: either deoxyribose or ribose - a nitrogen-containing base: adenine, cytosine, guanine, thymine, or uracil Nucleotides can be assembled into nucleic acids (DNA or RNA) or the energy compound adenosine triphosphate. Figure 2.28 Nucleotides (a) The building blocks of all nucleotides are one or more phosphate groups, a pentose sugar, and a nitrogen-containing base. (b) The nitrogen-containing bases of nucleotides. (c) The two pentose sugars of DNA and RNA. Nucleic Acids The nucleic acids differ in their type of pentose sugar. Deoxyribonucleic acid (DNA) is nucleotide that stores genetic information. DNA contains deoxyribose (so-called because it has one less atom of oxygen than ribose) plus one phosphate group and one nitrogen-containing base. The “choices” of base for DNA are adenine, cytosine, guanine, and thymine. Ribonucleic acid (RNA) is a ribose-containing nucleotide that helps manifest the genetic code as protein. RNA contains ribose, one phosphate group, and one nitrogen-containing base, but the “choices” of base for RNA are adenine, cytosine, guanine, and uracil. The nitrogen-containing bases adenine and guanine are classified as purines. A purine is a nitrogen-containing molecule with a double ring structure, which accommodates several nitrogen atoms. The bases cytosine, thymine (found in DNA only) and uracil (found in RNA only) are pyramidines. A pyramidine is a nitrogen-containing base with a single ring structure Bonds formed by dehydration synthesis between the pentose sugar of one nucleic acid monomer and the phosphate group of another form a “backbone,” from which the components’ nitrogen-containing bases protrude. In DNA, two such backbones attach at their protruding bases via hydrogen bonds. These twist to form a shape known as a double helix (Figure 2.29). The sequence of nitrogen-containing bases within a strand of DNA form the genes that act as a molecular code instructing cells in the assembly of amino acids into proteins. Humans have almost 22,000 genes in their DNA, locked up in the 46 chromosomes inside the nucleus of each cell (except red blood cells which lose their nuclei during development). These genes carry the genetic code to build one’s body, and are unique for each individual except identical twins. Figure 2.29 DNA In the DNA double helix, two strands attach via hydrogen bonds between the bases of the component nucleotides. In contrast, RNA consists of a single strand of sugar-phosphate backbone studded with bases. Messenger RNA (mRNA) is created during protein synthesis to carry the genetic instructions from the DNA to the cell’s protein manufacturing plants in the cytoplasm, the ribosomes. Adenosine Triphosphate The nucleotide adenosine triphosphate (ATP), is composed of a ribose sugar, an adenine base, and three phosphate groups (Figure 2.30). ATP is classified as a high energy compound because the two covalent bonds linking its three phosphates store a significant amount of potential energy. In the body, the energy released from these high energy bonds helps fuel the body’s activities, from muscle contraction to the transport of substances in and out of cells to anabolic chemical reactions. Figure 2.30 Structure of Adenosine Triphosphate (ATP) When a phosphate group is cleaved from ATP, the products are adenosine diphosphate (ADP) and inorganic phosphate (Pi). This hydrolysis reaction can be written: ATP + H2O → ADP + Pi + energyATP + H2O → ADP + Pi + energy Removal of a second phosphate leaves adenosine monophosphate (AMP) and two phosphate groups. Again, these reactions also liberate the energy that had been stored in the phosphate-phosphate bonds. They are reversible, too, as when ADP undergoes phosphorylation. Phosphorylation is the addition of a phosphate group to an organic compound, in this case, resulting in ATP. In such cases, the same level of energy that had been released during hydrolysis must be reinvested to power dehydration synthesis. Cells can also transfer a phosphate group from ATP to another organic compound. For example, when glucose first enters a cell, a phosphate group is transferred from ATP, forming glucose phosphate (C6H12O6—P) and ADP. Once glucose is phosphorylated in this way, it can be stored as glycogen or metabolized for immediate energy. Key Terms - acid - compound that releases hydrogen ions (H+) in solution - activation energy - amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed - adenosine triphosphate (ATP) - nucleotide containing ribose and an adenine base that is essential in energy transfer - amino acid - building block of proteins; characterized by an amino and carboxyl functional groups and a variable side-chain - anion - atom with a negative charge - atom - smallest unit of an element that retains the unique properties of that element - atomic number - number of protons in the nucleus of an atom - base - compound that accepts hydrogen ions (H+) in solution - bond - electrical force linking atoms - buffer - solution containing a weak acid or a weak base that opposes wide fluctuations in the pH of body fluids - carbohydrate - class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio - catalyst - substance that increases the rate of a chemical reaction without itself being changed in the process - cation - atom with a positive charge - chemical energy - form of energy that is absorbed as chemical bonds form, stored as they are maintained, and released as they are broken - colloid - liquid mixture in which the solute particles consist of clumps of molecules large enough to scatter light - compound - substance composed of two or more different elements joined by chemical bonds - concentration - number of particles within a given space - covalent bond - chemical bond in which two atoms share electrons, thereby completing their valence shells - decomposition reaction - type of catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms - denaturation - change in the structure of a molecule through physical or chemical means - deoxyribonucleic acid (DNA) - deoxyribose-containing nucleotide that stores genetic information - disaccharide - pair of carbohydrate monomers bonded by dehydration synthesis via a glycosidic bond - disulfide bond - covalent bond formed within a polypeptide between sulfide groups of sulfur-containing amino acids, for example, cysteine - electron - subatomic particle having a negative charge and nearly no mass; found orbiting the atom’s nucleus - electron shell - area of space a given distance from an atom’s nucleus in which electrons are grouped - element - substance that cannot be created or broken down by ordinary chemical means - enzyme - protein or RNA that catalyzes chemical reactions - exchange reaction - type of chemical reaction in which bonds are both formed and broken, resulting in the transfer of components - functional group - group of atoms linked by strong covalent bonds that tends to behave as a distinct unit in chemical reactions with other atoms - hydrogen bond - dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom - inorganic compound - substance that does not contain both carbon and hydrogen - ion - atom with an overall positive or negative charge - ionic bond - attraction between an anion and a cation - isotope - one of the variations of an element in which the number of neutrons differ from each other - kinetic energy - energy that matter possesses because of its motion - lipid - class of nonpolar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water - macromolecule - large molecule formed by covalent bonding - mass number - sum of the number of protons and neutrons in the nucleus of an atom - matter - physical substance; that which occupies space and has mass - molecule - two or more atoms covalently bonded together - monosaccharide - monomer of carbohydrate; also known as a simple sugar - neutron - heavy subatomic particle having no electrical charge and found in the atom’s nucleus - nucleotide - class of organic compounds composed of one or more phosphate groups, a pentose sugar, and a base - organic compound - substance that contains both carbon and hydrogen - peptide bond - covalent bond formed by dehydration synthesis between two amino acids - periodic table of the elements - arrangement of the elements in a table according to their atomic number; elements having similar properties because of their electron arrangements compose columns in the table, while elements having the same number of valence shells compose rows in the table - pH - negative logarithm of the hydrogen ion (H+) concentration of a solution - phospholipid - a lipid compound in which a phosphate group is combined with a diglyceride - phosphorylation - addition of one or more phosphate groups to an organic compound - polar molecule - molecule with regions that have opposite charges resulting from uneven numbers of electrons in the nuclei of the atoms participating in the covalent bond - polysaccharide - compound consisting of more than two carbohydrate monomers bonded by dehydration synthesis via glycosidic bonds - potential energy - stored energy matter possesses because of the positioning or structure of its components - product - one or more substances produced by a chemical reaction - prostaglandin - lipid compound derived from fatty acid chains and important in regulating several body processes - protein - class of organic compounds that are composed of many amino acids linked together by peptide bonds - proton - heavy subatomic particle having a positive charge and found in the atom’s nucleus - purine - nitrogen-containing base with a double ring structure; adenine and guanine - pyrimidine - nitrogen-containing base with a single ring structure; cytosine, thiamine, and uracil - radioactive isotope - unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy, as it decays; also called radioisotopes - reactant - one or more substances that enter into the reaction - ribonucleic acid (RNA) - ribose-containing nucleotide that helps manifest the genetic code as protein - solution - homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent - steroid - (also, sterol) lipid compound composed of four hydrocarbon rings bonded to a variety of other atoms and molecules - substrate - reactant in an enzymatic reaction - suspension - liquid mixture in which particles distributed in the liquid settle out over time - synthesis reaction - type of anabolic reaction in which two or more atoms or molecules bond, resulting in the formation of a larger molecule - triglyceride - lipid compound composed of a glycerol molecule bonded with three fatty acid chains - valence shell - outermost electron shell of an atom Chapter Review 2.1 Elements and Atoms: The Building Blocks of Matter The human body is composed of elements, the most abundant of which are oxygen (O), carbon (C), hydrogen (H) and nitrogen (N). You obtain these elements from the foods you eat and the air you breathe. The smallest unit of an element that retains all of the properties of that element is an atom. But, atoms themselves contain many subatomic particles, the three most important of which are protons, neutrons, and electrons. These particles do not vary in quality from one element to another; rather, what gives an element its distinctive identification is the quantity of its protons, called its atomic number. Protons and neutrons contribute nearly all of an atom’s mass; the number of protons and neutrons is an element’s mass number. Heavier and lighter versions of the same element can occur in nature because these versions have different numbers of neutrons. Different versions of an element are called isotopes. The tendency of an atom to be stable or to react readily with other atoms is largely due to the behavior of the electrons within the atom’s outermost electron shell, called its valence shell. Helium, as well as larger atoms with eight electrons in their valence shell, is unlikely to participate in chemical reactions because they are stable. All other atoms tend to accept, donate, or share electrons in a process that brings the electrons in their valence shell to eight (or in the case of hydrogen, to two). 2.2 Chemical Bonds Each moment of life, atoms of oxygen, carbon, hydrogen, and the other elements of the human body are making and breaking chemical bonds. Ions are charged atoms that form when an atom donates or accepts one or more negatively charged electrons. Cations (ions with a positive charge) are attracted to anions (ions with a negative charge). This attraction is called an ionic bond. In covalent bonds, the participating atoms do not lose or gain electrons, but rather share them. Molecules with nonpolar covalent bonds are electrically balanced, and have a linear three-dimensional shape. Molecules with polar covalent bonds have “poles”—regions of weakly positive and negative charge—and have a triangular three-dimensional shape. An atom of oxygen and two atoms of hydrogen form water molecules by means of polar covalent bonds. Hydrogen bonds link hydrogen atoms already participating in polar covalent bonds to anions or electronegative regions of other polar molecules. Hydrogen bonds link water molecules, resulting in the properties of water that are important to living things. 2.3 Chemical Reactions Chemical reactions, in which chemical bonds are broken and formed, require an initial investment of energy. Kinetic energy, the energy of matter in motion, fuels the collisions of atoms, ions, and molecules that are necessary if their old bonds are to break and new ones to form. All molecules store potential energy, which is released when their bonds are broken. Four forms of energy essential to human functioning are: chemical energy, which is stored and released as chemical bonds are formed and broken; mechanical energy, which directly powers physical activity; radiant energy, emitted as waves such as in sunlight; and electrical energy, the power of moving electrons. Chemical reactions begin with reactants and end with products. Synthesis reactions bond reactants together, a process that requires energy, whereas decomposition reactions break the bonds within a reactant and thereby release energy. In exchange reactions, bonds are both broken and formed, and energy is exchanged. The rate at which chemical reactions occur is influenced by several properties of the reactants: temperature, concentration and pressure, and the presence or absence of a catalyst. An enzyme is a catalytic protein that speeds up chemical reactions in the human body. 2.4 Inorganic Compounds Essential to Human Functioning Inorganic compounds essential to human functioning include water, salts, acids, and bases. These compounds are inorganic; that is, they do not contain both hydrogen and carbon. Water is a lubricant and cushion, a heat sink, a component of liquid mixtures, a byproduct of dehydration synthesis reactions, and a reactant in hydrolysis reactions. Salts are compounds that, when dissolved in water, dissociate into ions other than H+ or OH–. In contrast, acids release H+ in solution, making it more acidic. Bases accept H+, thereby making the solution more alkaline (caustic). The pH of any solution is its relative concentration of H+. A solution with pH 7 is neutral. Solutions with pH below 7 are acids, and solutions with pH above 7 are bases. A change in a single digit on the pH scale (e.g., from 7 to 8) represents a ten-fold increase or decrease in the concentration of H+. In a healthy adult, the pH of blood ranges from 7.35 to 7.45. Homeostatic control mechanisms important for keeping blood in a healthy pH range include chemicals called buffers, weak acids and weak bases released when the pH of blood or other body fluids fluctuates in either direction outside of this normal range. 2.5 Organic Compounds Essential to Human Functioning Organic compounds essential to human functioning include carbohydrates, lipids, proteins, and nucleotides. These compounds are said to be organic because they contain both carbon and hydrogen. Carbon atoms in organic compounds readily share electrons with hydrogen and other atoms, usually oxygen, and sometimes nitrogen. Carbon atoms also may bond with one or more functional groups such as carboxyls, hydroxyls, aminos, or phosphates. Monomers are single units of organic compounds. They bond by dehydration synthesis to form polymers, which can in turn be broken by hydrolysis. Carbohydrate compounds provide essential body fuel. Their structural forms include monosaccharides such as glucose, disaccharides such as lactose, and polysaccharides, including starches (polymers of glucose), glycogen (the storage form of glucose), and fiber. All body cells can use glucose for fuel. It is converted via an oxidation-reduction reaction to ATP. Lipids are hydrophobic compounds that provide body fuel and are important components of many biological compounds. Triglycerides are the most abundant lipid in the body, and are composed of a glycerol backbone attached to three fatty acid chains. Phospholipids are compounds composed of a diglyceride with a phosphate group attached at the molecule’s head. The result is a molecule with polar and nonpolar regions. Steroids are lipids formed of four hydrocarbon rings. The most important is cholesterol. Prostaglandins are signaling molecules derived from unsaturated fatty acids. Proteins are critical components of all body tissues. They are made up of monomers called amino acids, which contain nitrogen, joined by peptide bonds. Protein shape is critical to its function. Most body proteins are globular. An example is enzymes, which catalyze chemical reactions. Nucleotides are compounds with three building blocks: one or more phosphate groups, a pentose sugar, and a nitrogen-containing base. DNA and RNA are nucleic acids that function in protein synthesis. ATP is the body’s fundamental molecule of energy transfer. Removal or addition of phosphates releases or invests energy. Interactive Link Questions Visit this website to view the periodic table. In the periodic table of the elements, elements in a single column have the same number of electrons that can participate in a chemical reaction. These electrons are known as “valence electrons.” For example, the elements in the first column all have a single valence electron—an electron that can be “donated” in a chemical reaction with another atom. What is the meaning of a mass number shown in parentheses? 2.Visit this website to learn about electrical energy and the attraction/repulsion of charges. What happens to the charged electroscope when a conductor is moved between its plastic sheets, and why? 3.Watch this video to observe the formation of a disaccharide. What happens when water encounters a glycosidic bond? Review Questions Together, just four elements make up more than 95 percent of the body’s mass. These include ________. - calcium, magnesium, iron, and carbon - oxygen, calcium, iron, and nitrogen - sodium, chlorine, carbon, and hydrogen - oxygen, carbon, hydrogen, and nitrogen The smallest unit of an element that still retains the distinctive behavior of that element is an ________. - electron - atom - elemental particle - isotope The characteristic that gives an element its distinctive properties is its number of ________. - protons - neutrons - electrons - atoms On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have ________. - about 80 neutrons each - fewer than 80 neutrons each - more than 80 neutrons each - more electrons than neutrons Nitrogen has an atomic number of seven. How many electron shells does it likely have? - one - two - three - four Which of the following is a molecule, but not a compound? - H2O - 2H - H2 - H+ A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with ________. - ionic bonds - nonpolar covalent bonds - polar covalent bonds - hydrogen bonds When an atom donates an electron to another atom, it becomes - an ion - an anion - nonpolar - all of the above A substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n) ________. - noble gas - salt - electrolyte - dipole Which of the following statements about chemical bonds is true? - Covalent bonds are stronger than ionic bonds. - Hydrogen bonds occur between two atoms of hydrogen. - Bonding readily occurs between nonpolar and polar molecules. - A molecule of water is unlikely to bond with an ion. The energy stored in a foot of snow on a steep roof is ________. - potential energy - kinetic energy - radiant energy - activation energy The bonding of calcium, phosphorus, and other elements produces mineral crystals that are found in bone. This is an example of a(n) ________ reaction. - catabolic - synthesis - decomposition - exchange AB→A+BAB→A+B is a general notation for a(n) ________ reaction. - anabolic - endergonic - decomposition - exchange ________ reactions release energy. - Catabolic - Exergonic - Decomposition - Catabolic, exergonic, and decomposition Which of the following combinations of atoms is most likely to result in a chemical reaction? - hydrogen and hydrogen - hydrogen and helium - helium and helium - neon and helium Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. This is most likely due to the fact that ________. - the inside of the mouth maintains a very high temperature - chewing stores potential energy - chewing facilitates synthesis reactions - saliva contains enzymes CH4 is methane. This compound is ________. - inorganic - organic - reactive - a crystal Which of the following is most likely to be found evenly distributed in water in a homogeneous solution? - sodium ions and chloride ions - NaCl molecules - salt crystals - red blood cells Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate-chip batter is an example of a ________. - solvent - solute - solution - suspension A substance dissociates into K+ and Cl– in solution. The substance is a(n) ________. - acid - base - salt - buffer Ty is three years old and as a result of a “stomach bug” has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean? - Ty’s blood is slightly acidic. - Ty’s blood is slightly alkaline. - Ty’s blood is highly acidic. - Ty’s blood is within the normal range C6H12O6 is the chemical formula for a ________. - polymer of carbohydrate - pentose monosaccharide - hexose monosaccharide - all of the above What organic compound do brain cells primarily rely on for fuel? - glucose - glycogen - galactose - glycerol Which of the following is a functional group that is part of a building block of proteins? - phosphate - adenine - amino - ribose A pentose sugar is a part of the monomer used to build which type of macromolecule? - polysaccharides - nucleic acids - phosphorylated glucose - glycogen A phospholipid ________. - has both polar and nonpolar regions - is made up of a triglyceride bonded to a phosphate group - is a building block of ATP - can donate both cations and anions in solution In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________. - beta chain - pleated sheet - alpha helix - double helix Uracil ________. - contains nitrogen - is a pyrimidine - is found in RNA - all of the above The ability of an enzyme’s active sites to bind only substrates of compatible shape and charge is known as ________. - selectivity - specificity - subjectivity - specialty Critical Thinking Questions The most abundant elements in the foods and beverages you consume are oxygen, carbon, hydrogen, and nitrogen. Why might having these elements in consumables be useful? 34.Oxygen, whose atomic number is eight, has three stable isotopes: 16O, 17O, and 18O. Explain what this means in terms of the number of protons and neutrons. 35.Magnesium is an important element in the human body, especially in bones. Magnesium’s atomic number is 12. Is it stable or reactive? Why? If it were to react with another atom, would it be more likely to accept or to donate one or more electrons? 36.Explain why CH4 is one of the most common molecules found in nature. Are the bonds between the atoms ionic or covalent? 37.In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl? 38.Could two atoms of oxygen engage in ionic bonding? Why or why not? 39.AB+CD→AD+BEAB+CD→AD+BE Is this a legitimate example of an exchange reaction? Why or why not? 40.When you do a load of laundry, why do you not just drop a bar of soap into the washing machine? In other words, why is laundry detergent sold as a liquid or powder? 41.The pH of lemon juice is 2, and the pH of orange juice is 4. Which of these is more acidic, and by how much? What does this mean? 42.During a party, Eli loses a bet and is forced to drink a bottle of lemon juice. Not long thereafter, he begins complaining of having difficulty breathing, and his friends take him to the local emergency room. There, he is given an intravenous solution of bicarbonate. Why? 43.If the disaccharide maltose is formed from two glucose monosaccharides, which are hexose sugars, how many atoms of carbon, hydrogen, and oxygen does maltose contain and why? 44.Once dietary fats are digested and absorbed, why can they not be released directly into the bloodstream?	oercommons	2025-03-18T00:37:15.047236	07/23/2019	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/56352/overview", "title": "Anatomy and Physiology, Levels of Organization, The Chemical Level of Organization", "author": null }
https://oercommons.org/courseware/lesson/92491/overview	chapter 10 chapter 12 chapter 13 chapter 14 Chapter 14-Special Senses Chapter 16 Endocrine sys Chapter 18 blood Chapter 19 Heart chapter 2 Chapter 20 Blood Vessels Chapter 21-A Immune system Chapter 21-B Lymphatic system Chapter 22 Respiratory system Chapter 23 Digestive system Chapter 24 Urinary system Chapter 25 Fluids Chapter 26 Reproductive System chapter 3 chapter 4 chapter 5 chapter 6 chapter 9 Anatomy and Physiology I &II PowerPoints Overview PowerPoints for most of the A&P I & II courses. A&P I slides Those are PowerPoint files for the AP1 course. The axial, appendicular skeleton and muscular system chapters are not included in the slides as I only teach them in the lab. The nervous system chapters are mixed and do not follow the order of the book. In each chapter, there are several "group discussion questions." I assign those questions as pre-class assignments. Students must hand-write the answers and submit them through the LMS before we start the chapter for 4% of their total grade. This way, I guarantee they come and have an idea of what we are covering or are at least familiar with the terms. It must be hand-written to engage students in the activity; therefore, I grade them based on submission. In the lecture, I usually ask the students to check their answers within each group. Some slides have an "easy concept" tag. That indicates that the content of that particular slide is easy, and students can understand it by themselves. That helps me to skip the uncomplicated contents and gives me time to focus on the most challenging concepts. Please feel free to reach out if you have a question, correction, or a comment about the materials. Those are PowerPoint files for the AP1 course. The axial, appendicular skeleton and muscular system chapters are not included in the slides as I only teach them in the lab. The nervous system chapters are mixed and do not follow the order of the book. A&P II slides Those are PowerPoint files for the AP2 course. The blood vessels and the development and inheritance chapters are not included as I don't teach them. The lymphatic and immune system chapter is separated into two separate Powerpoints. . In each chapter, there are several "group discussion questions." I assign those questions as pre-class assignments. Students must hand-write the answers and submit them through the LMS before we start the chapter for 4% of their total grade. This way, I guarantee they come and have an idea of what we are covering or are at least familiar with the terms. It must be hand-written to engage students in the activity; therefore, I grade them based on submission. In the lecture, I usually ask the students to check their answers within each group. Some slides have an "easy concept" tag. That indicates that the content of that particular slide is easy, and students can understand it by themselves. That helps me to skip the uncomplicated contents and gives me time to focus on the most challenging concepts. Please feel free to reach out if you have a question, correction, or a comment about the materials. Those are PowerPoint files for the AP2 course. The blood vessels and the development and inheritance chapters are not included as I don't teach them. The lymphatic and immune system chapter is separated into two separate Powerpoints.	oercommons	2025-03-18T00:37:15.089908	05/05/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/92491/overview", "title": "Anatomy and Physiology I &II PowerPoints", "author": "Ahmed Katsha" }
https://oercommons.org/courseware/lesson/56366/overview	Axial Skeleton Introduction Figure 7.1 Lateral View of the Human Skull CHAPTER OBJECTIVES After studying this chapter, you will be able to: - Describe the functions of the skeletal system and define its two major subdivisions - Identify the bones and bony structures of the skull, the cranial suture lines, the cranial fossae, and the openings in the skull - Discuss the vertebral column and regional variations in its bony components and curvatures - Describe the components of the thoracic cage - Discuss the embryonic development of the axial skeleton The skeletal system forms the rigid internal framework of the body. It consists of the bones, cartilages, and ligaments. Bones support the weight of the body, allow for body movements, and protect internal organs. Cartilage provides flexible strength and support for body structures such as the thoracic cage, the external ear, and the trachea and larynx. At joints of the body, cartilage can also unite adjacent bones or provide cushioning between them. Ligaments are the strong connective tissue bands that hold the bones at a moveable joint together and serve to prevent excessive movements of the joint that would result in injury. Providing movement of the skeleton are the muscles of the body, which are firmly attached to the skeleton via connective tissue structures called tendons. As muscles contract, they pull on the bones to produce movements of the body. Thus, without a skeleton, you would not be able to stand, run, or even feed yourself! Each bone of the body serves a particular function, and therefore bones vary in size, shape, and strength based on these functions. For example, the bones of the lower back and lower limb are thick and strong to support your body weight. Similarly, the size of a bony landmark that serves as a muscle attachment site on an individual bone is related to the strength of this muscle. Muscles can apply very strong pulling forces to the bones of the skeleton. To resist these forces, bones have enlarged bony landmarks at sites where powerful muscles attach. This means that not only the size of a bone, but also its shape, is related to its function. For this reason, the identification of bony landmarks is important during your study of the skeletal system. Bones are also dynamic organs that can modify their strength and thickness in response to changes in muscle strength or body weight. Thus, muscle attachment sites on bones will thicken if you begin a workout program that increases muscle strength. Similarly, the walls of weight-bearing bones will thicken if you gain body weight or begin pounding the pavement as part of a new running regimen. In contrast, a reduction in muscle strength or body weight will cause bones to become thinner. This may happen during a prolonged hospital stay, following limb immobilization in a cast, or going into the weightlessness of outer space. Even a change in diet, such as eating only soft food due to the loss of teeth, will result in a noticeable decrease in the size and thickness of the jaw bones. Divisions of the Skeletal System - Discuss the functions of the skeletal system - Distinguish between the axial skeleton and appendicular skeleton - Define the axial skeleton and its components - Define the appendicular skeleton and its components The skeletal system includes all of the bones, cartilages, and ligaments of the body that support and give shape to the body and body structures. The skeleton consists of the bones of the body. For adults, there are 206 bones in the skeleton. Younger individuals have higher numbers of bones because some bones fuse together during childhood and adolescence to form an adult bone. The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity, and to provide a structure upon which muscles can act to produce movements of the body. The lower portion of the skeleton is specialized for stability during walking or running. In contrast, the upper skeleton has greater mobility and ranges of motion, features that allow you to lift and carry objects or turn your head and trunk. In addition to providing for support and movements of the body, the skeleton has protective and storage functions. It protects the internal organs, including the brain, spinal cord, heart, lungs, and pelvic organs. The bones of the skeleton serve as the primary storage site for important minerals such as calcium and phosphate. The bone marrow found within bones stores fat and houses the blood-cell producing tissue of the body. The skeleton is subdivided into two major divisions—the axial and appendicular. The Axial Skeleton The skeleton is subdivided into two major divisions—the axial and appendicular. The axial skeleton forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back (Figure 7.2). It serves to protect the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs. The axial skeleton of the adult consists of 80 bones, including the skull, the vertebral column, and the thoracic cage. The skull is formed by 22 bones. Also associated with the head are an additional seven bones, including the hyoid bone and the ear ossicles (three small bones found in each middle ear). The vertebral column consists of 24 bones, each called a vertebra, plus the sacrum and coccyx. The thoracic cage includes the 12 pairs of ribs, and the sternum, the flattened bone of the anterior chest. Figure 7.2 Axial and Appendicular Skeleton The axial skeleton supports the head, neck, back, and chest and thus forms the vertical axis of the body. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The appendicular skeleton is made up of all bones of the upper and lower limbs. The Appendicular Skeleton The appendicular skeleton includes all bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult. The bones of the appendicular skeleton are covered in a separate chapter. The Skull - List and identify the bones of the brain case and face - Locate the major suture lines of the skull and name the bones associated with each - Locate and define the boundaries of the anterior, middle, and posterior cranial fossae, the temporal fossa, and infratemporal fossa - Define the paranasal sinuses and identify the location of each - Name the bones that make up the walls of the orbit and identify the openings associated with the orbit - Identify the bones and structures that form the nasal septum and nasal conchae, and locate the hyoid bone - Identify the bony openings of the skull The cranium (skull) is the skeletal structure of the head that supports the face and protects the brain. It is subdivided into the facial bones and the brain case, or cranial vault (Figure 7.3). The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws. The rounded brain case surrounds and protects the brain and houses the middle and inner ear structures. In the adult, the skull consists of 22 individual bones, 21 of which are immobile and united into a single unit. The 22nd bone is the mandible (lower jaw), which is the only moveable bone of the skull. Figure 7.3 Parts of the Skull The skull consists of the rounded brain case that houses the brain and the facial bones that form the upper and lower jaws, nose, orbits, and other facial structures. INTERACTIVE LINK Watch this video to view a rotating and exploded skull, with color-coded bones. Which bone (yellow) is centrally located and joins with most of the other bones of the skull? Anterior View of Skull The anterior skull consists of the facial bones and provides the bony support for the eyes and structures of the face. This view of the skull is dominated by the openings of the orbits and the nasal cavity. Also seen are the upper and lower jaws, with their respective teeth (Figure 7.4). The orbit is the bony socket that houses the eyeball and muscles that move the eyeball or open the upper eyelid. The upper margin of the anterior orbit is the supraorbital margin. Located near the midpoint of the supraorbital margin is a small opening called the supraorbital foramen. This provides for passage of a sensory nerve to the skin of the forehead. Below the orbit is the infraorbital foramen, which is the point of emergence for a sensory nerve that supplies the anterior face below the orbit. Figure 7.4 Anterior View of Skull An anterior view of the skull shows the bones that form the forehead, orbits (eye sockets), nasal cavity, nasal septum, and upper and lower jaws. Inside the nasal area of the skull, the nasal cavity is divided into halves by the nasal septum. The upper portion of the nasal septum is formed by the perpendicular plate of the ethmoid bone and the lower portion is the vomer bone. Each side of the nasal cavity is triangular in shape, with a broad inferior space that narrows superiorly. When looking into the nasal cavity from the front of the skull, two bony plates are seen projecting from each lateral wall. The larger of these is the inferior nasal concha, an independent bone of the skull. Located just above the inferior concha is the middle nasal concha, which is part of the ethmoid bone. A third bony plate, also part of the ethmoid bone, is the superior nasal concha. It is much smaller and out of sight, above the middle concha. The superior nasal concha is located just lateral to the perpendicular plate, in the upper nasal cavity. Lateral View of Skull A view of the lateral skull is dominated by the large, rounded brain case above and the upper and lower jaws with their teeth below (Figure 7.5). Separating these areas is the bridge of bone called the zygomatic arch. The zygomatic arch is the bony arch on the side of skull that spans from the area of the cheek to just above the ear canal. It is formed by the junction of two bony processes: a short anterior component, the temporal process of the zygomatic bone (the cheekbone) and a longer posterior portion, the zygomatic process of the temporal bone, extending forward from the temporal bone. Thus the temporal process (anteriorly) and the zygomatic process (posteriorly) join together, like the two ends of a drawbridge, to form the zygomatic arch. One of the major muscles that pulls the mandible upward during biting and chewing arises from the zygomatic arch. On the lateral side of the brain case, above the level of the zygomatic arch, is a shallow space called the temporal fossa. Below the level of the zygomatic arch and deep to the vertical portion of the mandible is another space called the infratemporal fossa. Both the temporal fossa and infratemporal fossa contain muscles that act on the mandible during chewing. Figure 7.5 Lateral View of Skull The lateral skull shows the large rounded brain case, zygomatic arch, and the upper and lower jaws. The zygomatic arch is formed jointly by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. The shallow space above the zygomatic arch is the temporal fossa. The space inferior to the zygomatic arch and deep to the posterior mandible is the infratemporal fossa. Bones of the Brain Case The brain case contains and protects the brain. The interior space that is almost completely occupied by the brain is called the cranial cavity. This cavity is bounded superiorly by the rounded top of the skull, which is called the calvaria (skullcap), and the lateral and posterior sides of the skull. The bones that form the top and sides of the brain case are usually referred to as the “flat” bones of the skull. The floor of the brain case is referred to as the base of the skull. This is a complex area that varies in depth and has numerous openings for the passage of cranial nerves, blood vessels, and the spinal cord. Inside the skull, the base is subdivided into three large spaces, called the anterior cranial fossa, middle cranial fossa, and posterior cranial fossa (fossa = “trench or ditch”) (Figure 7.6). From anterior to posterior, the fossae increase in depth. The shape and depth of each fossa corresponds to the shape and size of the brain region that each houses. The boundaries and openings of the cranial fossae (singular = fossa) will be described in a later section. Figure 7.6 Cranial Fossae The bones of the brain case surround and protect the brain, which occupies the cranial cavity. The base of the brain case, which forms the floor of cranial cavity, is subdivided into the shallow anterior cranial fossa, the middle cranial fossa, and the deep posterior cranial fossa. The brain case consists of eight bones. These include the paired parietal and temporal bones, plus the unpaired frontal, occipital, sphenoid, and ethmoid bones. Parietal Bone The parietal bone forms most of the upper lateral side of the skull (see Figure 7.5). These are paired bones, with the right and left parietal bones joining together at the top of the skull. Each parietal bone is also bounded anteriorly by the frontal bone, inferiorly by the temporal bone, and posteriorly by the occipital bone. Temporal Bone The temporal bone forms the lower lateral side of the skull (see Figure 7.5). Common wisdom has it that the temporal bone (temporal = “time”) is so named because this area of the head (the temple) is where hair typically first turns gray, indicating the passage of time. The temporal bone is subdivided into several regions (Figure 7.7). The flattened, upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting inferiorly from this region is a large prominence, the mastoid process, which serves as a muscle attachment site. The mastoid process can easily be felt on the side of the head just behind your earlobe. On the interior of the skull, the petrous portion of each temporal bone forms the prominent, diagonally oriented petrous ridge in the floor of the cranial cavity. Located inside each petrous ridge are small cavities that house the structures of the middle and inner ears. Figure 7.7 Temporal Bone A lateral view of the isolated temporal bone shows the squamous, mastoid, and zygomatic portions of the temporal bone. Important landmarks of the temporal bone, as shown in Figure 7.8, include the following: - External acoustic meatus (ear canal)—This is the large opening on the lateral side of the skull that is associated with the ear. - Internal acoustic meatus—This opening is located inside the cranial cavity, on the medial side of the petrous ridge. It connects to the middle and inner ear cavities of the temporal bone. - Mandibular fossa—This is the deep, oval-shaped depression located on the external base of the skull, just in front of the external acoustic meatus. The mandible (lower jaw) joins with the skull at this site as part of the temporomandibular joint, which allows for movements of the mandible during opening and closing of the mouth. - Articular tubercle—The smooth ridge located immediately anterior to the mandibular fossa. Both the articular tubercle and mandibular fossa contribute to the temporomandibular joint, the joint that provides for movements between the temporal bone of the skull and the mandible. - Styloid process—Posterior to the mandibular fossa on the external base of the skull is an elongated, downward bony projection called the styloid process, so named because of its resemblance to a stylus (a pen or writing tool). This structure serves as an attachment site for several small muscles and for a ligament that supports the hyoid bone of the neck. (See also Figure 7.7.) - Stylomastoid foramen—This small opening is located between the styloid process and mastoid process. This is the point of exit for the cranial nerve that supplies the facial muscles. - Carotid canal—The carotid canal is a zig-zag shaped tunnel that provides passage through the base of the skull for one of the major arteries that supplies the brain. Its entrance is located on the outside base of the skull, anteromedial to the styloid process. The canal then runs anteromedially within the bony base of the skull, and then turns upward to its exit in the floor of the middle cranial cavity, above the foramen lacerum. Figure 7.8 External and Internal Views of Base of Skull (a) The hard palate is formed anteriorly by the palatine processes of the maxilla bones and posteriorly by the horizontal plate of the palatine bones. (b) The complex floor of the cranial cavity is formed by the frontal, ethmoid, sphenoid, temporal, and occipital bones. The lesser wing of the sphenoid bone separates the anterior and middle cranial fossae. The petrous ridge (petrous portion of temporal bone) separates the middle and posterior cranial fossae. Frontal Bone The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella (see Figure 7.5). The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin, is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin, forming rounded brow ridges. These are located just behind your eyebrows and vary in size among individuals, although they are generally larger in males. Inside the cranial cavity, the frontal bone extends posteriorly. This flattened region forms both the roof of the orbit below and the floor of the anterior cranial cavity above (see Figure 7.8b). Occipital Bone The occipital bone is the single bone that forms the posterior skull and posterior base of the cranial cavity (Figure 7.9; see also Figure 7.8). On its outside surface, at the posterior midline, is a small protrusion called the external occipital protuberance, which serves as an attachment site for a ligament of the posterior neck. Lateral to either side of this bump is a superior nuchal line (nuchal = “nape” or “posterior neck”). The nuchal lines represent the most superior point at which muscles of the neck attach to the skull, with only the scalp covering the skull above these lines. On the base of the skull, the occipital bone contains the large opening of the foramen magnum, which allows for passage of the spinal cord as it exits the skull. On either side of the foramen magnum is an oval-shaped occipital condyle. These condyles form joints with the first cervical vertebra and thus support the skull on top of the vertebral column. Figure 7.9 Posterior View of Skull This view of the posterior skull shows attachment sites for muscles and joints that support the skull. Sphenoid Bone The sphenoid bone is a single, complex bone of the central skull (Figure 7.10). It serves as a “keystone” bone, because it joins with almost every other bone of the skull. The sphenoid forms much of the base of the central skull (see Figure 7.8) and also extends laterally to contribute to the sides of the skull (see Figure 7.5). Inside the cranial cavity, the right and left lesser wings of the sphenoid bone, which resemble the wings of a flying bird, form the lip of a prominent ridge that marks the boundary between the anterior and middle cranial fossae. The sella turcica (“Turkish saddle”) is located at the midline of the middle cranial fossa. This bony region of the sphenoid bone is named for its resemblance to the horse saddles used by the Ottoman Turks, with a high back and a tall front. The rounded depression in the floor of the sella turcica is the hypophyseal (pituitary) fossa, which houses the pea-sized pituitary (hypophyseal) gland. The greater wings of the sphenoid bone extend laterally to either side away from the sella turcica, where they form the anterior floor of the middle cranial fossa. The greater wing is best seen on the outside of the lateral skull, where it forms a rectangular area immediately anterior to the squamous portion of the temporal bone. On the inferior aspect of the skull, each half of the sphenoid bone forms two thin, vertically oriented bony plates. These are the medial pterygoid plate and lateral pterygoid plate (pterygoid = “wing-shaped”). The right and left medial pterygoid plates form the posterior, lateral walls of the nasal cavity. The somewhat larger lateral pterygoid plates serve as attachment sites for chewing muscles that fill the infratemporal space and act on the mandible. Figure 7.10 Sphenoid Bone Shown in isolation in (a) superior and (b) posterior views, the sphenoid bone is a single midline bone that forms the anterior walls and floor of the middle cranial fossa. It has a pair of lesser wings and a pair of greater wings. The sella turcica surrounds the hypophyseal fossa. Projecting downward are the medial and lateral pterygoid plates. The sphenoid has multiple openings for the passage of nerves and blood vessels, including the optic canal, superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum. Ethmoid Bone The ethmoid bone is a single, midline bone that forms the roof and lateral walls of the upper nasal cavity, the upper portion of the nasal septum, and contributes to the medial wall of the orbit (Figure 7.11 and Figure 7.12). On the interior of the skull, the ethmoid also forms a portion of the floor of the anterior cranial cavity (see Figure 7.8b). Within the nasal cavity, the perpendicular plate of the ethmoid bone forms the upper portion of the nasal septum. The ethmoid bone also forms the lateral walls of the upper nasal cavity. Extending from each lateral wall are the superior nasal concha and middle nasal concha, which are thin, curved projections that extend into the nasal cavity (Figure 7.13). In the cranial cavity, the ethmoid bone forms a small area at the midline in the floor of the anterior cranial fossa. This region also forms the narrow roof of the underlying nasal cavity. This portion of the ethmoid bone consists of two parts, the crista galli and cribriform plates. The crista galli (“rooster’s comb or crest”) is a small upward bony projection located at the midline. It functions as an anterior attachment point for one of the covering layers of the brain. To either side of the crista galli is the cribriform plate (cribrum = “sieve”), a small, flattened area with numerous small openings termed olfactory foramina. Small nerve branches from the olfactory areas of the nasal cavity pass through these openings to enter the brain. The lateral portions of the ethmoid bone are located between the orbit and upper nasal cavity, and thus form the lateral nasal cavity wall and a portion of the medial orbit wall. Located inside this portion of the ethmoid bone are several small, air-filled spaces that are part of the paranasal sinus system of the skull. Figure 7.11 Sagittal Section of Skull This midline view of the sagittally sectioned skull shows the nasal septum. Figure 7.12 Ethmoid Bone The unpaired ethmoid bone is located at the midline within the central skull. It has an upward projection, the crista galli, and a downward projection, the perpendicular plate, which forms the upper nasal septum. The cribriform plates form both the roof of the nasal cavity and a portion of the anterior cranial fossa floor. The lateral sides of the ethmoid bone form the lateral walls of the upper nasal cavity, part of the medial orbit wall, and give rise to the superior and middle nasal conchae. The ethmoid bone also contains the ethmoid air cells. Figure 7.13 Lateral Wall of Nasal Cavity The three nasal conchae are curved bones that project from the lateral walls of the nasal cavity. The superior nasal concha and middle nasal concha are parts of the ethmoid bone. The inferior nasal concha is an independent bone of the skull. Sutures of the Skull A suture is an immobile joint between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the bones of the brain case are not straight, but instead follow irregular, tightly twisting paths. These twisting lines serve to tightly interlock the adjacent bones, thus adding strength to the skull for brain protection. The two suture lines seen on the top of the skull are the coronal and sagittal sutures. The coronal suture runs from side to side across the skull, within the coronal plane of section (see Figure 7.5). It joins the frontal bone to the right and left parietal bones. The sagittal suture extends posteriorly from the coronal suture, running along the midline at the top of the skull in the sagittal plane of section (see Figure 7.9). It unites the right and left parietal bones. On the posterior skull, the sagittal suture terminates by joining the lambdoid suture. The lambdoid suture extends downward and laterally to either side away from its junction with the sagittal suture. The lambdoid suture joins the occipital bone to the right and left parietal and temporal bones. This suture is named for its upside-down "V" shape, which resembles the capital letter version of the Greek letter lambda (Λ). The squamous suture is located on the lateral skull. It unites the squamous portion of the temporal bone with the parietal bone (see Figure 7.5). At the intersection of four bones is the pterion, a small, capital-H-shaped suture line region that unites the frontal bone, parietal bone, squamous portion of the temporal bone, and greater wing of the sphenoid bone. It is the weakest part of the skull. The pterion is located approximately two finger widths above the zygomatic arch and a thumb’s width posterior to the upward portion of the zygomatic bone. DISORDERS OF THE... Skeletal System Head and traumatic brain injuries are major causes of immediate death and disability, with bleeding and infections as possible additional complications. According to the Centers for Disease Control and Prevention (2010), approximately 30 percent of all injury-related deaths in the United States are caused by head injuries. The majority of head injuries involve falls. They are most common among young children (ages 0–4 years), adolescents (15–19 years), and the elderly (over 65 years). Additional causes vary, but prominent among these are automobile and motorcycle accidents. Strong blows to the brain-case portion of the skull can produce fractures. These may result in bleeding inside the skull with subsequent injury to the brain. The most common is a linear skull fracture, in which fracture lines radiate from the point of impact. Other fracture types include a comminuted fracture, in which the bone is broken into several pieces at the point of impact, or a depressed fracture, in which the fractured bone is pushed inward. In a contrecoup (counterblow) fracture, the bone at the point of impact is not broken, but instead a fracture occurs on the opposite side of the skull. Fractures of the occipital bone at the base of the skull can occur in this manner, producing a basilar fracture that can damage the artery that passes through the carotid canal. A blow to the lateral side of the head may fracture the bones of the pterion. The pterion is an important clinical landmark because located immediately deep to it on the inside of the skull is a major branch of an artery that supplies the skull and covering layers of the brain. A strong blow to this region can fracture the bones around the pterion. If the underlying artery is damaged, bleeding can cause the formation of a hematoma (collection of blood) between the brain and interior of the skull. As blood accumulates, it will put pressure on the brain. Symptoms associated with a hematoma may not be apparent immediately following the injury, but if untreated, blood accumulation will exert increasing pressure on the brain and can result in death within a few hours. INTERACTIVE LINK View this animation to see how a blow to the head may produce a contrecoup (counterblow) fracture of the basilar portion of the occipital bone on the base of the skull. Why may a basilar fracture be life threatening? Facial Bones of the Skull The facial bones of the skull form the upper and lower jaws, the nose, nasal cavity and nasal septum, and the orbit. The facial bones include 14 bones, with six paired bones and two unpaired bones. The paired bones are the maxilla, palatine, zygomatic, nasal, lacrimal, and inferior nasal conchae bones. The unpaired bones are the vomer and mandible bones. Although classified with the brain-case bones, the ethmoid bone also contributes to the nasal septum and the walls of the nasal cavity and orbit. Maxillary Bone The maxillary bone, often referred to simply as the maxilla (plural = maxillae), is one of a pair that together form the upper jaw, much of the hard palate, the medial floor of the orbit, and the lateral base of the nose (see Figure 7.4). The curved, inferior margin of the maxillary bone that forms the upper jaw and contains the upper teeth is the alveolar process of the maxilla(Figure 7.14). Each tooth is anchored into a deep socket called an alveolus. On the anterior maxilla, just below the orbit, is the infraorbital foramen. This is the point of exit for a sensory nerve that supplies the nose, upper lip, and anterior cheek. On the inferior skull, the palatine process from each maxillary bone can be seen joining together at the midline to form the anterior three-quarters of the hard palate (see Figure 7.8a). The hard palate is the bony plate that forms the roof of the mouth and floor of the nasal cavity, separating the oral and nasal cavities. Figure 7.14 Maxillary Bone The maxillary bone forms the upper jaw and supports the upper teeth. Each maxilla also forms the lateral floor of each orbit and the majority of the hard palate. Palatine Bone The palatine bone is one of a pair of irregularly shaped bones that contribute small areas to the lateral walls of the nasal cavity and the medial wall of each orbit. The largest region of each of the palatine bone is the horizontal plate. The plates from the right and left palatine bones join together at the midline to form the posterior quarter of the hard palate (see Figure 7.8a). Thus, the palatine bones are best seen in an inferior view of the skull and hard palate. HOMEOSTATIC IMBALANCES Cleft Lip and Cleft Palate During embryonic development, the right and left maxilla bones come together at the midline to form the upper jaw. At the same time, the muscle and skin overlying these bones join together to form the upper lip. Inside the mouth, the palatine processes of the maxilla bones, along with the horizontal plates of the right and left palatine bones, join together to form the hard palate. If an error occurs in these developmental processes, a birth defect of cleft lip or cleft palate may result. Cleft lip is a common development defect that affects approximately 1:1000 births, most of which are male. This defect involves a partial or complete failure of the right and left portions of the upper lip to fuse together, leaving a cleft (gap). A more severe developmental defect is cleft palate, which affects the hard palate. The hard palate is the bony structure that separates the nasal cavity from the oral cavity. It is formed during embryonic development by the midline fusion of the horizontal plates from the right and left palatine bones and the palatine processes of the maxilla bones. Cleft palate affects approximately 1:2500 births and is more common in females. It results from a failure of the two halves of the hard palate to completely come together and fuse at the midline, thus leaving a gap between them. This gap allows for communication between the nasal and oral cavities. In severe cases, the bony gap continues into the anterior upper jaw where the alveolar processes of the maxilla bones also do not properly join together above the front teeth. If this occurs, a cleft lip will also be seen. Because of the communication between the oral and nasal cavities, a cleft palate makes it very difficult for an infant to generate the suckling needed for nursing, thus leaving the infant at risk for malnutrition. Surgical repair is required to correct cleft palate defects. Zygomatic Bone The zygomatic bone is also known as the cheekbone. Each of the paired zygomatic bones forms much of the lateral wall of the orbit and the lateral-inferior margins of the anterior orbital opening (see Figure 7.4). The short temporal process of the zygomatic bone projects posteriorly, where it forms the anterior portion of the zygomatic arch (see Figure 7.5). Nasal Bone The nasal bone is one of two small bones that articulate (join) with each other to form the bony base (bridge) of the nose. They also support the cartilages that form the lateral walls of the nose (see Figure 7.11). These are the bones that are damaged when the nose is broken. Lacrimal Bone Each lacrimal bone is a small, rectangular bone that forms the anterior, medial wall of the orbit (see Figure 7.4 and Figure 7.5). The anterior portion of the lacrimal bone forms a shallow depression called the lacrimal fossa, and extending inferiorly from this is the nasolacrimal canal. The lacrimal fluid (tears of the eye), which serves to maintain the moist surface of the eye, drains at the medial corner of the eye into the nasolacrimal canal. This duct then extends downward to open into the nasal cavity, behind the inferior nasal concha. In the nasal cavity, the lacrimal fluid normally drains posteriorly, but with an increased flow of tears due to crying or eye irritation, some fluid will also drain anteriorly, thus causing a runny nose. Inferior Nasal Conchae The right and left inferior nasal conchae form a curved bony plate that projects into the nasal cavity space from the lower lateral wall (see Figure 7.13). The inferior concha is the largest of the nasal conchae and can easily be seen when looking into the anterior opening of the nasal cavity. Vomer Bone The unpaired vomer bone, often referred to simply as the vomer, is triangular-shaped and forms the posterior-inferior part of the nasal septum (see Figure 7.11). The vomer is best seen when looking from behind into the posterior openings of the nasal cavity (see Figure 7.8a). In this view, the vomer is seen to form the entire height of the nasal septum. A much smaller portion of the vomer can also be seen when looking into the anterior opening of the nasal cavity. Mandible The mandible forms the lower jaw and is the only moveable bone of the skull. At the time of birth, the mandible consists of paired right and left bones, but these fuse together during the first year to form the single U-shaped mandible of the adult skull. Each side of the mandible consists of a horizontal body and posteriorly, a vertically oriented ramus of the mandible (ramus = “branch”). The outside margin of the mandible, where the body and ramus come together is called the angle of the mandible(Figure 7.15). The ramus on each side of the mandible has two upward-going bony projections. The more anterior projection is the flattened coronoid process of the mandible, which provides attachment for one of the biting muscles. The posterior projection is the condylar process of the mandible, which is topped by the oval-shaped condyle. The condyle of the mandible articulates (joins) with the mandibular fossa and articular tubercle of the temporal bone. Together these articulations form the temporomandibular joint, which allows for opening and closing of the mouth (see Figure 7.5). The broad U-shaped curve located between the coronoid and condylar processes is the mandibular notch. Important landmarks for the mandible include the following: - Alveolar process of the mandible—This is the upper border of the mandibular body and serves to anchor the lower teeth. - Mental protuberance—The forward projection from the inferior margin of the anterior mandible that forms the chin (mental = “chin”). - Mental foramen—The opening located on each side of the anterior-lateral mandible, which is the exit site for a sensory nerve that supplies the chin. - Mylohyoid line—This bony ridge extends along the inner aspect of the mandibular body (see Figure 7.11). The muscle that forms the floor of the oral cavity attaches to the mylohyoid lines on both sides of the mandible. - Mandibular foramen—This opening is located on the medial side of the ramus of the mandible. The opening leads into a tunnel that runs down the length of the mandibular body. The sensory nerve and blood vessels that supply the lower teeth enter the mandibular foramen and then follow this tunnel. Thus, to numb the lower teeth prior to dental work, the dentist must inject anesthesia into the lateral wall of the oral cavity at a point prior to where this sensory nerve enters the mandibular foramen. - Lingula—This small flap of bone is named for its shape (lingula = “little tongue”). It is located immediately next to the mandibular foramen, on the medial side of the ramus. A ligament that anchors the mandible during opening and closing of the mouth extends down from the base of the skull and attaches to the lingula. Figure 7.15 Isolated Mandible The mandible is the only moveable bone of the skull. The Orbit The orbit is the bony socket that houses the eyeball and contains the muscles that move the eyeball or open the upper eyelid. Each orbit is cone-shaped, with a narrow posterior region that widens toward the large anterior opening. To help protect the eye, the bony margins of the anterior opening are thickened and somewhat constricted. The medial walls of the two orbits are parallel to each other but each lateral wall diverges away from the midline at a 45° angle. This divergence provides greater lateral peripheral vision. The walls of each orbit include contributions from seven skull bones (Figure 7.16). The frontal bone forms the roof and the zygomatic bone forms the lateral wall and lateral floor. The medial floor is primarily formed by the maxilla, with a small contribution from the palatine bone. The ethmoid bone and lacrimal bone make up much of the medial wall and the sphenoid bone forms the posterior orbit. At the posterior apex of the orbit is the opening of the optic canal, which allows for passage of the optic nerve from the retina to the brain. Lateral to this is the elongated and irregularly shaped superior orbital fissure, which provides passage for the artery that supplies the eyeball, sensory nerves, and the nerves that supply the muscles involved in eye movements. Figure 7.16 Bones of the Orbit Seven skull bones contribute to the walls of the orbit. Opening into the posterior orbit from the cranial cavity are the optic canal and superior orbital fissure. The Nasal Septum and Nasal Conchae The nasal septum consists of both bone and cartilage components (Figure 7.17; see also Figure 7.11). The upper portion of the septum is formed by the perpendicular plate of the ethmoid bone. The lower and posterior parts of the septum are formed by the triangular-shaped vomer bone. In an anterior view of the skull, the perpendicular plate of the ethmoid bone is easily seen inside the nasal opening as the upper nasal septum, but only a small portion of the vomer is seen as the inferior septum. A better view of the vomer bone is seen when looking into the posterior nasal cavity with an inferior view of the skull, where the vomer forms the full height of the nasal septum. The anterior nasal septum is formed by the septal cartilage, a flexible plate that fills in the gap between the perpendicular plate of the ethmoid and vomer bones. This cartilage also extends outward into the nose where it separates the right and left nostrils. The septal cartilage is not found in the dry skull. Attached to the lateral wall on each side of the nasal cavity are the superior, middle, and inferior nasal conchae (singular = concha), which are named for their positions (see Figure 7.13). These are bony plates that curve downward as they project into the space of the nasal cavity. They serve to swirl the incoming air, which helps to warm and moisturize it before the air moves into the delicate air sacs of the lungs. This also allows mucus, secreted by the tissue lining the nasal cavity, to trap incoming dust, pollen, bacteria, and viruses. The largest of the conchae is the inferior nasal concha, which is an independent bone of the skull. The middle concha and the superior conchae, which is the smallest, are both formed by the ethmoid bone. When looking into the anterior nasal opening of the skull, only the inferior and middle conchae can be seen. The small superior nasal concha is well hidden above and behind the middle concha. Figure 7.17 Nasal Septum The nasal septum is formed by the perpendicular plate of the ethmoid bone and the vomer bone. The septal cartilage fills the gap between these bones and extends into the nose. Cranial Fossae Inside the skull, the floor of the cranial cavity is subdivided into three cranial fossae (spaces), which increase in depth from anterior to posterior (see Figure 7.6, Figure 7.8b, and Figure 7.11). Since the brain occupies these areas, the shape of each conforms to the shape of the brain regions that it contains. Each cranial fossa has anterior and posterior boundaries and is divided at the midline into right and left areas by a significant bony structure or opening. Anterior Cranial Fossa The anterior cranial fossa is the most anterior and the shallowest of the three cranial fossae. It overlies the orbits and contains the frontal lobes of the brain. Anteriorly, the anterior fossa is bounded by the frontal bone, which also forms the majority of the floor for this space. The lesser wings of the sphenoid bone form the prominent ledge that marks the boundary between the anterior and middle cranial fossae. Located in the floor of the anterior cranial fossa at the midline is a portion of the ethmoid bone, consisting of the upward projecting crista galli and to either side of this, the cribriform plates. Middle Cranial Fossa The middle cranial fossa is deeper and situated posterior to the anterior fossa. It extends from the lesser wings of the sphenoid bone anteriorly, to the petrous ridges (petrous portion of the temporal bones) posteriorly. The large, diagonally positioned petrous ridges give the middle cranial fossa a butterfly shape, making it narrow at the midline and broad laterally. The temporal lobes of the brain occupy this fossa. The middle cranial fossa is divided at the midline by the upward bony prominence of the sella turcica, a part of the sphenoid bone. The middle cranial fossa has several openings for the passage of blood vessels and cranial nerves (see Figure 7.8). Openings in the middle cranial fossa are as follows: - Optic canal—This opening is located at the anterior lateral corner of the sella turcica. It provides for passage of the optic nerve into the orbit. - Superior orbital fissure—This large, irregular opening into the posterior orbit is located on the anterior wall of the middle cranial fossa, lateral to the optic canal and under the projecting margin of the lesser wing of the sphenoid bone. Nerves to the eyeball and associated muscles, and sensory nerves to the forehead pass through this opening. - Foramen rotundum—This rounded opening (rotundum = “round”) is located in the floor of the middle cranial fossa, just inferior to the superior orbital fissure. It is the exit point for a major sensory nerve that supplies the cheek, nose, and upper teeth. - Foramen ovale of the middle cranial fossa—This large, oval-shaped opening in the floor of the middle cranial fossa provides passage for a major sensory nerve to the lateral head, cheek, chin, and lower teeth. - Foramen spinosum—This small opening, located posterior-lateral to the foramen ovale, is the entry point for an important artery that supplies the covering layers surrounding the brain. The branching pattern of this artery forms readily visible grooves on the internal surface of the skull and these grooves can be traced back to their origin at the foramen spinosum. - Carotid canal—This is the zig-zag passageway through which a major artery to the brain enters the skull. The entrance to the carotid canal is located on the inferior aspect of the skull, anteromedial to the styloid process (see Figure 7.8a). From here, the canal runs anteromedially within the bony base of the skull. Just above the foramen lacerum, the carotid canal opens into the middle cranial cavity, near the posterior-lateral base of the sella turcica. - Foramen lacerum—This irregular opening is located in the base of the skull, immediately inferior to the exit of the carotid canal. This opening is an artifact of the dry skull, because in life it is completely filled with cartilage. All the openings of the skull that provide for passage of nerves or blood vessels have smooth margins; the word lacerum (“ragged” or “torn”) tells us that this opening has ragged edges and thus nothing passes through it. Posterior Cranial Fossa The posterior cranial fossa is the most posterior and deepest portion of the cranial cavity. It contains the cerebellum of the brain. The posterior fossa is bounded anteriorly by the petrous ridges, while the occipital bone forms the floor and posterior wall. It is divided at the midline by the large foramen magnum (“great aperture”), the opening that provides for passage of the spinal cord. Located on the medial wall of the petrous ridge in the posterior cranial fossa is the internal acoustic meatus (see Figure 7.11). This opening provides for passage of the nerve from the hearing and equilibrium organs of the inner ear, and the nerve that supplies the muscles of the face. Located at the anterior-lateral margin of the foramen magnum is the hypoglossal canal. These emerge on the inferior aspect of the skull at the base of the occipital condyle and provide passage for an important nerve to the tongue. Immediately inferior to the internal acoustic meatus is the large, irregularly shaped jugular foramen (see Figure 7.8a). Several cranial nerves from the brain exit the skull via this opening. It is also the exit point through the base of the skull for all the venous return blood leaving the brain. The venous structures that carry blood inside the skull form large, curved grooves on the inner walls of the posterior cranial fossa, which terminate at each jugular foramen. Paranasal Sinuses The paranasal sinuses are hollow, air-filled spaces located within certain bones of the skull (Figure 7.18). All of the sinuses communicate with the nasal cavity (paranasal = “next to nasal cavity”) and are lined with nasal mucosa. They serve to reduce bone mass and thus lighten the skull, and they also add resonance to the voice. This second feature is most obvious when you have a cold or sinus congestion. These produce swelling of the mucosa and excess mucus production, which can obstruct the narrow passageways between the sinuses and the nasal cavity, causing your voice to sound different to yourself and others. This blockage can also allow the sinuses to fill with fluid, with the resulting pressure producing pain and discomfort. The paranasal sinuses are named for the skull bone that each occupies. The frontal sinus is located just above the eyebrows, within the frontal bone (see Figure 7.17). This irregular space may be divided at the midline into bilateral spaces, or these may be fused into a single sinus space. The frontal sinus is the most anterior of the paranasal sinuses. The largest sinus is the maxillary sinus. These are paired and located within the right and left maxillary bones, where they occupy the area just below the orbits. The maxillary sinuses are most commonly involved during sinus infections. Because their connection to the nasal cavity is located high on their medial wall, they are difficult to drain. The sphenoid sinus is a single, midline sinus. It is located within the body of the sphenoid bone, just anterior and inferior to the sella turcica, thus making it the most posterior of the paranasal sinuses. The lateral aspects of the ethmoid bone contain multiple small spaces separated by very thin bony walls. Each of these spaces is called an ethmoid air cell. These are located on both sides of the ethmoid bone, between the upper nasal cavity and medial orbit, just behind the superior nasal conchae. Figure 7.18 Paranasal Sinuses The paranasal sinuses are hollow, air-filled spaces named for the skull bone that each occupies. The most anterior is the frontal sinus, located in the frontal bone above the eyebrows. The largest are the maxillary sinuses, located in the right and left maxillary bones below the orbits. The most posterior is the sphenoid sinus, located in the body of the sphenoid bone, under the sella turcica. The ethmoid air cells are multiple small spaces located in the right and left sides of the ethmoid bone, between the medial wall of the orbit and lateral wall of the upper nasal cavity. Hyoid Bone The hyoid bone is an independent bone that does not contact any other bone and thus is not part of the skull (Figure 7.19). It is a small U-shaped bone located in the upper neck near the level of the inferior mandible, with the tips of the “U” pointing posteriorly. The hyoid serves as the base for the tongue above, and is attached to the larynx below and the pharynx posteriorly. The hyoid is held in position by a series of small muscles that attach to it either from above or below. These muscles act to move the hyoid up/down or forward/back. Movements of the hyoid are coordinated with movements of the tongue, larynx, and pharynx during swallowing and speaking. Figure 7.19 Hyoid Bone The hyoid bone is located in the upper neck and does not join with any other bone. It provides attachments for muscles that act on the tongue, larynx, and pharynx. The Vertebral Column - Describe each region of the vertebral column and the number of bones in each region - Discuss the curves of the vertebral column and how these change after birth - Describe a typical vertebra and determine the distinguishing characteristics for vertebrae in each vertebral region and features of the sacrum and the coccyx - Define the structure of an intervertebral disc - Determine the location of the ligaments that provide support for the vertebral column The vertebral column is also known as the spinal column or spine (Figure 7.20). It consists of a sequence of vertebrae (singular = vertebra), each of which is separated and united by an intervertebral disc. Together, the vertebrae and intervertebral discs form the vertebral column. It is a flexible column that supports the head, neck, and body and allows for their movements. It also protects the spinal cord, which passes down the back through openings in the vertebrae. Figure 7.20 Vertebral Column The adult vertebral column consists of 24 vertebrae, plus the sacrum and coccyx. The vertebrae are divided into three regions: cervical C1–C7 vertebrae, thoracic T1–T12 vertebrae, and lumbar L1–L5 vertebrae. The vertebral column is curved, with two primary curvatures (thoracic and sacrococcygeal curves) and two secondary curvatures (cervical and lumbar curves). Regions of the Vertebral Column The vertebral column originally develops as a series of 33 vertebrae, but this number is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. The vertebral column is subdivided into five regions, with the vertebrae in each area named for that region and numbered in descending order. In the neck, there are seven cervical vertebrae, each designated with the letter “C” followed by its number. Superiorly, the C1 vertebra articulates (forms a joint) with the occipital condyles of the skull. Inferiorly, C1 articulates with the C2 vertebra, and so on. Below these are the 12 thoracic vertebrae, designated T1–T12. The lower back contains the L1–L5 lumbar vertebrae. The single sacrum, which is also part of the pelvis, is formed by the fusion of five sacral vertebrae. Similarly, the coccyx, or tailbone, results from the fusion of four small coccygeal vertebrae. However, the sacral and coccygeal fusions do not start until age 20 and are not completed until middle age. An interesting anatomical fact is that almost all mammals have seven cervical vertebrae, regardless of body size. This means that there are large variations in the size of cervical vertebrae, ranging from the very small cervical vertebrae of a shrew to the greatly elongated vertebrae in the neck of a giraffe. In a full-grown giraffe, each cervical vertebra is 11 inches tall. Curvatures of the Vertebral Column The adult vertebral column does not form a straight line, but instead has four curvatures along its length (see Figure 7.20). These curves increase the vertebral column’s strength, flexibility, and ability to absorb shock. When the load on the spine is increased, by carrying a heavy backpack for example, the curvatures increase in depth (become more curved) to accommodate the extra weight. They then spring back when the weight is removed. The four adult curvatures are classified as either primary or secondary curvatures. Primary curves are retained from the original fetal curvature, while secondary curvatures develop after birth. During fetal development, the body is flexed anteriorly into the fetal position, giving the entire vertebral column a single curvature that is concave anteriorly. In the adult, this fetal curvature is retained in two regions of the vertebral column as the thoracic curve, which involves the thoracic vertebrae, and the sacrococcygeal curve, formed by the sacrum and coccyx. Each of these is thus called a primary curve because they are retained from the original fetal curvature of the vertebral column. A secondary curve develops gradually after birth as the child learns to sit upright, stand, and walk. Secondary curves are concave posteriorly, opposite in direction to the original fetal curvature. The cervical curve of the neck region develops as the infant begins to hold their head upright when sitting. Later, as the child begins to stand and then to walk, the lumbar curve of the lower back develops. In adults, the lumbar curve is generally deeper in females. Disorders associated with the curvature of the spine include kyphosis (an excessive posterior curvature of the thoracic region), lordosis (an excessive anterior curvature of the lumbar region), and scoliosis (an abnormal, lateral curvature, accompanied by twisting of the vertebral column). DISORDERS OF THE... Vertebral Column Developmental anomalies, pathological changes, or obesity can enhance the normal vertebral column curves, resulting in the development of abnormal or excessive curvatures (Figure 7.21). Kyphosis, also referred to as humpback or hunchback, is an excessive posterior curvature of the thoracic region. This can develop when osteoporosis causes weakening and erosion of the anterior portions of the upper thoracic vertebrae, resulting in their gradual collapse (Figure 7.22). Lordosis, or swayback, is an excessive anterior curvature of the lumbar region and is most commonly associated with obesity or late pregnancy. The accumulation of body weight in the abdominal region results an anterior shift in the line of gravity that carries the weight of the body. This causes in an anterior tilt of the pelvis and a pronounced enhancement of the lumbar curve. Scoliosis is an abnormal, lateral curvature, accompanied by twisting of the vertebral column. Compensatory curves may also develop in other areas of the vertebral column to help maintain the head positioned over the feet. Scoliosis is the most common vertebral abnormality among girls. The cause is usually unknown, but it may result from weakness of the back muscles, defects such as differential growth rates in the right and left sides of the vertebral column, or differences in the length of the lower limbs. When present, scoliosis tends to get worse during adolescent growth spurts. Although most individuals do not require treatment, a back brace may be recommended for growing children. In extreme cases, surgery may be required. Excessive vertebral curves can be identified while an individual stands in the anatomical position. Observe the vertebral profile from the side and then from behind to check for kyphosis or lordosis. Then have the person bend forward. If scoliosis is present, an individual will have difficulty in bending directly forward, and the right and left sides of the back will not be level with each other in the bent position. Figure 7.21 Abnormal Curvatures of the Vertebral Column (a) Scoliosis is an abnormal lateral bending of the vertebral column. (b) An excessive curvature of the upper thoracic vertebral column is called kyphosis. (c) Lordosis is an excessive curvature in the lumbar region of the vertebral column. Figure 7.22 Osteoporosis Osteoporosis is an age-related disorder that causes the gradual loss of bone density and strength. When the thoracic vertebrae are affected, there can be a gradual collapse of the vertebrae. This results in kyphosis, an excessive curvature of the thoracic region. INTERACTIVE LINK Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. Watch this video to get a better understanding of how thoracic vertebrae may become weakened and may fracture due to this disease. How may vertebral osteoporosis contribute to kyphosis? General Structure of a Vertebra Within the different regions of the vertebral column, vertebrae vary in size and shape, but they all follow a similar structural pattern. A typical vertebra will consist of a body, a vertebral arch, and seven processes (Figure 7.23). The body is the anterior portion of each vertebra and is the part that supports the body weight. Because of this, the vertebral bodies progressively increase in size and thickness going down the vertebral column. The bodies of adjacent vertebrae are separated and strongly united by an intervertebral disc. The vertebral arch forms the posterior portion of each vertebra. It consists of four parts, the right and left pedicles and the right and left laminae. Each pedicle forms one of the lateral sides of the vertebral arch. The pedicles are anchored to the posterior side of the vertebral body. Each lamina forms part of the posterior roof of the vertebral arch. The large opening between the vertebral arch and body is the vertebral foramen, which contains the spinal cord. In the intact vertebral column, the vertebral foramina of all of the vertebrae align to form the vertebral (spinal) canal, which serves as the bony protection and passageway for the spinal cord down the back. When the vertebrae are aligned together in the vertebral column, notches in the margins of the pedicles of adjacent vertebrae together form an intervertebral foramen, the opening through which a spinal nerve exits from the vertebral column (Figure 7.24). Seven processes arise from the vertebral arch. Each paired transverse process projects laterally and arises from the junction point between the pedicle and lamina. The single spinous process (vertebral spine) projects posteriorly at the midline of the back. The vertebral spines can easily be felt as a series of bumps just under the skin down the middle of the back. The transverse and spinous processes serve as important muscle attachment sites. A superior articular process extends or faces upward, and an inferior articular process faces or projects downward on each side of a vertebrae. The paired superior articular processes of one vertebra join with the corresponding paired inferior articular processes from the next higher vertebra. These junctions form slightly moveable joints between the adjacent vertebrae. The shape and orientation of the articular processes vary in different regions of the vertebral column and play a major role in determining the type and range of motion available in each region. Figure 7.23 Parts of a Typical Vertebra A typical vertebra consists of a body and a vertebral arch. The arch is formed by the paired pedicles and paired laminae. Arising from the vertebral arch are the transverse, spinous, superior articular, and inferior articular processes. The vertebral foramen provides for passage of the spinal cord. Each spinal nerve exits through an intervertebral foramen, located between adjacent vertebrae. Intervertebral discs unite the bodies of adjacent vertebrae. Figure 7.24 Intervertebral Disc The bodies of adjacent vertebrae are separated and united by an intervertebral disc, which provides padding and allows for movements between adjacent vertebrae. The disc consists of a fibrous outer layer called the anulus fibrosus and a gel-like center called the nucleus pulposus. The intervertebral foramen is the opening formed between adjacent vertebrae for the exit of a spinal nerve. Regional Modifications of Vertebrae In addition to the general characteristics of a typical vertebra described above, vertebrae also display characteristic size and structural features that vary between the different vertebral column regions. Thus, cervical vertebrae are smaller than lumbar vertebrae due to differences in the proportion of body weight that each supports. Thoracic vertebrae have sites for rib attachment, and the vertebrae that give rise to the sacrum and coccyx have fused together into single bones. Cervical Vertebrae Typical cervical vertebrae, such as C4 or C5, have several characteristic features that differentiate them from thoracic or lumbar vertebrae (Figure 7.25). Cervical vertebrae have a small body, reflecting the fact that they carry the least amount of body weight. Cervical vertebrae usually have a bifid (Y-shaped) spinous process. The spinous processes of the C3–C6 vertebrae are short, but the spine of C7 is much longer. You can find these vertebrae by running your finger down the midline of the posterior neck until you encounter the prominent C7 spine located at the base of the neck. The transverse processes of the cervical vertebrae are sharply curved (U-shaped) to allow for passage of the cervical spinal nerves. Each transverse process also has an opening called the transverse foramen. An important artery that supplies the brain ascends up the neck by passing through these openings. The superior and inferior articular processes of the cervical vertebrae are flattened and largely face upward or downward, respectively. The first and second cervical vertebrae are further modified, giving each a distinctive appearance. The first cervical (C1) vertebra is also called the atlas, because this is the vertebra that supports the skull on top of the vertebral column (in Greek mythology, Atlas was the god who supported the heavens on his shoulders). The C1 vertebra does not have a body or spinous process. Instead, it is ring-shaped, consisting of an anterior arch and a posterior arch. The transverse processes of the atlas are longer and extend more laterally than do the transverse processes of any other cervical vertebrae. The superior articular processes face upward and are deeply curved for articulation with the occipital condyles on the base of the skull. The inferior articular processes are flat and face downward to join with the superior articular processes of the C2 vertebra. The second cervical (C2) vertebra is called the axis, because it serves as the axis for rotation when turning the head toward the right or left. The axis resembles typical cervical vertebrae in most respects, but is easily distinguished by the dens (odontoid process), a bony projection that extends upward from the vertebral body. The dens joins with the inner aspect of the anterior arch of the atlas, where it is held in place by transverse ligament. Figure 7.25 Cervical Vertebrae A typical cervical vertebra has a small body, a bifid spinous process, transverse processes that have a transverse foramen and are curved for spinal nerve passage. The atlas (C1 vertebra) does not have a body or spinous process. It consists of an anterior and a posterior arch and elongated transverse processes. The axis (C2 vertebra) has the upward projecting dens, which articulates with the anterior arch of the atlas. Thoracic Vertebrae The bodies of the thoracic vertebrae are larger than those of cervical vertebrae (Figure 7.26). The characteristic feature for a typical midthoracic vertebra is the spinous process, which is long and has a pronounced downward angle that causes it to overlap the next inferior vertebra. The superior articular processes of thoracic vertebrae face anteriorly and the inferior processes face posteriorly. These orientations are important determinants for the type and range of movements available to the thoracic region of the vertebral column. Thoracic vertebrae have several additional articulation sites, each of which is called a facet, where a rib is attached. Most thoracic vertebrae have two facets located on the lateral sides of the body, each of which is called a costal facet (costal = “rib”). These are for articulation with the head (end) of a rib. An additional facet is located on the transverse process for articulation with the tubercle of a rib. Figure 7.26 Thoracic Vertebrae A typical thoracic vertebra is distinguished by the spinous process, which is long and projects downward to overlap the next inferior vertebra. It also has articulation sites (facets) on the vertebral body and a transverse process for rib attachment. Figure 7.27 Rib Articulation in Thoracic Vertebrae Thoracic vertebrae have superior and inferior articular facets on the vertebral body for articulation with the head of a rib, and a transverse process facet for articulation with the rib tubercle. Lumbar Vertebrae Lumbar vertebrae carry the greatest amount of body weight and are thus characterized by the large size and thickness of the vertebral body (Figure 7.28). They have short transverse processes and a short, blunt spinous process that projects posteriorly. The articular processes are large, with the superior process facing backward and the inferior facing forward. Figure 7.28 Lumbar Vertebrae Lumbar vertebrae are characterized by having a large, thick body and a short, rounded spinous process. Sacrum and Coccyx The sacrum is a triangular-shaped bone that is thick and wide across its superior base where it is weight bearing and then tapers down to an inferior, non-weight bearing apex (Figure 7.29). It is formed by the fusion of five sacral vertebrae, a process that does not begin until after the age of 20. On the anterior surface of the older adult sacrum, the lines of vertebral fusion can be seen as four transverse ridges. On the posterior surface, running down the midline, is the median sacral crest, a bumpy ridge that is the remnant of the fused spinous processes (median = “midline”; while medial = “toward, but not necessarily at, the midline”). Similarly, the fused transverse processes of the sacral vertebrae form the lateral sacral crest. The sacral promontory is the anterior lip of the superior base of the sacrum. Lateral to this is the roughened auricular surface, which joins with the ilium portion of the hipbone to form the immobile sacroiliac joints of the pelvis. Passing inferiorly through the sacrum is a bony tunnel called the sacral canal, which terminates at the sacral hiatus near the inferior tip of the sacrum. The anterior and posterior surfaces of the sacrum have a series of paired openings called sacral foramina (singular = foramen) that connect to the sacral canal. Each of these openings is called a posterior (dorsal) sacral foramen or anterior (ventral) sacral foramen. These openings allow for the anterior and posterior branches of the sacral spinal nerves to exit the sacrum. The superior articular process of the sacrum, one of which is found on either side of the superior opening of the sacral canal, articulates with the inferior articular processes from the L5 vertebra. The coccyx, or tailbone, is derived from the fusion of four very small coccygeal vertebrae (see Figure 7.29). It articulates with the inferior tip of the sacrum. It is not weight bearing in the standing position, but may receive some body weight when sitting. Figure 7.29 Sacrum and Coccyx The sacrum is formed from the fusion of five sacral vertebrae, whose lines of fusion are indicated by the transverse ridges. The fused spinous processes form the median sacral crest, while the lateral sacral crest arises from the fused transverse processes. The coccyx is formed by the fusion of four small coccygeal vertebrae. Intervertebral Discs and Ligaments of the Vertebral Column The bodies of adjacent vertebrae are strongly anchored to each other by an intervertebral disc. This structure provides padding between the bones during weight bearing, and because it can change shape, also allows for movement between the vertebrae. Although the total amount of movement available between any two adjacent vertebrae is small, when these movements are summed together along the entire length of the vertebral column, large body movements can be produced. Ligaments that extend along the length of the vertebral column also contribute to its overall support and stability. Intervertebral Disc An intervertebral disc is a fibrocartilaginous pad that fills the gap between adjacent vertebral bodies (see Figure 7.24). Each disc is anchored to the bodies of its adjacent vertebrae, thus strongly uniting these. The discs also provide padding between vertebrae during weight bearing. Because of this, intervertebral discs are thin in the cervical region and thickest in the lumbar region, which carries the most body weight. In total, the intervertebral discs account for approximately 25 percent of your body height between the top of the pelvis and the base of the skull. Intervertebral discs are also flexible and can change shape to allow for movements of the vertebral column. Each intervertebral disc consists of two parts. The anulus fibrosus is the tough, fibrous outer layer of the disc. It forms a circle (anulus = “ring” or “circle”) and is firmly anchored to the outer margins of the adjacent vertebral bodies. Inside is the nucleus pulposus, consisting of a softer, more gel-like material. It has a high water content that serves to resist compression and thus is important for weight bearing. With increasing age, the water content of the nucleus pulposus gradually declines. This causes the disc to become thinner, decreasing total body height somewhat, and reduces the flexibility and range of motion of the disc, making bending more difficult. The gel-like nature of the nucleus pulposus also allows the intervertebral disc to change shape as one vertebra rocks side to side or forward and back in relation to its neighbors during movements of the vertebral column. Thus, bending forward causes compression of the anterior portion of the disc but expansion of the posterior disc. If the posterior anulus fibrosus is weakened due to injury or increasing age, the pressure exerted on the disc when bending forward and lifting a heavy object can cause the nucleus pulposus to protrude posteriorly through the anulus fibrosus, resulting in a herniated disc (“ruptured” or “slipped” disc) (Figure 7.30). The posterior bulging of the nucleus pulposus can cause compression of a spinal nerve at the point where it exits through the intervertebral foramen, with resulting pain and/or muscle weakness in those body regions supplied by that nerve. The most common sites for disc herniation are the L4/L5 or L5/S1 intervertebral discs, which can cause sciatica, a widespread pain that radiates from the lower back down the thigh and into the leg. Similar injuries of the C5/C6 or C6/C7 intervertebral discs, following forcible hyperflexion of the neck from a collision accident or football injury, can produce pain in the neck, shoulder, and upper limb. Figure 7.30 Herniated Intervertebral Disc Weakening of the anulus fibrosus can result in herniation (protrusion) of the nucleus pulposus and compression of a spinal nerve, resulting in pain and/or muscle weakness in the body regions supplied by that nerve. INTERACTIVE LINK Watch this animation to see what it means to “slip” a disk. Watch this second animation to see one possible treatment for a herniated disc, removing and replacing the damaged disc with an artificial one that allows for movement between the adjacent certebrae. How could lifting a heavy object produce pain in a lower limb? Ligaments of the Vertebral Column Adjacent vertebrae are united by ligaments that run the length of the vertebral column along both its posterior and anterior aspects (Figure 7.31). These serve to resist excess forward or backward bending movements of the vertebral column, respectively. The anterior longitudinal ligament runs down the anterior side of the entire vertebral column, uniting the vertebral bodies. It serves to resist excess backward bending of the vertebral column. Protection against this movement is particularly important in the neck, where extreme posterior bending of the head and neck can stretch or tear this ligament, resulting in a painful whiplash injury. Prior to the mandatory installation of seat headrests, whiplash injuries were common for passengers involved in a rear-end automobile collision. The supraspinous ligament is located on the posterior side of the vertebral column, where it interconnects the spinous processes of the thoracic and lumbar vertebrae. This strong ligament supports the vertebral column during forward bending motions. In the posterior neck, where the cervical spinous processes are short, the supraspinous ligament expands to become the nuchal ligament (nuchae = “nape” or “back of the neck”). The nuchal ligament is attached to the cervical spinous processes and extends upward and posteriorly to attach to the midline base of the skull, out to the external occipital protuberance. It supports the skull and prevents it from falling forward. This ligament is much larger and stronger in four-legged animals such as cows, where the large skull hangs off the front end of the vertebral column. You can easily feel this ligament by first extending your head backward and pressing down on the posterior midline of your neck. Then tilt your head forward and you will fill the nuchal ligament popping out as it tightens to limit anterior bending of the head and neck. Additional ligaments are located inside the vertebral canal, next to the spinal cord, along the length of the vertebral column. The posterior longitudinal ligament is found anterior to the spinal cord, where it is attached to the posterior sides of the vertebral bodies. Posterior to the spinal cord is the ligamentum flavum (“yellow ligament”). This consists of a series of short, paired ligaments, each of which interconnects the lamina regions of adjacent vertebrae. The ligamentum flavum has large numbers of elastic fibers, which have a yellowish color, allowing it to stretch and then pull back. Both of these ligaments provide important support for the vertebral column when bending forward. Figure 7.31 Ligaments of Vertebral Column The anterior longitudinal ligament runs the length of the vertebral column, uniting the anterior sides of the vertebral bodies. The supraspinous ligament connects the spinous processes of the thoracic and lumbar vertebrae. In the posterior neck, the supraspinous ligament enlarges to form the nuchal ligament, which attaches to the cervical spinous processes and to the base of the skull. INTERACTIVE LINK Use this tool to identify the bones, intervertebral discs, and ligaments of the vertebral column. The thickest portions of the anterior longitudinal ligament and the supraspinous ligament are found in which regions of the vertebral column? CAREER CONNECTION Chiropractor Chiropractors are health professionals who use nonsurgical techniques to help patients with musculoskeletal system problems that involve the bones, muscles, ligaments, tendons, or nervous system. They treat problems such as neck pain, back pain, joint pain, or headaches. Chiropractors focus on the patient’s overall health and can also provide counseling related to lifestyle issues, such as diet, exercise, or sleep problems. If needed, they will refer the patient to other medical specialists. Chiropractors use a drug-free, hands-on approach for patient diagnosis and treatment. They will perform a physical exam, assess the patient’s posture and spine, and may perform additional diagnostic tests, including taking X-ray images. They primarily use manual techniques, such as spinal manipulation, to adjust the patient’s spine or other joints. They can recommend therapeutic or rehabilitative exercises, and some also include acupuncture, massage therapy, or ultrasound as part of the treatment program. In addition to those in general practice, some chiropractors specialize in sport injuries, neurology, orthopaedics, pediatrics, nutrition, internal disorders, or diagnostic imaging. To become a chiropractor, students must have 3–4 years of undergraduate education, attend an accredited, four-year Doctor of Chiropractic (D.C.) degree program, and pass a licensure examination to be licensed for practice in their state. With the aging of the baby-boom generation, employment for chiropractors is expected to increase. The Thoracic Cage - Discuss the components that make up the thoracic cage - Identify the parts of the sternum and define the sternal angle - Discuss the parts of a rib and rib classifications The thoracic cage (rib cage) forms the thorax (chest) portion of the body. It consists of the 12 pairs of ribs with their costal cartilages and the sternum (Figure 7.32). The ribs are anchored posteriorly to the 12 thoracic vertebrae (T1–T12). The thoracic cage protects the heart and lungs. Figure 7.32 Thoracic Cage The thoracic cage is formed by the (a) sternum and (b) 12 pairs of ribs with their costal cartilages. The ribs are anchored posteriorly to the 12 thoracic vertebrae. The sternum consists of the manubrium, body, and xiphoid process. The ribs are classified as true ribs (1–7) and false ribs (8–12). The last two pairs of false ribs are also known as floating ribs (11–12). Sternum The sternum is the elongated bony structure that anchors the anterior thoracic cage. It consists of three parts: the manubrium, body, and xiphoid process. The manubrium is the wider, superior portion of the sternum. The top of the manubrium has a shallow, U-shaped border called the jugular (suprasternal) notch. This can be easily felt at the anterior base of the neck, between the medial ends of the clavicles. The clavicular notch is the shallow depression located on either side at the superior-lateral margins of the manubrium. This is the site of the sternoclavicular joint, between the sternum and clavicle. The first ribs also attach to the manubrium. The elongated, central portion of the sternum is the body. The manubrium and body join together at the sternal angle, so called because the junction between these two components is not flat, but forms a slight bend. The second rib attaches to the sternum at the sternal angle. Since the first rib is hidden behind the clavicle, the second rib is the highest rib that can be identified by palpation. Thus, the sternal angle and second rib are important landmarks for the identification and counting of the lower ribs. Ribs 3–7 attach to the sternal body. The inferior tip of the sternum is the xiphoid process. This small structure is cartilaginous early in life, but gradually becomes ossified starting during middle age. Ribs Each rib is a curved, flattened bone that contributes to the wall of the thorax. The ribs articulate posteriorly with the T1–T12 thoracic vertebrae, and most attach anteriorly via their costal cartilages to the sternum. There are 12 pairs of ribs. The ribs are numbered 1–12 in accordance with the thoracic vertebrae. Parts of a Typical Rib The posterior end of a typical rib is called the head of the rib (see Figure 7.27). This region articulates primarily with the costal facet located on the body of the same numbered thoracic vertebra and to a lesser degree, with the costal facet located on the body of the next higher vertebra. Lateral to the head is the narrowed neck of the rib. A small bump on the posterior rib surface is the tubercle of the rib, which articulates with the facet located on the transverse process of the same numbered vertebra. The remainder of the rib is the body of the rib (shaft). Just lateral to the tubercle is the angle of the rib, the point at which the rib has its greatest degree of curvature. The angles of the ribs form the most posterior extent of the thoracic cage. In the anatomical position, the angles align with the medial border of the scapula. A shallow costal groove for the passage of blood vessels and a nerve is found along the inferior margin of each rib. Rib Classifications The bony ribs do not extend anteriorly completely around to the sternum. Instead, each rib ends in a costal cartilage. These cartilages are made of hyaline cartilage and can extend for several inches. Most ribs are then attached, either directly or indirectly, to the sternum via their costal cartilage (see Figure 7.32). The ribs are classified into three groups based on their relationship to the sternum. Ribs 1–7 are classified as true ribs (vertebrosternal ribs). The costal cartilage from each of these ribs attaches directly to the sternum. Ribs 8–12 are called false ribs (vertebrochondral ribs). The costal cartilages from these ribs do not attach directly to the sternum. For ribs 8–10, the costal cartilages are attached to the cartilage of the next higher rib. Thus, the cartilage of rib 10 attaches to the cartilage of rib 9, rib 9 then attaches to rib 8, and rib 8 is attached to rib 7. The last two false ribs (11–12) are also called floating ribs (vertebral ribs). These are short ribs that do not attach to the sternum at all. Instead, their small costal cartilages terminate within the musculature of the lateral abdominal wall. Embryonic Development of the Axial Skeleton - Discuss the two types of embryonic bone development within the skull - Describe the development of the vertebral column and thoracic cage The axial skeleton begins to form during early embryonic development. However, growth, remodeling, and ossification (bone formation) continue for several decades after birth before the adult skeleton is fully formed. Knowledge of the developmental processes that give rise to the skeleton is important for understanding the abnormalities that may arise in skeletal structures. Development of the Skull During the third week of embryonic development, a rod-like structure called the notochord develops dorsally along the length of the embryo. The tissue overlying the notochord enlarges and forms the neural tube, which will give rise to the brain and spinal cord. By the fourth week, mesoderm tissue located on either side of the notochord thickens and separates into a repeating series of block-like tissue structures, each of which is called a somite. As the somites enlarge, each one will split into several parts. The most medial of these parts is called a sclerotome. The sclerotomes consist of an embryonic tissue called mesenchyme, which will give rise to the fibrous connective tissues, cartilages, and bones of the body. The bones of the skull arise from mesenchyme during embryonic development in two different ways. The first mechanism produces the bones that form the top and sides of the brain case. This involves the local accumulation of mesenchymal cells at the site of the future bone. These cells then differentiate directly into bone producing cells, which form the skull bones through the process of intramembranous ossification. As the brain case bones grow in the fetal skull, they remain separated from each other by large areas of dense connective tissue, each of which is called a fontanelle (Figure 7.33). The fontanelles are the soft spots on an infant’s head. They are important during birth because these areas allow the skull to change shape as it squeezes through the birth canal. After birth, the fontanelles allow for continued growth and expansion of the skull as the brain enlarges. The largest fontanelle is located on the anterior head, at the junction of the frontal and parietal bones. The fontanelles decrease in size and disappear by age 2. However, the skull bones remained separated from each other at the sutures, which contain dense fibrous connective tissue that unites the adjacent bones. The connective tissue of the sutures allows for continued growth of the skull bones as the brain enlarges during childhood growth. The second mechanism for bone development in the skull produces the facial bones and floor of the brain case. This also begins with the localized accumulation of mesenchymal cells. However, these cells differentiate into cartilage cells, which produce a hyaline cartilage model of the future bone. As this cartilage model grows, it is gradually converted into bone through the process of endochondral ossification. This is a slow process and the cartilage is not completely converted to bone until the skull achieves its full adult size. At birth, the brain case and orbits of the skull are disproportionally large compared to the bones of the jaws and lower face. This reflects the relative underdevelopment of the maxilla and mandible, which lack teeth, and the small sizes of the paranasal sinuses and nasal cavity. During early childhood, the mastoid process enlarges, the two halves of the mandible and frontal bone fuse together to form single bones, and the paranasal sinuses enlarge. The jaws also expand as the teeth begin to appear. These changes all contribute to the rapid growth and enlargement of the face during childhood. Figure 7.33 Newborn Skull The bones of the newborn skull are not fully ossified and are separated by large areas called fontanelles, which are filled with fibrous connective tissue. The fontanelles allow for continued growth of the skull after birth. At the time of birth, the facial bones are small and underdeveloped, and the mastoid process has not yet formed. Development of the Vertebral Column and Thoracic cage Development of the vertebrae begins with the accumulation of mesenchyme cells from each sclerotome around the notochord. These cells differentiate into a hyaline cartilage model for each vertebra, which then grow and eventually ossify into bone through the process of endochondral ossification. As the developing vertebrae grow, the notochord largely disappears. However, small areas of notochord tissue persist between the adjacent vertebrae and this contributes to the formation of each intervertebral disc. The ribs and sternum also develop from mesenchyme. The ribs initially develop as part of the cartilage model for each vertebra, but in the thorax region, the rib portion separates from the vertebra by the eighth week. The cartilage model of the rib then ossifies, except for the anterior portion, which remains as the costal cartilage. The sternum initially forms as paired hyaline cartilage models on either side of the anterior midline, beginning during the fifth week of development. The cartilage models of the ribs become attached to the lateral sides of the developing sternum. Eventually, the two halves of the cartilaginous sternum fuse together along the midline and then ossify into bone. The manubrium and body of the sternum are converted into bone first, with the xiphoid process remaining as cartilage until late in life. INTERACTIVE LINK View this video to review the two processes that give rise to the bones of the skull and body. What are the two mechanisms by which the bones of the body are formed and which bones are formed by each mechanism? HOMEOSTATIC IMBALANCES Craniosynostosis The premature closure (fusion) of a suture line is a condition called craniosynostosis. This error in the normal developmental process results in abnormal growth of the skull and deformity of the head. It is produced either by defects in the ossification process of the skull bones or failure of the brain to properly enlarge. Genetic factors are involved, but the underlying cause is unknown. It is a relatively common condition, occurring in approximately 1:2000 births, with males being more commonly affected. Primary craniosynostosis involves the early fusion of one cranial suture, whereas complex craniosynostosis results from the premature fusion of several sutures. The early fusion of a suture in primary craniosynostosis prevents any additional enlargement of the cranial bones and skull along this line. Continued growth of the brain and skull is therefore diverted to other areas of the head, causing an abnormal enlargement of these regions. For example, the early disappearance of the anterior fontanelle and premature closure of the sagittal suture prevents growth across the top of the head. This is compensated by upward growth by the bones of the lateral skull, resulting in a long, narrow, wedge-shaped head. This condition, known as scaphocephaly, accounts for approximately 50 percent of craniosynostosis abnormalities. Although the skull is misshapen, the brain still has adequate room to grow and thus there is no accompanying abnormal neurological development. In cases of complex craniosynostosis, several sutures close prematurely. The amount and degree of skull deformity is determined by the location and extent of the sutures involved. This results in more severe constraints on skull growth, which can alter or impede proper brain growth and development. Cases of craniosynostosis are usually treated with surgery. A team of physicians will open the skull along the fused suture, which will then allow the skull bones to resume their growth in this area. In some cases, parts of the skull will be removed and replaced with an artificial plate. The earlier after birth that surgery is performed, the better the outcome. After treatment, most children continue to grow and develop normally and do not exhibit any neurological problems. Key Terms - alveolar process of the mandible - upper border of mandibular body that contains the lower teeth - alveolar process of the maxilla - curved, inferior margin of the maxilla that supports and anchors the upper teeth - angle of the mandible - rounded corner located at outside margin of the body and ramus junction - angle of the rib - portion of rib with greatest curvature; together, the rib angles form the most posterior extent of the thoracic cage - anterior (ventral) sacral foramen - one of the series of paired openings located on the anterior (ventral) side of the sacrum - anterior arch - anterior portion of the ring-like C1 (atlas) vertebra - anterior cranial fossa - shallowest and most anterior cranial fossa of the cranial base that extends from the frontal bone to the lesser wing of the sphenoid bone - anterior longitudinal ligament - ligament that runs the length of the vertebral column, uniting the anterior aspects of the vertebral bodies - anulus fibrosus - tough, fibrous outer portion of an intervertebral disc, which is strongly anchored to the bodies of the adjacent vertebrae - appendicular skeleton - all bones of the upper and lower limbs, plus the girdle bones that attach each limb to the axial skeleton - articular tubercle - smooth ridge located on the inferior skull, immediately anterior to the mandibular fossa - atlas - first cervical (C1) vertebra - axial skeleton - central, vertical axis of the body, including the skull, vertebral column, and thoracic cage - axis - second cervical (C2) vertebra - body of the rib - shaft portion of a rib - brain case - portion of the skull that contains and protects the brain, consisting of the eight bones that form the cranial base and rounded upper skull - calvaria - (also, skullcap) rounded top of the skull - carotid canal - zig-zag tunnel providing passage through the base of the skull for the internal carotid artery to the brain; begins anteromedial to the styloid process and terminates in the middle cranial cavity, near the posterior-lateral base of the sella turcica - cervical curve - posteriorly concave curvature of the cervical vertebral column region; a secondary curve of the vertebral column - cervical vertebrae - seven vertebrae numbered as C1–C7 that are located in the neck region of the vertebral column - clavicular notch - paired notches located on the superior-lateral sides of the sternal manubrium, for articulation with the clavicle - coccyx - small bone located at inferior end of the adult vertebral column that is formed by the fusion of four coccygeal vertebrae; also referred to as the “tailbone” - condylar process of the mandible - thickened upward projection from posterior margin of mandibular ramus - condyle - oval-shaped process located at the top of the condylar process of the mandible - coronal suture - joint that unites the frontal bone to the right and left parietal bones across the top of the skull - coronoid process of the mandible - flattened upward projection from the anterior margin of the mandibular ramus - costal cartilage - hyaline cartilage structure attached to the anterior end of each rib that provides for either direct or indirect attachment of most ribs to the sternum - costal facet - site on the lateral sides of a thoracic vertebra for articulation with the head of a rib - costal groove - shallow groove along the inferior margin of a rib that provides passage for blood vessels and a nerve - cranial cavity - interior space of the skull that houses the brain - cranium - skull - cribriform plate - small, flattened areas with numerous small openings, located to either side of the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone - crista galli - small upward projection located at the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone - dens - bony projection (odontoid process) that extends upward from the body of the C2 (axis) vertebra - ear ossicles - three small bones located in the middle ear cavity that serve to transmit sound vibrations to the inner ear - ethmoid air cell - one of several small, air-filled spaces located within the lateral sides of the ethmoid bone, between the orbit and upper nasal cavity - ethmoid bone - unpaired bone that forms the roof and upper, lateral walls of the nasal cavity, portions of the floor of the anterior cranial fossa and medial wall of orbit, and the upper portion of the nasal septum - external acoustic meatus - ear canal opening located on the lateral side of the skull - external occipital protuberance - small bump located at the midline on the posterior skull - facet - small, flattened area on a bone for an articulation (joint) with another bone, or for muscle attachment - facial bones - fourteen bones that support the facial structures and form the upper and lower jaws and the hard palate - false ribs - vertebrochondral ribs 8–12 whose costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all - floating ribs - vertebral ribs 11–12 that do not attach to the sternum or to the costal cartilage of another rib - fontanelle - expanded area of fibrous connective tissue that separates the brain case bones of the skull prior to birth and during the first year after birth - foramen lacerum - irregular opening in the base of the skull, located inferior to the exit of carotid canal - foramen magnum - large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium - foramen ovale of the middle cranial fossa - oval-shaped opening in the floor of the middle cranial fossa - foramen rotundum - round opening in the floor of the middle cranial fossa, located between the superior orbital fissure and foramen ovale - foramen spinosum - small opening in the floor of the middle cranial fossa, located lateral to the foramen ovale - frontal bone - unpaired bone that forms forehead, roof of orbit, and floor of anterior cranial fossa - frontal sinus - air-filled space within the frontal bone; most anterior of the paranasal sinuses - glabella - slight depression of frontal bone, located at the midline between the eyebrows - greater wings of sphenoid bone - lateral projections of the sphenoid bone that form the anterior wall of the middle cranial fossa and an area of the lateral skull - hard palate - bony structure that forms the roof of the mouth and floor of the nasal cavity, formed by the palatine process of the maxillary bones and the horizontal plate of the palatine bones - head of the rib - posterior end of a rib that articulates with the bodies of thoracic vertebrae - horizontal plate - medial extension from the palatine bone that forms the posterior quarter of the hard palate - hyoid bone - small, U-shaped bone located in upper neck that does not contact any other bone - hypoglossal canal - paired openings that pass anteriorly from the anterior-lateral margins of the foramen magnum deep to the occipital condyles - hypophyseal (pituitary) fossa - shallow depression on top of the sella turcica that houses the pituitary (hypophyseal) gland - inferior articular process - bony process that extends downward from the vertebral arch of a vertebra that articulates with the superior articular process of the next lower vertebra - inferior nasal concha - one of the paired bones that project from the lateral walls of the nasal cavity to form the largest and most inferior of the nasal conchae - infraorbital foramen - opening located on anterior skull, below the orbit - infratemporal fossa - space on lateral side of skull, below the level of the zygomatic arch and deep (medial) to the ramus of the mandible - internal acoustic meatus - opening into petrous ridge, located on the lateral wall of the posterior cranial fossa - intervertebral disc - structure located between the bodies of adjacent vertebrae that strongly joins the vertebrae; provides padding, weight bearing ability, and enables vertebral column movements - intervertebral foramen - opening located between adjacent vertebrae for exit of a spinal nerve - jugular (suprasternal) notch - shallow notch located on superior surface of sternal manubrium - jugular foramen - irregularly shaped opening located in the lateral floor of the posterior cranial cavity - kyphosis - (also, humpback or hunchback) excessive posterior curvature of the thoracic vertebral column region - lacrimal bone - paired bones that contribute to the anterior-medial wall of each orbit - lacrimal fossa - shallow depression in the anterior-medial wall of the orbit, formed by the lacrimal bone that gives rise to the nasolacrimal canal - lambdoid suture - inverted V-shaped joint that unites the occipital bone to the right and left parietal bones on the posterior skull - lamina - portion of the vertebral arch on each vertebra that extends between the transverse and spinous process - lateral pterygoid plate - paired, flattened bony projections of the sphenoid bone located on the inferior skull, lateral to the medial pterygoid plate - lateral sacral crest - paired irregular ridges running down the lateral sides of the posterior sacrum that was formed by the fusion of the transverse processes from the five sacral vertebrae - lesser wings of the sphenoid bone - lateral extensions of the sphenoid bone that form the bony lip separating the anterior and middle cranial fossae - ligamentum flavum - series of short ligaments that unite the lamina of adjacent vertebrae - lingula - small flap of bone located on the inner (medial) surface of mandibular ramus, next to the mandibular foramen - lordosis - (also, swayback) excessive anterior curvature of the lumbar vertebral column region - lumbar curve - posteriorly concave curvature of the lumbar vertebral column region; a secondary curve of the vertebral column - lumbar vertebrae - five vertebrae numbered as L1–L5 that are located in lumbar region (lower back) of the vertebral column - mandible - unpaired bone that forms the lower jaw bone; the only moveable bone of the skull - mandibular foramen - opening located on the inner (medial) surface of the mandibular ramus - mandibular fossa - oval depression located on the inferior surface of the skull - mandibular notch - large U-shaped notch located between the condylar process and coronoid process of the mandible - manubrium - expanded, superior portion of the sternum - mastoid process - large bony prominence on the inferior, lateral skull, just behind the earlobe - maxillary bone - (also, maxilla) paired bones that form the upper jaw and anterior portion of the hard palate - maxillary sinus - air-filled space located with each maxillary bone; largest of the paranasal sinuses - medial pterygoid plate - paired, flattened bony projections of the sphenoid bone located on the inferior skull medial to the lateral pterygoid plate; form the posterior portion of the nasal cavity lateral wall - median sacral crest - irregular ridge running down the midline of the posterior sacrum that was formed from the fusion of the spinous processes of the five sacral vertebrae - mental foramen - opening located on the anterior-lateral side of the mandibular body - mental protuberance - inferior margin of anterior mandible that forms the chin - middle cranial fossa - centrally located cranial fossa that extends from the lesser wings of the sphenoid bone to the petrous ridge - middle nasal concha - nasal concha formed by the ethmoid bone that is located between the superior and inferior conchae - mylohyoid line - bony ridge located along the inner (medial) surface of the mandibular body - nasal bone - paired bones that form the base of the nose - nasal cavity - opening through skull for passage of air - nasal conchae - curved bony plates that project from the lateral walls of the nasal cavity; include the superior and middle nasal conchae, which are parts of the ethmoid bone, and the independent inferior nasal conchae bone - nasal septum - flat, midline structure that divides the nasal cavity into halves, formed by the perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage - nasolacrimal canal - passage for drainage of tears that extends downward from the medial-anterior orbit to the nasal cavity, terminating behind the inferior nasal conchae - neck of the rib - narrowed region of a rib, next to the rib head - notochord - rod-like structure along dorsal side of the early embryo; largely disappears during later development but does contribute to formation of the intervertebral discs - nuchal ligament - expanded portion of the supraspinous ligament within the posterior neck; interconnects the spinous processes of the cervical vertebrae and attaches to the base of the skull - nucleus pulposus - gel-like central region of an intervertebral disc; provides for padding, weight-bearing, and movement between adjacent vertebrae - occipital bone - unpaired bone that forms the posterior portions of the brain case and base of the skull - occipital condyle - paired, oval-shaped bony knobs located on the inferior skull, to either side of the foramen magnum - optic canal - opening spanning between middle cranial fossa and posterior orbit - orbit - bony socket that contains the eyeball and associated muscles - palatine bone - paired bones that form the posterior quarter of the hard palate and a small area in floor of the orbit - palatine process - medial projection from the maxilla bone that forms the anterior three quarters of the hard palate - paranasal sinuses - cavities within the skull that are connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consist of frontal, maxillary, sphenoidal, and ethmoidal sinuses - parietal bone - paired bones that form the upper, lateral sides of the skull - pedicle - portion of the vertebral arch that extends from the vertebral body to the transverse process - perpendicular plate of the ethmoid bone - downward, midline extension of the ethmoid bone that forms the superior portion of the nasal septum - petrous ridge - petrous portion of the temporal bone that forms a large, triangular ridge in the floor of the cranial cavity, separating the middle and posterior cranial fossae; houses the middle and inner ear structures - posterior (dorsal) sacral foramen - one of the series of paired openings located on the posterior (dorsal) side of the sacrum - posterior arch - posterior portion of the ring-like C1 (atlas) vertebra - posterior cranial fossa - deepest and most posterior cranial fossa; extends from the petrous ridge to the occipital bone - posterior longitudinal ligament - ligament that runs the length of the vertebral column, uniting the posterior sides of the vertebral bodies - primary curve - anteriorly concave curvatures of the thoracic and sacrococcygeal regions that are retained from the original fetal curvature of the vertebral column - pterion - H-shaped suture junction region that unites the frontal, parietal, temporal, and sphenoid bones on the lateral side of the skull - ramus of the mandible - vertical portion of the mandible - ribs - thin, curved bones of the chest wall - sacral canal - bony tunnel that runs through the sacrum - sacral foramina - series of paired openings for nerve exit located on both the anterior (ventral) and posterior (dorsal) aspects of the sacrum - sacral hiatus - inferior opening and termination of the sacral canal - sacral promontory - anterior lip of the base (superior end) of the sacrum - sacrococcygeal curve - anteriorly concave curvature formed by the sacrum and coccyx; a primary curve of the vertebral column - sacrum - single bone located near the inferior end of the adult vertebral column that is formed by the fusion of five sacral vertebrae; forms the posterior portion of the pelvis - sagittal suture - joint that unites the right and left parietal bones at the midline along the top of the skull - sclerotome - medial portion of a somite consisting of mesenchyme tissue that will give rise to bone, cartilage, and fibrous connective tissues - scoliosis - abnormal lateral curvature of the vertebral column - secondary curve - posteriorly concave curvatures of the cervical and lumbar regions of the vertebral column that develop after the time of birth - sella turcica - elevated area of sphenoid bone located at midline of the middle cranial fossa - septal cartilage - flat cartilage structure that forms the anterior portion of the nasal septum - skeleton - bones of the body - skull - bony structure that forms the head, face, and jaws, and protects the brain; consists of 22 bones - somite - one of the paired, repeating blocks of tissue located on either side of the notochord in the early embryo - sphenoid bone - unpaired bone that forms the central base of skull - sphenoid sinus - air-filled space located within the sphenoid bone; most posterior of the paranasal sinuses - spinous process - unpaired bony process that extends posteriorly from the vertebral arch of a vertebra - squamous suture - joint that unites the parietal bone to the squamous portion of the temporal bone on the lateral side of the skull - sternal angle - junction line between manubrium and body of the sternum and the site for attachment of the second rib to the sternum - sternum - flattened bone located at the center of the anterior chest - styloid process - downward projecting, elongated bony process located on the inferior aspect of the skull - stylomastoid foramen - opening located on inferior skull, between the styloid process and mastoid process - superior articular process - bony process that extends upward from the vertebral arch of a vertebra that articulates with the inferior articular process of the next higher vertebra - superior articular process of the sacrum - paired processes that extend upward from the sacrum to articulate (join) with the inferior articular processes from the L5 vertebra - superior nasal concha - smallest and most superiorly located of the nasal conchae; formed by the ethmoid bone - superior nuchal line - paired bony lines on the posterior skull that extend laterally from the external occipital protuberance - superior orbital fissure - irregularly shaped opening between the middle cranial fossa and the posterior orbit - supraorbital foramen - opening located on anterior skull, at the superior margin of the orbit - supraorbital margin - superior margin of the orbit - supraspinous ligament - ligament that interconnects the spinous processes of the thoracic and lumbar vertebrae - suture - junction line at which adjacent bones of the skull are united by fibrous connective tissue - temporal bone - paired bones that form the lateral, inferior portions of the skull, with squamous, mastoid, and petrous portions - temporal fossa - shallow space on the lateral side of the skull, above the level of the zygomatic arch - temporal process of the zygomatic bone - short extension from the zygomatic bone that forms the anterior portion of the zygomatic arch - thoracic cage - consists of 12 pairs of ribs and sternum - thoracic curve - anteriorly concave curvature of the thoracic vertebral column region; a primary curve of the vertebral column - thoracic vertebrae - twelve vertebrae numbered as T1–T12 that are located in the thoracic region (upper back) of the vertebral column - transverse foramen - opening found only in the transverse processes of cervical vertebrae - transverse process - paired bony processes that extends laterally from the vertebral arch of a vertebra - true ribs - vertebrosternal ribs 1–7 that attach via their costal cartilage directly to the sternum - tubercle of the rib - small bump on the posterior side of a rib for articulation with the transverse process of a thoracic vertebra - vertebra - individual bone in the neck and back regions of the vertebral column - vertebral (spinal) canal - bony passageway within the vertebral column for the spinal cord that is formed by the series of individual vertebral foramina - vertebral arch - bony arch formed by the posterior portion of each vertebra that surrounds and protects the spinal cord - vertebral column - entire sequence of bones that extend from the skull to the tailbone - vertebral foramen - opening associated with each vertebra defined by the vertebral arch that provides passage for the spinal cord - vomer bone - unpaired bone that forms the inferior and posterior portions of the nasal septum - xiphoid process - small process that forms the inferior tip of the sternum - zygomatic arch - elongated, free-standing arch on the lateral skull, formed anteriorly by the temporal process of the zygomatic bone and posteriorly by the zygomatic process of the temporal bone - zygomatic bone - cheekbone; paired bones that contribute to the lateral orbit and anterior zygomatic arch - zygomatic process of the temporal bone - extension from the temporal bone that forms the posterior portion of the zygomatic arch Chapter Review 7.1 Divisions of the Skeletal System The skeletal system includes all of the bones, cartilages, and ligaments of the body. It serves to support the body, protect the brain and other internal organs, and provides a rigid structure upon which muscles can pull to generate body movements. It also stores fat and the tissue responsible for the production of blood cells. The skeleton is subdivided into two parts. The axial skeleton forms a vertical axis that includes the head, neck, back, and chest. It has 80 bones and consists of the skull, vertebral column, and thoracic cage. The adult vertebral column consists of 24 vertebrae plus the sacrum and coccyx. The thoracic cage is formed by 12 pairs of ribs and the sternum. The appendicular skeleton consists of 126 bones in the adult and includes all of the bones of the upper and lower limbs plus the bones that anchor each limb to the axial skeleton. 7.2 The Skull The skull consists of the brain case and the facial bones. The brain case surrounds and protects the brain, which occupies the cranial cavity inside the skull. It consists of the rounded calvaria and a complex base. The brain case is formed by eight bones, the paired parietal and temporal bones plus the unpaired frontal, occipital, sphenoid, and ethmoid bones. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The sagittal suture joins the right and left parietal bones. The coronal suture joins the parietal bones to the frontal bone, the lamboid suture joins them to the occipital bone, and the squamous suture joins them to the temporal bone. The facial bones support the facial structures and form the upper and lower jaws. These consist of 14 bones, with the paired maxillary, palatine, zygomatic, nasal, lacrimal, and inferior conchae bones and the unpaired vomer and mandible bones. The ethmoid bone also contributes to the formation of facial structures. The maxilla forms the upper jaw and the mandible forms the lower jaw. The maxilla also forms the larger anterior portion of the hard palate, which is completed by the smaller palatine bones that form the posterior portion of the hard palate. The floor of the cranial cavity increases in depth from front to back and is divided into three cranial fossae. The anterior cranial fossa is located between the frontal bone and lesser wing of the sphenoid bone. A small area of the ethmoid bone, consisting of the crista galli and cribriform plates, is located at the midline of this fossa. The middle cranial fossa extends from the lesser wing of the sphenoid bone to the petrous ridge (petrous portion of temporal bone). The right and left sides are separated at the midline by the sella turcica, which surrounds the shallow hypophyseal fossa. Openings through the skull in the floor of the middle fossa include the optic canal and superior orbital fissure, which open into the posterior orbit, the foramen rotundum, foramen ovale, and foramen spinosum, and the exit of the carotid canal with its underlying foramen lacerum. The deep posterior cranial fossa extends from the petrous ridge to the occipital bone. Openings here include the large foramen magnum, plus the internal acoustic meatus, jugular foramina, and hypoglossal canals. Additional openings located on the external base of the skull include the stylomastoid foramen and the entrance to the carotid canal. The anterior skull has the orbits that house the eyeballs and associated muscles. The walls of the orbit are formed by contributions from seven bones: the frontal, zygomatic, maxillary, palatine, ethmoid, lacrimal, and sphenoid. Located at the superior margin of the orbit is the supraorbital foramen, and below the orbit is the infraorbital foramen. The mandible has two openings, the mandibular foramen on its inner surface and the mental foramen on its external surface near the chin. The nasal conchae are bony projections from the lateral walls of the nasal cavity. The large inferior nasal concha is an independent bone, while the middle and superior conchae are parts of the ethmoid bone. The nasal septum is formed by the perpendicular plate of the ethmoid bone, the vomer bone, and the septal cartilage. The paranasal sinuses are air-filled spaces located within the frontal, maxillary, sphenoid, and ethmoid bones. On the lateral skull, the zygomatic arch consists of two parts, the temporal process of the zygomatic bone anteriorly and the zygomatic process of the temporal bone posteriorly. The temporal fossa is the shallow space located on the lateral skull above the level of the zygomatic arch. The infratemporal fossa is located below the zygomatic arch and deep to the ramus of the mandible. The hyoid bone is located in the upper neck and does not join with any other bone. It is held in position by muscles and serves to support the tongue above, the larynx below, and the pharynx posteriorly. 7.3 The Vertebral Column The vertebral column forms the neck and back. The vertebral column originally develops as 33 vertebrae, but is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. The vertebrae are divided into the cervical region (C1–C7 vertebrae), the thoracic region (T1–T12 vertebrae), and the lumbar region (L1–L5 vertebrae). The sacrum arises from the fusion of five sacral vertebrae and the coccyx from the fusion of four small coccygeal vertebrae. The vertebral column has four curvatures, the cervical, thoracic, lumbar, and sacrococcygeal curves. The thoracic and sacrococcygeal curves are primary curves retained from the original fetal curvature. The cervical and lumbar curves develop after birth and thus are secondary curves. The cervical curve develops as the infant begins to hold up the head, and the lumbar curve appears with standing and walking. A typical vertebra consists of an enlarged anterior portion called the body, which provides weight-bearing support. Attached posteriorly to the body is a vertebral arch, which surrounds and defines the vertebral foramen for passage of the spinal cord. The vertebral arch consists of the pedicles, which attach to the vertebral body, and the laminae, which come together to form the roof of the arch. Arising from the vertebral arch are the laterally projecting transverse processes and the posteriorly oriented spinous process. The superior articular processes project upward, where they articulate with the downward projecting inferior articular processes of the next higher vertebrae. A typical cervical vertebra has a small body, a bifid (Y-shaped) spinous process, and U-shaped transverse processes with a transverse foramen. In addition to these characteristics, the axis (C2 vertebra) also has the dens projecting upward from the vertebral body. The atlas (C1 vertebra) differs from the other cervical vertebrae in that it does not have a body, but instead consists of bony ring formed by the anterior and posterior arches. The atlas articulates with the dens from the axis. A typical thoracic vertebra is distinguished by its long, downward projecting spinous process. Thoracic vertebrae also have articulation facets on the body and transverse processes for attachment of the ribs. Lumbar vertebrae support the greatest amount of body weight and thus have a large, thick body. They also have a short, blunt spinous process. The sacrum is triangular in shape. The median sacral crest is formed by the fused vertebral spinous processes and the lateral sacral crest is derived from the fused transverse processes. Anterior (ventral) and posterior (dorsal) sacral foramina allow branches of the sacral spinal nerves to exit the sacrum. The auricular surfaces are articulation sites on the lateral sacrum that anchor the sacrum to the hipbones to form the pelvis. The coccyx is small and derived from the fusion of four small vertebrae. The intervertebral discs fill in the gaps between the bodies of adjacent vertebrae. They provide strong attachments and padding between the vertebrae. The outer, fibrous layer of a disc is called the anulus fibrosus. The gel-like interior is called the nucleus pulposus. The disc can change shape to allow for movement between vertebrae. If the anulus fibrosus is weakened or damaged, the nucleus pulposus can protrude outward, resulting in a herniated disc. The anterior longitudinal ligament runs along the full length of the anterior vertebral column, uniting the vertebral bodies. The supraspinous ligament is located posteriorly and interconnects the spinous processes of the thoracic and lumbar vertebrae. In the neck, this ligament expands to become the nuchal ligament. The nuchal ligament is attached to the cervical spinous processes and superiorly to the base of the skull, out to the external occipital protuberance. The posterior longitudinal ligament runs within the vertebral canal and unites the posterior sides of the vertebral bodies. The ligamentum flavum unites the lamina of adjacent vertebrae. 7.4 The Thoracic Cage The thoracic cage protects the heart and lungs. It is composed of 12 pairs of ribs with their costal cartilages and the sternum. The ribs are anchored posteriorly to the 12 thoracic vertebrae. The sternum consists of the manubrium, body, and xiphoid process. The manubrium and body are joined at the sternal angle, which is also the site for attachment of the second ribs. Ribs are flattened, curved bones and are numbered 1–12. Posteriorly, the head of the rib articulates with the costal facets located on the bodies of thoracic vertebrae and the rib tubercle articulates with the facet located on the vertebral transverse process. The angle of the ribs forms the most posterior portion of the thoracic cage. The costal groove in the inferior margin of each rib carries blood vessels and a nerve. Anteriorly, each rib ends in a costal cartilage. True ribs (1–7) attach directly to the sternum via their costal cartilage. The false ribs (8–12) either attach to the sternum indirectly or not at all. Ribs 8–10 have their costal cartilages attached to the cartilage of the next higher rib. The floating ribs (11–12) are short and do not attach to the sternum or to another rib. 7.5 Embryonic Development of the Axial Skeleton Formation of the axial skeleton begins during early embryonic development with the appearance of the rod-like notochord along the dorsal length of the early embryo. Repeating, paired blocks of tissue called somites then appear along either side of notochord. As the somites grow, they split into parts, one of which is called a sclerotome. This consists of mesenchyme, the embryonic tissue that will become the bones, cartilages, and connective tissues of the body. Mesenchyme in the head region will produce the bones of the skull via two different mechanisms. The bones of the brain case arise via intramembranous ossification in which embryonic mesenchyme tissue converts directly into bone. At the time of birth, these bones are separated by fontanelles, wide areas of fibrous connective tissue. As the bones grow, the fontanelles are reduced to sutures, which allow for continued growth of the skull throughout childhood. In contrast, the cranial base and facial bones are produced by the process of endochondral ossification, in which mesenchyme tissue initially produces a hyaline cartilage model of the future bone. The cartilage model allows for growth of the bone and is gradually converted into bone over a period of many years. The vertebrae, ribs, and sternum also develop via endochondral ossification. Mesenchyme accumulates around the notochord and produces hyaline cartilage models of the vertebrae. The notochord largely disappears, but remnants of the notochord contribute to formation of the intervertebral discs. In the thorax region, a portion of the vertebral cartilage model splits off to form the ribs. These then become attached anteriorly to the developing cartilage model of the sternum. Growth of the cartilage models for the vertebrae, ribs, and sternum allow for enlargement of the thoracic cage during childhood and adolescence. The cartilage models gradually undergo ossification and are converted into bone. Interactive Link Questions Watch this video to view a rotating and exploded skull with color-coded bones. Which bone (yellow) is centrally located and joins with most of the other bones of the skull? 2.View this animation to see how a blow to the head may produce a contrecoup (counterblow) fracture of the basilar portion of the occipital bone on the base of the skull. Why may a basilar fracture be life threatening? 3.Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. Watch this videoto get a better understanding of how thoracic vertebrae may become weakened and may fractured due to this disease. How may vertebral osteoporosis contribute to kyphosis? 4.Watch this animation to see what it means to “slip” a disk. Watch this second animation to see one possible treatment for a herniated disc, removing and replacing the damaged disc with an artificial one that allows for movement between the adjacent certebrae. How could lifting a heavy object produce pain in a lower limb? 5.Use this tool to identify the bones, intervertebral discs, and ligaments of the vertebral column. The thickest portions of the anterior longitudinal ligament and the supraspinous ligament are found in which regions of the vertebral column? 6.View this video to review the two processes that give rise to the bones of the skull and body. What are the two mechanisms by which the bones of the body are formed and which bones are formed by each mechanism? Review Questions Which of the following is part of the axial skeleton? - shoulder bones - thigh bone - foot bones - vertebral column Which of the following is a function of the axial skeleton? - allows for movement of the wrist and hand - protects nerves and blood vessels at the elbow - supports trunk of body - allows for movements of the ankle and foot The axial skeleton ________. - consists of 126 bones - forms the vertical axis of the body - includes all bones of the body trunk and limbs - includes only the bones of the lower limbs Which of the following is a bone of the brain case? - parietal bone - zygomatic bone - maxillary bone - lacrimal bone The lambdoid suture joins the parietal bone to the ________. - frontal bone - occipital bone - other parietal bone - temporal bone The middle cranial fossa ________. - is bounded anteriorly by the petrous ridge - is bounded posteriorly by the lesser wing of the sphenoid bone - is divided at the midline by a small area of the ethmoid bone - has the foramen rotundum, foramen ovale, and foramen spinosum The paranasal sinuses are ________. - air-filled spaces found within the frontal, maxilla, sphenoid, and ethmoid bones only - air-filled spaces found within all bones of the skull - not connected to the nasal cavity - divided at the midline by the nasal septum Parts of the sphenoid bone include the ________. - sella turcica - squamous portion - glabella - zygomatic process The bony openings of the skull include the ________. - carotid canal, which is located in the anterior cranial fossa - superior orbital fissure, which is located at the superior margin of the anterior orbit - mental foramen, which is located just below the orbit - hypoglossal canal, which is located in the posterior cranial fossa The cervical region of the vertebral column consists of ________. - seven vertebrae - 12 vertebrae - five vertebrae - a single bone derived from the fusion of five vertebrae The primary curvatures of the vertebral column ________. - include the lumbar curve - are remnants of the original fetal curvature - include the cervical curve - develop after the time of birth A typical vertebra has ________. - a vertebral foramen that passes through the body - a superior articular process that projects downward to articulate with the superior portion of the next lower vertebra - lamina that spans between the transverse process and spinous process - a pair of laterally projecting spinous processes A typical lumbar vertebra has ________. - a short, rounded spinous process - a bifid spinous process - articulation sites for ribs - a transverse foramen Which is found only in the cervical region of the vertebral column? - nuchal ligament - ligamentum flavum - supraspinous ligament - anterior longitudinal ligament The sternum ________. - consists of only two parts, the manubrium and xiphoid process - has the sternal angle located between the manubrium and body - receives direct attachments from the costal cartilages of all 12 pairs of ribs - articulates directly with the thoracic vertebrae The sternal angle is the ________. - junction between the body and xiphoid process - site for attachment of the clavicle - site for attachment of the floating ribs - junction between the manubrium and body The tubercle of a rib ________. - is for articulation with the transverse process of a thoracic vertebra - is for articulation with the body of a thoracic vertebra - provides for passage of blood vessels and a nerve - is the area of greatest rib curvature True ribs are ________. - ribs 8–12 - attached via their costal cartilage to the next higher rib - made entirely of bone, and thus do not have a costal cartilage - attached via their costal cartilage directly to the sternum Embryonic development of the axial skeleton involves ________. - intramembranous ossification, which forms the facial bones. - endochondral ossification, which forms the ribs and sternum - the notochord, which produces the cartilage models for the vertebrae - the formation of hyaline cartilage models, which give rise to the flat bones of the skull A fontanelle ________. - is the cartilage model for a vertebra that later is converted into bone - gives rise to the facial bones and vertebrae - is the rod-like structure that runs the length of the early embryo - is the area of fibrous connective tissue found at birth between the brain case bones Critical Thinking Questions Define the two divisions of the skeleton. 28.Discuss the functions of the axial skeleton. 29.Define and list the bones that form the brain case or support the facial structures. 30.Identify the major sutures of the skull, their locations, and the bones united by each. 31.Describe the anterior, middle, and posterior cranial fossae and their boundaries, and give the midline structure that divides each into right and left areas. 32.Describe the parts of the nasal septum in both the dry and living skull. 33.Describe the vertebral column and define each region. 34.Describe a typical vertebra. 35.Describe the sacrum. 36.Describe the structure and function of an intervertebral disc. 37.Define the ligaments of the vertebral column. 38.Define the parts and functions of the thoracic cage. 39.Describe the parts of the sternum. 40.Discuss the parts of a typical rib. 41.Define the classes of ribs. 42.Discuss the processes by which the brain-case bones of the skull are formed and grow during skull enlargement. 43.Discuss the process that gives rise to the base and facial bones of the skull. 44.Discuss the development of the vertebrae, ribs, and sternum.	oercommons	2025-03-18T00:37:15.219373	07/23/2019	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/56366/overview", "title": "Anatomy and Physiology, Support and Movement, Axial Skeleton", "author": null }
https://oercommons.org/courseware/lesson/58775/overview	The Reproductive System Introduction Figure 27.1 Ovulation Following a surge of luteinizing hormone (LH), an oocyte (immature egg cell) will be released into the uterine tube, where it will then be available to be fertilized by a male’s sperm. Ovulation marks the end of the follicular phase of the ovarian cycle and the start of the luteal phase. CHAPTER OBJECTIVES After studying this chapter, you will be able to: - Describe the anatomy of the male and female reproductive systems, including their accessory structures - Explain the role of hypothalamic and pituitary hormones in male and female reproductive function - Trace the path of a sperm cell from its initial production through fertilization of an oocyte - Explain the events in the ovary prior to ovulation - Describe the development and maturation of the sex organs and the emergence of secondary sex characteristics during puberty Small, uncoordinated, and slick with amniotic fluid, a newborn encounters the world outside of her mother’s womb. We do not often consider that a child’s birth is proof of the healthy functioning of both her mother’s and father’s reproductive systems. Moreover, her parents’ endocrine systems had to secrete the appropriate regulating hormones to induce the production and release of unique male and female gametes, reproductive cells containing the parents’ genetic material (one set of 23 chromosomes). Her parent’s reproductive behavior had to facilitate the transfer of male gametes—the sperm—to the female reproductive tract at just the right time to encounter the female gamete, an oocyte (egg). Finally, combination of the gametes (fertilization) had to occur, followed by implantation and development. In this chapter, you will explore the male and female reproductive systems, whose healthy functioning can culminate in the powerful sound of a newborn’s first cry. Anatomy and Physiology of the Male Reproductive System - Describe the structure and function of the organs of the male reproductive system - Describe the structure and function of the sperm cell - Explain the events during spermatogenesis that produce haploid sperm from diploid cells - Identify the importance of testosterone in male reproductive function Unique for its role in human reproduction, a gamete is a specialized sex cell carrying 23 chromosomes—one half the number in body cells. At fertilization, the chromosomes in one male gamete, called a sperm (or spermatozoon), combine with the chromosomes in one female gamete, called an oocyte. The function of the male reproductive system (Figure 27.2) is to produce sperm and transfer them to the female reproductive tract. The paired testes are a crucial component in this process, as they produce both sperm and androgens, the hormones that support male reproductive physiology. In humans, the most important male androgen is testosterone. Several accessory organs and ducts aid the process of sperm maturation and transport the sperm and other seminal components to the penis, which delivers sperm to the female reproductive tract. In this section, we examine each of these different structures, and discuss the process of sperm production and transport. Figure 27.2 Male Reproductive System The structures of the male reproductive system include the testes, the epididymides, the penis, and the ducts and glands that produce and carry semen. Sperm exit the scrotum through the ductus deferens, which is bundled in the spermatic cord. The seminal vesicles and prostate gland add fluids to the sperm to create semen. Scrotum The testes are located in a skin-covered, highly pigmented, muscular sack called the scrotum that extends from the body behind the penis (see Figure 27.2). This location is important in sperm production, which occurs within the testes, and proceeds more efficiently when the testes are kept 2 to 4°C below core body temperature. The dartos muscle makes up the subcutaneous muscle layer of the scrotum (Figure 27.3). It continues internally to make up the scrotal septum, a wall that divides the scrotum into two compartments, each housing one testis. Descending from the internal oblique muscle of the abdominal wall are the two cremaster muscles, which cover each testis like a muscular net. By contracting simultaneously, the dartos and cremaster muscles can elevate the testes in cold weather (or water), moving the testes closer to the body and decreasing the surface area of the scrotum to retain heat. Alternatively, as the environmental temperature increases, the scrotum relaxes, moving the testes farther from the body core and increasing scrotal surface area, which promotes heat loss. Externally, the scrotum has a raised medial thickening on the surface called the raphae. Figure 27.3 The Scrotum and Testes This anterior view shows the structures of the scrotum and testes. Testes The testes (singular = testis) are the male gonads—that is, the male reproductive organs. They produce both sperm and androgens, such as testosterone, and are active throughout the reproductive lifespan of the male. Paired ovals, the testes are each approximately 4 to 5 cm in length and are housed within the scrotum (see Figure 27.3). They are surrounded by two distinct layers of protective connective tissue (Figure 27.4). The outer tunica vaginalis is a serous membrane that has both a parietal and a thin visceral layer. Beneath the tunica vaginalis is the tunica albuginea, a tough, white, dense connective tissue layer covering the testis itself. Not only does the tunica albuginea cover the outside of the testis, it also invaginates to form septa that divide the testis into 300 to 400 structures called lobules. Within the lobules, sperm develop in structures called seminiferous tubules. During the seventh month of the developmental period of a male fetus, each testis moves through the abdominal musculature to descend into the scrotal cavity. This is called the “descent of the testis.” Cryptorchidism is the clinical term used when one or both of the testes fail to descend into the scrotum prior to birth. Figure 27.4 Anatomy of the Testis This sagittal view shows the seminiferous tubules, the site of sperm production. Formed sperm are transferred to the epididymis, where they mature. They leave the epididymis during an ejaculation via the ductus deferens. The tightly coiled seminiferous tubules form the bulk of each testis. They are composed of developing sperm cells surrounding a lumen, the hollow center of the tubule, where formed sperm are released into the duct system of the testis. Specifically, from the lumens of the seminiferous tubules, sperm move into the straight tubules (or tubuli recti), and from there into a fine meshwork of tubules called the rete testes. Sperm leave the rete testes, and the testis itself, through the 15 to 20 efferent ductules that cross the tunica albuginea. Inside the seminiferous tubules are six different cell types. These include supporting cells called sustentacular cells, as well as five types of developing sperm cells called germ cells. Germ cell development progresses from the basement membrane—at the perimeter of the tubule—toward the lumen. Let’s look more closely at these cell types. Sertoli Cells Surrounding all stages of the developing sperm cells are elongate, branching Sertoli cells. Sertoli cells are a type of supporting cell called a sustentacular cell, or sustentocyte, that are typically found in epithelial tissue. Sertoli cells secrete signaling molecules that promote sperm production and can control whether germ cells live or die. They extend physically around the germ cells from the peripheral basement membrane of the seminiferous tubules to the lumen. Tight junctions between these sustentacular cells create the blood–testis barrier, which keeps bloodborne substances from reaching the germ cells and, at the same time, keeps surface antigens on developing germ cells from escaping into the bloodstream and prompting an autoimmune response. Germ Cells The least mature cells, the spermatogonia (singular = spermatogonium), line the basement membrane inside the tubule. Spermatogonia are the stem cells of the testis, which means that they are still able to differentiate into a variety of different cell types throughout adulthood. Spermatogonia divide to produce primary and secondary spermatocytes, then spermatids, which finally produce formed sperm. The process that begins with spermatogonia and concludes with the production of sperm is called spermatogenesis. Spermatogenesis As just noted, spermatogenesis occurs in the seminiferous tubules that form the bulk of each testis (see Figure 27.4). The process begins at puberty, after which time sperm are produced constantly throughout a man’s life. One production cycle, from spermatogonia through formed sperm, takes approximately 64 days. A new cycle starts approximately every 16 days, although this timing is not synchronous across the seminiferous tubules. Sperm counts—the total number of sperm a man produces—slowly decline after age 35, and some studies suggest that smoking can lower sperm counts irrespective of age. The process of spermatogenesis begins with mitosis of the diploid spermatogonia (Figure 27.5). Because these cells are diploid (2n), they each have a complete copy of the father’s genetic material, or 46 chromosomes. However, mature gametes are haploid (1n), containing 23 chromosomes—meaning that daughter cells of spermatogonia must undergo a second cellular division through the process of meiosis. Figure 27.5 Spermatogenesis (a) Mitosis of a spermatogonial stem cell involves a single cell division that results in two identical, diploid daughter cells (spermatogonia to primary spermatocyte). Meiosis has two rounds of cell division: primary spermatocyte to secondary spermatocyte, and then secondary spermatocyte to spermatid. This produces four haploid daughter cells (spermatids). (b) In this electron micrograph of a cross-section of a seminiferous tubule from a rat, the lumen is the light-shaded area in the center of the image. The location of the primary spermatocytes is near the basement membrane, and the early spermatids are approaching the lumen (tissue source: rat). EM × 900. (Micrograph provided by the Regents of University of Michigan Medical School © 2012) Two identical diploid cells result from spermatogonia mitosis. One of these cells remains a spermatogonium, and the other becomes a primary spermatocyte, the next stage in the process of spermatogenesis. As in mitosis, DNA is replicated in a primary spermatocyte, before it undergoes a cell division called meiosis I. During meiosis I each of the 23 pairs of chromosomes separates. This results in two cells, called secondary spermatocytes, each with only half the number of chromosomes. Now a second round of cell division (meiosis II) occurs in both of the secondary spermatocytes. During meiosis II each of the 23 replicated chromosomes divides, similar to what happens during mitosis. Thus, meiosis results in separating the chromosome pairs. This second meiotic division results in a total of four cells with only half of the number of chromosomes. Each of these new cells is a spermatid. Although haploid, early spermatids look very similar to cells in the earlier stages of spermatogenesis, with a round shape, central nucleus, and large amount of cytoplasm. A process called spermiogenesis transforms these early spermatids, reducing the cytoplasm, and beginning the formation of the parts of a true sperm. The fifth stage of germ cell formation—spermatozoa, or formed sperm—is the end result of this process, which occurs in the portion of the tubule nearest the lumen. Eventually, the sperm are released into the lumen and are moved along a series of ducts in the testis toward a structure called the epididymis for the next step of sperm maturation. Structure of Formed Sperm Sperm are smaller than most cells in the body; in fact, the volume of a sperm cell is 85,000 times less than that of the female gamete. Approximately 100 to 300 million sperm are produced each day, whereas women typically ovulate only one oocyte per month. As is true for most cells in the body, the structure of sperm cells speaks to their function. Sperm have a distinctive head, mid-piece, and tail region (Figure 27.6). The head of the sperm contains the extremely compact haploid nucleus with very little cytoplasm. These qualities contribute to the overall small size of the sperm (the head is only 5 μm long). A structure called the acrosome covers most of the head of the sperm cell as a “cap” that is filled with lysosomal enzymes important for preparing sperm to participate in fertilization. Tightly packed mitochondria fill the mid-piece of the sperm. ATP produced by these mitochondria will power the flagellum, which extends from the neck and the mid-piece through the tail of the sperm, enabling it to move the entire sperm cell. The central strand of the flagellum, the axial filament, is formed from one centriole inside the maturing sperm cell during the final stages of spermatogenesis. Figure 27.6 Structure of Sperm Sperm cells are divided into a head, containing DNA; a mid-piece, containing mitochondria; and a tail, providing motility. The acrosome is oval and somewhat flattened. Sperm Transport To fertilize an egg, sperm must be moved from the seminiferous tubules in the testes, through the epididymis, and—later during ejaculation—along the length of the penis and out into the female reproductive tract. Role of the Epididymis From the lumen of the seminiferous tubules, the immotile sperm are surrounded by testicular fluid and moved to the epididymis(plural = epididymides), a coiled tube attached to the testis where newly formed sperm continue to mature (see Figure 27.4). Though the epididymis does not take up much room in its tightly coiled state, it would be approximately 6 m (20 feet) long if straightened. It takes an average of 12 days for sperm to move through the coils of the epididymis, with the shortest recorded transit time in humans being one day. Sperm enter the head of the epididymis and are moved along predominantly by the contraction of smooth muscles lining the epididymal tubes. As they are moved along the length of the epididymis, the sperm further mature and acquire the ability to move under their own power. Once inside the female reproductive tract, they will use this ability to move independently toward the unfertilized egg. The more mature sperm are then stored in the tail of the epididymis (the final section) until ejaculation occurs. Duct System During ejaculation, sperm exit the tail of the epididymis and are pushed by smooth muscle contraction to the ductus deferens(also called the vas deferens). The ductus deferens is a thick, muscular tube that is bundled together inside the scrotum with connective tissue, blood vessels, and nerves into a structure called the spermatic cord (see Figure 27.2 and Figure 27.3). Because the ductus deferens is physically accessible within the scrotum, surgical sterilization to interrupt sperm delivery can be performed by cutting and sealing a small section of the ductus (vas) deferens. This procedure is called a vasectomy, and it is an effective form of male birth control. Although it may be possible to reverse a vasectomy, clinicians consider the procedure permanent, and advise men to undergo it only if they are certain they no longer wish to father children. INTERACTIVE LINK Watch this video to learn about a vasectomy. As described in this video, a vasectomy is a procedure in which a small section of the ductus (vas) deferens is removed from the scrotum. This interrupts the path taken by sperm through the ductus deferens. If sperm do not exit through the vas, either because the man has had a vasectomy or has not ejaculated, in what region of the testis do they remain? From each epididymis, each ductus deferens extends superiorly into the abdominal cavity through the inguinal canal in the abdominal wall. From here, the ductus deferens continues posteriorly to the pelvic cavity, ending posterior to the bladder where it dilates in a region called the ampulla (meaning “flask”). Sperm make up only 5 percent of the final volume of semen, the thick, milky fluid that the male ejaculates. The bulk of semen is produced by three critical accessory glands of the male reproductive system: the seminal vesicles, the prostate, and the bulbourethral glands. Seminal Vesicles As sperm pass through the ampulla of the ductus deferens at ejaculation, they mix with fluid from the associated seminal vesicle (see Figure 27.2). The paired seminal vesicles are glands that contribute approximately 60 percent of the semen volume. Seminal vesicle fluid contains large amounts of fructose, which is used by the sperm mitochondria to generate ATP to allow movement through the female reproductive tract. The fluid, now containing both sperm and seminal vesicle secretions, next moves into the associated ejaculatory duct, a short structure formed from the ampulla of the ductus deferens and the duct of the seminal vesicle. The paired ejaculatory ducts transport the seminal fluid into the next structure, the prostate gland. Prostate Gland As shown in Figure 27.2, the centrally located prostate gland sits anterior to the rectum at the base of the bladder surrounding the prostatic urethra (the portion of the urethra that runs within the prostate). About the size of a walnut, the prostate is formed of both muscular and glandular tissues. It excretes an alkaline, milky fluid to the passing seminal fluid—now called semen—that is critical to first coagulate and then decoagulate the semen following ejaculation. The temporary thickening of semen helps retain it within the female reproductive tract, providing time for sperm to utilize the fructose provided by seminal vesicle secretions. When the semen regains its fluid state, sperm can then pass farther into the female reproductive tract. The prostate normally doubles in size during puberty. At approximately age 25, it gradually begins to enlarge again. This enlargement does not usually cause problems; however, abnormal growth of the prostate, or benign prostatic hyperplasia (BPH), can cause constriction of the urethra as it passes through the middle of the prostate gland, leading to a number of lower urinary tract symptoms, such as a frequent and intense urge to urinate, a weak stream, and a sensation that the bladder has not emptied completely. By age 60, approximately 40 percent of men have some degree of BPH. By age 80, the number of affected individuals has jumped to as many as 80 percent. Treatments for BPH attempt to relieve the pressure on the urethra so that urine can flow more normally. Mild to moderate symptoms are treated with medication, whereas severe enlargement of the prostate is treated by surgery in which a portion of the prostate tissue is removed. Another common disorder involving the prostate is prostate cancer. According to the Centers for Disease Control and Prevention (CDC), prostate cancer is the second most common cancer in men. However, some forms of prostate cancer grow very slowly and thus may not ever require treatment. Aggressive forms of prostate cancer, in contrast, involve metastasis to vulnerable organs like the lungs and brain. There is no link between BPH and prostate cancer, but the symptoms are similar. Prostate cancer is detected by a medical history, a blood test, and a rectal exam that allows physicians to palpate the prostate and check for unusual masses. If a mass is detected, the cancer diagnosis is confirmed by biopsy of the cells. Bulbourethral Glands The final addition to semen is made by two bulbourethral glands (or Cowper’s glands) that release a thick, salty fluid that lubricates the end of the urethra and the vagina, and helps to clean urine residues from the penile urethra. The fluid from these accessory glands is released after the male becomes sexually aroused, and shortly before the release of the semen. It is therefore sometimes called pre-ejaculate. It is important to note that, in addition to the lubricating proteins, it is possible for bulbourethral fluid to pick up sperm already present in the urethra, and therefore it may be able to cause pregnancy. INTERACTIVE LINK Watch this video to explore the structures of the male reproductive system and the path of sperm, which starts in the testes and ends as the sperm leave the penis through the urethra. Where are sperm deposited after they leave the ejaculatory duct? The Penis The penis is the male organ of copulation (sexual intercourse). It is flaccid for non-sexual actions, such as urination, and turgid and rod-like with sexual arousal. When erect, the stiffness of the organ allows it to penetrate into the vagina and deposit semen into the female reproductive tract. Figure 27.7 Cross-Sectional Anatomy of the Penis Three columns of erectile tissue make up most of the volume of the penis. The shaft of the penis surrounds the urethra (Figure 27.7). The shaft is composed of three column-like chambers of erectile tissue that span the length of the shaft. Each of the two larger lateral chambers is called a corpus cavernosum (plural = corpora cavernosa). Together, these make up the bulk of the penis. The corpus spongiosum, which can be felt as a raised ridge on the erect penis, is a smaller chamber that surrounds the spongy, or penile, urethra. The end of the penis, called the glans penis, has a high concentration of nerve endings, resulting in very sensitive skin that influences the likelihood of ejaculation (see Figure 27.2). The skin from the shaft extends down over the glans and forms a collar called the prepuce (or foreskin). The foreskin also contains a dense concentration of nerve endings, and both lubricate and protect the sensitive skin of the glans penis. A surgical procedure called circumcision, often performed for religious or social reasons, removes the prepuce, typically within days of birth. Both sexual arousal and REM sleep (during which dreaming occurs) can induce an erection. Penile erections are the result of vasocongestion, or engorgement of the tissues because of more arterial blood flowing into the penis than is leaving in the veins. During sexual arousal, nitric oxide (NO) is released from nerve endings near blood vessels within the corpora cavernosa and spongiosum. Release of NO activates a signaling pathway that results in relaxation of the smooth muscles that surround the penile arteries, causing them to dilate. This dilation increases the amount of blood that can enter the penis and induces the endothelial cells in the penile arterial walls to also secrete NO and perpetuate the vasodilation. The rapid increase in blood volume fills the erectile chambers, and the increased pressure of the filled chambers compresses the thin-walled penile venules, preventing venous drainage of the penis. The result of this increased blood flow to the penis and reduced blood return from the penis is erection. Depending on the flaccid dimensions of a penis, it can increase in size slightly or greatly during erection, with the average length of an erect penis measuring approximately 15 cm. DISORDERS OF THE... Male Reproductive System Erectile dysfunction (ED) is a condition in which a man has difficulty either initiating or maintaining an erection. The combined prevalence of minimal, moderate, and complete ED is approximately 40 percent in men at age 40, and reaches nearly 70 percent by 70 years of age. In addition to aging, ED is associated with diabetes, vascular disease, psychiatric disorders, prostate disorders, the use of some drugs such as certain antidepressants, and problems with the testes resulting in low testosterone concentrations. These physical and emotional conditions can lead to interruptions in the vasodilation pathway and result in an inability to achieve an erection. Recall that the release of NO induces relaxation of the smooth muscles that surround the penile arteries, leading to the vasodilation necessary to achieve an erection. To reverse the process of vasodilation, an enzyme called phosphodiesterase (PDE) degrades a key component of the NO signaling pathway called cGMP. There are several different forms of this enzyme, and PDE type 5 is the type of PDE found in the tissues of the penis. Scientists discovered that inhibiting PDE5 increases blood flow, and allows vasodilation of the penis to occur. PDEs and the vasodilation signaling pathway are found in the vasculature in other parts of the body. In the 1990s, clinical trials of a PDE5 inhibitor called sildenafil were initiated to treat hypertension and angina pectoris (chest pain caused by poor blood flow through the heart). The trial showed that the drug was not effective at treating heart conditions, but many men experienced erection and priapism (erection lasting longer than 4 hours). Because of this, a clinical trial was started to investigate the ability of sildenafil to promote erections in men suffering from ED. In 1998, the FDA approved the drug, marketed as Viagra®. Since approval of the drug, sildenafil and similar PDE inhibitors now generate over a billion dollars a year in sales, and are reported to be effective in treating approximately 70 to 85 percent of cases of ED. Importantly, men with health problems—especially those with cardiac disease taking nitrates—should avoid Viagra or talk to their physician to find out if they are a candidate for the use of this drug, as deaths have been reported for at-risk users. Testosterone Testosterone, an androgen, is a steroid hormone produced by Leydig cells. The alternate term for Leydig cells, interstitial cells, reflects their location between the seminiferous tubules in the testes. In male embryos, testosterone is secreted by Leydig cells by the seventh week of development, with peak concentrations reached in the second trimester. This early release of testosterone results in the anatomical differentiation of the male sexual organs. In childhood, testosterone concentrations are low. They increase during puberty, activating characteristic physical changes and initiating spermatogenesis. Functions of Testosterone The continued presence of testosterone is necessary to keep the male reproductive system working properly, and Leydig cells produce approximately 6 to 7 mg of testosterone per day. Testicular steroidogenesis (the manufacture of androgens, including testosterone) results in testosterone concentrations that are 100 times higher in the testes than in the circulation. Maintaining these normal concentrations of testosterone promotes spermatogenesis, whereas low levels of testosterone can lead to infertility. In addition to intratesticular secretion, testosterone is also released into the systemic circulation and plays an important role in muscle development, bone growth, the development of secondary sex characteristics, and maintaining libido (sex drive) in both males and females. In females, the ovaries secrete small amounts of testosterone, although most is converted to estradiol. A small amount of testosterone is also secreted by the adrenal glands in both sexes. Control of Testosterone The regulation of testosterone concentrations throughout the body is critical for male reproductive function. The intricate interplay between the endocrine system and the reproductive system is shown in Figure 27.8. Figure 27.8 Regulation of Testosterone Production The hypothalamus and pituitary gland regulate the production of testosterone and the cells that assist in spermatogenesis. GnRH activates the anterior pituitary to produce LH and FSH, which in turn stimulate Leydig cells and Sertoli cells, respectively. The system is a negative feedback loop because the end products of the pathway, testosterone and inhibin, interact with the activity of GnRH to inhibit their own production. The regulation of Leydig cell production of testosterone begins outside of the testes. The hypothalamus and the pituitary gland in the brain integrate external and internal signals to control testosterone synthesis and secretion. The regulation begins in the hypothalamus. Pulsatile release of a hormone called gonadotropin-releasing hormone (GnRH) from the hypothalamus stimulates the endocrine release of hormones from the pituitary gland. Binding of GnRH to its receptors on the anterior pituitary gland stimulates release of the two gonadotropins: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These two hormones are critical for reproductive function in both men and women. In men, FSH binds predominantly to the Sertoli cells within the seminiferous tubules to promote spermatogenesis. FSH also stimulates the Sertoli cells to produce hormones called inhibins, which function to inhibit FSH release from the pituitary, thus reducing testosterone secretion. These polypeptide hormones correlate directly with Sertoli cell function and sperm number; inhibin B can be used as a marker of spermatogenic activity. In men, LH binds to receptors on Leydig cells in the testes and upregulates the production of testosterone. A negative feedback loop predominantly controls the synthesis and secretion of both FSH and LH. Low blood concentrations of testosterone stimulate the hypothalamic release of GnRH. GnRH then stimulates the anterior pituitary to secrete LH into the bloodstream. In the testis, LH binds to LH receptors on Leydig cells and stimulates the release of testosterone. When concentrations of testosterone in the blood reach a critical threshold, testosterone itself will bind to androgen receptors on both the hypothalamus and the anterior pituitary, inhibiting the synthesis and secretion of GnRH and LH, respectively. When the blood concentrations of testosterone once again decline, testosterone no longer interacts with the receptors to the same degree and GnRH and LH are once again secreted, stimulating more testosterone production. This same process occurs with FSH and inhibin to control spermatogenesis. AGING AND THE... Male Reproductive System Declines in Leydig cell activity can occur in men beginning at 40 to 50 years of age. The resulting reduction in circulating testosterone concentrations can lead to symptoms of andropause, also known as male menopause. While the reduction in sex steroids in men is akin to female menopause, there is no clear sign—such as a lack of a menstrual period—to denote the initiation of andropause. Instead, men report feelings of fatigue, reduced muscle mass, depression, anxiety, irritability, loss of libido, and insomnia. A reduction in spermatogenesis resulting in lowered fertility is also reported, and sexual dysfunction can also be associated with andropausal symptoms. Whereas some researchers believe that certain aspects of andropause are difficult to tease apart from aging in general, testosterone replacement is sometimes prescribed to alleviate some symptoms. Recent studies have shown a benefit from androgen replacement therapy on the new onset of depression in elderly men; however, other studies caution against testosterone replacement for long-term treatment of andropause symptoms, showing that high doses can sharply increase the risk of both heart disease and prostate cancer. Anatomy and Physiology of the Female Reproductive System - Describe the structure and function of the organs of the female reproductive system - List the steps of oogenesis - Describe the hormonal changes that occur during the ovarian and menstrual cycles - Trace the path of an oocyte from ovary to fertilization The female reproductive system functions to produce gametes and reproductive hormones, just like the male reproductive system; however, it also has the additional task of supporting the developing fetus and delivering it to the outside world. Unlike its male counterpart, the female reproductive system is located primarily inside the pelvic cavity (Figure 27.9). Recall that the ovaries are the female gonads. The gamete they produce is called an oocyte. We’ll discuss the production of oocytes in detail shortly. First, let’s look at some of the structures of the female reproductive system. Figure 27.9 Female Reproductive System The major organs of the female reproductive system are located inside the pelvic cavity. External Female Genitals The external female reproductive structures are referred to collectively as the vulva (Figure 27.10). The mons pubis is a pad of fat that is located at the anterior, over the pubic bone. After puberty, it becomes covered in pubic hair. The labia majora (labia = “lips”; majora = “larger”) are folds of hair-covered skin that begin just posterior to the mons pubis. The thinner and more pigmented labia minora (labia = “lips”; minora = “smaller”) extend medial to the labia majora. Although they naturally vary in shape and size from woman to woman, the labia minora serve to protect the female urethra and the entrance to the female reproductive tract. The superior, anterior portions of the labia minora come together to encircle the clitoris (or glans clitoris), an organ that originates from the same cells as the glans penis and has abundant nerves that make it important in sexual sensation and orgasm. The hymen is a thin membrane that sometimes partially covers the entrance to the vagina. An intact hymen cannot be used as an indication of “virginity”; even at birth, this is only a partial membrane, as menstrual fluid and other secretions must be able to exit the body, regardless of penile–vaginal intercourse. The vaginal opening is located between the opening of the urethra and the anus. It is flanked by outlets to the Bartholin’s glands (or greater vestibular glands). Figure 27.10 The Vulva The external female genitalia are referred to collectively as the vulva. Vagina The vagina, shown at the bottom of Figure 27.9 and Figure 27.9, is a muscular canal (approximately 10 cm long) that serves as the entrance to the reproductive tract. It also serves as the exit from the uterus during menses and childbirth. The outer walls of the anterior and posterior vagina are formed into longitudinal columns, or ridges, and the superior portion of the vagina—called the fornix—meets the protruding uterine cervix. The walls of the vagina are lined with an outer, fibrous adventitia; a middle layer of smooth muscle; and an inner mucous membrane with transverse folds called rugae. Together, the middle and inner layers allow the expansion of the vagina to accommodate intercourse and childbirth. The thin, perforated hymen can partially surround the opening to the vaginal orifice. The hymen can be ruptured with strenuous physical exercise, penile–vaginal intercourse, and childbirth. The Bartholin’s glands and the lesser vestibular glands (located near the clitoris) secrete mucus, which keeps the vestibular area moist. The vagina is home to a normal population of microorganisms that help to protect against infection by pathogenic bacteria, yeast, or other organisms that can enter the vagina. In a healthy woman, the most predominant type of vaginal bacteria is from the genus Lactobacillus. This family of beneficial bacterial flora secretes lactic acid, and thus protects the vagina by maintaining an acidic pH (below 4.5). Potential pathogens are less likely to survive in these acidic conditions. Lactic acid, in combination with other vaginal secretions, makes the vagina a self-cleansing organ. However, douching—or washing out the vagina with fluid—can disrupt the normal balance of healthy microorganisms, and actually increase a woman’s risk for infections and irritation. Indeed, the American College of Obstetricians and Gynecologists recommend that women do not douche, and that they allow the vagina to maintain its normal healthy population of protective microbial flora. Ovaries The ovaries are the female gonads (see Figure 27.9). Paired ovals, they are each about 2 to 3 cm in length, about the size of an almond. The ovaries are located within the pelvic cavity, and are supported by the mesovarium, an extension of the peritoneum that connects the ovaries to the broad ligament. Extending from the mesovarium itself is the suspensory ligament that contains the ovarian blood and lymph vessels. Finally, the ovary itself is attached to the uterus via the ovarian ligament. The ovary comprises an outer covering of cuboidal epithelium called the ovarian surface epithelium that is superficial to a dense connective tissue covering called the tunica albuginea. Beneath the tunica albuginea is the cortex, or outer portion, of the organ. The cortex is composed of a tissue framework called the ovarian stroma that forms the bulk of the adult ovary. Oocytes develop within the outer layer of this stroma, each surrounded by supporting cells. This grouping of an oocyte and its supporting cells is called a follicle. The growth and development of ovarian follicles will be described shortly. Beneath the cortex lies the inner ovarian medulla, the site of blood vessels, lymph vessels, and the nerves of the ovary. You will learn more about the overall anatomy of the female reproductive system at the end of this section. The Ovarian Cycle The ovarian cycle is a set of predictable changes in a female’s oocytes and ovarian follicles. During a woman’s reproductive years, it is a roughly 28-day cycle that can be correlated with, but is not the same as, the menstrual cycle (discussed shortly). The cycle includes two interrelated processes: oogenesis (the production of female gametes) and folliculogenesis (the growth and development of ovarian follicles). Oogenesis Gametogenesis in females is called oogenesis. The process begins with the ovarian stem cells, or oogonia (Figure 27.11). Oogonia are formed during fetal development, and divide via mitosis, much like spermatogonia in the testis. Unlike spermatogonia, however, oogonia form primary oocytes in the fetal ovary prior to birth. These primary oocytes are then arrested in this stage of meiosis I, only to resume it years later, beginning at puberty and continuing until the woman is near menopause (the cessation of a woman’s reproductive functions). The number of primary oocytes present in the ovaries declines from one to two million in an infant, to approximately 400,000 at puberty, to zero by the end of menopause. The initiation of ovulation—the release of an oocyte from the ovary—marks the transition from puberty into reproductive maturity for women. From then on, throughout a woman’s reproductive years, ovulation occurs approximately once every 28 days. Just prior to ovulation, a surge of luteinizing hormone triggers the resumption of meiosis in a primary oocyte. This initiates the transition from primary to secondary oocyte. However, as you can see in Figure 27.11, this cell division does not result in two identical cells. Instead, the cytoplasm is divided unequally, and one daughter cell is much larger than the other. This larger cell, the secondary oocyte, eventually leaves the ovary during ovulation. The smaller cell, called the first polar body, may or may not complete meiosis and produce second polar bodies; in either case, it eventually disintegrates. Therefore, even though oogenesis produces up to four cells, only one survives. Figure 27.11 Oogenesis The unequal cell division of oogenesis produces one to three polar bodies that later degrade, as well as a single haploid ovum, which is produced only if there is penetration of the secondary oocyte by a sperm cell. How does the diploid secondary oocyte become an ovum—the haploid female gamete? Meiosis of a secondary oocyte is completed only if a sperm succeeds in penetrating its barriers. Meiosis II then resumes, producing one haploid ovum that, at the instant of fertilization by a (haploid) sperm, becomes the first diploid cell of the new offspring (a zygote). Thus, the ovum can be thought of as a brief, transitional, haploid stage between the diploid oocyte and diploid zygote. The larger amount of cytoplasm contained in the female gamete is used to supply the developing zygote with nutrients during the period between fertilization and implantation into the uterus. Interestingly, sperm contribute only DNA at fertilization —not cytoplasm. Therefore, the cytoplasm and all of the cytoplasmic organelles in the developing embryo are of maternal origin. This includes mitochondria, which contain their own DNA. Scientific research in the 1980s determined that mitochondrial DNA was maternally inherited, meaning that you can trace your mitochondrial DNA directly to your mother, her mother, and so on back through your female ancestors. EVERYDAY CONNECTION Mapping Human History with Mitochondrial DNA When we talk about human DNA, we’re usually referring to nuclear DNA; that is, the DNA coiled into chromosomal bundles in the nucleus of our cells. We inherit half of our nuclear DNA from our father, and half from our mother. However, mitochondrial DNA (mtDNA) comes only from the mitochondria in the cytoplasm of the fat ovum we inherit from our mother. She received her mtDNA from her mother, who got it from her mother, and so on. Each of our cells contains approximately 1700 mitochondria, with each mitochondrion packed with mtDNA containing approximately 37 genes. Mutations (changes) in mtDNA occur spontaneously in a somewhat organized pattern at regular intervals in human history. By analyzing these mutational relationships, researchers have been able to determine that we can all trace our ancestry back to one woman who lived in Africa about 200,000 years ago. Scientists have given this woman the biblical name Eve, although she is not, of course, the first Homo sapiens female. More precisely, she is our most recent common ancestor through matrilineal descent. This doesn’t mean that everyone’s mtDNA today looks exactly like that of our ancestral Eve. Because of the spontaneous mutations in mtDNA that have occurred over the centuries, researchers can map different “branches” off of the “main trunk” of our mtDNA family tree. Your mtDNA might have a pattern of mutations that aligns more closely with one branch, and your neighbor’s may align with another branch. Still, all branches eventually lead back to Eve. But what happened to the mtDNA of all of the other Homo sapiens females who were living at the time of Eve? Researchers explain that, over the centuries, their female descendants died childless or with only male children, and thus, their maternal line—and its mtDNA—ended. Folliculogenesis Again, ovarian follicles are oocytes and their supporting cells. They grow and develop in a process called folliculogenesis, which typically leads to ovulation of one follicle approximately every 28 days, along with death to multiple other follicles. The death of ovarian follicles is called atresia, and can occur at any point during follicular development. Recall that, a female infant at birth will have one to two million oocytes within her ovarian follicles, and that this number declines throughout life until menopause, when no follicles remain. As you’ll see next, follicles progress from primordial, to primary, to secondary and tertiary stages prior to ovulation—with the oocyte inside the follicle remaining as a primary oocyte until right before ovulation. Folliculogenesis begins with follicles in a resting state. These small primordial follicles are present in newborn females and are the prevailing follicle type in the adult ovary (Figure 27.12). Primordial follicles have only a single flat layer of support cells, called granulosa cells, that surround the oocyte, and they can stay in this resting state for years—some until right before menopause. After puberty, a few primordial follicles will respond to a recruitment signal each day, and will join a pool of immature growing follicles called primary follicles. Primary follicles start with a single layer of granulosa cells, but the granulosa cells then become active and transition from a flat or squamous shape to a rounded, cuboidal shape as they increase in size and proliferate. As the granulosa cells divide, the follicles—now called secondary follicles (see Figure 27.12)—increase in diameter, adding a new outer layer of connective tissue, blood vessels, and theca cells—cells that work with the granulosa cells to produce estrogens. Within the growing secondary follicle, the primary oocyte now secretes a thin acellular membrane called the zona pellucida that will play a critical role in fertilization. A thick fluid, called follicular fluid, that has formed between the granulosa cells also begins to collect into one large pool, or antrum. Follicles in which the antrum has become large and fully formed are considered tertiary follicles (or antral follicles). Several follicles reach the tertiary stage at the same time, and most of these will undergo atresia. The one that does not die will continue to grow and develop until ovulation, when it will expel its secondary oocyte surrounded by several layers of granulosa cells from the ovary. Keep in mind that most follicles don’t make it to this point. In fact, roughly 99 percent of the follicles in the ovary will undergo atresia, which can occur at any stage of folliculogenesis. Figure 27.12 Folliculogenesis (a) The maturation of a follicle is shown in a clockwise direction proceeding from the primordial follicles. FSH stimulates the growth of a tertiary follicle, and LH stimulates the production of estrogen by granulosa and theca cells. Once the follicle is mature, it ruptures and releases the oocyte. Cells remaining in the follicle then develop into the corpus luteum. (b) In this electron micrograph of a secondary follicle, the oocyte, theca cells (thecae folliculi), and developing antrum are clearly visible. EM × 1100. (Micrograph provided by the Regents of University of Michigan Medical School © 2012) Hormonal Control of the Ovarian Cycle The process of development that we have just described, from primordial follicle to early tertiary follicle, takes approximately two months in humans. The final stages of development of a small cohort of tertiary follicles, ending with ovulation of a secondary oocyte, occur over a course of approximately 28 days. These changes are regulated by many of the same hormones that regulate the male reproductive system, including GnRH, LH, and FSH. As in men, the hypothalamus produces GnRH, a hormone that signals the anterior pituitary gland to produce the gonadotropins FSH and LH (Figure 27.13). These gonadotropins leave the pituitary and travel through the bloodstream to the ovaries, where they bind to receptors on the granulosa and theca cells of the follicles. FSH stimulates the follicles to grow (hence its name of follicle-stimulating hormone), and the five or six tertiary follicles expand in diameter. The release of LH also stimulates the granulosa and theca cells of the follicles to produce the sex steroid hormone estradiol, a type of estrogen. This phase of the ovarian cycle, when the tertiary follicles are growing and secreting estrogen, is known as the follicular phase. The more granulosa and theca cells a follicle has (that is, the larger and more developed it is), the more estrogen it will produce in response to LH stimulation. As a result of these large follicles producing large amounts of estrogen, systemic plasma estrogen concentrations increase. Following a classic negative feedback loop, the high concentrations of estrogen will stimulate the hypothalamus and pituitary to reduce the production of GnRH, LH, and FSH. Because the large tertiary follicles require FSH to grow and survive at this point, this decline in FSH caused by negative feedback leads most of them to die (atresia). Typically only one follicle, now called the dominant follicle, will survive this reduction in FSH, and this follicle will be the one that releases an oocyte. Scientists have studied many factors that lead to a particular follicle becoming dominant: size, the number of granulosa cells, and the number of FSH receptors on those granulosa cells all contribute to a follicle becoming the one surviving dominant follicle. Figure 27.13 Hormonal Regulation of Ovulation The hypothalamus and pituitary gland regulate the ovarian cycle and ovulation. GnRH activates the anterior pituitary to produce LH and FSH, which stimulate the production of estrogen and progesterone by the ovaries. When only the one dominant follicle remains in the ovary, it again begins to secrete estrogen. It produces more estrogen than all of the developing follicles did together before the negative feedback occurred. It produces so much estrogen that the normal negative feedback doesn’t occur. Instead, these extremely high concentrations of systemic plasma estrogen trigger a regulatory switch in the anterior pituitary that responds by secreting large amounts of LH and FSH into the bloodstream (see Figure 27.13). The positive feedback loop by which more estrogen triggers release of more LH and FSH only occurs at this point in the cycle. It is this large burst of LH (called the LH surge) that leads to ovulation of the dominant follicle. The LH surge induces many changes in the dominant follicle, including stimulating the resumption of meiosis of the primary oocyte to a secondary oocyte. As noted earlier, the polar body that results from unequal cell division simply degrades. The LH surge also triggers proteases (enzymes that cleave proteins) to break down structural proteins in the ovary wall on the surface of the bulging dominant follicle. This degradation of the wall, combined with pressure from the large, fluid-filled antrum, results in the expulsion of the oocyte surrounded by granulosa cells into the peritoneal cavity. This release is ovulation. In the next section, you will follow the ovulated oocyte as it travels toward the uterus, but there is one more important event that occurs in the ovarian cycle. The surge of LH also stimulates a change in the granulosa and theca cells that remain in the follicle after the oocyte has been ovulated. This change is called luteinization (recall that the full name of LH is luteinizing hormone), and it transforms the collapsed follicle into a new endocrine structure called the corpus luteum, a term meaning “yellowish body” (see Figure 27.12). Instead of estrogen, the luteinized granulosa and theca cells of the corpus luteum begin to produce large amounts of the sex steroid hormone progesterone, a hormone that is critical for the establishment and maintenance of pregnancy. Progesterone triggers negative feedback at the hypothalamus and pituitary, which keeps GnRH, LH, and FSH secretions low, so no new dominant follicles develop at this time. The post-ovulatory phase of progesterone secretion is known as the luteal phase of the ovarian cycle. If pregnancy does not occur within 10 to 12 days, the corpus luteum will stop secreting progesterone and degrade into the corpus albicans, a nonfunctional “whitish body” that will disintegrate in the ovary over a period of several months. During this time of reduced progesterone secretion, FSH and LH are once again stimulated, and the follicular phase begins again with a new cohort of early tertiary follicles beginning to grow and secrete estrogen. The Uterine Tubes The uterine tubes (also called fallopian tubes or oviducts) serve as the conduit of the oocyte from the ovary to the uterus (Figure 27.14). Each of the two uterine tubes is close to, but not directly connected to, the ovary and divided into sections. The isthmus is the narrow medial end of each uterine tube that is connected to the uterus. The wide distal infundibulum flares out with slender, finger-like projections called fimbriae. The middle region of the tube, called the ampulla, is where fertilization often occurs. The uterine tubes also have three layers: an outer serosa, a middle smooth muscle layer, and an inner mucosal layer. In addition to its mucus-secreting cells, the inner mucosa contains ciliated cells that beat in the direction of the uterus, producing a current that will be critical to move the oocyte. Following ovulation, the secondary oocyte surrounded by a few granulosa cells is released into the peritoneal cavity. The nearby uterine tube, either left or right, receives the oocyte. Unlike sperm, oocytes lack flagella, and therefore cannot move on their own. So how do they travel into the uterine tube and toward the uterus? High concentrations of estrogen that occur around the time of ovulation induce contractions of the smooth muscle along the length of the uterine tube. These contractions occur every 4 to 8 seconds, and the result is a coordinated movement that sweeps the surface of the ovary and the pelvic cavity. Current flowing toward the uterus is generated by coordinated beating of the cilia that line the outside and lumen of the length of the uterine tube. These cilia beat more strongly in response to the high estrogen concentrations that occur around the time of ovulation. As a result of these mechanisms, the oocyte–granulosa cell complex is pulled into the interior of the tube. Once inside, the muscular contractions and beating cilia move the oocyte slowly toward the uterus. When fertilization does occur, sperm typically meet the egg while it is still moving through the ampulla. INTERACTIVE LINK Watch this video to observe ovulation and its initiation in response to the release of FSH and LH from the pituitary gland. What specialized structures help guide the oocyte from the ovary into the uterine tube? If the oocyte is successfully fertilized, the resulting zygote will begin to divide into two cells, then four, and so on, as it makes its way through the uterine tube and into the uterus. There, it will implant and continue to grow. If the egg is not fertilized, it will simply degrade—either in the uterine tube or in the uterus, where it may be shed with the next menstrual period. Figure 27.14 Ovaries, Uterine Tubes, and Uterus This anterior view shows the relationship of the ovaries, uterine tubes (oviducts), and uterus. Sperm enter through the vagina, and fertilization of an ovulated oocyte usually occurs in the distal uterine tube. From left to right, LM × 400, LM × 20. (Micrographs provided by the Regents of University of Michigan Medical School © 2012) The open-ended structure of the uterine tubes can have significant health consequences if bacteria or other contagions enter through the vagina and move through the uterus, into the tubes, and then into the pelvic cavity. If this is left unchecked, a bacterial infection (sepsis) could quickly become life-threatening. The spread of an infection in this manner is of special concern when unskilled practitioners perform abortions in non-sterile conditions. Sepsis is also associated with sexually transmitted bacterial infections, especially gonorrhea and chlamydia. These increase a woman’s risk for pelvic inflammatory disease (PID), infection of the uterine tubes or other reproductive organs. Even when resolved, PID can leave scar tissue in the tubes, leading to infertility. INTERACTIVE LINK Watch this series of videos to look at the movement of the oocyte through the ovary. The cilia in the uterine tube promote movement of the oocyte. What would likely occur if the cilia were paralyzed at the time of ovulation? The Uterus and Cervix The uterus is the muscular organ that nourishes and supports the growing embryo (see Figure 27.14). Its average size is approximately 5 cm wide by 7 cm long (approximately 2 in by 3 in) when a female is not pregnant. It has three sections. The portion of the uterus superior to the opening of the uterine tubes is called the fundus. The middle section of the uterus is called the body of uterus (or corpus). The cervix is the narrow inferior portion of the uterus that projects into the vagina. The cervix produces mucus secretions that become thin and stringy under the influence of high systemic plasma estrogen concentrations, and these secretions can facilitate sperm movement through the reproductive tract. Several ligaments maintain the position of the uterus within the abdominopelvic cavity. The broad ligament is a fold of peritoneum that serves as a primary support for the uterus, extending laterally from both sides of the uterus and attaching it to the pelvic wall. The round ligament attaches to the uterus near the uterine tubes, and extends to the labia majora. Finally, the uterosacral ligament stabilizes the uterus posteriorly by its connection from the cervix to the pelvic wall. The wall of the uterus is made up of three layers. The most superficial layer is the serous membrane, or perimetrium, which consists of epithelial tissue that covers the exterior portion of the uterus. The middle layer, or myometrium, is a thick layer of smooth muscle responsible for uterine contractions. Most of the uterus is myometrial tissue, and the muscle fibers run horizontally, vertically, and diagonally, allowing the powerful contractions that occur during labor and the less powerful contractions (or cramps) that help to expel menstrual blood during a woman’s period. Anteriorly directed myometrial contractions also occur near the time of ovulation, and are thought to possibly facilitate the transport of sperm through the female reproductive tract. The innermost layer of the uterus is called the endometrium. The endometrium contains a connective tissue lining, the lamina propria, which is covered by epithelial tissue that lines the lumen. Structurally, the endometrium consists of two layers: the stratum basalis and the stratum functionalis (the basal and functional layers). The stratum basalis layer is part of the lamina propria and is adjacent to the myometrium; this layer does not shed during menses. In contrast, the thicker stratum functionalis layer contains the glandular portion of the lamina propria and the endothelial tissue that lines the uterine lumen. It is the stratum functionalis that grows and thickens in response to increased levels of estrogen and progesterone. In the luteal phase of the menstrual cycle, special branches off of the uterine artery called spiral arteries supply the thickened stratum functionalis. This inner functional layer provides the proper site of implantation for the fertilized egg, and—should fertilization not occur—it is only the stratum functionalis layer of the endometrium that sheds during menstruation. Recall that during the follicular phase of the ovarian cycle, the tertiary follicles are growing and secreting estrogen. At the same time, the stratum functionalis of the endometrium is thickening to prepare for a potential implantation. The post-ovulatory increase in progesterone, which characterizes the luteal phase, is key for maintaining a thick stratum functionalis. As long as a functional corpus luteum is present in the ovary, the endometrial lining is prepared for implantation. Indeed, if an embryo implants, signals are sent to the corpus luteum to continue secreting progesterone to maintain the endometrium, and thus maintain the pregnancy. If an embryo does not implant, no signal is sent to the corpus luteum and it degrades, ceasing progesterone production and ending the luteal phase. Without progesterone, the endometrium thins and, under the influence of prostaglandins, the spiral arteries of the endometrium constrict and rupture, preventing oxygenated blood from reaching the endometrial tissue. As a result, endometrial tissue dies and blood, pieces of the endometrial tissue, and white blood cells are shed through the vagina during menstruation, or the menses. The first menses after puberty, called menarche, can occur either before or after the first ovulation. The Menstrual Cycle Now that we have discussed the maturation of the cohort of tertiary follicles in the ovary, the build-up and then shedding of the endometrial lining in the uterus, and the function of the uterine tubes and vagina, we can put everything together to talk about the three phases of the menstrual cycle—the series of changes in which the uterine lining is shed, rebuilds, and prepares for implantation. The timing of the menstrual cycle starts with the first day of menses, referred to as day one of a woman’s period. Cycle length is determined by counting the days between the onset of bleeding in two subsequent cycles. Because the average length of a woman’s menstrual cycle is 28 days, this is the time period used to identify the timing of events in the cycle. However, the length of the menstrual cycle varies among women, and even in the same woman from one cycle to the next, typically from 21 to 32 days. Just as the hormones produced by the granulosa and theca cells of the ovary “drive” the follicular and luteal phases of the ovarian cycle, they also control the three distinct phases of the menstrual cycle. These are the menses phase, the proliferative phase, and the secretory phase. Menses Phase The menses phase of the menstrual cycle is the phase during which the lining is shed; that is, the days that the woman menstruates. Although it averages approximately five days, the menses phase can last from 2 to 7 days, or longer. As shown in Figure 27.15, the menses phase occurs during the early days of the follicular phase of the ovarian cycle, when progesterone, FSH, and LH levels are low. Recall that progesterone concentrations decline as a result of the degradation of the corpus luteum, marking the end of the luteal phase. This decline in progesterone triggers the shedding of the stratum functionalis of the endometrium. Figure 27.15 Hormone Levels in Ovarian and Menstrual Cycles The correlation of the hormone levels and their effects on the female reproductive system is shown in this timeline of the ovarian and menstrual cycles. The menstrual cycle begins at day one with the start of menses. Ovulation occurs around day 14 of a 28-day cycle, triggered by the LH surge. Proliferative Phase Once menstrual flow ceases, the endometrium begins to proliferate again, marking the beginning of the proliferative phase of the menstrual cycle (see Figure 27.15). It occurs when the granulosa and theca cells of the tertiary follicles begin to produce increased amounts of estrogen. These rising estrogen concentrations stimulate the endometrial lining to rebuild. Recall that the high estrogen concentrations will eventually lead to a decrease in FSH as a result of negative feedback, resulting in atresia of all but one of the developing tertiary follicles. The switch to positive feedback—which occurs with the elevated estrogen production from the dominant follicle—then stimulates the LH surge that will trigger ovulation. In a typical 28-day menstrual cycle, ovulation occurs on day 14. Ovulation marks the end of the proliferative phase as well as the end of the follicular phase. Secretory Phase In addition to prompting the LH surge, high estrogen levels increase the uterine tube contractions that facilitate the pick-up and transfer of the ovulated oocyte. High estrogen levels also slightly decrease the acidity of the vagina, making it more hospitable to sperm. In the ovary, the luteinization of the granulosa cells of the collapsed follicle forms the progesterone-producing corpus luteum, marking the beginning of the luteal phase of the ovarian cycle. In the uterus, progesterone from the corpus luteum begins the secretory phase of the menstrual cycle, in which the endometrial lining prepares for implantation (see Figure 27.15). Over the next 10 to 12 days, the endometrial glands secrete a fluid rich in glycogen. If fertilization has occurred, this fluid will nourish the ball of cells now developing from the zygote. At the same time, the spiral arteries develop to provide blood to the thickened stratum functionalis. If no pregnancy occurs within approximately 10 to 12 days, the corpus luteum will degrade into the corpus albicans. Levels of both estrogen and progesterone will fall, and the endometrium will grow thinner. Prostaglandins will be secreted that cause constriction of the spiral arteries, reducing oxygen supply. The endometrial tissue will die, resulting in menses—or the first day of the next cycle. DISORDERS OF THE... Female Reproductive System Research over many years has confirmed that cervical cancer is most often caused by a sexually transmitted infection with human papillomavirus (HPV). There are over 100 related viruses in the HPV family, and the characteristics of each strain determine the outcome of the infection. In all cases, the virus enters body cells and uses its own genetic material to take over the host cell’s metabolic machinery and produce more virus particles. HPV infections are common in both men and women. Indeed, a recent study determined that 42.5 percent of females had HPV at the time of testing. These women ranged in age from 14 to 59 years and differed in race, ethnicity, and number of sexual partners. Of note, the prevalence of HPV infection was 53.8 percent among women aged 20 to 24 years, the age group with the highest infection rate. HPV strains are classified as high or low risk according to their potential to cause cancer. Though most HPV infections do not cause disease, the disruption of normal cellular functions in the low-risk forms of HPV can cause the male or female human host to develop genital warts. Often, the body is able to clear an HPV infection by normal immune responses within 2 years. However, the more serious, high-risk infection by certain types of HPV can result in cancer of the cervix (Figure 27.16). Infection with either of the cancer-causing variants HPV 16 or HPV 18 has been linked to more than 70 percent of all cervical cancer diagnoses. Although even these high-risk HPV strains can be cleared from the body over time, infections persist in some individuals. If this happens, the HPV infection can influence the cells of the cervix to develop precancerous changes. Risk factors for cervical cancer include having unprotected sex; having multiple sexual partners; a first sexual experience at a younger age, when the cells of the cervix are not fully mature; failure to receive the HPV vaccine; a compromised immune system; and smoking. The risk of developing cervical cancer is doubled with cigarette smoking. Figure 27.16 Development of Cervical Cancer In most cases, cells infected with the HPV virus heal on their own. In some cases, however, the virus continues to spread and becomes an invasive cancer. When the high-risk types of HPV enter a cell, two viral proteins are used to neutralize proteins that the host cells use as checkpoints in the cell cycle. The best studied of these proteins is p53. In a normal cell, p53 detects DNA damage in the cell’s genome and either halts the progression of the cell cycle—allowing time for DNA repair to occur—or initiates apoptosis. Both of these processes prevent the accumulation of mutations in a cell’s genome. High-risk HPV can neutralize p53, keeping the cell in a state in which fast growth is possible and impairing apoptosis, allowing mutations to accumulate in the cellular DNA. The prevalence of cervical cancer in the United States is very low because of regular screening exams called pap smears. Pap smears sample cells of the cervix, allowing the detection of abnormal cells. If pre-cancerous cells are detected, there are several highly effective techniques that are currently in use to remove them before they pose a danger. However, women in developing countries often do not have access to regular pap smears. As a result, these women account for as many as 80 percent of the cases of cervical cancer worldwide. In 2006, the first vaccine against the high-risk types of HPV was approved. There are now two HPV vaccines available: Gardasil® and Cervarix®. Whereas these vaccines were initially only targeted for women, because HPV is sexually transmitted, both men and women require vaccination for this approach to achieve its maximum efficacy. A recent study suggests that the HPV vaccine has cut the rates of HPV infection by the four targeted strains at least in half. Unfortunately, the high cost of manufacturing the vaccine is currently limiting access to many women worldwide. The Breasts Whereas the breasts are located far from the other female reproductive organs, they are considered accessory organs of the female reproductive system. The function of the breasts is to supply milk to an infant in a process called lactation. The external features of the breast include a nipple surrounded by a pigmented areola (Figure 27.17), whose coloration may deepen during pregnancy. The areola is typically circular and can vary in size from 25 to 100 mm in diameter. The areolar region is characterized by small, raised areolar glands that secrete lubricating fluid during lactation to protect the nipple from chafing. When a baby nurses, or draws milk from the breast, the entire areolar region is taken into the mouth. Breast milk is produced by the mammary glands, which are modified sweat glands. The milk itself exits the breast through the nipple via 15 to 20 lactiferous ducts that open on the surface of the nipple. These lactiferous ducts each extend to a lactiferous sinus that connects to a glandular lobe within the breast itself that contains groups of milk-secreting cells in clusters called alveoli (see Figure 27.17). The clusters can change in size depending on the amount of milk in the alveolar lumen. Once milk is made in the alveoli, stimulated myoepithelial cells that surround the alveoli contract to push the milk to the lactiferous sinuses. From here, the baby can draw milk through the lactiferous ducts by suckling. The lobes themselves are surrounded by fat tissue, which determines the size of the breast; breast size differs between individuals and does not affect the amount of milk produced. Supporting the breasts are multiple bands of connective tissue called suspensory ligaments that connect the breast tissue to the dermis of the overlying skin. Figure 27.17 Anatomy of the Breast During lactation, milk moves from the alveoli through the lactiferous ducts to the nipple. During the normal hormonal fluctuations in the menstrual cycle, breast tissue responds to changing levels of estrogen and progesterone, which can lead to swelling and breast tenderness in some individuals, especially during the secretory phase. If pregnancy occurs, the increase in hormones leads to further development of the mammary tissue and enlargement of the breasts. Hormonal Birth Control Birth control pills take advantage of the negative feedback system that regulates the ovarian and menstrual cycles to stop ovulation and prevent pregnancy. Typically they work by providing a constant level of both estrogen and progesterone, which negatively feeds back onto the hypothalamus and pituitary, thus preventing the release of FSH and LH. Without FSH, the follicles do not mature, and without the LH surge, ovulation does not occur. Although the estrogen in birth control pills does stimulate some thickening of the endometrial wall, it is reduced compared with a normal cycle and is less likely to support implantation. Some birth control pills contain 21 active pills containing hormones, and 7 inactive pills (placebos). The decline in hormones during the week that the woman takes the placebo pills triggers menses, although it is typically lighter than a normal menstrual flow because of the reduced endometrial thickening. Newer types of birth control pills have been developed that deliver low-dose estrogens and progesterone for the entire cycle (these are meant to be taken 365 days a year), and menses never occurs. While some women prefer to have the proof of a lack of pregnancy that a monthly period provides, menstruation every 28 days is not required for health reasons, and there are no reported adverse effects of not having a menstrual period in an otherwise healthy individual. Because birth control pills function by providing constant estrogen and progesterone levels and disrupting negative feedback, skipping even just one or two pills at certain points of the cycle (or even being several hours late taking the pill) can lead to an increase in FSH and LH and result in ovulation. It is important, therefore, that the woman follow the directions on the birth control pill package to successfully prevent pregnancy. AGING AND THE... Female Reproductive System Female fertility (the ability to conceive) peaks when women are in their twenties, and is slowly reduced until a women reaches 35 years of age. After that time, fertility declines more rapidly, until it ends completely at the end of menopause. Menopause is the cessation of the menstrual cycle that occurs as a result of the loss of ovarian follicles and the hormones that they produce. A woman is considered to have completed menopause if she has not menstruated in a full year. After that point, she is considered postmenopausal. The average age for this change is consistent worldwide at between 50 and 52 years of age, but it can normally occur in a woman’s forties, or later in her fifties. Poor health, including smoking, can lead to earlier loss of fertility and earlier menopause. As a woman reaches the age of menopause, depletion of the number of viable follicles in the ovaries due to atresia affects the hormonal regulation of the menstrual cycle. During the years leading up to menopause, there is a decrease in the levels of the hormone inhibin, which normally participates in a negative feedback loop to the pituitary to control the production of FSH. The menopausal decrease in inhibin leads to an increase in FSH. The presence of FSH stimulates more follicles to grow and secrete estrogen. Because small, secondary follicles also respond to increases in FSH levels, larger numbers of follicles are stimulated to grow; however, most undergo atresia and die. Eventually, this process leads to the depletion of all follicles in the ovaries, and the production of estrogen falls off dramatically. It is primarily the lack of estrogens that leads to the symptoms of menopause. The earliest changes occur during the menopausal transition, often referred to as peri-menopause, when a women’s cycle becomes irregular but does not stop entirely. Although the levels of estrogen are still nearly the same as before the transition, the level of progesterone produced by the corpus luteum is reduced. This decline in progesterone can lead to abnormal growth, or hyperplasia, of the endometrium. This condition is a concern because it increases the risk of developing endometrial cancer. Two harmless conditions that can develop during the transition are uterine fibroids, which are benign masses of cells, and irregular bleeding. As estrogen levels change, other symptoms that occur are hot flashes and night sweats, trouble sleeping, vaginal dryness, mood swings, difficulty focusing, and thinning of hair on the head along with the growth of more hair on the face. Depending on the individual, these symptoms can be entirely absent, moderate, or severe. After menopause, lower amounts of estrogens can lead to other changes. Cardiovascular disease becomes as prevalent in women as in men, possibly because estrogens reduce the amount of cholesterol in the blood vessels. When estrogen is lacking, many women find that they suddenly have problems with high cholesterol and the cardiovascular issues that accompany it. Osteoporosis is another problem because bone density decreases rapidly in the first years after menopause. The reduction in bone density leads to a higher incidence of fractures. Hormone therapy (HT), which employs medication (synthetic estrogens and progestins) to increase estrogen and progestin levels, can alleviate some of the symptoms of menopause. In 2002, the Women’s Health Initiative began a study to observe women for the long-term outcomes of hormone replacement therapy over 8.5 years. However, the study was prematurely terminated after 5.2 years because of evidence of a higher than normal risk of breast cancer in patients taking estrogen-only HT. The potential positive effects on cardiovascular disease were also not realized in the estrogen-only patients. The results of other hormone replacement studies over the last 50 years, including a 2012 study that followed over 1,000 menopausal women for 10 years, have shown cardiovascular benefits from estrogen and no increased risk for cancer. Some researchers believe that the age group tested in the 2002 trial may have been too old to benefit from the therapy, thus skewing the results. In the meantime, intense debate and study of the benefits and risks of replacement therapy is ongoing. Current guidelines approve HT for the reduction of hot flashes or flushes, but this treatment is generally only considered when women first start showing signs of menopausal changes, is used in the lowest dose possible for the shortest time possible (5 years or less), and it is suggested that women on HT have regular pelvic and breast exams. Development of the Male and Female Reproductive Systems - Explain how bipotential tissues are directed to develop into male or female sex organs - Name the rudimentary duct systems in the embryo that are precursors to male or female internal sex organs - Describe the hormonal changes that bring about puberty, and the secondary sex characteristics of men and women The development of the reproductive systems begins soon after fertilization of the egg, with primordial gonads beginning to develop approximately one month after conception. Reproductive development continues in utero, but there is little change in the reproductive system between infancy and puberty. Development of the Sexual Organs in the Embryo and Fetus Females are considered the “fundamental” sex—that is, without much chemical prompting, all fertilized eggs would develop into females. To become a male, an individual must be exposed to the cascade of factors initiated by a single gene on the male Y chromosome. This is called the SRY (Sex-determining Region of the Y chromosome). Because females do not have a Y chromosome, they do not have the SRY gene. Without a functional SRY gene, an individual will be female. In both male and female embryos, the same group of cells has the potential to develop into either the male or female gonads; this tissue is considered bipotential. The SRY gene actively recruits other genes that begin to develop the testes, and suppresses genes that are important in female development. As part of this SRY-prompted cascade, germ cells in the bipotential gonads differentiate into spermatogonia. Without SRY, different genes are expressed, oogonia form, and primordial follicles develop in the primitive ovary. Soon after the formation of the testis, the Leydig cells begin to secrete testosterone. Testosterone can influence tissues that are bipotential to become male reproductive structures. For example, with exposure to testosterone, cells that could become either the glans penis or the glans clitoris form the glans penis. Without testosterone, these same cells differentiate into the clitoris. Not all tissues in the reproductive tract are bipotential. The internal reproductive structures (for example the uterus, uterine tubes, and part of the vagina in females; and the epididymis, ductus deferens, and seminal vesicles in males) form from one of two rudimentary duct systems in the embryo. For proper reproductive function in the adult, one set of these ducts must develop properly, and the other must degrade. In males, secretions from sustentacular cells trigger a degradation of the female duct, called the Müllerian duct. At the same time, testosterone secretion stimulates growth of the male tract, the Wolffian duct. Without such sustentacular cell secretion, the Müllerian duct will develop; without testosterone, the Wolffian duct will degrade. Thus, the developing offspring will be female. For more information and a figure of differentiation of the gonads, seek additional content on fetal development. INTERACTIVE LINK A baby’s gender is determined at conception, and the different genitalia of male and female fetuses develop from the same tissues in the embryo. View this animation to see a comparison of the development of structures of the female and male reproductive systems in a growing fetus. Where are the testes located for most of gestational time? Further Sexual Development Occurs at Puberty Puberty is the stage of development at which individuals become sexually mature. Though the outcomes of puberty for boys and girls are very different, the hormonal control of the process is very similar. In addition, though the timing of these events varies between individuals, the sequence of changes that occur is predictable for male and female adolescents. As shown in Figure 27.18, a concerted release of hormones from the hypothalamus (GnRH), the anterior pituitary (LH and FSH), and the gonads (either testosterone or estrogen) is responsible for the maturation of the reproductive systems and the development of secondary sex characteristics, which are physical changes that serve auxiliary roles in reproduction. The first changes begin around the age of eight or nine when the production of LH becomes detectable. The release of LH occurs primarily at night during sleep and precedes the physical changes of puberty by several years. In pre-pubertal children, the sensitivity of the negative feedback system in the hypothalamus and pituitary is very high. This means that very low concentrations of androgens or estrogens will negatively feed back onto the hypothalamus and pituitary, keeping the production of GnRH, LH, and FSH low. As an individual approaches puberty, two changes in sensitivity occur. The first is a decrease of sensitivity in the hypothalamus and pituitary to negative feedback, meaning that it takes increasingly larger concentrations of sex steroid hormones to stop the production of LH and FSH. The second change in sensitivity is an increase in sensitivity of the gonads to the FSH and LH signals, meaning the gonads of adults are more responsive to gonadotropins than are the gonads of children. As a result of these two changes, the levels of LH and FSH slowly increase and lead to the enlargement and maturation of the gonads, which in turn leads to secretion of higher levels of sex hormones and the initiation of spermatogenesis and folliculogenesis. In addition to age, multiple factors can affect the age of onset of puberty, including genetics, environment, and psychological stress. One of the more important influences may be nutrition; historical data demonstrate the effect of better and more consistent nutrition on the age of menarche in girls in the United States, which decreased from an average age of approximately 17 years of age in 1860 to the current age of approximately 12.75 years in 1960, as it remains today. Some studies indicate a link between puberty onset and the amount of stored fat in an individual. This effect is more pronounced in girls, but has been documented in both sexes. Body fat, corresponding with secretion of the hormone leptin by adipose cells, appears to have a strong role in determining menarche. This may reflect to some extent the high metabolic costs of gestation and lactation. In girls who are lean and highly active, such as gymnasts, there is often a delay in the onset of puberty. Figure 27.18 Hormones of Puberty During puberty, the release of LH and FSH from the anterior pituitary stimulates the gonads to produce sex hormones in both male and female adolescents. Signs of Puberty Different sex steroid hormone concentrations between the sexes also contribute to the development and function of secondary sexual characteristics. Examples of secondary sexual characteristics are listed in Table 27.1. Development of the Secondary Sexual Characteristics \| Male \| Female \| \|---\|---\| \| Increased larynx size and deepening of the voice \| Deposition of fat, predominantly in breasts and hips \| \| Increased muscular development \| Breast development \| \| Growth of facial, axillary, and pubic hair, and increased growth of body hair \| Broadening of the pelvis and growth of axillary and pubic hair \| Table 27.1 As a girl reaches puberty, typically the first change that is visible is the development of the breast tissue. This is followed by the growth of axillary and pubic hair. A growth spurt normally starts at approximately age 9 to 11, and may last two years or more. During this time, a girl’s height can increase 3 inches a year. The next step in puberty is menarche, the start of menstruation. In boys, the growth of the testes is typically the first physical sign of the beginning of puberty, which is followed by growth and pigmentation of the scrotum and growth of the penis. The next step is the growth of hair, including armpit, pubic, chest, and facial hair. Testosterone stimulates the growth of the larynx and thickening and lengthening of the vocal folds, which causes the voice to drop in pitch. The first fertile ejaculations typically appear at approximately 15 years of age, but this age can vary widely across individual boys. Unlike the early growth spurt observed in females, the male growth spurt occurs toward the end of puberty, at approximately age 11 to 13, and a boy’s height can increase as much as 4 inches a year. In some males, pubertal development can continue through the early 20s. Key Terms - alveoli - (of the breast) milk-secreting cells in the mammary gland - ampulla - (of the uterine tube) middle portion of the uterine tube in which fertilization often occurs - antrum - fluid-filled chamber that characterizes a mature tertiary (antral) follicle - areola - highly pigmented, circular area surrounding the raised nipple and containing areolar glands that secrete fluid important for lubrication during suckling - Bartholin’s glands - (also, greater vestibular glands) glands that produce a thick mucus that maintains moisture in the vulva area; also referred to as the greater vestibular glands - blood–testis barrier - tight junctions between Sertoli cells that prevent bloodborne pathogens from gaining access to later stages of spermatogenesis and prevent the potential for an autoimmune reaction to haploid sperm - body of uterus - middle section of the uterus - broad ligament - wide ligament that supports the uterus by attaching laterally to both sides of the uterus and pelvic wall - bulbourethral glands - (also, Cowper’s glands) glands that secrete a lubricating mucus that cleans and lubricates the urethra prior to and during ejaculation - cervix - elongate inferior end of the uterus where it connects to the vagina - clitoris - (also, glans clitoris) nerve-rich area of the vulva that contributes to sexual sensation during intercourse - corpus albicans - nonfunctional structure remaining in the ovarian stroma following structural and functional regression of the corpus luteum - corpus cavernosum - either of two columns of erectile tissue in the penis that fill with blood during an erection - corpus luteum - transformed follicle after ovulation that secretes progesterone - corpus spongiosum - (plural = corpora cavernosa) column of erectile tissue in the penis that fills with blood during an erection and surrounds the penile urethra on the ventral portion of the penis - ductus deferens - (also, vas deferens) duct that transports sperm from the epididymis through the spermatic cord and into the ejaculatory duct; also referred as the vas deferens - ejaculatory duct - duct that connects the ampulla of the ductus deferens with the duct of the seminal vesicle at the prostatic urethra - endometrium - inner lining of the uterus, part of which builds up during the secretory phase of the menstrual cycle and then sheds with menses - epididymis - (plural = epididymides) coiled tubular structure in which sperm start to mature and are stored until ejaculation - fimbriae - fingerlike projections on the distal uterine tubes - follicle - ovarian structure of one oocyte and surrounding granulosa (and later theca) cells - folliculogenesis - development of ovarian follicles from primordial to tertiary under the stimulation of gonadotropins - fundus - (of the uterus) domed portion of the uterus that is superior to the uterine tubes - gamete - haploid reproductive cell that contributes genetic material to form an offspring - glans penis - bulbous end of the penis that contains a large number of nerve endings - gonadotropin-releasing hormone (GnRH) - hormone released by the hypothalamus that regulates the production of follicle-stimulating hormone and luteinizing hormone from the pituitary gland - gonads - reproductive organs (testes in men and ovaries in women) that produce gametes and reproductive hormones - granulosa cells - supportive cells in the ovarian follicle that produce estrogen - hymen - membrane that covers part of the opening of the vagina - infundibulum - (of the uterine tube) wide, distal portion of the uterine tube terminating in fimbriae - inguinal canal - opening in abdominal wall that connects the testes to the abdominal cavity - isthmus - narrow, medial portion of the uterine tube that joins the uterus - labia majora - hair-covered folds of skin located behind the mons pubis - labia minora - thin, pigmented, hairless flaps of skin located medial and deep to the labia majora - lactiferous ducts - ducts that connect the mammary glands to the nipple and allow for the transport of milk - lactiferous sinus - area of milk collection between alveoli and lactiferous duct - Leydig cells - cells between the seminiferous tubules of the testes that produce testosterone; a type of interstitial cell - mammary glands - glands inside the breast that secrete milk - menarche - first menstruation in a pubertal female - menses - shedding of the inner portion of the endometrium out though the vagina; also referred to as menstruation - menses phase - phase of the menstrual cycle in which the endometrial lining is shed - menstrual cycle - approximately 28-day cycle of changes in the uterus consisting of a menses phase, a proliferative phase, and a secretory phase - mons pubis - mound of fatty tissue located at the front of the vulva - Müllerian duct - duct system present in the embryo that will eventually form the internal female reproductive structures - myometrium - smooth muscle layer of uterus that allows for uterine contractions during labor and expulsion of menstrual blood - oocyte - cell that results from the division of the oogonium and undergoes meiosis I at the LH surge and meiosis II at fertilization to become a haploid ovum - oogenesis - process by which oogonia divide by mitosis to primary oocytes, which undergo meiosis to produce the secondary oocyte and, upon fertilization, the ovum - oogonia - ovarian stem cells that undergo mitosis during female fetal development to form primary oocytes - ovarian cycle - approximately 28-day cycle of changes in the ovary consisting of a follicular phase and a luteal phase - ovaries - female gonads that produce oocytes and sex steroid hormones (notably estrogen and progesterone) - ovulation - release of a secondary oocyte and associated granulosa cells from an ovary - ovum - haploid female gamete resulting from completion of meiosis II at fertilization - penis - male organ of copulation - perimetrium - outer epithelial layer of uterine wall - polar body - smaller cell produced during the process of meiosis in oogenesis - prepuce - (also, foreskin) flap of skin that forms a collar around, and thus protects and lubricates, the glans penis; also referred as the foreskin - primary follicles - ovarian follicles with a primary oocyte and one layer of cuboidal granulosa cells - primordial follicles - least developed ovarian follicles that consist of a single oocyte and a single layer of flat (squamous) granulosa cells - proliferative phase - phase of the menstrual cycle in which the endometrium proliferates - prostate gland - doughnut-shaped gland at the base of the bladder surrounding the urethra and contributing fluid to semen during ejaculation - puberty - life stage during which a male or female adolescent becomes anatomically and physiologically capable of reproduction - rugae - (of the vagina) folds of skin in the vagina that allow it to stretch during intercourse and childbirth - scrotum - external pouch of skin and muscle that houses the testes - secondary follicles - ovarian follicles with a primary oocyte and multiple layers of granulosa cells - secondary sex characteristics - physical characteristics that are influenced by sex steroid hormones and have supporting roles in reproductive function - secretory phase - phase of the menstrual cycle in which the endometrium secretes a nutrient-rich fluid in preparation for implantation of an embryo - semen - ejaculatory fluid composed of sperm and secretions from the seminal vesicles, prostate, and bulbourethral glands - seminal vesicle - gland that produces seminal fluid, which contributes to semen - seminiferous tubules - tube structures within the testes where spermatogenesis occurs - Sertoli cells - cells that support germ cells through the process of spermatogenesis; a type of sustentacular cell - sperm - (also, spermatozoon) male gamete - spermatic cord - bundle of nerves and blood vessels that supplies the testes; contains ductus deferens - spermatid - immature sperm cells produced by meiosis II of secondary spermatocytes - spermatocyte - cell that results from the division of spermatogonium and undergoes meiosis I and meiosis II to form spermatids - spermatogenesis - formation of new sperm, occurs in the seminiferous tubules of the testes - spermatogonia - (singular = spermatogonium) diploid precursor cells that become sperm - spermiogenesis - transformation of spermatids to spermatozoa during spermatogenesis - suspensory ligaments - bands of connective tissue that suspend the breast onto the chest wall by attachment to the overlying dermis - tertiary follicles - (also, antral follicles) ovarian follicles with a primary or secondary oocyte, multiple layers of granulosa cells, and a fully formed antrum - testes - (singular = testis) male gonads - theca cells - estrogen-producing cells in a maturing ovarian follicle - uterine tubes - (also, fallopian tubes or oviducts) ducts that facilitate transport of an ovulated oocyte to the uterus - uterus - muscular hollow organ in which a fertilized egg develops into a fetus - vagina - tunnel-like organ that provides access to the uterus for the insertion of semen and from the uterus for the birth of a baby - vulva - external female genitalia - Wolffian duct - duct system present in the embryo that will eventually form the internal male reproductive structures Chapter Review 27.1 Anatomy and Physiology of the Male Reproductive System Gametes are the reproductive cells that combine to form offspring. Organs called gonads produce the gametes, along with the hormones that regulate human reproduction. The male gametes are called sperm. Spermatogenesis, the production of sperm, occurs within the seminiferous tubules that make up most of the testis. The scrotum is the muscular sac that holds the testes outside of the body cavity. Spermatogenesis begins with mitotic division of spermatogonia (stem cells) to produce primary spermatocytes that undergo the two divisions of meiosis to become secondary spermatocytes, then the haploid spermatids. During spermiogenesis, spermatids are transformed into spermatozoa (formed sperm). Upon release from the seminiferous tubules, sperm are moved to the epididymis where they continue to mature. During ejaculation, sperm exit the epididymis through the ductus deferens, a duct in the spermatic cord that leaves the scrotum. The ampulla of the ductus deferens meets the seminal vesicle, a gland that contributes fructose and proteins, at the ejaculatory duct. The fluid continues through the prostatic urethra, where secretions from the prostate are added to form semen. These secretions help the sperm to travel through the urethra and into the female reproductive tract. Secretions from the bulbourethral glands protect sperm and cleanse and lubricate the penile (spongy) urethra. The penis is the male organ of copulation. Columns of erectile tissue called the corpora cavernosa and corpus spongiosum fill with blood when sexual arousal activates vasodilatation in the blood vessels of the penis. Testosterone regulates and maintains the sex organs and sex drive, and induces the physical changes of puberty. Interplay between the testes and the endocrine system precisely control the production of testosterone with a negative feedback loop. 27.2 Anatomy and Physiology of the Female Reproductive System The external female genitalia are collectively called the vulva. The vagina is the pathway into and out of the uterus. The man’s penis is inserted into the vagina to deliver sperm, and the baby exits the uterus through the vagina during childbirth. The ovaries produce oocytes, the female gametes, in a process called oogenesis. As with spermatogenesis, meiosis produces the haploid gamete (in this case, an ovum); however, it is completed only in an oocyte that has been penetrated by a sperm. In the ovary, an oocyte surrounded by supporting cells is called a follicle. In folliculogenesis, primordial follicles develop into primary, secondary, and tertiary follicles. Early tertiary follicles with their fluid-filled antrum will be stimulated by an increase in FSH, a gonadotropin produced by the anterior pituitary, to grow in the 28-day ovarian cycle. Supporting granulosa and theca cells in the growing follicles produce estrogens, until the level of estrogen in the bloodstream is high enough that it triggers negative feedback at the hypothalamus and pituitary. This results in a reduction of FSH and LH, and most tertiary follicles in the ovary undergo atresia (they die). One follicle, usually the one with the most FSH receptors, survives this period and is now called the dominant follicle. The dominant follicle produces more estrogen, triggering positive feedback and the LH surge that will induce ovulation. Following ovulation, the granulosa cells of the empty follicle luteinize and transform into the progesterone-producing corpus luteum. The ovulated oocyte with its surrounding granulosa cells is picked up by the infundibulum of the uterine tube, and beating cilia help to transport it through the tube toward the uterus. Fertilization occurs within the uterine tube, and the final stage of meiosis is completed. The uterus has three regions: the fundus, the body, and the cervix. It has three layers: the outer perimetrium, the muscular myometrium, and the inner endometrium. The endometrium responds to estrogen released by the follicles during the menstrual cycle and grows thicker with an increase in blood vessels in preparation for pregnancy. If the egg is not fertilized, no signal is sent to extend the life of the corpus luteum, and it degrades, stopping progesterone production. This decline in progesterone results in the sloughing of the inner portion of the endometrium in a process called menses, or menstruation. The breasts are accessory sexual organs that are utilized after the birth of a child to produce milk in a process called lactation. Birth control pills provide constant levels of estrogen and progesterone to negatively feed back on the hypothalamus and pituitary, and suppress the release of FSH and LH, which inhibits ovulation and prevents pregnancy. 27.3 Development of the Male and Female Reproductive Systems The reproductive systems of males and females begin to develop soon after conception. A gene on the male’s Y chromosome called SRY is critical in stimulating a cascade of events that simultaneously stimulate testis development and repress the development of female structures. Testosterone produced by Leydig cells in the embryonic testis stimulates the development of male sexual organs. If testosterone is not present, female sexual organs will develop. Whereas the gonads and some other reproductive tissues are considered bipotential, the tissue that forms the internal reproductive structures stems from ducts that will develop into only male (Wolffian) or female (Müllerian) structures. To be able to reproduce as an adult, one of these systems must develop properly and the other must degrade. Further development of the reproductive systems occurs at puberty. The initiation of the changes that occur in puberty is the result of a decrease in sensitivity to negative feedback in the hypothalamus and pituitary gland, and an increase in sensitivity of the gonads to FSH and LH stimulation. These changes lead to increases in either estrogen or testosterone, in female and male adolescents, respectively. The increase in sex steroid hormones leads to maturation of the gonads and other reproductive organs. The initiation of spermatogenesis begins in boys, and girls begin ovulating and menstruating. Increases in sex steroid hormones also lead to the development of secondary sex characteristics such as breast development in girls and facial hair and larynx growth in boys. Interactive Link Questions Watch this video to learn about vasectomy. As described in this video, a vasectomy is a procedure in which a small section of the ductus (vas) deferens is removed from the scrotum. This interrupts the path taken by sperm through the ductus deferens. If sperm do not exit through the vas, either because the man has had a vasectomy or has not ejaculated, in what region of the testis do they remain? 2.Watch this video to explore the structures of the male reproductive system and the path of sperm that starts in the testes and ends as the sperm leave the penis through the urethra. Where are sperm deposited after they leave the ejaculatory duct? 3.Watch this video to observe ovulation and its initiation in response to the release of FSH and LH from the pituitary gland. What specialized structures help guide the oocyte from the ovary into the uterine tube? 4.Watch this series of videos to look at the movement of the oocyte through the ovary. The cilia in the uterine tube promote movement of the oocyte. What would likely occur if the cilia were paralyzed at the time of ovulation? 5.A baby’s gender is determined at conception, and the different genitalia of male and female fetuses develop from the same tissues in the embryo. View this animation that compares the development of structures of the female and male reproductive systems in a growing fetus. Where are the testes located for most of gestational time? Review Questions What are male gametes called? - ova - sperm - testes - testosterone Leydig cells ________. - secrete testosterone - activate the sperm flagellum - support spermatogenesis - secrete seminal fluid Which hypothalamic hormone contributes to the regulation of the male reproductive system? - luteinizing hormone - gonadotropin-releasing hormone - follicle-stimulating hormone - androgens What is the function of the epididymis? - sperm maturation and storage - produces the bulk of seminal fluid - provides nitric oxide needed for erections - spermatogenesis Spermatogenesis takes place in the ________. - prostate gland - glans penis - seminiferous tubules - ejaculatory duct What are the female gonads called? - oocytes - ova - oviducts - ovaries When do the oogonia undergo mitosis? - before birth - at puberty - at the beginning of each menstrual cycle - during fertilization From what structure does the corpus luteum originate? - uterine corpus - dominant follicle - fallopian tube - corpus albicans Where does fertilization of the egg by the sperm typically occur? - vagina - uterus - uterine tube - ovary Why do estrogen levels fall after menopause? - The ovaries degrade. - There are no follicles left to produce estrogen. - The pituitary secretes a menopause-specific hormone. - The cells of the endometrium degenerate. The vulva includes the ________. - lactiferous duct, rugae, and hymen - lactiferous duct, endometrium, and bulbourethral glands - mons pubis, endometrium, and hymen - mons pubis, labia majora, and Bartholin’s glands What controls whether an embryo will develop testes or ovaries? - pituitary gland - hypothalamus - Y chromosome - presence or absence of estrogen Without SRY expression, an embryo will develop ________. - male reproductive structures - female reproductive structures - no reproductive structures - male reproductive structures 50 percent of the time and female reproductive structures 50 percent of the time The timing of puberty can be influenced by which of the following? - genes - stress - amount of body fat - all of the above Critical Thinking Questions Briefly explain why mature gametes carry only one set of chromosomes. 21.What special features are evident in sperm cells but not in somatic cells, and how do these specializations function? 22.What do each of the three male accessory glands contribute to the semen? 23.Describe how penile erection occurs. 24.While anabolic steroids (synthetic testosterone) bulk up muscles, they can also affect testosterone production in the testis. Using what you know about negative feedback, describe what would happen to testosterone production in the testis if a male takes large amounts of synthetic testosterone. 25.Follow the path of ejaculated sperm from the vagina to the oocyte. Include all structures of the female reproductive tract that the sperm must swim through to reach the egg. 26.Identify some differences between meiosis in men and women. 27.Explain the hormonal regulation of the phases of the menstrual cycle. 28.Endometriosis is a disorder in which endometrial cells implant and proliferate outside of the uterus—in the uterine tubes, on the ovaries, or even in the pelvic cavity. Offer a theory as to why endometriosis increases a woman’s risk of infertility. 29.Identify the changes in sensitivity that occur in the hypothalamus, pituitary, and gonads as a boy or girl approaches puberty. Explain how these changes lead to the increases of sex steroid hormone secretions that drive many pubertal changes. 30.Explain how the internal female and male reproductive structures develop from two different duct systems. 31.Explain what would occur during fetal development to an XY individual with a mutation causing a nonfunctional SRYgene.	oercommons	2025-03-18T00:37:15.319469	10/14/2019	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/58775/overview", "title": "Anatomy and Physiology, Human Development and the Continuity of Life, The Reproductive System", "author": null }
https://oercommons.org/courseware/lesson/72075/overview	Chapter 4 Reading Guide Overview This reading guide is intended to be used with the Open Stax Anatomy and Physiology textbook. Open Stax Anatomy and Physiology Chapter 4 Reading Guide Human Anatomy and Physiology Chapter 4: The Tissue Level of Organization 4.1 Types of Tissues The Four Types of Tissues - _____________ – (epithelium), are sheets of cells that cover the exterior surfaces of the body, line internal cavities and passageways, and form glands. - _____________ – binds the cells and organs of the body together - Functions in the protection, support, and integration of all body parts. - _____________ – excitable cells respond to stimulation and contraction to provide movement - Three major types: skeletal (voluntary), smooth, and cardiac. - ____________________ – excitable cells that transmit electrochemical impulses throughout the body. - Embryonic Origin of Tissues - _____________ – A single cell formed by the fusion of sperm and egg. - Undergoes repeated mitotic cell divisions (cleavage) to form an embryo. - These first embryonic cells are _____________, meaning that each one of these cells has the capacity to form a new organism - As cell division and cellular specialization continues three distinct germ layers form in the embryo. - _____________ – outer layer - _____________ – middle layer - _____________– inner layer Tissue Membranes - ____________________– a thin layer of sheet of cells that covers the outside of the body, the organs, and internal passageways that lead to the exterior of the body, and the lining of the movable joint cavities - Two types of tissue membranes - Connective tissue - Epithelial membranes - Figure 4.4 Tissue Membranes - Connective Tissue Membranes - ____________________________ is formed from connective tissue - ____________________– lines the cavity of a freely movable joint - E.g. shoulder, elbow, and knee - Synovial fluid is produced by the synovial membrane which exchanges water and nutrients with blood. Epithelial membranes - ____________________ is formed of epithelium attached to a layer of connective tissue (your skin). - ____________________– a composite of connective and epithelial tissues - Line the body cavities - Hollow passageways (blood vessels) - Digestive, respiratory, excretory, and reproductive tracts - ____________________ – connective tissue that underlies the fragile epithelial layer. - ____________________ – an epithelial membrane derived from mesothelium, line all body cavities that do not open to the exterior. - Secrete serous fluid which reduces internal friction - _____________ membranes cover the lungs - _____________ covers the heart - _____________ – covers the abdominal organs and forms mesenteries - ____________________ – the skin - Stratified squamous epithelium resting on top of connective tissue - 4.2: Epithelial Tissue - Characteristics of Epithelial Tissue - Large sheets of cells covering all body surfaces inside and outside. - Forms most of the glandular tissue of the body. - Derived from all three germ layers - Important structural and functional features - No extracellular material - Epithelial cells form specialized intercellular connections called ____________________. - Cells exhibit polarity between the exposed (_____________) surface and the _____________ surface (attached to underlying tissues). - ____________________ secreted by epithelial cells attaches the basal surface to underlying connective tissue. - _____________ is secreted by underlying connective tissue attaches to the basal lamina to form a ____________________ that holds it all together. - Avascular does not have its own blood supply. - Continuously dividing to replace damaged and dead cells. Cell to Cell Junctions - Three basic types that allow interaction between cells. - ____________________– separates cells into apical and basal compartments. - Two adjacent epithelia cells linked by tight junctions have no extra cellular space between them, thus blocking the movement of substances between cells. - ____________________ – stabilize epithelial tissues, common on the lateral and basal surfaces, and provide strong, flexible connections. - ____________________ – occur in patches and link cells together. - ____________________– link cells to the basal lamina. - _____________– influence the shape and folding of epithelial tissue. - ____________________ – forms an intercellular passageway between adjacent cells. Allow the movement of small molecules and ions between cells. - Classification of Epithelial Tissues - Figure 4.6 Cells of Epithelial Tissue - Simple Epithelium - ______________________________Cells appear as flat scales - Absorption of chemical compounds, diffusion of gases - Line blood vessels (_____________), alveoli of lungs, segments of kidney tubules - Forms ____________________ that forms the surface layer of serous membranes. - Stratified Epithelium - Consists of stacked layers of cells that protect against wear and tear. - ____________________ - Most common type of stratified epithelium in the body. - Apical cells are squamous with the basal layer consisting of columnar or cuboidal cells. - The top layer may be covered with dead, keratinized cells (as in human skin). - The lining of the mouth is an example of unkeratinized stratified squamous epithelium. - Stratified cuboidal and stratified columnar epithelium is found in certain glands or ducts but is mostly uncommon in the human body. - ____________________ is found only in the urinary system, the shape of the cells changes as it is stretched. Glandular Epithelium - Glands are structures that synthesize and secrete chemical substances - Classification of glands - ____________________ – ductless glands that release secretions directly into surrounding tissues and fluids. - Secrete hormones into the interstitial fluid, the blood stream and delivered to targets. - Pituitary gland, thymus, adrenal cortex, pancreas, and gonads - ____________________– secretions leave through a duct opening directly or indirectly into the external environment. - Mucous, sweat, saliva, and breast milk. - Structure of exocrine glands - Unicellular – goblet cells that are found in mucous membranes - Multicellular - Serous glands secrete directly into the body cavity - Simple glands release secretions through s single tubular duct - Compound glands – the duct is divided not one or more branches Methods and Types of Secretion - ____________________ – secretion by vesicles where the contents are released by exocytosis - Goblet cells, sweat glands - ____________________Secretions accumulate at the apical end of the cell, which pinches off and is released. - Apocrine sweat glands in the axillary and genital areas - ____________________ - Involves the rupture and destruction of the gland cell. - New gland cells replace the lost cells. - Sebaceous glands of the skin and scalp. - ____________________ - Produce watery, blood plasma like secretions rich in enzymes. - ____________________ - Releases products rich in mucin. 4.3 Connective Tissue: Shapes and Protects - Characteristics of Connective Tissue - Composed of cells dispersed throughout an extracellular _____________. - A mixture of secretions produced by the connective tissue cells embedded in it. - The major component is an amorphous ____________________with protein fibers. This substance may be liquid or mineralized. - Functions of Connective Tissues - Support and connect other tissues - Protection - Defend the body from microorganisms - Transport of fluids, waste, and hormones - Store surplus energy as fat and contribute to thermal insulation of the body. Embryonic Connective Tissue - All connective tissue derives from the mesoderm layer of the embryo. - _____________ - the first connective tissue found in the embryo, is the stem cell line from which all connective tissues develop from. - _____________ connective tissue (Wharton’s jelly) – only forms in umbilical cord, not present after birth. - Classification of Connective Tissue - _____________ Tissue Proper – consist of a variety of cell types and protein fibers embedded in ground substance - _____________ connective tissue – Fibers are loosely organized leaving large spaces between - _____________ connective tissue – Reinforced by bundles of fibers closely packed together that provide strength, elasticity, and protection - _____________ connective tissue – includes bone and cartilage - Few distinct cell types with tightly packed fibers - _____________ connective tissue – lymph and blood - Specialized cells circulate in a watery fluid containing dissolved salts, nutrients, gases, and dissolved proteins. - Connective Tissue Proper - Cell Types - _____________ are the dominant cell type, form the extracellular matrix. - _____________ – less active and the second most common cell type. - _____________ store lipids - _____________ – multipotent adult stem cell can differentiate into any type of connective tissue cell needed. - _____________ – type of leukocyte, essential component of immune system - _____________– involved in inflammatory responses, release histamine. - Connective Tissue Fibers and Ground Substance - _____________ fibers – made of fibrous protein subunits, form long and straight fibers - Flexible with great tensile strength, resist stretching give tendons and ligaments their resilience and strength. - _____________ fibers contain the protein elastin, may be stretched, and return to its original shape - Found in skin and elastic ligaments of the vertebral column. - _____________ fiber – formed from the same protein subunits as collagen fibers. - Fibers are narrow and arranged in a branched network. - Most abundant in the liver and spleen. - Anchor and provide structural support to the functional cells, blood vessels and nerves of those organs (parenchyma) - Ground substance - Secreted by fibroblasts, made of polysaccharides, specifically hyaluronic acid, and proteins - Loose Connective Tissue - Found between organs, acts as a shock absorber, and binds tissues together. - ____________________– make of fat storage cells (adipocytes) with little extracellular matrix. - _____________contributes to lipid storage and insulation - _____________ – thermogenic as it breaks down heat is released - _____________ tissue underlies most epithelia and represents the connective tissue component of epithelial membranes - _____________ tissue forms a mesh-like supportive framework for soft organs, spleen, and liver. Dense Connective Tissue - Contains more collagen fibers than loose connective tissue, has greater resistance to stretching. - Two major categories of dense connective tissue - R_____________ – Contain elastic fibers along with collagen fibers that are parallel to each other, enhancing tensile strength and resistance to stretching. - Ligaments and tendons, and vocal fold ligaments. - Ir_____________ – Fibers proceed in random directions, tissue may form a mesh, - Dermis of skin, arterial vessel walls Supportive Connective Tissues - Allow the body to maintain its posture and protect internal organs. - Cartilage - Ground substance contains chondroitin sulfates - _____________ – cartilage cells embedded in ground substance - _____________ – (lacuna) space occupied by chondrocytes. - Enveloped by the perichondrium, a layer of dense irregular connective tissue - Avascular - Three main types of cartilage - H_____________ – most abundant found in rib cage, nose, and lines joints, forms the embryonic skeleton. - F____________________ – tough with thick bundles of collagen fibers, form menisci of the knee and vertebral discs. - E_____________ – contain elastic fibers, your earlobe. - Figure 4.16 Types of Cartilage - Bone is the hardest connective tissue. It provides protection and support. - An extracellular matrix of collagen fibers embedded in mineralized ground substance called hydroxyapatite, a form of calcium phosphate. - Osteocytes – bone cells located inside lacunae - Highly vascularized - Types of bone tissue - Ca_____________ – has a spongy appearance, lighter than compact bone - Found in the interior of bones and at the end of long bones. - Co_____________ – is solid and has greater structural strength Fluid Connective Tissue - Specialized cells circulate in a liquid extracellular matrix. - All blood cells are derived from hematopoietic stem cells found in red bone marrow. - E_____________ – red blood cells contain hemoglobin and transport oxygen and carbon dioxide. - L_____________ – white blood cells defend against microorganisms or harmful molecules - Pl_____________ – cell fragments involved in blood clotting. - L_____________ – consists of a liquid matrix and white blood cells - L_____________ capillaries capture excess interstitial fluid and transport it back to the blood vessels - Specialized lymphatic capillaries (l_____________) transport absorbed fat away from the intestine and deliver it to the blood. 4.4 Muscle Tissue and Motion - Characteristics of Muscle Tissue - Responds to stimuli - Allows movement - Made up of contractile cells - Movement may be voluntary or involuntary - Classifications of Muscle Tissue - 3 types according to structure and function - Sk_____________ - C_____________ - Sm_____________ - Comparison of Structure and Properties of Muscle Tissue Types - Sk_____________ muscle: - Attached to bones, contraction make movement possible - Shivering generates heat - Derived from mesoderm, myoblasts give rise to myocytes (muscle fibers). - Fibers are arranged in bundles surrounded by connective tissues - Microscopic appearance shows striations with many nuclei - Striations are composed of the contractile protein's a______ and m________ - Skeletal muscle fibers are many myocytes joined end to end to form a long muscle fiber. - _____________ muscle - Forms the contractile walls of the heart - Cardiomyocytes are single cells with a centrally located nucleus. - Each cell contracts on its own without external stimulation - Cardiomyocytes attach to others with intercalated discs (specialized cell junctions). - Under involuntary control - _____________ muscle - Involuntary movements in the internal organs - Contractile component of the digestive, urinary, and reproductive tracts. - Airways and arteries - Spindle shaped cells, single nucleus, no visible striations 4.5: Nervous Tissue Mediates Perception and Response - Characteristics of Nervous tissue - Excitable, sends and receives electrochemical signals to provide the body with information. - Nervous tissue is composed of - N_____________ - Generate nerve impulses (action potentials) - Display distinct morphology - Three main parts - _____ body includes most of the cytoplasm, organelles, and nucleus - D__________ are numerous branches off the cell body - A_____– a single long process, extending from the cell body, wrapped in an insulating material called _______. - N_________ - Support and nourish neurons - Have very complex roles in the functioning of the brain and nervous system - A_____________ – distinct star shape abundant in CNS, regulate ion concentrations, uptake and breakdown of neurotransmitters, formation of blood – brain barrier. - O____________________ – produce myelin in the CNS. - S_____________ cells – produce myelin in the peripheral nervous system 4.6: Tissue Injury and Aging - Tissue Injury and Repair - Inflammation – the body’s initial response to any injury - Limits the extent of injury, helps eliminate the cause of injury, initiates repair and regeneration of damaged tissue. - N_____________ – accidental cell death is one cause of inflammation - Ap_____________ – programmed cell death, destroys cells not needed by the body does not cause inflammation. - _____________ inflammation is resolved over time by the healing of tissue - _____________ inflammation is when inflammation persists over time and leads to diseased conditions such as: - Arthritis - Tuberculosis - Four cardinal signs of inflammation have been known since antiquity - Redness, swelling, pain and local heat along with loss of function. - Upon tissue injury - Damaged cells release chemical signals - Mast cells release h_____________ a vasodilator - V_____________ – widening of the blood vessels in the injured area which increases blood flow leading to redness and heat - This attracts white blood cells to the damaged area - Local blood vessels endothelium becomes leaky allowing white blood cells and fluid to move into the interstitial space causing e_____ a localized swelling. - Stretched pain receptors cause pain. - Cl_________ occurs (coagulation) reducing blood loss forming a fibrin patch to bind the edges of the wound together resulting in scab formation. - Fibroblasts replace collagen and lost extracellular material. - A_____________ the growth of new blood vessels occurs - New tissue forms (granulation tissue) - P___________ union – describes the healing of a wound when the edges are close together. - S_____________ union – describes a gaping wound in which the edges are pulled together by _____________ contraction, which results in scar formation. - Sutures are recommended for wounds more than ¼ inch deep to promote primary union and avoid scar formation.	oercommons	2025-03-18T00:37:15.384997	09/04/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/72075/overview", "title": "Chapter 4 Reading Guide", "author": "Bryon Spicci" }
https://oercommons.org/courseware/lesson/101308/overview	Death and Dying Overview To think about the fact that death is a part of life, we introduce this concept here. Testing Testing. 1, 2, and 3.	oercommons	2025-03-18T00:37:15.403072	02/24/2023	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/101308/overview", "title": "Death and Dying", "author": "Kristin Juarez" }
https://oercommons.org/courseware/lesson/73505/overview	Figure 1.15 Dorsal and Ventral Body Cavities (stripped) Overview Testable Fig 1.15 from section 1.6 of OpenStax Anatomy and Physiology. Stripped-away the boxes and lines. 1.6 Anatomical Terminology - Dorsal and Ventral Body Cavities Testable image from section 1.6 of OpenStax Anatomy and Physiology. Stripped-away the boxes and lines.	oercommons	2025-03-18T00:37:15.420102	Diagram/Illustration	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/73505/overview", "title": "Figure 1.15 Dorsal and Ventral Body Cavities (stripped)", "author": "Assessment" }
https://oercommons.org/courseware/lesson/105105/overview	OREGON MATH STANDARDS (2021): [1.OA] Overview The intent of clarifying statements is to provide additional guidance for educators to communicate the intent of the standard to support the future development of curricular resources and assessments aligned to the 2021 math standards. Clarifying statements can be in the form of succinct sentences or paragraphs that attend to one of four types of clarifications: (1) Student Experiences; (2) Examples; (3) Boundaries; and (4) Connection to Math Practices. 2021 Oregon Math Guidance: 1.OA.A.1 Cluster: 1.OA.A - Represent and solve problems involving addition and subtraction. STANDARD: 1.OA.A.1 Standards Statement (2021): Use addition and subtraction within 20 to solve and represent problems in authentic contexts involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| 1.OA.D.8, K.OA.A.1, K.OA.A.2 \| 1.OA.A.2, 2.OA.A.1 \| 1.DR.B.2 \| 1.OA.A.1 1.OA.A Crosswalk \| Standards Guidance: Clarifications - Students should be given opportunities to use mental reasoning to solve problems involving number strings within 20. - Students should also solve problem situations with an unknown in all positions. - Students recognize and represent taking from, taking apart, and comparing situations as either subtraction or addition with a missing addend. Boundaries - Students should not be encouraged to use key/clue words because they will not work with subsequent problem types. - The unknown quantity should be represented in all positions. Terminology - Addition and Subtraction Situations by Grade Level are presented in Table 1 pictured here, which include: - adding to, - taking from, - putting together, taking apart, and - comparing, with unknowns in all positions. - Please reference pages 9 and 14 in the Progression document for additional information. Teaching Strategies - Symbols can be used to represent unknown amounts in equations. - Use the relationship between addition and subtraction within 20 (knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (6 + 7 is the same as 6 + 6 + 1 = 12 + 1 = 13). - Students should be provided with learning experiences to develop strategies such as: - Advanced Counting; Counting On, Making Ten, Decomposing a number leading to a ten - Counting All: 5 + 2 = . The student counts five counters. The student adds two more. The student counts 1, 2, 3, 4, 5, 6, 7 to get the answer. - Counting Back: 12 – 3 = . The student counts twelve counters. The student removes a counter and says 11, removes another counter and says 10, and removes a third counter and says 9. The student knows the answer is 9 since they counted back 3. Examples - Represent addition and subtraction word problems using objects, drawings, and equations. Write an addition or subtraction equation with a symbol for the unknown number in different position, such as: - 13 + 5 = n, 13 - 5 = n, 13 + n= 18, 18 - n= 13. - Recognize and represent adding to and putting together situations as addition. - Illustrative Mathematics: - Student Achievement Partners: 2021 Oregon Math Guidance: 1.OA.A.2 Cluster: 1.OA.A - Represent and solve problems involving addition and subtraction. STANDARD: 1.OA.A.2 Standards Statement (2021): Solve problems that call for addition of three whole numbers whose sum is less than or equal to 20 using objects, drawings or equations. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| 1.OA.A.1 \| N/A \| 1.DR.B.2 \| 1.OA.A.2 1.OA.A Crosswalk \| Standards Guidance: Clarifications - Students should understand subtraction as an unknown-addend problem. - Students are not expected to know nor use the term inverse. Terminology - The terms below are used to clarify expectations for the teaching professional. Students are not required to use this terminology when engaging with the learning objective. - Addend – a number that is added to another number in an addition expression or equation. For example, in the expression 5 + 8, 5 and 8 are both addends. - An inverse relationship shows the relationship between addition and subtraction where addition can be used to find the quantity of a set after some in the set are removed. For example, 3+2 = 5 is related to 5 - 3 = 2 because of the inverse relationship. Boundaries - Problems should be within 20. Examples - Solve word problems by using objects, drawings or equations to represent the quantities in the problem. - Solve word problems with an equation where a symbol stands for the unknown. For example, 5 + 4 + 6 = ___. - Understand that objects, drawings, and equations are interchangeable representations of a story problem. - There are 14 birds in the tree. 8 of them flew away. How many birds are left in the tree? - The student thinks of 14 – 8 = as 8 + = 14 - Jenny had 10 pencils and gave some to Eric. Jenny now has 8 pencils. How many pencils did she give to Eric? - The student thinks of 10 - = 8 as + 8 = 10 - Illustrative Mathematics: 2021 Oregon Math Guidance: 1.OA.B.3 Cluster: 1.OA.B - Understand and apply properties of operations and the relationship between addition and subtraction. STANDARD: 1.OA.B.3 Standards Statement (2021): Apply properties of operations as strategies to add and subtract. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| K.OA.A.2 \| 1.OA.C.6 \| 2.NBT.B.9, 3.NBT.A.2 \| 1.OA.B.3 1.OA.B Crosswalk \| Standards Guidance: Clarifications - Students should solve problem situations with an unknown in all positions. - Understand that numbers can be added flexibly. - Students do not necessarily have to justify their representations or solution using properties, but they can begin to learn to recognize these properties in action and discuss their use after solving. (Please reference page 15 in the Progression document) Boundaries - Students should not be encouraged to use key/clue words because they will not work with subsequent problem types. - The unknown quantity should be represented in all positions. - The terminology above is used to clarify expectations for the teaching professional. Students are not required to use this terminology when engaging with the learning objective. Terminology - Properties of operations used as strategies include: - Commutative property of addition: For example, if 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. - Associative property of addition: For example, add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. - Addend – any number that is added to another number in an addition expression or equation. For example, in the expression 7 + 3, 7 and 3 are addends. Examples - Illustrative Mathematics: 2021 Oregon Math Guidance: 1.OA.B.4 Cluster: 1.OA.B - Understand and apply properties of operations and the relationship between addition and subtraction. STANDARD: 1.OA.B.4 Standards Statement (2021): Understand subtraction as an unknown-addend problem. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| K.OA.A.2 \| 1.OA.C.6 \| 2.NBT.B.9, 3.NBT.A.2 \| 1.OA.B.4 1.OA.B Crosswalk \| Standards Guidance: Teaching Strategies - Restate a subtraction problem as a missing addend problem using the relationship between addition and subtraction. - Recognize the inverse relationship between subtraction and addition within 20 and use this inverse relationship to solve real-life problems. Progressions - Put Together/Take Apart problems with Addend Unknown afford students the opportunity to see subtraction as the opposite of addition in a different way than as reversing the action, namely as finding an unknown addend. - The meaning of subtraction as an unknown-addend addition problem is one of the essential understandings students will need in middle school in order to extend arithmetic to negative rational numbers. (Please reference page 13 in the Progression document). Examples - Subtract 10 – 8 by finding the number that makes 10 when added to 8. - Understand that subtraction is equivalent to an unknown-addend problem because both ask for the unknown part in a situation where the total and another part are known. - Illustrative Mathematics: - Student Achievement Partners: 2021 Oregon Math Guidance: 1.OA.C.5 Cluster: 1.OA.C - Add and subtract within 20. STANDARD: 1.OA.C.5 Standards Statement (2021): Relate counting to addition and subtraction. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| K.NCC.B.4 \| 1.OA.C.6 \| N/A \| 1.OA.C.5 1.OA.C Crosswalk \| Standards Guidance: Clarifications - Students should be able to relate counting to addition and subtraction by counting all, counting on, and counting back when making sense of contextual addition and subtraction problems within 20. Teaching Strategies - Students should understand how addition and subtraction relate by solving situations in context. - Students should use strategies to count up, count back, etc., to model this relationship on tools such as ten frames, rekenreks, number lines (predetermined and open), etc. - Relate counting on to addition. For example, recognize counting on two after 15 as solving 15+2. - Relate counting back to subtraction. For example, recognize counting back two from 15 as solving 15-2. - Relate counting between two numbers to finding their difference. For example, recognize counting two number between 15 and 17 as solving 17-15. Progression - Unlike counting down, counting on reinforces that subtraction is an unknown-addend problem. Learning to think of and solve subtractions as unknown addend problems makes subtraction as easy as addition (or even easier), and it emphasizes the relationship between addition and subtraction. (Please reference page 20 in the Progression document). Examples - When students count on 3 from 4, they should write this as 4+3=7. - When students count on for subtraction, 3 from 7, they should connect this to 7−3=4. Students write "7−3= ?” and think “I count on 3+ ?=7.” - Illustrative Mathematics: 2021 Oregon Math Guidance: 1.OA.C.6 Cluster: 1.OA.C - Add and subtract within 20. STANDARD: 1.OA.C.6 Standards Statement (2021): Add and subtract within 20, demonstrating fluency for addition and subtraction within 10 with accurate, efficient, and flexible strategies. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| K.OA.A.2, K.OA.A.3, K.OA.A.4, K.OA.A.5, 1.OA.C.5, 1.OA.B.4, 1.OA.B.3 \| 2.OA.B.2 \| 1.NBT.C.4 \| 1.OA.C.6 1.OA.C Crosswalk \| Standards Guidance: Terminology - Fluently/Fluency – To achieve fluency, students should be able to choose flexibly among methods and strategies to solve mathematical problems accurately and efficiently. - Accuracy includes attending to precision. - Efficiency includes using well-understood strategy with ease. - Flexibility involves using strategies such as making 5 or making 10. Boundaries - Fluency does not lend itself to timed tests or speed. Progression - Students might use the commutative property of addition to change ? + 6 = 15 to 6 + ? = 15, then count on or use methods to compose 4 (to make ten) plus 5 (ones in the 15) to find 9. - Students might reverse the action in the situation represented by ? - 6 = 9 so that is becomes 9 + 6 = ?. Or they might use their knowledge that the total is the first number in a subtraction equation and the last number in an addition equation to rewrite the situation equation as a solution equation: ? - 6 = 9 becomes 9 + 6 = ? or 6 + 9 = ?. (Please reference page 16 in the Progression document). Examples - Use strategies such as counting on; making ten, for example 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14; decomposing a number leading to a ten for example, 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9; - Use the relationship between addition and subtraction, for example, knowing that 8 + 4 = 12, one knows 12 – 8 = 4; - Create equivalent but easier or known sums, for example, adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13. - Illustrative Mathematics: - Student Achievement Partners: 2021 Oregon Math Guidance: 1.OA.D.7 Cluster: 1.OA.D - Work with addition and subtraction equations. STANDARD: 1.OA.D.7 Standards Statement (2021): Use the meaning of the equal sign to determine whether equations involving addition and subtraction are true or false. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| N/A \| 1.OA.D.8, 2.OA.C.3, 2.OA.C.4 \| N/A \| 1.OA.D.7 1.OA.D Crosswalk \| Standards Guidance: Clarifications - Students should explore and explain the relationship of the equal sign to quantities and orally justify if equations involving addition and subtraction are “true” (equal) or “false” (not equal). Teaching Strategies - Use the meaning of the equal sign (“is the same as”) to determine if two expressions involving a whole number and/or addition or subtraction expressions are equivalent. Examples - Determine if the equation is true or false, for example determining that 3-1 = 2+3 is false because the expressions do not have equal values. - Which of the following equations are true and which are false? How do you know? - 6 = 6 (True/Correct Statement) - 7 = 8 – 1 (True/Correct Statement) - 5 + 2 = 2 + 5 (True/Correct Statement) - 4 + 1 = 5 + 2 (False/Incorrect Statement) - Illustrative Mathematics: 2021 Oregon Math Guidance: 1.OA.D.8 Cluster: 1.OA.D - Work with addition and subtraction equations. STANDARD: 1.OA.D.8 Standards Statement (2021): Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. Connections: Preceding Pathway Content (2021) \| Subsequent Pathway Content (2021) \| Cross Domain Connections (2021) \| Common Core (CCSS) (2010) \| 1.OA.D.7 \| 1.OA.A.1 \| N/A \| 1.OA.D.8 1.OA.D Crosswalk \| Standards Guidance: Clarifications - Determine the unknown whole number relating three whole numbers, with the unknown in any position. Teaching Strategies - Symbols can be used to represent unknown amounts in equations. Progressions - Students advancement of methods can be clearly seen in the context of situations with unknown addends. These are the situations that can be represented by an addition equation with one unknown addend, e.g., 9 + = 13. Students can start solving for some unknown addend problems by trial and error or by knowing the relevant decomposition of the total. But a more advanced counting on solution involves seeing the 9 as part of 13, and understanding that counting the 9 things can be “taken as done” if we begin the count from 9. (Please reference page 14 in the Progression document). Examples - Students should be given the opportunity to find missing part given a known part and total, such as: - A missing addend in an addition equation, for example 3+_=5. - A missing subtrahend in a subtraction equation, for example 5-_=2. - A missing difference in a subtraction equation, for example 5-3=_ - Students should be given the opportunity to find missing totals given known parts, such as: - A missing sum in an addition equation, for example 3+2=_. - A missing minuend in a subtraction equation, for example _-2=3. - Determine the unknown number that makes the equation true in each of the equations: 8 + ? = 10, 5 = – 3, 3 + 4 = ∆. These are some possible ways to record equations that indicate an unknown number. - Illustrative Mathematics: - Student Achievement Partners:	oercommons	2025-03-18T00:37:15.547885	06/12/2023	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/105105/overview", "title": "OREGON MATH STANDARDS (2021): [1.OA]", "author": "Mark Freed" }
https://oercommons.org/courseware/lesson/71359/overview	excel Overview este material esta didicado para estudiantes de secundaria contiene : - ARCHIVOS EN PDF - VIDEOS EXCEL 2016 Introducción. Elementos de Excel (I) Excel es un programa del tipo Hoja de Cálculo que permite realizar operaciones con números organizados en una cuadrícula. Es útil para realizar desde simples sumas hasta cálculos de préstamos hipotecarios. Si no has trabajado nunca con Excel en este tema básico puedes ver con más detalle qué es y para qué sirve una hoja de cálculo . Ahora vamos a ver cuáles son los elementos básicos de Excel 2016, la pantalla, las barras, etc, para saber diferenciar entre cada uno de ellos. Aprenderás cómo se llaman, dónde están y para qué sirven. También cómo obtener ayuda, por si en algún momento no sabes cómo seguir trabajando. Cuando conozcas todo esto estarás en disposición de empezar a crear hojas de cálculo en el siguiente tema.	oercommons	2025-03-18T00:37:15.562710	08/18/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/71359/overview", "title": "excel", "author": "nelson franklin pacco garcia" }
https://oercommons.org/courseware/lesson/102366/overview	https://drive.google.com/file/d/1LhtyAtbcQnUonW606tYV31lF2ipQMjGP/view?usp=sharing Powerful Implementation Driver of MTSS2 Assistive Technology in the Schools: Introduction to Assistive Technology Overview The Assistive Technology in the Schools Course aims to to familiarize educators and parents with assistive technology devices and services, and provide a foundational understanding of what it means to consider, assess, and implement assistive technology (AT) with students to remove learning barriers. This course includes four modules: Introduction to Assistive Technology, AT Consideration, AT Assessment, and AT Implementation. This first module, Introduction to Assistive Technology, highlights the difference between accessible technology and assistive technology. This module explores examples of how assistive technology devices and services can help reduce learning barriers for students with disabilities across learning environments. Module Objective: - Participants will be able to understand and describe inclusive technology and the difference between accessible educational material(AEM), accessible technology, and assistive technology(AT). - Participants will be able to identify 3 examples of assistive technology devices/tools that have the potential to remove learning barriers for students. - Participants will be able to identify 2 examples of assistive technology services within the education system. Module Description & Goals Assistive Technology in the Schools Course Overview The purpose of the course, Assistive Technology in the Schools, is to familiarize educators and parents with assistive technology devices and services. The modules will provide an understanding of what it means to consider, assess, and implement assistive technology to remove learning barriers for students. This course includes four modules: Introduction to Assistive Technology, AT Consideration, AT Assessment, and AT Implementation. Module 1 Introduction to Assistive Technology This first module, Introduction to Assistive Technology, highlights the difference between accessible technology and assistive technology. This module explores examples of how assistive technology devices and services can help reduce learning barriers for students with disabilities within the education system. Module Objective: - Participants will be able to understand and describe inclusive technology and the difference between accessible educational material(AEM), accessible technology, and assistive technology(AT). - Participants will be able to identify 3 examples of assistive technology devices/tools that have the potential to remove learning barriers for students. - Participants will be able to identify 2 examples of assistive technology services within the schools. Module Sections Assistive Technology in Action What are Assistive Technology Services Resources to Learn More About Assistive Technology What is Assistive Technology? Defining Assistive Technology Assistive technology (AT) is technology used by individuals with disabilities to perform functions that might otherwise be difficult or impossible. The following video provides examples of assistive technology. How does Assistive Technology Relate to "Inclusive Technologies?" Inclusive technologies, also referred to as accessible technologies or universal technologies, reduce or remove barriers to student learning experiences. The Center on Inclusive Technology & Education Systems (CITES) describes inclusive technologies as having 3 categories: - Accessible Educational Materials (AEM) - Accessible Technology - Assistive Technology (AT) Accessible Educational Materials(AEM) Accessible Educational Materials Print and technology-based educational materials, including printed and electronic textbooks and related core materials that are designed or enhanced in a way that makes them usable across the widest range of learner variability, regardless of format (e.g., print, digital, graphic, audio, video). The National Instructional Materials Access Center (NIMAC) is a federally funded online file repository of accessible source files for textbooks, as well as other kinds of educational materials. Learn more about AEM in this video, AEM In Simple Language. (4.34 min.) Accessible Technology Accessible technologies are "the hardware and software that are designed to provide all learners with access to the content in digital materials. Examples of accessible technologies include an application that allows the user to write or verbalize their responses, a mobile phone with an optional zoom display, and a PDF with high color contrast." This definition is the language used in the Individuals with Disability Education Act (IDEA) and was highlighted in Myths & Facts Surrounding Assistive Technology Devices and Services released by the Office of Special Education Programs (OSEP). Assistive Technology Devices The Individuals with Disabilities Education Act (IDEA) defines assistive technology devices as "any item, piece of equipment, or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve the functional capabilities of a child with a disability. In plain language, assistive technology is a technology that assists a student in removing the barriers that can prevent the student from accessing their education. _________________________________________________________________________ Myths & Facts MYTH: AT always involves an electronic device and is always high-tech. FACT: Many AT devices or tools may be computer-based, but items like visual schedules and calendars, binder clips, squishy balls, or stickers may also be considered AT. \| The IRIS Center, a technical assistance center funded by the U.S. Department of Education’s Office of Special Education Programs (OSEP) created a chart that categorizes AT devices into low-tech, mid-tech, and high-tech devices. In Myths and Facts Surrounding Assistive Devices and Services, the Office of Special Education Programs (OSEP) provides the following chart, giving examples of assistive technology devices. Type \| Definition \| Example \| \| Low-Tech \| Devices that are readily available, inexpensive, and typically do not require batteries or electricity \| \| \| Mid-Tech \| Devices that are usually digital and may require batteries or another power source \| \| \| High-Tech \| Devices that are typically computer-based, likely to have sophisticated features, and can be tailored to the specific needs of an individual student \| \| Assistive technology can make a dramatic difference in a student's ability to access curriculum, express their knowledge, and optimize learning in general education classrooms. As a student's IEP team identifies barriers to their student's learning, assistive technology options can be explored to improve academic, behavioral, and social/emotional outcomes. The visual below depicts an array of assistive technology tools for learning. Assistive Technology in Action The article, 20+ Examples of Assistive Technology to Help Kids Learn provides many examples of assistive technology and how it removes barriers for students across learning environments. This resource from We Are Teachers also shares videos and written examples of students using assistive technology. Student Examples Meet Alex In this video, we hear how Alex blooms with learning using assistive technology. A learning disability was holding him back in school. Alex uses speech-to-text to get his thoughts out for written expression. Alex improved from barely being able to craft a few sentences His teacher describes how assistive technology has allowed Alex to show us what he knows and what he is capable of in school. Meet Jean. In this video, we see how Jean uses an iPad to access the general education curriculum, complete assignments, and participate in state testing. She also uses hearing aids with technology that converts her hearing aids to headphones to improve access to curriculum, books, and music. Her teachers share how assistive technology increases Jean's independence at school. Meet Arial. Arial is a 6-year-old girl who loves to read, laugh and play. She has cerebral palsy and uses her eyes to access a communication device that allows her to talk. Communication devices are often called augmentative alternative communication (AAC). Her AAC gives her a voice of her own, allowing her to interact with her friends and participate in her learning in general education. Meet Aiden Aiden is a boy with lots to say. He has hearing loss, low vision, and autism. Assistive technology has helped Aiden communicate his thoughts and participate in school. The team reports that his behaviors have significantly improved because he can use his augmentative alternative communication device to communicate, reducing his frustration. In this video, his team shares their journey in trialing and determining the AAC and AT that Aiden required. More Examples of Assistive Technology: \| Jeff is a student with low vision who uses a screen reader to read internet articles in science and to access his science book. With this technology, he can access the general education curriculum across content areas and make progress toward grade-level standards. Without this technology, Jeff would not have equitable access to curriculum. \| \| Alex is a student with dyslexia who listens to audiobooks for ELA class. With this technology, he has full equitable access to his general education ELA curriculum. Without this technology, he would not have access to the required reading in ELA, nor would he be equipped to complete assignments and participate in class discussions and assessments. \| \| \| Leah is a student with dysgraphia who uses a combination of word prediction and speech-to-text to write a report for a history class. She uses text-to-speech to listen to what she has written to edit her work before turning it in. With these assistive technologies, Leah is excelling across content areas because she can express her learning in both assignments and assessments. \| In each example above, the student can do the same work as their peers with the help of assistive technology. They require assistive technology to either access the general education curriculum or to express their learning. For these students, assistive technology removes learning and participation barriers and creates a more inclusive equitable learning experience. __________________________________________________________________________ Myth: Assistive technology may prevent students from learning certain skills or that it is cheating. Fact: AT supports increased learning opportunities, vocabulary, productivity, and student motivation. The next video provides more insights into how you can address this myth. \| What are Assistive Technology Services? According to the Individuals with Disabilities in Education Act (IDEA), each time an IEP Team develops, reviews, or revises a child’s IEP, the IEP Team must consider whether the child requires AT devices and AT services. In previous sections, we explored AT devices. In this section, we will define assistive technology services. In this video, Chris Bugaj defines both AT devices and AT services. In later modules, we will dive deeper into what it means to consider AT devices and services within the IEP. Assistive Technology Services: "The term “assistive technology service” means any service that directly assists a child with a disability in the selection, acquisition, or use of an assistive technology device." Assistive technology services include the evaluation, acquisition, adaptation, customization, coordination, training, and assistance for the student and staff to make sure the student can use and benefit from the assistive technology. In future modules, we will address the consideration of AT devices and AT services within the Individual Education Program (IEP) team meeting. An example of an AT service could be training for the student who will be using assistive technology, as well as training for staff or parents who will be supporting the student with implementing AT. ________________________________________________________________________ MYTH: Children can learn to use an AT device on their own; educators have no obligation to provide training to a child or to their family. FACT: It is the responsibility of the LEA (Local Education Agency) to ensure that the child with a disability, parents, and educators know how the AT device works through the provision of AT services. \| Resources to learn more about Assistive Technology Explore Resources to Learn More About Assistive Technology To explore the topic of Assistive Technology Implementation further, select from these articles, websites, and videos to read about the topic and explore some examples. Read & Learn \| Watch & Learn \| What is Assistive Technology? (Assistive Technology Industry Association) AT Internet Modules on Assessment (login to access) What is Augmentative Alternative Communication (AAC)? (American Speech-Language-Hearing Association) \| Assistive Technology! (a 3-minute video giving an overview of Assistive Technology) Understanding Assistive Tech -Simply Said (2-minute video introducing AT in schools) A Teacher's View of Assistive Technology (9 min video with various teachers explaining how they use and implement AT in the classroom with their students.) \| \| Learning more about technology to support reading \| Learn more about technology to support writing \| Washington State Agencies Designed to Support Assistive Technology Within most states, there are state or regional agencies that exist to support school districts with consultation and lending library support for AT assessment. Within Washington State, there are two such agencies. They are as follows: Inclusive Technology within Multi-Tiered Systems of Support (MTSS) A common education initiative, Multi-Tiered Systems of Support (MTSS), aims to provide inclusive education for all students. As discussed in section one, inclusive technology includes Accessible Educational Material (AEM), accessible technology, and assistive technology (AT). Understanding how inclusive technologies integrate into the MTSS is essential to supporting students who require assistive technology (AT). This video explains more about inclusive technologies within MTSS: Inclusive Technologies as Powerful Implementation Drivers within MTSS Accessible Educational Material (AEM), accessible technology, and assistive technology are powerful implementation drivers within a Multi-Tiered System of Support (MTSS) because they help to ensure equitable access to core curriculum across all tiers of intervention. AEM paired with technology enables the removal of learning barriers by assuring accessible instructional content and personalization of tools to access that content. This promotes engagement, as well as academic and behavioral success by fostering an environment where all learners can thrive. Providing AEM and accessible technologies aligns with Universal Design for Learning (UDL) which emphasizes giving students different ways to learn, show what they know, and stay engaged in their learning. Accessible Educational Material (AEM) and accessible technology set the stage for inclusive learning and move us away from only providing accessibility on the basis of “necessity.” \| Reflections on Learning Reflection 1. Consider the definition of accessible technology in section 1. What is one kind of accessible technology you would like to incorporate into your practice? 2. Consider a learning barrier that one of your students is facing. Could assistive technology reduce or eliminate the learning barrier? What is one technology you could try with your student? 3. Use the attached document entitled "AT: Putting Learning into Action" to consider a student you work with and the learning barriers they face. Are there AT devices and services that may eliminate or reduce learning barriers? This form will help you record your thoughts as you think through possible solutions. 3. Reflect on where are you on the continuum. \| Knowledge level 1 \| Understanding \| Application \| \|---\|---\|---\| \| \| \| We invite you to explore the three other modules in the AT in the Schools course. Research & Glossary Research Articles & References Biegun, D., Peterson, Y., McNaught, J., & Sutterfield, C. (2020). Including Student Voice in IEP Meetings Through Use of Assistive Technology. Teaching Exceptional Children, 52(5), 348–350. https://doi.org/10.1177/0040059920920148 DeCoste, D. C., & Bowser, M. G. (2020). The Evolving Landscape of Assistive Technology in K-12 Settings. Assistive Technology Outcomes and Benefits, 14(1), 94–110. Jones, & Hinesmon-Matthews, L. J. (2014). Effective Assistive Technology Consideration and Implications for Diverse Students. Computers in the Schools, 31(3), 220–232. https://doi.org/10.1080/07380569.2014.932682 Marino, M. T., Marino, E. C., & Shaw, S. F. (2006). Making Informed Assistive Technology Decisions for Students with High Incidence Disabilities. Teaching Exceptional Children, 38(6), 18–25. https://doi.org/10.1177/00400599060380060 Peterson-Karlan, & Parette, H. P. (2007). Evidence-Based Practice and the Consideration of Assistive Technology: Effectiveness and Outcomes. Assistive Technology Outcomes and Benefits, 4(1), 130–139. Quinn, B. S., Behrmann, M., Mastropieri, M., Chung, Y., Bausch, M. E., & Ault, M. J. (2009). Who is Using Assistive Technology in Schools? Journal of Special Education Technology, 24(1), 1–13. https://doi.org/10.1177/016264340902400101 Watts, O’Brian, M., & Wojcik, B. W. (2003). Four Models of Assistive Technology Consideration: How Do They Compare to Recommended Educational Assessment Practices? Journal of Special Education Technology, 19(1), 43–56. https://doi.org/10.1177/016264340401900104 Glossary Assistive Technology (AT) - products, equipment, and systems that enhance learning, working, and daily living for persons with disabilities. (https://www.atia.org/home/at-resources/what-is-at/#what-is-assistive-technology) Educational Barriers - Characteristics of curriculum, including instruction, that make it inaccessible to students. An example of this is text that cannot be read by a screen reader or text to speech app. Note: The student or student special needs are Never the barriers.	oercommons	2025-03-18T00:37:15.613577	Full Course	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/102366/overview", "title": "Assistive Technology in the Schools: Introduction to Assistive Technology", "author": "Technology" }
https://oercommons.org/courseware/lesson/122724/overview	Introduction to Global Challenges and Solutions Activity Overview This activity uses legos to introduce students to a course focused on global challenges and solutions. Overview Overview: This activity introduces students to the topic of global challenges and encourages them to think creatively about solutions using LEGO bricks. Discipline This activity could be used in any social sciences course that addresses global challenges. Learning Objectives 1. Students will identify key aspects of a specific global challenge and discuss its significance within their campus or local community context. 2. Students will collaboratively design and build a practical, micro-level solution to a global challenge, fostering innovation and critical thinking. 3. Students will practice effective collaboration, reflect on the creative process, and articulate the impact and feasibility of their proposed solutions. Time Needed This exercise will take approximately 45-minutes to complete. Materials Needed LEGO sets (enough for small groups of 3-4 students) Printed cards with different global challenges with specific application to your campus or local community (e.g., climate change, clean water access, poverty, renewable energy, etc.) Timer Large paper for group reflection (markers etc) Sticky notes for gallery walk Lesson Instructions Introduction (5 minutes): 1. Briefly introduce the concept of global challenge 2. Explain that today’s activity will involve using LEGO bricks to think creatively about solutions to global challenges. Form Groups (2 minutes): 1. Divide the students into small groups of 3-4. 2. Distribute a set of LEGO bricks to each group. Challenge Assignment (3 minutes): 1. Give each group a card with a specific global challenge written on it. 2. Explain that their task is to build a model that represents a solution to their assigned challenge using the LEGO bricks. 3. Let them know if should be a practical, “mirco” level solution that could be implemented on their campus/in their community. Building Phase (10 minutes): 1. Set a timer for 10 minutes. 2. Encourage the groups to discuss and build their solutions. Remind them to think creatively and collaboratively. Presentation (7 minutes): 1. Once the time is up, have each group present their LEGO model to the class. 2. Ask them to explain the challenge they were addressing and how their model represents a solution. Reflection (10 minutes): Have students go back to their small groups and reflect on the experience. Ask them to draw/take notes of the large pieces of white paper and hang them up around the room. Use (some of) the following questions to guide the reflection: What did you learn about the global challenge your group addressed? Why do you think this challenge is important to solve? How did your group come up with the solution represented by your LEGO model? What were some of the ideas that you considered but didn’t use? Why did you choose the final idea? How did your group work together to build the model? What roles did each member take on? What challenges did you face while working as a team, and how did you overcome them? How do you think your solution could make a difference in addressing the global challenge? What are some potential limitations or obstacles to implementing your solution in the real world? Gallery Walk (10 minutes): 1. After the students hang up their reflections (with their LEGO models visible), invite all groups to do a gallery walk to read/reflect on the notes different groups made. 2. Invite students to make comments on the large pieces of white paper by adding sticky notes. - Comments might focus on how peers think the solution could make a positive difference in addressing the global challenge or potential limittions or obstacles to implementing the solution. Discussion (3 minutes): Highlight the importance of creativity and collaboration in solving global challenges.	oercommons	2025-03-18T00:37:15.636634	Melissa Nelson	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/122724/overview", "title": "Introduction to Global Challenges and Solutions Activity", "author": "Anne Stone" }
https://oercommons.org/courseware/lesson/65713/overview	Education Standards Bellingham Temperature Blank Pictograph Blank Rain Bar Graph Brewster Temperature Colville Rain Colville Temperature Grandview Rain Grandview Temperature Kindergarten Analyze and Interpret Data Teacher Directions KinderRainyGraph KinderSnowyGraph KinderSunnyGraph Long Beach Rain Long Beach Temperature Neah Bay Rain Neah Bay Temperature Our Weather Prediction Our Weather Prediction for Ozette Plants on Our Plates Pullman Rain Pullman Temperature Third Grade Analyzing and Interpreting Data Weather Data Locations Native American Stories Science Connections Overview The original Native American story component lesson was developed as part of an Office of Superintendent of Public Instruction (OSPI) and Washington State Leadership and Assistance for Science Education Reform (LASER) project funded through an EPA Region 10 grant. The stories were told by Roger Fernandes of the Lower Elwha Klallam tribe. Mr. Fernandes has been given permission by the tribes to tell these stories. As these lessons and stories were shared prior to the adoption of the Washington State Science Learning Standards in 2013, there was a need to align these stories with the current science standards. This resource provides a current alignment and possible lesson suggestions on how these stories can be incorporated into the classroom. This alignment work has been funded by the NGSS & Climate Science Proviso of the Washington State Legislature as a part of North Central Educational Service District's award. Introduction The original Native American story component lesson was developed as part of an Office of Superintendent of Public Instruction (OSPI) and Washington State Leadership and Assistance for Science Education Reform (LASER) project funded through an EPA Region 10 grant. The stories were told by Roger Fernandes of the Lower Elwha Klallam tribe. Mr. Fernandes has been given permission by the tribes to tell these stories. As these lessons and stories were shared prior to the adoption of the Washington State Science Learning Standards in 2013, there was a need to align these stories with the current science standards. This resource provides a current alignment and possible lesson suggestions on how these stories can be incorporated into the classroom. This alignment work has been funded by the NGSS & Climate Science Proviso of the Washington State Legislature as a part of North Central Educational Service District's award. Attribution NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, DC: The National Academies Press \| Public License All the stories in this collection are read by Roger Fernandes of the Lower Elwa Klallam tribe. The stories and video retelling are included in this lesson with permission and do not fall under the open license for this resource. License Except where otherwise noted, this work by Mechelle LaLanne for North Central Educational Service District is licensed under a Creative Commons Attribution 4.0 International License. All logos and trademarks are property of their respective owners. This resource contains links to websites operated by third parties. These links are provided for your convenience only and do not constitute or imply any endorsement or monitoring by North Central Educational Service District. Please confirm the license status of any third-party resources and understand their terms of use before reusing them. Blue-Jay and Bear (Chehalis, Western WA) Blue-Jay and Bear (Chehalis, Western WA) Blue-Jay and Bear is a story from the Chehalis People near Longview, WA. This story is about Blue-Jay and his desire to be able to do the things other animals are able to do and how Bear takes care of him after Blue-Jay becomes injured. Video Transcript Washington State Science Learning Standards The connections made to these standards are based on the description of the structure and function of Fishing Duck's external parts and Bear's padded feet. 1-LS1-1: Use materials to design a solution to a human problem by mimicking how plants and/or animals use their external parts to help them survive, grow, and meet their needs.* [Clarification Statement: Examples of human problems that can be solved by mimicking plant or animal solutions could include designing clothing or equipment to protect bicyclists by mimicking turtle shells, acorn shells, and animal scales; stabilizing structures by mimicking animal tails and roots on plants; keeping out intruders by mimicking thorns on branches and animal quills; and, detecting intruders by mimicking eyes and ears.] 4-LS1-1: Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction. [Clarification Statement: Examples of structures could include thorns, stems, roots, colored petals, heart, stomach, lung, brain, and skin.] [Assessment Boundary: Assessment is limited to macroscopic structures within plant and animal systems.] First Grade Inspired by Nature STEM Storyline \| Educational Service DIstrict 112 \| CC BY Explore the practice of biomimicry by answering the driving question: How can we use our understanding of nature to help our family solve a problem? (Also aligned to 1-LS3) Fourth Grade Animal Mouth Structures \| PBS Learning Media \| free online This is a resource vetted by NSTA that allows students to explore how the mouth structures of different animals help them meet their needs. Beaver and Mouse (Tulalip, Western WA) Beaver and Mouse (Tulalip, Western, WA) This story is about Beaver who really wants to talk with Field Mouse and when he does, Field Mouse tells him that he is too fat. Beaver remembers how useful Cedar Tree is and how Cedar Tree could help him. Video Transcript Washington State Science Learning Standards 2-PS1-2: Analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose.* [Clarification Statement: Examples of properties could include, strength, flexibility, hardness, texture, and absorbency.] [Assessment Boundary: Assessment of quantitative measurements is limited to length.] K-2-ETS1-2: Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem. 3-5-ETS1-2: Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem. General Resources Beaver video for K-5 Beavers. (2020). Retrieved April 29, 2020, from PBS LearningMedia website: https://thinktv.pbslearningmedia.org/resource/tdc02.sci.life.colt.beaver/beavers/#.XqnL0ZNKjBI Cedar Clothing Exhibit Clothing \| AMNH. (2020). Retrieved April 29, 2020, from American Museum of Natural History website: https://www.amnh.org/exhibitions/permanent/northwest-coast/kwakwa-ka-wakw/kwakwa-ka-wakw-collection/clothing Kindergarten- Second Grade Have students review the different weave patterns and sketch a clothing design for various weather. Basketry. (2020). Retrieved April 29, 2020, from Burkemuseum.org website: https://www.burkemuseum.org/static/baskets/Teachersguideforbasketry.htm Third-Fifth Grade Students examine different types of fabric and their characteristics. Using magnifying glasses and sandpaper, they test and observe the weave and wear quality of fabric samples. By comparing the qualities of different fabrics they come to understand why so many different types of fabric exist and are able to recognize or suggest different uses for them. Compare Fabric Materials - Activity. (2018, February 10). Retrieved April 29, 2020, from TeachEngineering.org website: https://www.teachengineering.org/activities/view/compare_fabric_materials Changer and Dog Salmon (All tribes, Western WA) Changer and Dog Salmon (All Tribes, Western, WA) This story describes how Changer who was born of an Earth mother who was carried into the Sky World and married a Star. Changer was stolen by the Dog Salmon People and when he was to return to his mother, he made his first transformation. Video Transcript Washington State Science Learning Standards HS-ESS2-7: Construct an argument based on evidence about the simultaneous coevolution of Earth’s systems and life on Earth. [Clarification Statement: Emphasis is on the dynamic causes, effects, and feedbacks between the biosphere and Earth’s other systems, whereby geoscience factors control the evolution of life, which in turn continuously alters Earth’s surface. Examples include how photosynthetic life altered the atmosphere through the production of oxygen, which in turn increased weathering rates and allowed for the evolution of animal life; how microbial life on land increased the formation of soil, which in turn allowed for the evolution of land plants; or how the evolution of corals created reefs that altered patterns of erosion and deposition along coastlines and provided habitats for the evolution of new life forms.] [Assessment Boundary: Assessment does not include a comprehensive understanding of the mechanisms of how the biosphere interacts with all of Earth’s other systems.] Resources Evolutionary history of Pacific salmon in dynamic environments is an article that describes the evoultionary history of the Pacific salmon in a changing landscape. This could be a great resource as a teacher to develop a lesson. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352440/ Waples, R. S., Pess, G. R., & Beechie, T. (2008). Evolutionary history of Pacific salmon in dynamic environments. Evolutionary applications, 1(2), 189–206. https://doi.org/10.1111/j.1752-4571.2008.00023.x The Coming of Slehal (All tribes, Western, WA) The Coming of Slehal (All tribes, Western, WA) This story is about the order of the world and how it came to be. Video Transcript Washington State Science Learning Standards MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations. [Clarification Statement: Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.] HS-LS2-6: Evaluate claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem. [Clarification Statement: Examples of changes in ecosystem conditions could include modest biological or physical changes, such as moderate hunting or a seasonal flood; and extreme changes, such as volcanic eruption or sea level rise.] HS-LS4-6: Create or revise a simulation to test a solution to mitigate adverse impacts of human activity on biodiversity.* [Clarification Statement: Emphasis is on testing solutions for a proposed problem related to threatened or endangered species, or to genetic variation of organisms for multiple species.] Middle School Link to WA History Curriculum, OSPI Tribal Sovereignty Curriculum for the Social Studies Indian-Ed.Org \| WA – Contemporary Washington State. (2020). Retrieved May 5, 2020, from Indian-ed.org website: http://www.indian-ed.org/curriculum/middle-school-curriculum/wa-contemporary-washington-state/ The Invasive Species Council has a unit with several lesson. Lesson 3 aligns well, but you could really use most of their activities. Palador. (2020, February 6). School Curriculum - Invasive Species Council. Retrieved May 5, 2020, from Invasive Species Council website: https://invasivespecies.wa.gov/educational-materials/teacher-curriculum/ High School Link to the Northwest Indian Fisheries Commission Treaty Hunting Rights FAQ Treaty Hunting Rights FAQ. (2008, June 5). Retrieved May 5, 2020, from Northwest Indian Fisheries Commission website: https://nwifc.org/about-us/wildlife/treaty-hunting-rights-faq/ Population Dynamics 5E Instructional Model Plan from New Visions for Public Schools Population Dynamics 5E Instructional Model Plan - New Visions Science Curriculum. (2020). Retrieved May 5, 2020, from New Visions - Science website: https://curriculum.newvisions.org/science/resources/resource/living-environment-unit-7-5E-instructional-model-plan-population-dynamics-5e-instructional-model-plan/ Coyote and Bear (All tribes, Eastern WA) Coyote and Bear (All tribes, Eastern WA) Video Transcript Washington State Science Learning Standards 1-LS3-1: Make observations to construct an evidence-based account that young plants and animals are like, but not exactly like, their parents. [Clarification Statement: Examples of patterns could include features plants or animals share. Examples of observations could include leaves from the same kind of plant are the same shape but can differ in size; and, a particular breed of dog looks like its parents but is not exactly the same.] [Assessment Boundary: Assessment does not include inheritance or animals that undergo metamorphosis or hybrids.] 4-LS1-1: Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction. [Clarification Statement: Examples of structures could include thorns, stems, roots, colored petals, heart, stomach, lung, brain, and skin.] [Assessment Boundary: Assessment is limited to macroscopic structures within plant and animal systems.] First Grade Plants on Our Plates. (n.d.). Retrieved from https://www.wastatelaser.org/wp-content/uploads/Plants_on_Our_Plates.pdf Fourth Grade That's Not a Plant, It's a Weed! Discovering Functions of External Plant Parts; What Makes a Plant a Plant? Mary Ellen Kanthack. (2015, July 10). That’s Not a Plant, It’s a Weed! Discovering Functions of External Plant Parts; What Makes a Plant a Plant? Retrieved May 5, 2020, from BetterLesson website: https://betterlesson.com/lesson/603965/that-s-not-a-plant-it-s-a-weed-discovering-functions-of-external-plant-parts-what-makes-a-plant-a-plant?from=cc_lesson Father Ocean (All tribes, Western WA) Father Ocean (All tribes, Western WA) This story is about Ocean’s children, the Clouds, and how they would travel across the land. Video Transcript Washington State Science Learning Standards K-ESS2-1: Use and share observations of local weather conditions to describe patterns over time. [Clarification Statement: Examples of qualitative observations could include descriptions of the weather (such as sunny, cloudy, rainy, and warm); examples of quantitative observations could include numbers of sunny, windy, and rainy days in a month. Examples of patterns could include that it is usually cooler in the morning than in the afternoon and the number of sunny days versus cloudy days in different months.] [Assessment Boundary: Assessment of quantitative observations limited to whole numbers and relative measures such as warmer/cooler.] 3-ESS2-1: Represent data in tables and graphical displays to describe typical weather conditions expected during a particular season. [Clarification Statement: Examples of data could include average temperature, precipitation, and wind direction.] [Assessment Boundary: Assessment of graphical displays is limited to pictographs and bar graphs. Assessment does not include climate change.] 5-ESS2-1: Develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact. [Clarification Statement: Examples could include the influence of the ocean on ecosystems, landform shape, and climate; the influence of the atmosphere on landforms and ecosystems through weather and climate; and the influence of mountain ranges on winds and clouds in the atmosphere. The geosphere, hydrosphere, atmosphere, and biosphere are each a system.] [Assessment Boundary: Assessment is limited to the interactions of two systems at a time.] MS-ESS2-4: Develop a model to describe the cycling of water through Earth's systems driven by energy from the sun and the force of gravity. [Clarification Statement: Emphasis is on the ways water changes its state as it moves through the multiple pathways of the hydrologic cycle. Examples of models can be conceptual or physical.] [Assessment Boundary: A quantitative understanding of the latent heats of vaporization and fusion is not assessed.] MS-ESS2-5: Collect data to provide evidence for how the motions and complex interactions of air masses result in changes in weather conditions. [Clarification Statement: Emphasis is on how air masses flow from regions of high pressure to low pressure, causing weather (defined by temperature, pressure, humidity, precipitation, and wind) at a fixed location to change over time, and how sudden changes in weather can result when different air masses collide. Emphasis is on how weather can be predicted within probabilistic ranges. Examples of data can be provided to students (such as weather maps, diagrams, and visualizations) or obtained through laboratory experiments (such as with condensation).] [Assessment Boundary: Assessment does not include recalling the names of cloud types or weather symbols used on weather maps or the reported diagrams from weather stations.] MS-ESS2-6: Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates. [Clarification Statement: Emphasis is on how patterns vary by latitude, altitude, and geographic land distribution. Emphasis of atmospheric circulation is on the sunlight-driven latitudinal banding, the Coriolis effect, and resulting prevailing winds; emphasis of ocean circulation is on the transfer of heat by the global ocean convection cycle, which is constrained by the Coriolis effect and the outlines of continents. Examples of models can be diagrams, maps and globes, or digital representations.] [Assessment Boundary: Assessment does not include the dynamics of the Coriolis effect.] Kindergarten Feeling Hot, Hot, Hot! \| Kilauea School and Maunawili School for Gather, Reason, Communicate \| CC BY SA Addresses Patterns in Daily Temperature and the Phenomenon focus is: We are hotter and sweatier after lunch recess than morning recess. The investigation is about patterns and graphing with simple data. Includes formative assessment. Analyzing and Interpreting Data - Kindergarten Develop for the Climate Science Proviso Canvas Course hosted by Capital Region ESD in Tumwater. (See attached resources) Third Grade Analyzing and Interpreting Data - Third Grade Develop for the Climate Science Proviso Canvas Course hosted by Capital Region ESD in Tumwater. (See attached resources) Fifth Grade Nelson, K. (2015, July 10). Researching The Rain Shadow Effect. Retrieved May 13, 2020, from BetterLesson website: https://betterlesson.com/lesson/634353/researching-the-rain-shadow-effect?from=cc_lesson Middle School Grade, & Macnevin, L. (n.d.). General Science: Weather and Heat Transfers. Retrieved from https://ambitiousscienceteaching.org/wp-content/uploads/2017/06/Gen-Sci-Weather-and-Heat-Transfer.pdf The Gossiping Clam (Puget Sound, Western WA) The Gossiping Clam (Puget Sound, Western WA) This is a story about the Clams being everywhere and gossiping about you until a little clam gossips about Raven and Raven takes the clams and pushed them under the sand on the beach. Video Transcript Washington State Science Learning Standards 3-LS4-1: Analyze and interpret data from fossils to provide evidence of the organisms and the environments in which they lived long ago. [Clarification Statement: Examples of data could include type, size, and distributions of fossil organisms. Examples of fossils and environments could include marine fossils found on dry land, tropical plant fossils found in Arctic areas, and fossils of extinct organisms.] [Assessment Boundary: Assessment does not include identification of specific fossils or present plants and animals. Assessment is limited to major fossil types and relative ages.] MS-LS4-1: Analyze and interpret data for patterns in the fossil record that document the existence, diversity, extinction, and change of life forms throughout the history of life on Earth under the assumption that natural laws operate today as in the past. [Clarification Statement: Emphasis is on finding patterns of changes in the level of complexity of anatomical structures in organisms and the chronological order of fossil appearance in the rock layers.] [Assessment Boundary: Assessment does not include the names of individual species or geological eras in the fossil record.] Third Grade Mud Fossils. (2014, July 22). Retrieved May 13, 2020, from Earth Science Week website: https://www.earthsciweek.org/classroom-activities/mud-fossils Middle School NSTA. (2019). Deep Thinking Over Geologic Time. Retrieved May 13, 2020, from Nsta.org website: https://ngss.nsta.org/Resource.aspx?ResourceID=999 Handout: http://static.nsta.org/connections/middleschool/201712Handout.pdf Student Guide: http://static.nsta.org/connections/middleschool/201712StudentGuide.pdf Teacher Guide: http://static.nsta.org/connections/middleschool/201712TeacherGuideNew.pdf ay-ay-ásh (Yakama, Eastern WA) ay-ay-ásh (Yakima, Eastern WA) This story is about a little girl who didn't listen very well to her family, adults, or other children and was called ay-ay-ásh (pronounced i-i-esh meaning stupid) by everyone. Cedar tree taught her to weave a basket, but it took several attempts for her to make a basket that would hold water. Video Transcript Washington State Science Learning Standards K-2-ETS1-1: Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool. K-2-ETS1-2: Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem. K-2-ETS1-3: Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs. 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost. 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem. 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved. MS-ETS1-1:Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions. MS-ETS1-2: Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem. MS-ETS1-3: Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. HS-ETS1-1: Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants. HS-ETS1-2: Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering. HS-ETS1-3: Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts. K-2 Kindergarten – Designing Paper Baskets – PictureSTEM. (2017). Retrieved May 13, 2020, from Picturestem.org website: http://picturestem.org/picturestem-units/kindergarten-baskets/ First Grade – Designing Hamster Habitats – PictureSTEM. (2018). Retrieved May 13, 2020, from Picturestem.org website: http://picturestem.org/picturestem-units/first-grade-hamsters/ Second Grade – Designing Toy Box Organizers – PictureSTEM. (2017). Retrieved May 13, 2020, from Picturestem.org website: http://picturestem.org/picturestem-units/second-grade-toy-box/ 3-5 Entwined with Life: Native American Basketry - Home - Burke Museum. (2020). Retrieved May 13, 2020, from Burkemuseum.org website: https://www.burkemuseum.org/static/baskets/index.html https://www.burkemuseum.org/static/baskets/Teachersguideforbasketry.html Middle School Roots of Wisdom - Education Resources. (2015). Retrieved May 13, 2020, from Omsi.edu website: https://omsi.edu/exhibitions/row/education-resources/ https://omsi.edu/exhibitions/row/docs/Roots-of-Wisdom_Weaving-Activity-Guide.pdf High School Teachings of the Tree People : : Curriculum for Engaged Learning Through Film. (n.d.). Retrieved from https://www.newday.com/sites/default/files/resources/TeachingsCurriculum.pdf - Use the weaving lesson and incorporate specific criteria and constraints. - To rent the film https://www.newday.com/film/teachings-tree-people-work-bruce-miller The Huckleberry Medicine (Puget Sound, Western WA) The Huckleberry Medicine (Puget Sound, Western WA) A man's daughter became ill and nothing seemed to help her condition. The father prayed for help to the spirits and the ancestors and he had a dream about how to help his daughter. Video Transcript Washington State Science Learning Standards MS-LS1-3: Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells. [Clarification Statement: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems.] [Assessment Boundary: Assessment does not include the mechanism of one body system independent of others. Assessment is limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.] MS-LS1-5: Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms. [Clarification Statement: Examples of local environmental conditions could include availability of food, light, space, and water. Examples of genetic factors could include large breed cattle and species of grass affecting growth of organisms. Examples of evidence could include drought decreasing plant growth, fertilizer increasing plant growth, different varieties of plant seeds growing at different rates in different conditions, and fish growing larger in large ponds than they do in small ponds.] [Assessment Boundary: Assessment does not include genetic mechanisms, gene regulation, or biochemical processes.] MS-PS1-3: Gather and make sense of information to describe that synthetic materials come from natural resources and impact society. [Clarification Statement: Emphasis is on natural resources that undergo a chemical process to form the synthetic material. Examples of new materials could include new medicine, foods, and alternative fuels.] [Assessment Boundary: Assessment is limited to qualitative information.] Resources Straus, K. M., & Chudler, E. H. (2016). Online Teaching Resources about Medicinal Plants and Ethnobotany. CBE—Life Sciences Education, 15(4), fe9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5132387/ Middle School Lessons - Sowing the Seeds of Neuroscience. (2013). Lessons - Sowing the Seeds of Neuroscience. Retrieved May 13, 2020, from Neuroseeds.org website: http://www.neuroseeds.org/Lessons Columbia River Story (All tribes, Eastern WA) Columbia River Story (All tribes, Eastern WA) A man's daughter became ill and nothing seemed to help her condition. The father prayed for help to the spirits and the ancestors and he had a dream about how to help his daughter. Video Transcript Washington State Science Learning Standards 4-ESS2-1: Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation. [Clarification Statement: Examples of variables to test could include angle of slope in the downhill movement of water, amount of vegetation, speed of wind, relative rate of deposition, cycles of freezing and thawing of water, cycles of heating and cooling, and volume of water flow.] [Assessment Boundary: Assessment is limited to a single form of weathering or erosion.] 4-ESS2-2: Analyze and interpret data from maps to describe patterns of Earth’s features. [Clarification Statement: Maps can include topographic maps of Earth’s land and ocean floor, as well as maps of the locations of mountains, continental boundaries, volcanoes, and earthquakes.] MS-ESS2-2: Construct an explanation based on evidence for how geoscience processes have changed Earth's surface at varying time and spatial scales. [Clarification Statement: Emphasis is on how processes change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges) or small (such as rapid landslides or microscopic geochemical reactions), and how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events. Examples of geoscience processes include surface weathering and deposition by the movements of water, ice, and wind. Emphasis is on geoscience processes that shape local geographic features, where appropriate.] HS-ESS2-1: Develop a model to illustrate how Earth’s internal and surface processes operate at different spatial and temporal scales to form continental and ocean-floor features. [Clarification Statement: Emphasis is on how the appearance of land features (such as mountains, valleys, and plateaus) and sea-floor features (such as trenches, ridges, and seamounts) are a result of both constructive forces (such as volcanism, tectonic uplift, and orogeny) and destructive mechanisms (such as weathering, mass wasting, and coastal erosion).] [Assessment Boundary: Assessment does not include memorization of the details of the formation of specific geographic features of Earth’s surface.] HS-ESS2-2: Analyze geoscience data to make the claim that one change to Earth's surface can create feedbacks that cause changes to other Earth systems. [Clarification Statement: Examples should include climate feedbacks, such as how an increase in greenhouse gases causes a rise in global temperatures that melts glacial ice, which reduces the amount of sunlight reflected from Earth's surface, increasing surface temperatures and further reducing the amount of ice. Examples could also be taken from other system interactions, such as how the loss of ground vegetation causes an increase in water runoff and soil erosion; how dammed rivers increase groundwater recharge, decrease sediment transport, and increase coastal erosion; or how the loss of wetlands causes a decrease in local humidity that further reduces the wetland extent.] HS-ESS2-5: Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes. [Clarification Statement: Emphasis is on mechanical and chemical investigations with water and a variety of solid materials to provide the evidence for connections between the hydrologic cycle and system interactions commonly known as the rock cycle. Examples of mechanical investigations include stream transportation and deposition using a stream table, erosion using variations in soil moisture content, or frost wedging by the expansion of water as it freezes. Examples of chemical investigations include chemical weathering and recrystallization (by testing the solubility of different materials) or melt generation (by examining how water lowers the melting temperature of most solids).] Resources An Introduction to the Ice Age Floods – Ice Age Floods Institute. (2020). Retrieved May 13, 2020, from Iafi.org website: https://iafi.org/about-the-ice-age-floods/introduction/ NOVA \| Mystery of the Megaflood \| Explore the Scablands (non-Flash) \| PBS. (2020). Retrieved May 13, 2020, from Pbs.org website: https://www.pbs.org/wgbh/nova/megaflood/scab-nf.html Glacial Lake Missoula and the Ice Age Floods. (2020). Retrieved May 13, 2020, from Glaciallakemissoula.org website: http://www.glaciallakemissoula.org/story.html Ice Age Floods-Discover Glacial Lake Missoula and Lake Bonneville. (2015, November 3). Retrieved May 13, 2020, from Hugefloods.com website: http://hugefloods.com/ Sculpted by Floods: The Northwest’s Ice Age Legacy \| PBS LearningMedia. (2020). Retrieved May 13, 2020, from PBS LearningMedia website: https://www.pbslearningmedia.org/resource/sculpted-by-floods-the-northwests-ice-age-legacy/sculpted-by-floods-the-northwests-ice-age-legacy/support-materials/ Fourth Grade Glaciers, Water and Wind, Oh My! - Activity. (2019, October 9). Retrieved May 13, 2020, from TeachEngineering.org website: https://www.teachengineering.org/activities/view/cub_earth_lesson5_activity1 Grade 4 - 4-ESS2 Earth’s Systems. (2020). Retrieved May 13, 2020, from Exploringnature.org website: https://www.exploringnature.org/db/view/Grade-4-4-ESS2-Earthrsquos-Systems Middle School Goldberg, A. (2013, November 15). AUTHENTIC LANDSCAPES INDOORS. Retrieved May 13, 2020, from Nsta.org website: http://digital.nsta.org/publication/?i=184198&article_id=1562453&view=articleBrowser&ver=html5 High School See Resources section above. Coyote’s Deal with the Wind (Spokane. Eastern WA) Coyote’s Deal with the Wind (Spokane. Eastern WA) This story shares about how the Wind would blow through the land and how Coyote set a trap to capture the Wind. Video Transcript Washington State Science Learning Standards 2-ESS2-1: Compare multiple solutions designed to slow or prevent wind or water from changing the shape of the land.* [Clarification Statement: Examples of solutions could include different designs of dikes and windbreaks to hold back wind and water, and different designs for using shrubs, grass, and trees to hold back the land.] 3-ESS2-1: Represent data in tables and graphical displays to describe typical weather conditions expected during a particular season. [Clarification Statement: Examples of data could include average temperature, precipitation, and wind direction.] [Assessment Boundary: Assessment of graphical displays is limited to pictographs and bar graphs. Assessment does not include climate change.] 4-ESS2-1: Make observations and/or measurements to provide evidence of the effects of weathering or the rate of erosion by water, ice, wind, or vegetation. [Clarification Statement: Examples of variables to test could include angle of slope in the downhill movement of water, amount of vegetation, speed of wind, relative rate of deposition, cycles of freezing and thawing of water, cycles of heating and cooling, and volume of water flow.] [Assessment Boundary: Assessment is limited to a single form of weathering or erosion.] MS-ESS2-5: Collect data to provide evidence for how the motions and complex interactions of air masses result in changes in weather conditions. [Clarification Statement: Emphasis is on how air masses flow from regions of high pressure to low pressure, causing weather (defined by temperature, pressure, humidity, precipitation, and wind) at a fixed location to change over time, and how sudden changes in weather can result when different air masses collide. Emphasis is on how weather can be predicted within probabilistic ranges. Examples of data can be provided to students (such as weather maps, diagrams, and visualizations) or obtained through laboratory experiments (such as with condensation).] [Assessment Boundary: Assessment does not include recalling the names of cloud types or weather symbols used on weather maps or the reported diagrams from weather stations.] MS-ESS2-6: Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates. [Clarification Statement: Emphasis is on how patterns vary by latitude, altitude, and geographic land distribution. Emphasis of atmospheric circulation is on the sunlight-driven latitudinal banding, the Coriolis effect, and resulting prevailing winds; emphasis of ocean circulation is on the transfer of heat by the global ocean convection cycle, which is constrained by the Coriolis effect and the outlines of continents. Examples of models can be diagrams, maps and globes, or digital representations.] [Assessment Boundary: Assessment does not include the dynamics of the Coriolis effect.] Second Grade Collins, M. (2015, June). Preventing Wind Erosion. Retrieved May 13, 2020, from BetterLesson website: https://betterlesson.com/lesson/637474/preventing-wind-erosion?from=search_results Faber, J. (2015, June 15). How Can Wind Change the Shape of the Land? Retrieved May 13, 2020, from BetterLesson website: https://betterlesson.com/lesson/632923/how-can-wind-change-the-shape-of-the-land Third Grade Espin, M. (2015, March 2). Which Way Does The Wind Blow? A Weather Vane Can Show You! Retrieved May 13, 2020, from BetterLesson website: https://betterlesson.com/lesson/635186/which-way-does-the-wind-blow-a-weather-vane-can-show-you?from=cc_lesson STEM: Weather. (2013). Retrieved May 13, 2020, from Thinkport.org website: http://weather.thinkport.org/home.html Fourth Grade Experiment: Demonstrating Wind Erosion. (n.d.). Retrieved from https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs141p2_035714.pdf Middle School Tornado Alley! (Middle School NGSS Unit) https://www.oercommons.org/authoring/28983-tornado-alley-middle-school-ngss-unit How Fire Came to Earth (All tribes, Eastern WA) How Fire Came to Earth (All tribes, Eastern WA)) This story shares how the animals went to the Sky World to get fire. Video Transcript Washington State Science Learning Standards 5-PS1-3: Make observations and measurements to identify materials based on their properties. [Clarification Statement: Examples of materials to be identified could include baking soda and other powders, metals, minerals, and liquids. Examples of properties could include color, hardness, reflectivity, electrical conductivity, thermal conductivity, response to magnetic forces, and solubility; density is not intended as an identifiable property.] [Assessment Boundary: Assessment does not include density or distinguishing mass and weight.] MS-PS1-2: Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred. [Clarification Statement: Examples of reactions could include burning sugar or steel wool, fat reacting with sodium hydroxide, and mixing zinc with hydrogen chloride.] [Assessment boundary: Assessment is limited to analysis of the following properties: density, melting point, boiling point, solubility, flammability, and odor.] Fifth Grade Mystery Powders. (2018). Retrieved May 13, 2020, from Uen.org website: https://www.uen.org/lessonplan/view/2176 Middle School What’s This Stuff? \| PBS LearningMedia. (2020). Retrieved May 13, 2020, from PBS LearningMedia website: https://www.pbslearningmedia.org/resource/nvms.sci.phys.matter.makingstuff/whats-this-stuff/	oercommons	2025-03-18T00:37:15.964811	Environmental Science	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/65713/overview", "title": "Native American Stories Science Connections", "author": "Elementary Education" }
https://oercommons.org/courseware/lesson/55424/overview	Diversity and Cultural Competency Overview Diversity: the art of thinking independently together. —Malcolm Forbes, entrepreneur, founder of Forbes magazine LEARNING OBJECTIVES By the end of this section, you will be able to: - Define diversity and identify many aspects of diversity - Differentiate between surface diversity and deep diversity, and explain the relationship between the two - Define and apply principles of cultural competency - Explore the positive effects of diversity in an educational setting Diversity and Cultural Competency Diversity and Cultural Competency Introduction Cultural diversity is found everywhere in college, and it should be respected, appreciated, and celebrated. To be successful as a college student, it is critical that you understand and can describe your own diverse background. Being self-aware allows you to identify what makes you who you are while recognizing the differences that exist between you, other students, your professors, and all the members of a campus community. This section will discuss the factors that make up a person’s culture and how one can effectively communicate and work with people who may be different. You will also learn about aspects of a college culture in order to successfully navigate this new world. Diversity: the art of thinking independently together. —Malcolm Forbes, entrepreneur, founder of Forbes magazine What Is Diversity? There are few words in the English language that have more diverse interpretations than diversity. What does diversity mean? Better yet—what does diversity mean to you? And what does it mean to your best friend, your teacher, your parents, your religious leader, or the person standing behind you in a grocery store? For each of us, diversity has unique meaning. Below are a few of the many definitions offered by college students at a 2010 conference on the topic of diversity. Which of these definitions rings out to you as most accurate and thoughtful? Which definitions could use some embellishment or clarification, in your opinion? Diversity is a group of people who are different in the same place. Diversity to me is the ability for differences to coexist together, with some type of mutual understanding or acceptance present. Acceptance of different viewpoints is key. Tolerance of thought, ideas, people with differing viewpoints, backgrounds, and life experiences. Anything that sets one individual apart from another. People with different opinions, backgrounds (degrees and social experience), religious beliefs, political beliefs, sexual orientations, heritage, and life experience. Dissimilar Having a multitude of people from different backgrounds and cultures together in the same environment working for the same goals. Difference in students’ background, especially race and gender. Differences in characteristics of humans. Diversity is a satisfying mix of ideas, cultures, races, genders, economic statuses and other characteristics necessary for promoting growth and learning among a group. Diversity is the immersion and comprehensive integration of various cultures, experiences, and people. Heterogeneity brings about opportunities to share, learn and grow from the journeys of others. Without it, limitations arise and knowledge is gained in the absence of understanding. Diversity is not tolerance for difference but inclusion of those who are not the majority. It should not be measured as a count or a fraction—that is somehow demeaning. Success at maintaining diversity would be when we no longer ask if we are diverse enough, because it has become the norm, not remarkable.[1] Diversity means different things to people, and it can be understood differently in different environments. In the context of your college experience, diversity generally refers to people around you who differ by race, culture, ethnicity, religion, socioeconomic status, sexual orientation, abilities, opinions, political views, and in other ways. When it comes to diversity on the college campus, we also think about how groups interact with one another, given their differences (even if they are just perceived differences.) How do diverse populations experience and explore their relationships? “More and more organizations define diversity really broadly,” says Eric Peterson, who works on diversity issues for the Society for Human Resource Management (SHRM). “Really, it’s any way any group of people can differ significantly from another group of people—appearance, sexual orientation, veteran status, your level in the organization. It has moved far beyond the legally protected categories that we’ve always looked at.”[2] These are just some of the types of diversity you are likely to encounter on college campuses and in our society generally. In the following video, students from Juniata College describe what diversity means to them and explain why it’s an important aspect of their college experience. Surface Diversity and Deep Diversity Surface diversity and deep diversity are categories of personal attributes—or differences in attributes—that people perceive to exist between people or groups of people. Surface-level diversity refers to differences you can generally observe in others, like ethnicity, race, gender, age, culture, language, disability, etc. You can quickly and easily observe these features in a person. And people often do just that, making subtle judgments at the same time, which can lead to bias or discrimination. For example, if a teacher believes that older students perform better than younger students, she may give slightly higher grades to the older students than the younger students. This bias is based on a perception of the attribute of age, which is surface-level diversity. Deep-level diversity, on the other hand, reflects differences that are less visible, like personality, attitude, beliefs, and values. These attributes are generally communicated verbally and non-verbally, so they are not easily noticeable or measurable. You may not detect deep-level diversity in a classmate, for example, until you get to know him or her, at which point you may find that you are either comfortable with these deeper character levels, or perhaps not. But once you gain this deeper level of awareness, you may focus less on surface diversity. For example, at the beginning of a term, a classmate belonging to a minority ethnic group whose native language is not English (surface diversity) may be treated differently by fellow classmates in another ethnic group. But as the term gets underway, classmates begin discovering the person’s values and beliefs (deep-level diversity), which they find they are comfortable with. The surface-level attributes of language and perhaps skin color become more “transparent” (less noticeable) as comfort is gained with deep-level attributes. The following video is a quick summary of the differences between surface-level and deep-level diversity. (link: http://bit.ly/C20SurfaceDeepDiv) As we’ll use the term here, diversity refers to the great variety of human characteristics—ways that we are different even as we are all human and share more similarities than differences. These differences are an essential part of what enriches humanity. Aspects of diversity may be cultural, biological, or personal in nature. Diversity generally involves things that may significantly affect some people’s perceptions of others—not just any way people happen to be different. For example, having different tastes in music, movies, or books is not what we usually refer to as diversity. When discussing diversity, it is often difficult to avoid seeming to generalize about different types of people—and such generalizations can seem similar to dangerous stereotypes. The following descriptions are meant only to suggest that individuals are different from other individuals in many possible ways and that we can all learn things from people whose ideas, beliefs, attitudes, values, backgrounds, experiences, and behaviors are different from our own. This is a primary reason college admissions departments frequently seek diversity in the student body. Following are various aspects of diversity: - Race: Race refers to what we generally think of as biological differences and is often defined by what some think of as skin color. Such perceptions are often at least as much social as they are biological. - Ethnicity: Ethnicity is a cultural distinction that is different from race. Ethnic groups share a common identity and a perceived cultural heritage that often involves shared ways of speaking and behaving, religion, traditions, and other traits. The term “ethnic” also refers to such a group that is a minority within the larger society. Race and ethnicity are sometimes interrelated but not automatically so. - Cultural background: Culture, like ethnicity, refers to shared characteristics, language, beliefs, behaviors, and identity. We are all influenced by our culture to some extent. While ethnic groups are typically smaller groups within a larger society, the larger society itself is often called the “dominant culture.” The term is often used rather loosely to refer to any group with identifiable shared characteristics. - Educational background: Colleges do not use a cookie-cutter approach to admit only students with identical academic skills. A diversity of educational background helps ensure a free flow of ideas and challenges those who might become set in their ways. - Geography: People from different places within the United States or the world often have a range of differences in ideas, attitudes, and behaviors. - Socioeconomic background: People’s identities are influenced by how they grow up, and part of that background involves socioeconomic factors. Socioeconomic diversity can contribute to a wide variety of ideas and attitudes. - Gender roles: Women hold virtually all professional and social roles, including those once dominated by men, and men have taken on many roles, such as raising a child, that were formerly occupied mostly by women. These changing roles have brought diverse new ideas and attitudes to college campuses. - Gender identity: Gender identity is one’s personal experience of one’s own gender. Gender identity can correlate with the sex at birth – male or female, or can differ from it completely: males may identify as female or vice versa, or a person may identify as a third gender or as falling somewhere along the continuum between male and female. - Age: While younger students attending college immediately after high school are generally within the same age range, older students returning to school bring a diversity of age. Because they often have broader life experiences, many older students bring different ideas and attitudes to the campus. - Sexual orientation: Gays and lesbians make up a significant percentage of people in American society and students on college campuses. Exposure to this diversity helps others overcome stereotypes and become more accepting of human differences. - Religion: For many people, religion is not just a Sunday morning practice but a larger spiritual force that infuses their lives. Religion helps shape different ways of thinking and behaving. - Political views: A diversity of political views helps broaden the level of discourse on campuses concerning current events and the roles of government and leadership at all levels. - Physical ability: Some students have athletic talents. Some students have physical disabilities. Physical differences among students bring yet another kind of diversity to colleges—a diversity that both widens opportunities for a college education and also helps all students better understand how people relate to the world in physical as well as intellectual ways. Cultural Competency As a college student, you are likely to find yourself in diverse classrooms, organizations, and – eventually – workplaces. It is important to prepare yourself to be able to adapt to diverse environments. Cultural competency can be defined as the ability to recognize and adapt to cultural differences and similarities. It involves “(a) the cultivation of deep cultural self-awareness and understanding (i.e., how one’s own beliefs, values, perceptions, interpretations, judgments, and behaviors are influenced by one’s cultural community or communities) and (b) increased cultural other-understanding (i.e., comprehension of the different ways people from other cultural groups make sense of and respond to the presence of cultural differences).”1 In other words, cultural competency requires you to be aware of your own cultural practices, values, and experiences, and to be able to read, interpret, and respond to those of others. Such awareness will help you successfully navigate the cultural differences you will encounter in diverse environments. Cultural competency is critical to working and building relationships with people from different cultures; it is so critical, in fact, that it is now one of the most highly desired skills in the modern workforce.2 In the following video, representatives from Rutgers University Behavioral Health Care elaborate on the concept of cultural competency: We don’t automatically understand differences among people and celebrate the value of those differences. Cultural competency is a skill that you can learn and improve upon over time and with practice. What actions can you take to build your cultural competency skills? KEY TAKEAWAYS - Diversity refers to a great variety of human characteristics and ways in which people differ. - Surface-level diversity refers to characteristics you can easily observe, while deep-level diversity refers to attributes that are not visible and must be communicated in order to understand. - Cultural competency is the ability to recognize and adapt to cultural differences and similarities. - Diverse environments expose you to new perspectives and can help deepen your learning. - Bennett, J. M. (2015). "Intercultural Competence Development." The SAGE Encyclopedia of Intercultural Competence. Thousand Oaks, CA: SAGE Publications, Inc. - Bennett, J. M. (2015). "Intercultural Competence Development." The SAGE Encyclopedia of Intercultural Competence. Thousand Oaks, CA: SAGE Publications, Inc. - "10 Reasons Why We Need Diversity on College Campuses." Center for American Progress. 2016. Web. 2 Feb 2016. ACTIVITY: DEVELOPING YOUR CULTURAL COMPETENCY Objective - Define and apply principles of cultural competency Instructions This activity will help you examine ways in which you can develop your awareness of and commitment to diversity on campus. Answer the following questions to the best of your ability: - What are my plans for expanding myself personally and intellectually in college? - What kind of community will help me expand most fully, with diversity as a factor in my expansion? - What are my comfort zones, and how might I expand them to connect with more diverse groups? - Do I want to be challenged by new viewpoints, or will I feel more comfortable connecting with people who are like me? - What are my biggest questions about diversity? - Submit this assignment according to directions from your instructor. Consider the following strategies to help you answer the questions: - Examine extracurricular activities. Can you get involved with clubs or organizations that promote and expand diversity? - Review your college’s curriculum. In what ways does it reflect diversity? Does it have departments and courses on historically unrepresented peoples, e.g., cultural and ethnic studies, and gender and sexuality studies. Look for study-abroad programs, as well. - Read your college’s mission statement. Read the mission statement of other colleges. How do they match up with your values and beliefs? How do they align with the value of diversity? - Inquire with friends, faculty, colleagues, family. Be open about diversity. What does it mean to others? What positive effects has it had on them? Ask people about diversity. - Research can help. You might consult college literature, Web sites, resource centers and organizations on campus, etc. LICENSES AND ATTRIBUTIONS LICENSES AND ATTRIBUTIONS CC LICENSED CONTENT, ORIGINAL - Diversity and Cultural Competency. Authored by: Laura Lucas. Provided by: Austin Community College. License: CC BY: Attribution CC LICENSED CONTENT, SPECIFIC ATTRIBUTION - Chapter cover image. Authored by: maxlkt. Provided by: Pixabay. Located at: https://pixabay.com/en/hand-united-hands-united-together-1917895/. License: CC0: No Rights Reserved - Gender Identity. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Gender_identity. License: CC BY-SA: Attribution-ShareAlike - 9.2 Living with Diversity. Provided by: University of Minnesota Libraries. Located at: http://open.lib.umn.edu/collegesuccess/chapter/9-2-living-with-diversity/. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike ALL RIGHTS RESERVED CONTENT - Cultural Competency at Rutgers University Behavioral Health Care. Provided by: UBHC Production Studio. Located at: https://www.youtube.com/watch?v=c-h1ZuRXBpg. License: All Rights Reserved. License Terms: Standard YouTube License LUMEN LEARNING AUTHORED CONTENT - Diversity and Accessibility. Located at: https://courses.lumenlearning.com/collegesuccess-lumen/chapter/diversity-and-accessibility/. License: CC BY: Attribution	oercommons	2025-03-18T00:37:16.068284	Daniella Washington	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/55424/overview", "title": "Diversity and Cultural Competency", "author": "Module" }
https://oercommons.org/courseware/lesson/98096/overview	Service-Learning Manual Overview Resource for teachers and students in programs that require service-learning. Service-Learning Manual Walters State Community College Service-Learning Manual For Intro to Social Work Dr. Angie Elkins Service-Learning Service-learning is a teaching strategy that uses meaningful community service, combined with guided reflections, to enrich and enhance student learning. Service-learning incorporates two fundamental components: SERVICE, a project that meets an identifiable community need; and LEARNING, classroom activities and reflection which connect the service project to the academic curriculum. What exactly is service-learning? Service-learning is a blending of academic study and community service. Academic credit is given for the actual learning that occurs during the volunteering and not just for the clock hours of service to the community. Students can choose to be placed in one of many available non profit agencies, educational sites, and government offices. They are then given specific assignments, based on both an academic learning plan and the specific need of the community site. Service-learning is, therefore, an effort to promote the fact that much learning takes place when we can connect classroom instruction to real-life situations. Furthermore, emphasis is placed on linking what students are doing at their individual sites with broader community issues and involvement. What is the difference between service-learning, volunteerism, and internships? Service-Learning There are a number of core requirements that students have to meet before they can be given credit for these classes and/or projects. These requirements ensure that students reflect upon what they are doing and evaluate what they are learning. Volunteering Volunteering is a worthwhile activity, but we generally do not learn from our volunteering in the same way, nor do we connect it to classroom instruction and academic course content. Internships Internships place little or no emphasis on the student providing service to the site, whereas service-learning emphasizes the student making a contribution to the community while the student uses the site as a vehicle for learning. How do I demonstrate what I am learning and how am I graded? You demonstrate what you are learning by what you write in your reflective journal, your verbal exchanges with your faculty supervisor, and your final analytical paper. Each participating faculty supervisor will tell you ahead of time what their basic requirements are for a specific grade. Student responsibilities to agencies - To be open and honest at your site from the beginning - To participate in any training that is required by the particular agency - To respect confidentiality - Maintain professionalism: observe dress codes, report on time, avoid gossip, etc... - To understand commitments of time and task and to fulfill them - To seek honest feedback - If in doubt, seek advice - To accept guidance and direction when they are offered - To enter into service with enthusiasm and commitment - To be considerate of the agency, your supervisor, other volunteers and staff, and any clients that the agency serves - To be effective advocates for change as needed - To utilize all your talents and experiences in order to do a good job for the agency Guidelines for reflective journals As a student in Intro to Social Work, you will be required to complete 15 weekly journals related to your service-learning experience through the class discussion boards. Journals do not have a length requirement but your response should fully answer the writing prompt and show connection to your service-learning experience and/or the materials covered in class. You must reply to at least one classmate for each journal and connect your response to the service-learning experience and/or materials covered in class. Keeping a reflective journal Keeping a journal is an excellent way for you to reconstruct, reflect on, and think about your involvement experience. Processing your service through your perceptions and emotions helps you to gain insight into what you are experiencing and how you are feeling about it. A journal also serves as a useful record of your service and learning. To be most effective, a journal should not just be a log of events. It should be a way for you to analyze the activities you are engaged in and the new things you are learning, to note important events, and to relate your objectives and goals to what you are learning and doing. This journal involves weekly writing prompts designed to create conversation about the experiences you have during your service-learning and relate it back to the materials covered in the classroom. Each week you will be required to fully respond to the writing prompt and reply to at least one other student. Both posts should connect the writing prompt to the service-learning and/or the course materials. Guidelines for writing an analytical paper Your final paper for this class is an analytical paper related to your service-learning. This paper is a minimum of 3 pages. The outline below is a starting point. You do not have to answer all the questions as they may not apply to you or your organization. However, please include the three sections. - Part 1: Description (approximately 1 page) - What were your duties and responsibilities? - What was your work situation and environment? - What are the goals of the agency? - What skills did you acquire as a result of your service-learning experience? - How did the service-learning experience evolve and change during the semester? - Part 2: Evaluation (approximately 1 - 2 pages) - What does service mean in your life? - What impact do you feel you had on the community? - What are the community needs? - What did you learn: - From your service-learning experience? - About the agency you worked in, the supervisor/s you worked for, the responsibilities of this office/supervisor? - About the strengths and limitations of this site in carrying out its responsibilities to the community? - About the experience of working in an agency/school/government setting? - About yourself - your own strengths and limitations; about how this experience affected your own personal goals and career objectives? - How could you improve the quality of your service? - If you were in charge of the place where you volunteer, what would you do to improve it? Would you have the volunteers do anything different from what you are doing? Would you treat them differently? - Part 3: Integration (approximately 1 - 2 pages) - How has the service-learning experience changed what you thought you knew about local schools, government offices, community service agencies, or special interest groups? - How has your experience affected your evaluation of our political system/society? - Has this service-learning experience helped you to develop a sense of civic responsibility? (i.e. more insight into social/public policy formation and legislation, and how to advocate to make a difference). Give examples. - What specific problem(s) or issue(s) did you encounter during your service learning experience that either broadened your interest in our political/social system or increased your awareness of connections between community needs and policy formation? - How has your experience affected your educational goals? - How would you change the service-learning experience to make it a more valuable learning experience? - Were there any conflicts between your service responsibilities and learning objectives? - Does race and socio-economic background affect the service you are doing? For example, who “does” service - in terms of ethnicity/race and socio-economic background? Do different groups have different reasons for doing service? - Why is service predominantly done by females, by humanities not science majors? How can these tendencies be changed? - How do those persons in the community, who are being served, perceive you and/or the site you represent? - Does your site conduct needs assessments to establish community needs? - How has this experience helped you to integrate knowledge gained in the classroom? - Relate your experience to the materials covered in the classroom - what connections did you see? Service-learning forms These forms must be completed and turned in BEFORE you begin your service-learning. - Complete your service-learning application here: Application - Print and sign your Release/Hold Harmless agreement form and submit a photograph or scan of the form in the appropriate dropbox. - Print your Referral Confirmation Form, take it to your agency and complete it with your agency supervisor. Submit a photograph or scan of the form in the appropriate dropbox. - Print your Volunteer Placement Agreement, take it to your agency and have your agency supervisor complete it. Submit a photograph or scan of the form in the appropriate dropbox. Use this log to keep track of your hours as you complete your service-learning. This form must be completed by your supervisor AFTER you complete your service-learning. - Print this form Final Student Evaluation, give it to your agency supervisor and ask that they email it back to your professor. My email is listed at the top of the page. Note: This form must come directly from your supervisor to your professor.	oercommons	2025-03-18T00:37:16.093773	Assessment	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/98096/overview", "title": "Service-Learning Manual", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/116479/overview	Decoding Emotions in Ourselves and Others Overview Clil Didactic Sequence: Decoding Emotions in Ourselves and Others_ Highschool Learning Objectives: - Students will be able to identify and name basic emotions. - Students will be able to describe the physiological and behavioral changes associated with emotions. - Students will be able to recognize emotions in facial expressions, body language, and tone of voice. - Students will be able to analyze the influence of emotions on thoughts and actions. - Students will be able to develop strategies for managing emotions effectively. Sequence of Activities: Unit 1: The Emotional Landscape (2 sessions) - CLIL Standards: Science (Biology) - English Standards: Reading comprehension, vocabulary development - ICT Standards: Online research, multimedia presentations Activities: - Brainstorming: Begin by asking students to brainstorm a list of emotions they experience. Write these on the board and categorize them (positive, negative, neutral). Discuss the universality of emotions and how they are expressed across cultures. - Emotional Rollercoaster: Divide the class into small groups and assign each group a different emotion (e.g., joy, anger, fear). Students research the physiological changes associated with their assigned emotion (increased heart rate, sweating, etc.) and create a short skit or multimedia presentation demonstrating these changes. - "Feeling Faces" Activity: Present students with high-quality images depicting various facial expressions (https://greatergood.berkeley.edu/quizzes/ei_quiz). Ask them to identify the emotions conveyed and discuss the role of facial expressions in nonverbal communication. Unit 2: Emotional Intelligence (2 sessions) - CLIL Standards: Psychology - English Standards: Critical thinking, persuasive writing - ICT Standards: Online discussions, data analysis tools (optional) Activities: - The EQ Test: Introduce the concept of emotional intelligence (EQ) and its importance in personal and social interactions. Students can take an online EQ quiz (there are many free options available) to gain insights into their own emotional strengths and weaknesses. Facilitate a class discussion on the importance of developing EQ. - Emotional Regulation Strategies: Students research and discuss various strategies for managing emotions effectively (e.g., deep breathing, relaxation techniques, positive self-talk). Encourage them to create a personalized "emotional toolbox" with strategies they find helpful. - Persuasive Writing: Students write a persuasive essay arguing for the importance of emotional intelligence in achieving success in a chosen field (e.g., business, healthcare, arts). Unit 3: Emotions in Literature (2 sessions) - CLIL Standards: Literature - English Standards: Literary analysis, character development - ICT Standards: Online literature resources, multimedia presentations (optional) Activities: - Literary Detectives: Students select a short story or poem (ensure it is age-appropriate) rich in emotional content. As a class, analyze the characters' emotions, how they are expressed in the text (figurative language, word choice), and the impact of emotions on the plot. - Character Portrayals: Divide the class into pairs. Each pair selects a scene from the chosen literary work where emotions play a key role. Students create a short role-play depicting the scene, focusing on accurately portraying the characters' emotions through dialogue, facial expressions, and body language. Assessment: - Participation in class discussions and activities - Presentations and skits created by students - EQ quiz results (optional) - Persuasive essay - Literary analysis assignments Resources: - Greater Good Science Center at UC Berkeley: https://greatergood.berkeley.edu/ - National Institute of Mental Health: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749626/ - LearningRX: https://psychcentral.com/health/ways-to-manage-your-emotions - Project Happiness: https://projecthappiness.org/ Differentiation: - Provide students with graphic organizers or templates to support vocabulary development and note-taking. - Offer alternative assignments for students who struggle with writing, such as creating visual representations of emotions. - Allow students to choose literary works that resonate with their interests.	oercommons	2025-03-18T00:37:16.111210	05/30/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/116479/overview", "title": "Decoding Emotions in Ourselves and Others", "author": "Gabriela Andrade" }
https://oercommons.org/courseware/lesson/15391/overview	Introduction What comes to mind when you think about therapy for psychological problems? You might picture someone lying on a couch talking about his childhood while the therapist sits and takes notes, à la Sigmund Freud. But can you envision a therapy session in which someone is wearing virtual reality headgear to conquer a fear of snakes? In this chapter, you will see that approaches to therapy include both psychological and biological interventions, all with the goal of alleviating distress. Because psychological problems can originate from various sources—biology, genetics, childhood experiences, conditioning, and sociocultural influences—psychologists have developed many different therapeutic techniques and approaches. The Ocean Therapy program shown in Figure uses multiple approaches to support the mental health of veterans in the group. References Abbass, A., Kisely, S., & Kroenke, K. (2006). Short-term psychodynamic psychotherapy for somatic disorders: Systematic review and meta-analysis of clinical trials. Psychotherapy and Psychosomatics, 78, 265–274. Ahmed, S., Wilson, K. B., Henriksen, R. C., & Jones, J. W. (2011). What does it mean to be a culturally competent counselor? Journal for Social Action in Counseling and Psychology, 3(1), 17–28. Alavi, A., Sharifi, B., Ghanizadeh, A., & Dehbozorgi, G. (2013). Effectiveness of cognitive-behavioral therapy in decreasing suicidal ideation and hopelessness of the adolescents with previous suicidal attempts. Iranian Journal of Pediatrics, 23(4), 467–472. Alegría, M., Chatterji, P., Wells, K., Cao, Z., Chen, C. N., Takeuchi, D., . . . Meng, X. L. (2008). Disparity in depression treatment among racial and ethnic minority populations in the United States. Psychiatric Services, 59(11), 1264–1272. American Psychological Association. (2005). Policy statement on evidence-based practice in psychology. Retrieved from http://www.apapracticecentral.org/ce/courses/ebpstatement.pdf American Psychological Association. (2014). Can psychologists prescribe medications for their patients? Retrieved from http://www.apa.org/news/press/releases/2004/05/louisiana-rx.aspx American Psychological Association. (2014). Psychotherapy: Understanding group therapy. Retrieved from http://www.apa.org/helpcenter/group-therapy.aspx Beck, A. T., Rush, A. J., Shaw, B. F., & Emery, G. (1979). Cognitive therapy of depression. New York, NY: The Guilford Press. Beck Institute for Cognitive Behavior Therapy. (n.d.). History of cognitive therapy. Retrieved from http://www.beckinstitute.org/history-of-cbt/ Beck, J. S. (2011). Cognitive behavior therapy: Basics and beyond (2nd ed.). New York, NY: The Guilford Press. Belgrave, F., & Allison, K. (2010). African-American psychology: From Africa to America (2nd ed.). Thousand Oaks, CA: Sage Publications. Bertrand, K., Richer, I., Brunelle, N., Beaudoin, I., Lemieux, A., & Ménard, J-M. (2013). Substance abuse treatment for adolescents: How are family factors related to substance use change? Journal of Psychoactive Drugs, 45(1), 28–38. Blank, M. B., Mahmood, M., Fox, J. C., & Guterbock, T. (2002). Alternative mental health services: The role of the black church in the South. American Journal of Public Health, 92, 1668–1672. Blumberg, J. (2007, October 24). A brief history of the Salem witch trials. Smithsonian.com. Retrieved from http://www.smithsonianmag.com/history-archaeology/brief-salem.html?c=y&page=2 Butlera, A. C., Chapmanb, J. E., Formanc, E. M., & Becka, A. T. (2006). The empirical status of cognitive-behavioral therapy: A review of meta-analyses. Clinical Psychology Review, 26,17–31. Center for Substance Abuse Treatment. (2005). Substance Abuse Treatment: Group Therapy. Treatment Improvement Protocol (TIP) Series 41. DHHS Publication No. (SMA) 05-3991. Rockville, MD: Substance Abuse and Mental Health Services Administration. Centers for Disease Control and Prevention. (2014). Suicide prevention: Youth suicide. Retrieved from http://www.cdc.gov/violenceprevention/pub/youth_suicide.html Chambless, D. L., & Ollendick, T. H. (2001). Empirically supported psychological interventions: Controversies and evidence. Annual Review of Psychology, 52, 685–716. Charman, D., & Barkham, M. (2005). Psychological treatments: Evidence-based practice and practice-based evidence. InPsych Highlights. Retrieved from www.psychology.org.au/publications/inpsych/treatments Chorpita, B. F., Daleiden, E. L., Ebesutani, C., Young, J., Becker, K. D., Nakamura, B. J., . . . Starace, N. (2011), Evidence-based treatments for children and adolescents: An updated review of indicators of efficacy and effectiveness. Clinical Psychology: Science and Practice, 18, 154–172. Clement, S., Schauman, O., Graham, T., Maggioni, F., Evans-Lacko, S., Bezborodovs, N., . . . Thornicroft, G. (2014, February 25). What is the impact of mental health-related stigma on help-seeking? A systematic review of quantitative and qualitative studies. Psychological Medicine, l–17. Daniel, D. (n.d.). Rational emotive in behavior therapy the context of modern psychlogical research. Retrieved from albertellis.org/rebt-in-the-context-of-modern-psychological-research Davidson, W. S. (1974). Studies of aversive conditioning for alcoholics: A critical review of theory and research methodology. Psychological Bulletin, 81(9), 571–581. DeRubeis, R. J., Hollon, S. D., Amsterdam, J. D., Shelton, R. C., Young, P. R., Salomon, R. M., . . . Gallop, R. (2005). Cognitive Therapy vs medications in the treatment of moderate to severe depression. Archives of General Psychiatry, 62(4), 409–416. DeYoung, S. H. (2013, November 14). The woman who raised that monster [Web log post]. Retrieved from http://www.huffingtonpost.com/suzy-hayman-deyoung/the-woman-who-raised-that_b_4266621.html Dickerson, F. B., Tenhula, W. N., & Green-Paden, L. D. (2005). The token economy for schizophrenia: Review of the literature and recommendations for future research. Schizophrenia Research, 75(2), 405–416. Donahue, A. B. (2000). Electroconvulsive therapy and memory loss: A personal journey. The Journal of ECT, 162, 133–143. Elkins, R. L. (1991). An appraisal of chemical aversion (emetic therapy) approaches to alcoholism treatment. Behavior Research and Therapy, 29(5), 387–413. Gary, F. A. (2005). Stigma: Barrier to mental health care among ethnic minorities. Issues in Mental Health Nursing, 26(10), 979–999. Gerardi, M., Cukor, J., Difede, J., Rizzo, A., & Rothbaum, B. O. (2010). Virtual reality exposure therapy for post-traumatic stress disorder and other anxiety disorders. Current Psychiatry Reports, 12(298), 299–305. Harter, S. (1977). A cognitive-developmental approach to children's expression of conflicting feelings and a technique to facilitate such expression in play therapy. Journal of Consulting and Clinical Psychology, 45(3), 417–432. Hemphill, R. E. (1966). Historical witchcraft and psychiatric illness in Western Europe. Proceedings of the Royal Society of Medicine, 59(9), 891–902. Ivey, S. L., Scheffler, R., & Zazzali, J. L. (1998). Supply dynamics of the mental health workforce: Implications for health policy. Milbank Quarterly, 76(1), 25–58. Jang, Y., Chiriboga, D. A., & Okazaki, S. (2009). Attitudes toward mental health services: Age group differences in Korean American adults. Aging & Mental Health, 13(1), 127–134. Jones, M. C. (1924). A laboratory study of fear: The case of Peter. Pedagogical Seminary, 31, 308–315. Kalff, D. M. (1991). Introduction to sandplay therapy. Journal of Sandplay Therapy, 1(1), 9. Leblanc, M., & Ritchie, M. (2001). A meta-analysis of play therapy outcomes. Counselling Psychology Quarterly, 14(2), 149–163. Lovaas, O. I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting & Clinical Psychology, 55, 3–9. Lovaas, O. I. (2003). Teaching individuals with developmental delays: Basic intervention techniques. Austin, TX: Pro-Ed. Lowinger, R. J., & Rombom, H. (2012). The effectiveness of cognitive behavioral therapy for PTSD in New York City Transit Workers. North American Journal of Psychology, 14(3), 471–484. Madanes, C. (1991). Strategic family therapy. In A. S. Gurman and D. P. Kniskern (Eds.), Handbook of Family Therapy, Vol. 2. (pp. 396–416). Philadelphia, PA: Brunner/Mazel. Marques, L., Alegría, M., Becker, A. E., Chen, C. N., Fang, A., Chosak, A., & Diniz, J. B. (2011). Comparative prevalence, correlates of impairment, and service utilization for eating disorders across US ethnic groups: Implications for reducing ethnic disparities in health care access for eating disorders. International Journal of Eating Disorders, 44(5), 412–420. Martin, B. (2007). In-Depth: Cognitive behavioral therapy. Retrieved from http://psychcentral.com/lib/in-depth-cognitive-behavioral-therapy/000907 Mayo Clinic. (2012). Tests and procedures: Transcranial magnetic stimulation. Retrieved from http://www.mayoclinic.org/tests-procedures/transcranial-magnetic-stimulation/basics/definition/PRC-20020555 McGovern, M. P., & Carroll, K. M. (2003). Evidence-based practices for substance use disorders. Psychiatric Clinics of North America, 26, 991–1010. McGrath, R. J., Cumming, G. F., Burchard, B. L., Zeoli, S., & Ellerby, L. (2009). Current practices and emerging trends in sexual abuser management: The safer society North American survey. Brandon, VT: The SaferSociety Press. McLellan, A. T., Lewis, D. C., O’Brien, C. P., & Kleber, H. D. (2000). Drug dependence, a chronic medical illness: Implications for treatment, insurance, and outcomes evaluation. JAMA, 284(13), 1689–1695. Minuchin, P. (1985). Families and individual development: Provocations from the field of family therapy. Child Development, 56(2), 289–302. Mullen, E. J., & Streiner, D. L. (2004). The evidence for and against evidence-based practice. Brief Treatment and Crisis Intervention, 4(2), 111–121. Muñoz-Cuevas, F. J., Athilingam, J., Piscopo, D., & Wilbrecht, L. (2013). Cocaine-induced structural plasticity in frontal cortex correlates with conditioned place preference. Nature Neuroscience, 16, 1367–1369. National Association of Cognitive-Behavioral Therapists. (2009). History of cognitive behavioral therapy. Retrieved from: http://nacbt.org/historyofcbt.htm. National Institute of Mental Health. (n.d.-a) Any disorder among children. Retrieved from http://www.nimh.nih.gov/statistics/1ANYDIS_CHILD.shtml National Institute of Mental Health. (n.d.-b) Use of mental health services and treatment among adults. Retrieved from http://www.nimh.nih.gov/statistics/3use_mt_adult.shtml National Institute of Mental Health. (n.d.-c). Use of mental health services and treatment among children. Retrieved from http://www.nimh.nih.gov/statistics/1NHANES.shtml National Institutes of Health. (2013, August 6). Important events in NIMH history. Retrieved from http://www.nih.gov/about/almanac/organization/NIMH.htm National Institute on Drug Abuse. (2008). Addiction science: From Molecules to managed care. Retrieved from http://www.drugabuse.gov/publications/addiction-science/relapse National Institute on Drug Abuse. (2011). Drug facts: Comorbidity: Addiction and other mental disorders. Retrieved from http://www.drugabuse.gov/publications/drugfacts/comorbidity-addiction-other-mental-disorders National Institute on Drug Abuse. (2012). Principles of drug addiction treatment: A research-based guide (3rd ed.). Retrieved from http://www.drugabuse.gov/publications/principles-drug-addiction-treatment-research-based-guide-third-edition/principles-effective-treatment Nelson, P. (1993). Autobiography in Five Short Chapters. In There’s a Hole in my Sidewalk: The Romance of Self-Discovery. Hillsboro, OR: Beyond Words Publishing. O’Connor, K. J. (2000). The play therapy primer (2nd ed.). New York, NY: Wiley. Page, R. C., & Berkow, D. N. (1994). Unstructured group therapy: Creating contact, choosing relationship. San Francisco, CA: Jossey Bass. Pagnin, D., de Queiroz, V., Pini, S., & Cassano, G. B. (2004). Efficacy of ECT in depression: A meta-analytic review. Journal of ECT, 20, 13–20. Prins, S. J., & Draper, L. (2009). Improving outcomes for people with mental illnesses under community corrections supervision: A guide to research-informed policy and practice. New York, NY: Council of State Governments Justice Center. Prochaska, J. O., & Norcross, J. C. (2010). Systems of psychotherapy (7th ed.). Belmont, CA: Wadsworth. Prudic, J., Peyser, S., & Sackeim, H. A. (2000). Subjective memory complaints: A review of patient self-assessment of memory after electroconvulsive therapy. The Journal of ECT, 16(2), 121–132. Rathus, J. H., & Sanderson, W. C. (1999). Marital distress: Cognitive behavioral treatments for couples. Northvale, NJ: Jason Aronson. Reti, I. R. (n.d.). Electroconvulsive therapy today. Retrieved from Johns Hopkins Medicine: http://www.hopkinsmedicine.org/psychiatry/specialty_areas/brain_stimulation/docs/DepBulletin407_ECT_extract.pdf Richman, L. S., Kohn-Wood, L. P., & Williams, D. R. (2007). The role of discrimination and racial identity for mental health service utilization. Journal of Social and Clinical Psychology, 26(8), 960–981. Rizzo, A., Newman, B., Parsons, T., Difede, J., Reger, G., Holloway, K., . . . Bordnick, P. (2010). Development and clinical results from the Virtual Iraq exposure therapy application for PTSD. Annals of the New York Academy of Sciences, 1208, 114–125. Rogers, C. (1951). Client-centered psychotherapy. Boston, MA: Houghton-Mifflin. Sackett, D. L., & Rosenberg, W. M. (1995). On the need for evidence-based medicine. Journal of Public Health, 17, 330–334. Sallows, G. O., & Graupner, T. D. (2005). Intensive behavioral treatment for children with autism: Four-year outcome and predictors. American Journal of Mental Retardation, 110(6), 417–438. Scott, L. D., McCoy, H., Munson, M. R., Snowden, L. R., & McMillen, J. C. (2011). Cultural mistrust of mental health professionals among Black males transitioning from foster care. Journal of Child and Family Studies, 20, 605–613. Shechtman, Z. (2002). Child group psychotherapy in the school at the threshold of a new millennium. Journal of Counseling and Development, 80(3), 293–299. Shedler, J. (2010). The efficacy of psychodynamic psychotherapy. American Psychologist, 65, 98–109. Simpson D. D. (1981). Treatment for drug abuse. Archives of General Psychiatry, 38, 875–880. Simpson D. D, Joe, G. W, & Bracy, S. A. (1982). Six-year follow-up of opioid addicts after admission to treatment. Archives General Psychiatry, 39, 1318–1323. Snowden, L. R. (2001). Barriers to effective mental health services for African Americans. Mental Health Services Research, 3, 181–187. Stensland, M., Watson, P. R., & Grazier, K. L. (2012). An examination of costs, charges, and payments for inpatient psychiatric treatment in community hospitals. Psychiatric Services, 63(7), 66–71. Stewart, S. M., Simmons, A., & Habibpour, E. (2012). Treatment of culturally diverse children and adolescents with depression. Journal of Child and Adolescent Psychopharmacology, 22(1), 72–79. Streeton, C., & Whelan, G. (2001). Naltrexone, a relapse prevention maintenance treatment of alcohol dependence: A meta-analysis of randomized controlled trials. Alcohol and Alcoholism, 36(6), 544–552. Sue, D. W. (2001). Multidimensional facets of cultural competence. Counseling Psychologist, 29(6), 790–821. Sue, D. W. (2004). Multicultural counseling and therapy (MCT). In J. A. Banks and C. Banks (Eds.), Handbook of research on multicultural education (2nd ed., pp. 813–827). San Francisco, CA: Jossey-Bass. Sue, D. W., & Sue, D. (2007). Counseling the culturally different: Theory and practice (5th ed.). New York, NY: Wiley. Sussman, L. K., Robins, L. N., & Earls, F. (1987). Treatment–seeking for depression by Black and White Americans. Social Science & Medicine, 24, 187–196. Szasz, T. S. (1960). The Myth of Mental Illness. American Psychologist, 15, 113–118. Thomas, K. C., & Snowden, L. R. (2002). Minority response to health insurance coverage for mental health services. Journal of Mental Health Policy and Economics, 4, 35–41. Tiffany, F. (2012/1891). Life of Dorothea Lynde Dix (7th ed.). Boston, MA: Houghton, Mifflin. Torrey, E. F. (1997). Out of the shadows: Confronting America's mental illness crisis. New York, NY: Wiley. Torrey, E. F., Zdanowicz, M. T., Kennard, A. D., Lamb, H. R., Eslinger, D. F., Biasotti, M. C., & Fuller, D. A. (2014, April 8). The treatment of persons with mental illness in prisons and jails: A state survey. Arlington, VA: Treatment Advocacy Center. Retrieved from http://tacreports.org/storage/documents/treatment-behind-bars/treatment-behind-bars.pdf Townes D. L., Cunningham N. J., & Chavez-Korell, S. (2009). Reexaming the relationships between racial identity, cultural mistrust, help-seeking attitudes, and preference for a Black counselor. Journal of Counseling Psychology, 56(2), 330–336. U.S. Department of Agriculture. (2013, December 10). USDA announces support for mental health facilities in rural areas [Press release No. 0234.13]. Retrieved from http://www.usda.gov/wps/portal/usda/usdahome?contentid=2013/12/0234.xml U.S. Department of Health and Human Services. (1999). Mental health: A report of the Surgeon General. Rockville, MD: U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Mental Health Services, National Institutes of Health, National Institute of Mental Health. U.S. Department of Health and Human Services, Health Resources and Services Administration, Office of Rural Health Policy. (2005). Mental health and rural America: 1984-2005. Retrieved from ftp://ftp.hrsa.gov/ruralhealth/RuralMentalHealth.pdf U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. (2013, December). Results from the 2012 National Survey on Drug Use and Health: Mental Health Findings (NSDUH Series H-47, HHS Publication No. [SMA] 13-4805). Retrieved from http://www.samhsa.gov/data/NSDUH/2k12MH_FindingsandDetTables/2K12MHF/NSDUHmhfr2012.htm U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. (2011, September). Results from the 2010 National Survey on Drug Use and Health: Summary of National Findings (NSDUH Series H-41, HHS Publication No. [SMA] 11-4658). Retrieved from http://www.samhsa.gov/data/NSDUH/2k10ResultsRev/NSDUHresultsRev2010.htm U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. (2013, September). Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings (NSDUH Series H-46, HHS Publication No. [SMA] 13-4795). Retrieved from http://www.samhsa.gov/data/NSDUH/2012SummNatFindDetTables/NationalFindings/NSDUHresults2012.htm#ch2.2 U.S. Department of Housing and Urban Development, Office of Community Planning and Development. (2011). The 2010 Annual Homeless Assessment Report to Congress. Washington, DC. Retrieved from http://www.hudhre.info/documents/2010HomelessAssessmentReport.pdf U.S. Department of Labor. (n.d.). Mental health parity. Retrieved from: http://www.dol.gov/ebsa/mentalhealthparity/ U.S. Public Health Service. (2000). Report of the Surgeon General’s conference on children’s mental health: A national action agenda. Washington, DC: Department of Health and Human Services. Wagenfeld, M. O., Murray, J. D., Mohatt, D. F., & DeBruiynb, J. C. (Eds.). (1994). Mental health and rural America: 1980–1993 (NIH Publication No. 94-3500). Washington, DC: U.S. Government Printing Office. Wampold, B. E. (2007). Psychotherapy: The humanistic (and effective) treatment. American Psychologist, 62, 857–873. doi:10.1037/0003-066X.62.8.857 Weil, E. (2012, March 2). Does couples therapy work? The New York Times. Retrieved from http://www.nytimes.com/2012/03/04/fashion/couples-therapists-confront-the-stresses-of-their-field.html?pagewanted=all&_r=0 Weiss, R. D., Jaffee, W. B., de Menil, V. P., & Cogley, C. B. (2004). Group therapy for substance abuse disorders: What do we know? Harvard Review of Psychiatry, 12(6), 339–350. Willard Psychiatric Center. (2009). Echoes of Willard. Retrieved from http://www.echoesofwillard.com/willard-psychiatric-centre/ Wolf, M., & Risley, T. (1967). Application of operant conditioning procedures to the behavior problems of an autistic child: A follow-up and extension. Behavior Research and Therapy, 5(2), 103–111. Wolpe, J. (1958). Psychotherapy by reciprocal inhibition. Stanford, CA: Stanford University Press.	oercommons	2025-03-18T00:37:16.140739	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15391/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/15392/overview	Mental Health Treatment: Past and Present Overview By the end of this section, you will be able to: - Explain how people with psychological disorders have been treated throughout the ages - Discuss deinstitutionalization - Discuss the ways in which mental health services are delivered today - Distinguish between voluntary and involuntary treatment Before we explore the various approaches to therapy used today, let’s begin our study of therapy by looking at how many people experience mental illness and how many receive treatment. According to the U.S. Department of Health and Human Services (2013), 19% of U.S. adults experienced mental illness in 2012. For teens (ages 13–18), the rate is similar to that of adults, and for children ages 8–15, current estimates suggest that 13% experience mental illness in a given year (National Institute of Mental Health [NIMH], n.d.-a) With many different treatment options available, approximately how many people receive mental health treatment per year? According to the Substance Abuse and Mental Health Services Administration (SAMHSA), in 2008, 13.4% of adults received treatment for a mental health issue (NIMH, n.d.-b). These percentages, shown in Figure, reflect the number of adults who received care in inpatient and outpatient settings and/or used prescription medication for psychological disorders. Children and adolescents also receive mental health services. The Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey (NHANES) found that approximately half (50.6%) of children with mental disorders had received treatment for their disorder within the past year (NIMH, n.d.-c). However, there were some differences between treatment rates by category of disorder (Figure). For example, children with anxiety disorders were least likely to have received treatment in the past year, while children with ADHD or a conduct disorder were more likely to receive treatment. Can you think of some possible reasons for these differences in receiving treatment? Considering the many forms of treatment for mental health disorders available today, how did these forms of treatment emerge? Let’s take a look at the history of mental health treatment from the past (with some questionable approaches in light of modern understanding of mental illness) to where we are today. TREATMENT IN THE PAST For much of history, the mentally ill have been treated very poorly. It was believed that mental illness was caused by demonic possession, witchcraft, or an angry god (Szasz, 1960). For example, in medieval times, abnormal behaviors were viewed as a sign that a person was possessed by demons. If someone was considered to be possessed, there were several forms of treatment to release spirits from the individual. The most common treatment was exorcism, often conducted by priests or other religious figures: Incantations and prayers were said over the person’s body, and she may have been given some medicinal drinks. Another form of treatment for extreme cases of mental illness was trephining: A small hole was made in the afflicted individual’s skull to release spirits from the body. Most people treated in this manner died. In addition to exorcism and trephining, other practices involved execution or imprisonment of people with psychological disorders. Still others were left to be homeless beggars. Generally speaking, most people who exhibited strange behaviors were greatly misunderstood and treated cruelly. The prevailing theory of psychopathology in earlier history was the idea that mental illness was the result of demonic possession by either an evil spirit or an evil god because early beliefs incorrectly attributed all unexplainable phenomena to deities deemed either good or evil. From the late 1400s to the late 1600s, a common belief perpetuated by some religious organizations was that some people made pacts with the devil and committed horrible acts, such as eating babies (Blumberg, 2007). These people were considered to be witches and were tried and condemned by courts—they were often burned at the stake. Worldwide, it is estimated that tens of thousands of mentally ill people were killed after being accused of being witches or under the influence of witchcraft (Hemphill, 1966) By the 18th century, people who were considered odd and unusual were placed in asylums (Figure). Asylums were the first institutions created for the specific purpose of housing people with psychological disorders, but the focus was ostracizing them from society rather than treating their disorders. Often these people were kept in windowless dungeons, beaten, chained to their beds, and had little to no contact with caregivers. In the late 1700s, a French physician, Philippe Pinel, argued for more humane treatment of the mentally ill. He suggested that they be unchained and talked to, and that’s just what he did for patients at La Salpêtrière in Paris in 1795 (Figure). Patients benefited from this more humane treatment, and many were able to leave the hospital. In the 19th century, Dorothea Dix led reform efforts for mental health care in the United States (Figure). She investigated how those who are mentally ill and poor were cared for, and she discovered an underfunded and unregulated system that perpetuated abuse of this population (Tiffany, 1891). Horrified by her findings, Dix began lobbying various state legislatures and the U.S. Congress for change (Tiffany, 1891). Her efforts led to the creation of the first mental asylums in the United States. Despite reformers’ efforts, however, a typical asylum was filthy, offered very little treatment, and often kept people for decades. At Willard Psychiatric Center in upstate New York, for example, one treatment was to submerge patients in cold baths for long periods of time. Electroshock treatment was also used, and the way the treatment was administered often broke patients’ backs; in 1943, doctors at Willard administered 1,443 shock treatments (Willard Psychiatric Center, 2009). (Electroshock is now called electroconvulsive treatment, and the therapy is still used, but with safeguards and under anesthesia. A brief application of electric stimulus is used to produce a generalized seizure. Controversy continues over its effectiveness versus the side effects.) Many of the wards and rooms were so cold that a glass of water would be frozen by morning (Willard Psychiatric Center, 2009). Willard’s doors were not closed until 1995. Conditions like these remained commonplace until well into the 20th century. Starting in 1954 and gaining popularity in the 1960s, antipsychotic medications were introduced. These proved a tremendous help in controlling the symptoms of certain psychological disorders, such as psychosis. Psychosis was a common diagnosis of individuals in mental hospitals, and it was often evidenced by symptoms like hallucinations and delusions, indicating a loss of contact with reality. Then in 1963, Congress passed and John F. Kennedy signed the Mental Retardation Facilities and Community Mental Health Centers Construction Act, which provided federal support and funding for community mental health centers (National Institutes of Health, 2013). This legislation changed how mental health services were delivered in the United States. It started the process of deinstitutionalization, the closing of large asylums, by providing for people to stay in their communities and be treated locally. In 1955, there were 558,239 severely mentally ill patients institutionalized at public hospitals (Torrey, 1997). By 1994, by percentage of the population, there were 92% fewer hospitalized individuals (Torrey, 1997). MENTAL HEALTH TREATMENT TODAY Today, there are community mental health centers across the nation. They are located in neighborhoods near the homes of clients, and they provide large numbers of people with mental health services of various kinds and for many kinds of problems. Unfortunately, part of what occurred with deinstitutionalization was that those released from institutions were supposed to go to newly created centers, but the system was not set up effectively. Centers were underfunded, staff was not trained to handle severe illnesses such as schizophrenia, there was high staff burnout, and no provision was made for the other services people needed, such as housing, food, and job training. Without these supports, those people released under deinstitutionalization often ended up homeless. Even today, a large portion of the homeless population is considered to be mentally ill (Figure). Statistics show that 26% of homeless adults living in shelters experience mental illness (U.S. Department of Housing and Urban Development [HUD], 2011). Another group of the mentally ill population is involved in the corrections system. According to a 2006 special report by the Bureau of Justice Statistics (BJS), approximately 705,600 mentally ill adults were incarcerated in the state prison system, and another 78,800 were incarcerated in the federal prison system. A further 479,000 were in local jails. According to the study, “people with mental illnesses are overrepresented in probation and parole populations at estimated rates ranging from two to four times the general population” (Prins & Draper, 2009, p. 23). The Treatment Advocacy Center reported that the growing number of mentally ill inmates has placed a burden on the correctional system (Torrey et al., 2014). Today, instead of asylums, there are psychiatric hospitals run by state governments and local community hospitals focused on short-term care. In all types of hospitals, the emphasis is on short-term stays, with the average length of stay being less than two weeks and often only several days. This is partly due to the very high cost of psychiatric hospitalization, which can be about $800 to $1000 per night (Stensland, Watson, & Grazier, 2012). Therefore, insurance coverage often limits the length of time a person can be hospitalized for treatment. Usually individuals are hospitalized only if they are an imminent threat to themselves or others. View this timeline showing the history of mental institutions in the United States. Most people suffering from mental illnesses are not hospitalized. If someone is feeling very depressed, complains of hearing voices, or feels anxious all the time, he or she might seek psychological treatment. A friend, spouse, or parent might refer someone for treatment. The individual might go see his primary care physician first and then be referred to a mental health practitioner. Some people seek treatment because they are involved with the state’s child protective services—that is, their children have been removed from their care due to abuse or neglect. The parents might be referred to psychiatric or substance abuse facilities and the children would likely receive treatment for trauma. If the parents are interested in and capable of becoming better parents, the goal of treatment might be family reunification. For other children whose parents are unable to change—for example, the parent or parents who are heavily addicted to drugs and refuse to enter treatment—the goal of therapy might be to help the children adjust to foster care and/or adoption (Figure). Some people seek therapy because the criminal justice system referred them or required them to go. For some individuals, for example, attending weekly counseling sessions might be a condition of parole. If an individual is mandated to attend therapy, she is seeking services involuntarily. Involuntary treatment refers to therapy that is not the individual’s choice. Other individuals might voluntarily seek treatment. Voluntary treatment means the person chooses to attend therapy to obtain relief from symptoms. Psychological treatment can occur in a variety of places. An individual might go to a community mental health center or a practitioner in private or community practice. A child might see a school counselor, school psychologist, or school social worker. An incarcerated person might receive group therapy in prison. There are many different types of treatment providers, and licensing requirements vary from state to state. Besides psychologists and psychiatrists, there are clinical social workers, marriage and family therapists, and trained religious personnel who also perform counseling and therapy. A range of funding sources pay for mental health treatment: health insurance, government, and private pay. In the past, even when people had health insurance, the coverage would not always pay for mental health services. This changed with the Mental Health Parity and Addiction Equity Act of 2008, which requires group health plans and insurers to make sure there is parity of mental health services (U.S. Department of Labor, n.d.). This means that co-pays, total number of visits, and deductibles for mental health and substance abuse treatment need to be equal to and cannot be more restrictive or harsher than those for physical illnesses and medical/surgical problems. Finding treatment sources is also not always easy: there may be limited options, especially in rural areas and low-income urban areas; waiting lists; poor quality of care available for indigent patients; and financial obstacles such as co-pays, deductibles, and time off from work. Over 85% of the l,669 federally designated mental health professional shortage areas are rural; often primary care physicians and law enforcement are the first-line mental health providers (Ivey, Scheffler, & Zazzali, 1998), although they do not have the specialized training of a mental health professional, who often would be better equipped to provide care. Availability, accessibility, and acceptability (the stigma attached to mental illness) are all problems in rural areas. Approximately two-thirds of those with symptoms receive no care at all (U.S. Department of Health and Human Services, 2005; Wagenfeld, Murray, Mohatt, & DeBruiynb, 1994). At the end of 2013, the U.S. Department of Agriculture announced an investment of $50 million to help improve access and treatment for mental health problems as part of the Obama administration’s effort to strengthen rural communities. Summary It was once believed that people with psychological disorders, or those exhibiting strange behavior, were possessed by demons. These people were forced to take part in exorcisms, were imprisoned, or executed. Later, asylums were built to house the mentally ill, but the patients received little to no treatment, and many of the methods used were cruel. Philippe Pinel and Dorothea Dix argued for more humane treatment of people with psychological disorders. In the mid-1960s, the deinstitutionalization movement gained support and asylums were closed, enabling people with mental illness to return home and receive treatment in their own communities. Some did go to their family homes, but many became homeless due to a lack of resources and support mechanisms. Today, instead of asylums, there are psychiatric hospitals run by state governments and local community hospitals, with the emphasis on short-term stays. However, most people suffering from mental illness are not hospitalized. A person suffering symptoms could speak with a primary care physician, who most likely would refer him to someone who specializes in therapy. The person can receive outpatient mental health services from a variety of sources, including psychologists, psychiatrists, marriage and family therapists, school counselors, clinical social workers, and religious personnel. These therapy sessions would be covered through insurance, government funds, or private (self) pay. Review Questions Who of the following does not support the humane and improved treatment of mentally ill persons? - Philippe Pinel - medieval priests - Dorothea Dix - All of the above Hint: B The process of closing large asylums and providing for people to stay in the community to be treated locally is known as ________. - deinstitutionalization - exorcism - deactivation - decentralization Hint: A Joey was convicted of domestic violence. As part of his sentence, the judge has ordered that he attend therapy for anger management. This is considered ________ treatment. - involuntary - voluntary - forced - mandatory Hint: A Today, most people with psychological problems are not hospitalized. Typically they are only hospitalized if they ________. - have schizophrenia - have insurance - are an imminent threat to themselves or others - require therapy Hint: C Critical Thinking Questions People with psychological disorders have been treated poorly throughout history. Describe some efforts to improve treatment, include explanations for the success or lack thereof. Hint: Beginning in the Middle Ages and up until the mid-20th century, the mentally ill were misunderstood and treated cruelly. In the 1700s, Philippe Pinel advocated for patients to be unchained, and he was able to affect this in a Paris hospital. In the 1800s, Dorothea Dix urged the government to provide better funded and regulated care, which led to the creation of asylums, but treatment generally remained quite poor. Federally mandated deinstitutionalization in the 1960s began the elimination of asylums, but it was often inadequate in providing the infrastructure for replacement treatment. Usually someone is hospitalized only if they are an imminent threat to themselves or others. Describe a situation that might meet these criteria. Hint: Frank is severely depressed. He lost his job one year ago and has not been able to find another one. A few months after losing his job, his home was foreclosed and his wife left him. Lately, he has been thinking that he would be better off dead. He’s begun giving his possessions away and has purchased a handgun. He plans to kill himself on what would have been his 20th wedding anniversary, which is coming up in a few weeks. Personal Application Questions Do you think there is a stigma associated with mentally ill persons today? Why or why not? What are some places in your community that offer mental health services? Would you feel comfortable seeking assistance at one of these facilities? Why or why not?	oercommons	2025-03-18T00:37:16.174314	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15392/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/15393/overview	Types of Treatment Overview By the end of this section, you will be able to: - Distinguish between psychotherapy and biomedical therapy - Recognize various orientations to psychotherapy - Discuss psychotropic medications and recognize which medications are used to treat specific psychological disorders One of the goals of therapy is to help a person stop repeating and reenacting destructive patterns and to start looking for better solutions to difficult situations. This goal is reflected in the following poem: Autobiography in Five Short Chapters by Portia Nelson (1993) Chapter One I walk down the street. There is a deep hole in the sidewalk. I fall in. I am lost. . . . I am helpless. It isn't my fault. It takes forever to find a way out. Chapter Two I walk down the same street. There is a deep hole in the sidewalk. I pretend I don't see it. I fall in again. I can't believe I am in this same place. But, it isn't my fault. It still takes a long time to get out. Chapter Three I walk down the same street. There is a deep hole in the sidewalk. I see it is there. I still fall in . . . it's a habit . . . but, my eyes are open. I know where I am. It is my fault. I get out immediately. Chapter Four I walk down the same street. There is a deep hole in the sidewalk. I walk around it. Chapter Five I walk down another street. Two types of therapy are psychotherapy and biomedical therapy. Both types of treatment help people with psychological disorders, such as depression, anxiety, and schizophrenia. Psychotherapy is a psychological treatment that employs various methods to help someone overcome personal problems, or to attain personal growth. In modern practice, it has evolved ino what is known as psychodynamic therapy, which will be discussed later. Biomedical therapy involves medication and/or medical procedures to treat psychological disorders. First, we will explore the various psychotherapeutic orientations outlined in Table (many of these orientations were discussed in the Introduction chapter). \| Type \| Description \| Example \| \|---\|---\|---\| \| Psychodynamic psychotherapy \| Talk therapy based on belief that the unconscious and childhood conflicts impact behavior \| Patient talks about his past \| \| Play therapy \| Psychoanalytical therapy wherein interaction with toys is used instead of talk; used in child therapy \| Patient (child) acts out family scenes with dolls \| \| Behavior therapy \| Principles of learning applied to change undesirable behaviors \| Patient learns to overcome fear of elevators through several stages of relaxation techniques \| \| Cognitive therapy \| Awareness of cognitive process helps patients eliminate thought patterns that lead to distress \| Patient learns not to overgeneralize failure based on single failure \| \| Cognitive-behavioral therapy \| Work to change cognitive distortions and self-defeating behaviors \| Patient learns to identify self-defeating behaviors to overcome an eating disorder \| \| Humanistic therapy \| Increase self-awareness and acceptance through focus on conscious thoughts \| Patient learns to articulate thoughts that keep her from achieving her goals \| PSYCHOTHERAPY TECHNIQUES: PSYCHOANALYSIS Psychoanalysis was developed by Sigmund Freud and was the first form of psychotherapy. It was the dominant therapeutic technique in the early 20th century, but it has since waned significantly in popularity. Freud believed most of our psychological problems are the result of repressed impulses and trauma experienced in childhood, and he believed psychoanalysis would help uncover long-buried feelings. In a psychoanalyst’s office, you might see a patient lying on a couch speaking of dreams or childhood memories, and the therapist using various Freudian methods such as free association and dream analysis (Figure). In free association, the patient relaxes and then says whatever comes to mind at the moment. However, Freud felt that the ego would at times try to block, or repress, unacceptable urges or painful conflicts during free association. Consequently, a patient would demonstrate resistance to recalling these thoughts or situations. In dream analysis, a therapist interprets the underlying meaning of dreams. Psychoanalysis is a therapy approach that typically takes years. Over the course of time, the patient reveals a great deal about himself to the therapist. Freud suggested that during this patient-therapist relationship, the patient comes to develop strong feelings for the therapist—maybe positive feelings, maybe negative feelings. Freud called this transference: the patient transfers all the positive or negative emotions associated with the patient’s other relationships to the psychoanalyst. For example, Crystal is seeing a psychoanalyst. During the years of therapy, she comes to see her therapist as a father figure. She transfers her feelings about her father onto her therapist, perhaps in an effort to gain the love and attention she did not receive from her own father. Today, Freud’s psychoanalytical perspective has been expanded upon by the developments of subsequent theories and methodologies: the psychodynamic perspective. This approach to therapy remains centered on the role of people’s internal drives and forces, but treatment is less intensive than Freud’s original model. View a brief video that presents an overview of psychoanalysis theory, research, and practice. PSYCHOTHERAPY: PLAY THERAPY Play therapy is often used with children since they are not likely to sit on a couch and recall their dreams or engage in traditional talk therapy. This technique uses a therapeutic process of play to “help clients prevent or resolve psychosocial difficulties and achieve optimal growth” (O’Connor, 2000, p. 7). The idea is that children play out their hopes, fantasies, and traumas while using dolls, stuffed animals, and sandbox figurines (Figure). Play therapy can also be used to help a therapist make a diagnosis. The therapist observes how the child interacts with toys (e.g., dolls, animals, and home settings) in an effort to understand the roots of the child’s disturbed behavior. Play therapy can be nondirective or directive. In nondirective play therapy, children are encouraged to work through their problems by playing freely while the therapist observes (LeBlanc & Ritchie, 2001). In directive play therapy, the therapist provides more structure and guidance in the play session by suggesting topics, asking questions, and even playing with the child (Harter, 1977). PSYCHOTHERAPY: BEHAVIOR THERAPY In psychoanalysis, therapists help their patients look into their past to uncover repressed feelings. In behavior therapy, a therapist employs principles of learning to help clients change undesirable behaviors—rather than digging deeply into one’s unconscious. Therapists with this orientation believe that dysfunctional behaviors, like phobias and bedwetting, can be changed by teaching clients new, more constructive behaviors. Behavior therapy employs both classical and operant conditioning techniques to change behavior. One type of behavior therapy utilizes classical conditioning techniques. Therapists using these techniques believe that dysfunctional behaviors are conditioned responses. Applying the conditioning principles developed by Ivan Pavlov, these therapists seek to recondition their clients and thus change their behavior. Emmie is eight years old, and frequently wets her bed at night. She’s been invited to several sleepovers, but she won’t go because of her problem. Using a type of conditioning therapy, Emmie begins to sleep on a liquid-sensitive bed pad that is hooked to an alarm. When moisture touches the pad, it sets off the alarm, waking up Emmie. When this process is repeated enough times, Emmie develops an association between urinary relaxation and waking up, and this stops the bedwetting. Emmie has now gone three weeks without wetting her bed and is looking forward to her first sleepover this weekend. One commonly used classical conditioning therapeutic technique is counterconditioning: a client learns a new response to a stimulus that has previously elicited an undesirable behavior. Two counterconditioning techniques are aversive conditioning and exposure therapy. Aversive conditioning uses an unpleasant stimulus to stop an undesirable behavior. Therapists apply this technique to eliminate addictive behaviors, such as smoking, nail biting, and drinking. In aversion therapy, clients will typically engage in a specific behavior (such as nail biting) and at the same time are exposed to something unpleasant, such as a mild electric shock or a bad taste. After repeated associations between the unpleasant stimulus and the behavior, the client can learn to stop the unwanted behavior. Aversion therapy has been used effectively for years in the treatment of alcoholism (Davidson, 1974; Elkins, 1991; Streeton & Whelan, 2001). One common way this occurs is through a chemically based substance known as Antabuse. When a person takes Antabuse and then consumes alcohol, uncomfortable side effects result including nausea, vomiting, increased heart rate, heart palpitations, severe headache, and shortness of breath. Antabuse is repeatedly paired with alcohol until the client associates alcohol with unpleasant feelings, which decreases the client’s desire to consume alcohol. Antabuse creates a conditioned aversion to alcohol because it replaces the original pleasure response with an unpleasant one. In exposure therapy, a therapist seeks to treat clients’ fears or anxiety by presenting them with the object or situation that causes their problem, with the idea that they will eventually get used to it. This can be done via reality, imagination, or virtual reality. Exposure therapy was first reported in 1924 by Mary Cover Jones, who is considered the mother of behavior therapy. Jones worked with a boy named Peter who was afraid of rabbits. Her goal was to replace Peter’s fear of rabbits with a conditioned response of relaxation, which is a response that is incompatible with fear (Figure). How did she do it? Jones began by placing a caged rabbit on the other side of a room with Peter while he ate his afternoon snack. Over the course of several days, Jones moved the rabbit closer and closer to where Peter was seated with his snack. After two months of being exposed to the rabbit while relaxing with his snack, Peter was able to hold the rabbit and pet it while eating (Jones, 1924). Thirty years later, Joseph Wolpe (1958) refined Jones’s techniques, giving us the behavior therapy technique of exposure therapy that is used today. A popular form of exposure therapy is systematic desensitization, wherein a calm and pleasant state is gradually associated with increasing levels of anxiety-inducing stimuli. The idea is that you can’t be nervous and relaxed at the same time. Therefore, if you can learn to relax when you are facing environmental stimuli that make you nervous or fearful, you can eventually eliminate your unwanted fear response (Wolpe, 1958) (Figure). How does exposure therapy work? Jayden is terrified of elevators. Nothing bad has ever happened to him on an elevator, but he’s so afraid of elevators that he will always take the stairs. That wasn’t a problem when Jayden worked on the second floor of an office building, but now he has a new job—on the 29th floor of a skyscraper in downtown Los Angeles. Jayden knows he can’t climb 29 flights of stairs in order to get to work each day, so he decided to see a behavior therapist for help. The therapist asks Jayden to first construct a hierarchy of elevator-related situations that elicit fear and anxiety. They range from situations of mild anxiety such as being nervous around the other people in the elevator, to the fear of getting an arm caught in the door, to panic-provoking situations such as getting trapped or the cable snapping. Next, the therapist uses progressive relaxation. She teaches Jayden how to relax each of his muscle groups so that he achieves a drowsy, relaxed, and comfortable state of mind. Once he’s in this state, she asks Jayden to imagine a mildly anxiety-provoking situation. Jayden is standing in front of the elevator thinking about pressing the call button. If this scenario causes Jayden anxiety, he lifts his finger. The therapist would then tell Jayden to forget the scene and return to his relaxed state. She repeats this scenario over and over until Jayden can imagine himself pressing the call button without anxiety. Over time the therapist and Jayden use progressive relaxation and imagination to proceed through all of the situations on Jayden’s hierarchy until he becomes desensitized to each one. After this, Jayden and the therapist begin to practice what he only previously envisioned in therapy, gradually going from pressing the button to actually riding an elevator. The goal is that Jayden will soon be able to take the elevator all the way up to the 29th floor of his office without feeling any anxiety. Sometimes, it’s too impractical, expensive, or embarrassing to re-create anxiety- producing situations, so a therapist might employ virtual reality exposure therapy by using a simulation to help conquer fears. Virtual reality exposure therapy has been used effectively to treat numerous anxiety disorders such as the fear of public speaking, claustrophobia (fear of enclosed spaces), aviophobia (fear of flying), and post-traumatic stress disorder (PTSD), a trauma and stressor-related disorder (Gerardi, Cukor, Difede, Rizzo, & Rothbaum, 2010). A new virtual reality exposure therapy is being used to treat PTSD in soldiers. Virtual Iraq is a simulation that mimics Middle Eastern cities and desert roads with situations similar to those soldiers experienced while deployed in Iraq. This method of virtual reality exposure therapy has been effective in treating PTSD for combat veterans. Approximately 80% of participants who completed treatment saw clinically significant reduction in their symptoms of PTSD, anxiety, and depression (Rizzo et al., 2010). Watch this Virtual Iraq video showing soldiers being treated via simulation. Some behavior therapies employ operant conditioning. Recall what you learned about operant conditioning: We have a tendency to repeat behaviors that are reinforced. What happens to behaviors that are not reinforced? They become extinguished. These principles can be applied to help people with a wide range of psychological problems. For instance, operant conditioning techniques designed to reinforce positive behaviors and punish unwanted behaviors have been an effective tool to help children with autism (Lovaas, 1987, 2003; Sallows & Graupner, 2005; Wolf & Risley, 1967). This technique is called Applied Behavior Analysis (ABA). In this treatment, child-specific reinforcers (e.g., stickers, praise, candy, bubbles, and extra play time) are used to reward and motivate autistic children when they demonstrate desired behaviors such as sitting on a chair when requested, verbalizing a greeting, or making eye contact. Punishment such as a timeout or a sharp “No!” from the therapist or parent might be used to discourage undesirable behaviors such as pinching, scratching, and pulling hair. One popular operant conditioning intervention is called the token economy. This involves a controlled setting where individuals are reinforced for desirable behaviors with tokens, such as a poker chip, that can be exchanged for items or privileges. Token economies are often used in psychiatric hospitals to increase patient cooperation and activity levels. Patients are rewarded with tokens when they engage in positive behaviors (e.g., making their beds, brushing their teeth, coming to the cafeteria on time, and socializing with other patients). They can later exchange the tokens for extra TV time, private rooms, visits to the canteen, and so on (Dickerson, Tenhula, & Green-Paden, 2005). PSYCHOTHERAPY: COGNITIVE THERAPY Cognitive therapy is a form of psychotherapy that focuses on how a person’s thoughts lead to feelings of distress. The idea behind cognitive therapy is that how you think determines how you feel and act. Cognitive therapists help their clients change dysfunctional thoughts in order to relieve distress. They help a client see how they misinterpret a situation (cognitive distortion). For example, a client may overgeneralize. Because Ray failed one test in his Psychology 101 course, he feels he is stupid and worthless. These thoughts then cause his mood to worsen. Therapists also help clients recognize when they blow things out of proportion. Because Ray failed his Psychology 101 test, he has concluded that he’s going to fail the entire course and probably flunk out of college altogether. These errors in thinking have contributed to Ray’s feelings of distress. His therapist will help him challenge these irrational beliefs, focus on their illogical basis, and correct them with more logical and rational thoughts and beliefs. Cognitive therapy was developed by psychiatrist Aaron Beck in the 1960s. His initial focus was on depression and how a client’s self-defeating attitude served to maintain a depression despite positive factors in her life (Beck, Rush, Shaw, & Emery, 1979) (Figure). Through questioning, a cognitive therapist can help a client recognize dysfunctional ideas, challenge catastrophizing thoughts about themselves and their situations, and find a more positive way to view things (Beck, 2011). View a brief video in which Judith Beck talks about cognitive therapy and conducts a session with a client. PSYCHOTHERAPY: COGNITIVE-BEHAVIORAL THERAPY Cognitive-behavioral therapists focus much more on present issues than on a patient’s childhood or past, as in other forms of psychotherapy. One of the first forms of cognitive-behavioral therapy was rational emotive therapy (RET), which was founded by Albert Ellis and grew out of his dislike of Freudian psychoanalysis (Daniel, n.d.). Behaviorists such as Joseph Wolpe also influenced Ellis’s therapeutic approach (National Association of Cognitive-Behavioral Therapists, 2009). Cognitive-behavioral therapy (CBT) helps clients examine how their thoughts affect their behavior. It aims to change cognitive distortions and self-defeating behaviors. In essence, this approach is designed to change the way people think as well as how they act. It is similar to cognitive therapy in that CBT attempts to make individuals aware of their irrational and negative thoughts and helps people replace them with new, more positive ways of thinking. It is also similar to behavior therapies in that CBT teaches people how to practice and engage in more positive and healthy approaches to daily situations. In total, hundreds of studies have shown the effectiveness of cognitive-behavioral therapy in the treatment of numerous psychological disorders such as depression, PTSD, anxiety disorders, eating disorders, bipolar disorder, and substance abuse (Beck Institute for Cognitive Behavior Therapy, n.d.). For example, CBT has been found to be effective in decreasing levels of hopelessness and suicidal thoughts in previously suicidal teenagers (Alavi, Sharifi, Ghanizadeh, & Dehbozorgi, 2013). Cognitive-behavioral therapy has also been effective in reducing PTSD in specific populations, such as transit workers (Lowinger & Rombom, 2012). Cognitive-behavioral therapy aims to change cognitive distortions and self-defeating behaviors using techniques like the ABC model. With this model, there is an Action (sometimes called an activating event), the Belief about the event, and the Consequences of this belief. Let’s say, Jon and Joe both go to a party. Jon and Joe each have met a young woman at the party: Jon is talking with Megan most of the party, and Joe is talking with Amanda. At the end of the party, Jon asks Megan for her phone number and Joe asks Amanda. Megan tells Jon she would rather not give him her number, and Amanda tells Joe the same thing. Both Jon and Joe are surprised, as they thought things were going well. What can Jon and Joe tell themselves about why the women were not interested? Let’s say Jon tells himself he is a loser, or is ugly, or “has no game.” Jon then gets depressed and decides not to go to another party, which starts a cycle that keeps him depressed. Joe tells himself that he had bad breath, goes out and buys a new toothbrush, goes to another party, and meets someone new. Jon’s belief about what happened results in a consequence of further depression, whereas Joe’s belief does not. Jon is internalizing the attribution or reason for the rebuffs, which triggers his depression. On the other hand, Joe is externalizing the cause, so his thinking does not contribute to feelings of depression. Cognitive-behavioral therapy examines specific maladaptive and automatic thoughts and cognitive distortions. Some examples of cognitive distortions are all-or-nothing thinking, overgeneralization, and jumping to conclusions. In overgeneralization, someone takes a small situation and makes it huge—for example, instead of saying, “This particular woman was not interested in me,” the man says, “I am ugly, a loser, and no one is ever going to be interested in me.” All or nothing thinking, which is a common type of cognitive distortion for people suffering from depression, reflects extremes. In other words, everything is black or white. After being turned down for a date, Jon begins to think, “No woman will ever go out with me. I’m going to be alone forever.” He begins to feel anxious and sad as he contemplates his future. The third kind of distortion involves jumping to conclusions—assuming that people are thinking negatively about you or reacting negatively to you, even though there is no evidence. Consider the example of Savannah and Hillaire, who recently met at a party. They have a lot in common, and Savannah thinks they could become friends. She calls Hillaire to invite her for coffee. Since Hillaire doesn’t answer, Savannah leaves her a message. Several days go by and Savannah never hears back from her potential new friend. Maybe Hillaire never received the message because she lost her phone or she is too busy to return the phone call. But if Savannah believes that Hillaire didn’t like Savannah or didn’t want to be her friend, she is demonstrating the cognitive distortion of jumping to conclusions. How effective is CBT? One client said this about his cognitive-behavioral therapy: I have had many painful episodes of depression in my life, and this has had a negative effect on my career and has put considerable strain on my friends and family. The treatments I have received, such as taking antidepressants and psychodynamic counseling, have helped [me] to cope with the symptoms and to get some insights into the roots of my problems. CBT has been by far the most useful approach I have found in tackling these mood problems. It has raised my awareness of how my thoughts impact on my moods. How the way I think about myself, about others and about the world can lead me into depression. It is a practical approach, which does not dwell so much on childhood experiences, whilst acknowledging that it was then that these patterns were learned. It looks at what is happening now, and gives tools to manage these moods on a daily basis. (Martin, 2007, n.p.) PSYCHOTHERAPY: HUMANISTIC THERAPY Humanistic psychology focuses on helping people achieve their potential. So it makes sense that the goal of humanistic therapy is to help people become more self-aware and accepting of themselves. In contrast to psychoanalysis, humanistic therapists focus on conscious rather than unconscious thoughts. They also emphasize the patient’s present and future, as opposed to exploring the patient’s past. Psychologist Carl Rogers developed a therapeutic orientation known as Rogerian, or client-centered therapy. Note the change from patients to clients. Rogers (1951) felt that the term patient suggested the person seeking help was sick and looking for a cure. Since this is a form of nondirective therapy, a therapeutic approach in which the therapist does not give advice or provide interpretations but helps the person to identify conflicts and understand feelings, Rogers (1951) emphasized the importance of the person taking control of his own life to overcome life’s challenges. In client-centered therapy, the therapist uses the technique of active listening. In active listening, the therapist acknowledges, restates, and clarifies what the client expresses. Therapists also practice what Rogers called unconditional positive regard, which involves not judging clients and simply accepting them for who they are. Rogers (1951) also felt that therapists should demonstrate genuineness, empathy, and acceptance toward their clients because this helps people become more accepting of themselves, which results in personal growth. EVALUATING VARIOUS FORMS OF PSYCHOTHERAPY How can we assess the effectiveness of psychotherapy? Is one technique more effective than another? For anyone considering therapy, these are important questions. According to the American Psychological Association, three factors work together to produce successful treatment. The first is the use of evidence-based treatment that is deemed appropriate for your particular issue. The second important factor is the clinical expertise of the psychologist or therapist. The third factor is your own characteristics, values, preferences, and culture. Many people begin psychotherapy feeling like their problem will never be resolved; however, psychotherapy helps people see that they can do things to make their situation better. Psychotherapy can help reduce a person’s anxiety, depression, and maladaptive behaviors. Through psychotherapy, individuals can learn to engage in healthy behaviors designed to help them better express emotions, improve relationships, think more positively, and perform more effectively at work or school. Many studies have explored the effectiveness of psychotherapy. For example, one large-scale study that examined 16 meta-analyses of CBT reported that it was equally effective or more effective than other therapies in treating PTSD, generalized anxiety disorder, depression, and social phobia (Butlera, Chapmanb, Formanc, & Becka, 2006). Another study found that CBT was as effective at treating depression (43% success rate) as prescription medication (50% success rate) compared to the placebo rate of 25% (DeRubeis et al., 2005). Another meta-analysis found that psychodynamic therapy was also as effective at treating these types of psychological issues as CBT (Shedler, 2010). However, no studies have found one psychotherapeutic approach more effective than another (Abbass, Kisely, & Kroenke, 2006; Chorpita et al., 2011), nor have they shown any relationship between a client’s treatment outcome and the level of the clinician’s training or experience (Wampold, 2007). Regardless of which type of psychotherapy an individual chooses, one critical factor that determines the success of treatment is the person’s relationship with the psychologist or therapist. BIOMEDICAL THERAPIES Individuals can be prescribed biologically based treatments or psychotropic medications that are used to treat mental disorders. While these are often used in combination with psychotherapy, they also are taken by individuals not in therapy. This is known as biomedical therapy. Medications used to treat psychological disorders are called psychotropic medications and are prescribed by medical doctors, including psychiatrists. In Louisiana and New Mexico, psychologists are able to prescribe some types of these medications (American Psychological Association, 2014). Different types and classes of medications are prescribed for different disorders. A depressed person might be given an antidepressant, a bipolar individual might be given a mood stabilizer, and a schizophrenic individual might be given an antipsychotic. These medications treat the symptoms of a psychological disorder. They can help people feel better so that they can function on a daily basis, but they do not cure the disorder. Some people may only need to take a psychotropic medication for a short period of time. Others with severe disorders like bipolar disorder or schizophrenia may need to take psychotropic medication for a long time. Table shows the types of medication and how they are used. \| Type of Medication \| Used to Treat \| Brand Names of Commonly Prescribed Medications \| How They Work \| Side Effects \| \|---\|---\|---\|---\|---\| \| Antipsychotics (developed in the 1950s) \| Schizophrenia and other types of severe thought disorders \| Haldol, Mellaril, Prolixin, Thorazine \| Treat positive psychotic symptoms such as auditory and visual hallucinations, delusions, and paranoia by blocking the neurotransmitter dopamine \| Long-term use can lead to tardive dyskinesia, involuntary movements of the arms, legs, tongue and facial muscles, resulting in Parkinson’s-like tremors \| \| Atypical Antipsychotics (developed in the late 1980s) \| Schizophrenia and other types of severe thought disorders \| Abilify, Risperdal, Clozaril \| Treat the negative symptoms of schizophrenia, such as withdrawal and apathy, by targeting both dopamine and serotonin receptors; newer medications may treat both positive and negative symptoms \| Can increase the risk of obesity and diabetes as well as elevate cholesterol levels; constipation, dry mouth, blurred vision, drowsiness, and dizziness \| \| Anti-depressants \| Depression and increasingly for anxiety \| Paxil, Prozac, Zoloft (selective serotonin reuptake inhibitors, [SSRIs]); Tofranil and Elavil (tricyclics) \| Alter levels of neurotransmitters such as serotonin and norepinephrine \| SSRIs: headache, nausea, weight gain, drowsiness, reduced sex drive Tricyclics: dry mouth, constipation, blurred vision, drowsiness, reduced sex drive, increased risk of suicide \| \| Anti-anxiety agents \| Anxiety and agitation that occur in OCD, PTSD, panic disorder, and social phobia \| Xanax, Valium, Ativan \| Depress central nervous system activity \| Drowsiness, dizziness, headache, fatigue, lightheadedness \| \| Mood Stabilizers \| Bipolar disorder \| Lithium, Depakote, Lamictal, Tegretol \| Treat episodes of mania as well as depression \| Excessive thirst, irregular heartbeat, itching/rash, swelling (face, mouth, and extremities), nausea, loss of appetite \| \| Stimulants \| ADHD \| Adderall, Ritalin \| Improve ability to focus on a task and maintain attention \| Decreased appetite, difficulty sleeping, stomachache, headache \| Another biologically based treatment that continues to be used, although infrequently, is electroconvulsive therapy (ECT) (formerly known by its unscientific name as electroshock therapy). It involves using an electrical current to induce seizures to help alleviate the effects of severe depression. The exact mechanism is unknown, although it does help alleviate symptoms for people with severe depression who have not responded to traditional drug therapy (Pagnin, de Queiroz, Pini, & Cassano, 2004). About 85% of people treated with ECT improve (Reti, n.d.). However, the memory loss associated with repeated administrations has led to it being implemented as a last resort (Donahue, 2000; Prudic, Peyser, & Sackeim, 2000). A more recent alternative is transcranial magnetic stimulation (TMS), a procedure approved by the FDA in 2008 that uses magnetic fields to stimulate nerve cells in the brain to improve depression symptoms; it is used when other treatments have not worked (Mayo Clinic, 2012). Evidence-based Practice A buzzword in therapy today is evidence-based practice. However, it’s not a novel concept but one that has been used in medicine for at least two decades. Evidence-based practice is used to reduce errors in treatment selection by making clinical decisions based on research (Sackett & Rosenberg, 1995). In any case, evidence-based treatment is on the rise in the field of psychology. So what is it, and why does it matter? In an effort to determine which treatment methodologies are evidenced-based, professional organizations such as the American Psychological Association (APA) have recommended that specific psychological treatments be used to treat certain psychological disorders (Chambless & Ollendick, 2001). According to the APA (2005), “Evidence-based practice in psychology (EBPP) is the integration of the best available research with clinical expertise in the context of patient characteristics, culture, and preferences” (p. 1). The foundational idea behind evidence based treatment is that best practices are determined by research evidence that has been compiled by comparing various forms of treatment (Charman & Barkham, 2005). These treatments are then operationalized and placed in treatment manuals—trained therapists follow these manuals. The benefits are that evidence-based treatment can reduce variability between therapists to ensure that a specific approach is delivered with integrity (Charman & Barkham, 2005). Therefore, clients have a higher chance of receiving therapeutic interventions that are effective at treating their specific disorder. While EBPP is based on randomized control trials, critics of EBPP reject it stating that the results of trials cannot be applied to individuals and instead determinations regarding treatment should be based on a therapist’s judgment (Mullen & Streiner, 2004). Summary Psychoanalysis was developed by Sigmund Freud. Freud’s theory is that a person’s psychological problems are the result of repressed impulses or childhood trauma. The goal of the therapist is to help a person uncover buried feelings by using techniques such as free association and dream analysis. Play therapy is a psychodynamic therapy technique often used with children. The idea is that children play out their hopes, fantasies, and traumas, using dolls, stuffed animals, and sandbox figurines. In behavior therapy, a therapist employs principles of learning from classical and operant conditioning to help clients change undesirable behaviors. Counterconditioning is a commonly used therapeutic technique in which a client learns a new response to a stimulus that has previously elicited an undesirable behavior via classical conditioning. Principles of operant conditioning can be applied to help people deal with a wide range of psychological problems. Token economy is an example of a popular operant conditioning technique. Cognitive therapy is a technique that focuses on how thoughts lead to feelings of distress. The idea behind cognitive therapy is that how you think determines how you feel and act. Cognitive therapists help clients change dysfunctional thoughts in order to relieve distress. Cognitive-behavioral therapy explores how our thoughts affect our behavior. Cognitive-behavioral therapy aims to change cognitive distortions and self-defeating behaviors. Humanistic therapy focuses on helping people achieve their potential. One form of humanistic therapy developed by Carl Rogers is known as client-centered or Rogerian therapy. Client-centered therapists use the techniques of active listening, unconditional positive regard, genuineness, and empathy to help clients become more accepting of themselves. Often in combination with psychotherapy, people can be prescribed biologically based treatments such as psychotropic medications and/or other medical procedures such as electro-convulsive therapy. Review Questions The idea behind ________ is that how you think determines how you feel and act. - cognitive therapy - cognitive-behavioral therapy - behavior therapy - client-centered therapy Hint: A Mood stabilizers, such as lithium, are used to treat ________. - anxiety disorders - depression - bipolar disorder - ADHD Hint: C Clay is in a therapy session. The therapist asks him to relax and say whatever comes to his mind at the moment. This therapist is using ________, which is a technique of ________. - active listening; client-centered therapy - systematic desensitization; behavior therapy - transference; psychoanalysis - free association; psychoanalysis Hint: D Critical Thinking Question Imagine that you are a psychiatrist. Your patient, Pat, comes to you with the following symptoms: anxiety and feelings of sadness. Which therapeutic approach would you recommend and why? Hint: I would recommend psychodynamic talk therapy or cognitive therapy to help the person see how her thoughts and behaviors are having negative effects. Personal Application Question If you were to choose a therapist practicing one of the techniques presented in this section, which kind of therapist would you choose and why?	oercommons	2025-03-18T00:37:16.220554	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15393/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/15394/overview	Treatment Modalities Overview By the end of this section, you will be able to: - Distinguish between the various modalities of treatment - Discuss benefits of group therapy Once a person seeks treatment, whether voluntarily or involuntarily, he has an intake done to assess his clinical needs. An intake is the therapist’s first meeting with the client. The therapist gathers specific information to address the client’s immediate needs, such as the presenting problem, the client’s support system, and insurance status. The therapist informs the client about confidentiality, fees, and what to expect in treatment. Confidentiality means the therapist cannot disclose confidential communications to any third party unless mandated or permitted by law to do so. During the intake, the therapist and client will work together to discuss treatment goals. Then a treatment plan will be formulated, usually with specific measurable objectives. Also, the therapist and client will discuss how treatment success will be measured and the estimated length of treatment. There are several different modalities of treatment (Figure): Individual therapy, family therapy, couples therapy, and group therapy are the most common. INDIVIDUAL THERAPY In individual therapy, also known as individual psychotherapy or individual counseling, the client and clinician meet one-on-one (usually from 45 minutes to 1 hour). These meetings typically occur weekly or every other week, and sessions are conducted in a confidential and caring environment (Figure). The clinician will work with clients to help them explore their feelings, work through life challenges, identify aspects of themselves and their lives that they wish to change, and set goals to help them work towards these changes. A client might see a clinician for only a few sessions, or the client may attend individual therapy sessions for a year or longer. The amount of time spent in therapy depends on the needs of the client as well as her personal goals. GROUP THERAPY In group therapy, a clinician meets together with several clients with similar problems (Figure). When children are placed in group therapy, it is particularly important to match clients for age and problems. One benefit of group therapy is that it can help decrease a client’s shame and isolation about a problem while offering needed support, both from the therapist and other members of the group (American Psychological Association, 2014). A nine-year-old sexual abuse victim, for example, may feel very embarrassed and ashamed. If he is placed in a group with other sexually abused boys, he will realize that he is not alone. A child struggling with poor social skills would likely benefit from a group with a specific curriculum to foster special skills. A woman suffering from post-partum depression could feel less guilty and more supported by being in a group with similar women. Group therapy also has some specific limitations. Members of the group may be afraid to speak in front of other people because sharing secrets and problems with complete strangers can be stressful and overwhelming. There may be personality clashes and arguments among group members. There could also be concerns about confidentiality: Someone from the group might share what another participant said to people outside of the group. Another benefit of group therapy is that members can confront each other about their patterns. For those with some types of problems, such as sexual abusers, group therapy is the recommended treatment. Group treatment for this population is considered to have several benefits: Group treatment is more economical than individual, couples, or family therapy. Sexual abusers often feel more comfortable admitting and discussing their offenses in a treatment group where others are modeling openness. Clients often accept feedback about their behavior more willingly from other group members than from therapists. Finally, clients can practice social skills in group treatment settings. (McGrath, Cumming, Burchard, Zeoli, & Ellerby, 2009) Groups that have a strong educational component are called psycho-educational groups. For example, a group for children whose parents have cancer might discuss in depth what cancer is, types of treatment for cancer, and the side effects of treatments, such as hair loss. Often, group therapy sessions with children take place in school. They are led by a school counselor, a school psychologist, or a school social worker. Groups might focus on test anxiety, social isolation, self-esteem, bullying, or school failure (Shechtman, 2002). Whether the group is held in school or in a clinician’s office, group therapy has been found to be effective with children facing numerous kinds of challenges (Shechtman, 2002). During a group session, the entire group could reflect on an individual’s problem or difficulties, and others might disclose what they have done in that situation. When a clinician is facilitating a group, the focus is always on making sure that everyone benefits and participates in the group and that no one person is the focus of the entire session. Groups can be organized in various ways: some have an overarching theme or purpose, some are time-limited, some have open membership that allows people to come and go, and some are closed. Some groups are structured with planned activities and goals, while others are unstructured: There is no specific plan, and group members themselves decide how the group will spend its time and on what goals it will focus. This can become a complex and emotionally charged process, but it is also an opportunity for personal growth (Page & Berkow, 1994). COUPLES THERAPY Couples therapy involves two people in an intimate relationship who are having difficulties and are trying to resolve them (Figure). The couple may be dating, partnered, engaged, or married. The primary therapeutic orientation used in couples counseling is cognitive-behavioral therapy (Rathus & Sanderson, 1999). Couples meet with a therapist to discuss conflicts and/or aspects of their relationship that they want to change. The therapist helps them see how their individual backgrounds, beliefs, and actions are affecting their relationship. Often, a therapist tries to help the couple resolve these problems, as well as implement strategies that will lead to a healthier and happier relationship, such as how to listen, how to argue, and how to express feelings. However, sometimes, after working with a therapist, a couple will realize that they are too incompatible and will decide to separate. Some couples seek therapy to work out their problems, while others attend therapy to determine whether staying together is the best solution. Counseling couples in a high-conflict and volatile relationship can be difficult. In fact, psychologists Peter Pearson and Ellyn Bader, who founded the Couples Institute in Palo Alto, California, have compared the experience of the clinician in couples’ therapy to be like “piloting a helicopter in a hurricane” (Weil, 2012, para. 7). FAMILY THERAPY Family therapy is a special form of group therapy, consisting of one or more families. Although there are many theoretical orientations in family therapy, one of the most predominant is the systems approach. The family is viewed as an organized system, and each individual within the family is a contributing member who creates and maintains processes within the system that shape behavior (Minuchin, 1985). Each member of the family influences and is influenced by the others. The goal of this approach is to enhance the growth of each family member as well as that of the family as a whole. Often, dysfunctional patterns of communication that develop between family members can lead to conflict. A family with this dynamic might wish to attend therapy together rather than individually. In many cases, one member of the family has problems that detrimentally affect everyone. For example, a mother’s depression, teen daughter’s eating disorder, or father’s alcohol dependence could affect all members of the family. The therapist would work with all members of the family to help them cope with the issue, and to encourage resolution and growth in the case of the individual family member with the problem. With family therapy, the nuclear family (i.e., parents and children) or the nuclear family plus whoever lives in the household (e.g., grandparent) come into treatment. Family therapists work with the whole family unit to heal the family. There are several different types of family therapy. In structural family therapy, the therapist examines and discusses the boundaries and structure of the family: who makes the rules, who sleeps in the bed with whom, how decisions are made, and what are the boundaries within the family. In some families, the parents do not work together to make rules, or one parent may undermine the other, leading the children to act out. The therapist helps them resolve these issues and learn to communicate more effectively. Watch this video to view a structural family session. In strategic family therapy, the goal is to address specific problems within the family that can be dealt with in a relatively short amount of time. Typically, the therapist would guide what happens in the therapy session and design a detailed approach to resolving each member’s problem (Madanes, 1991). Summary There are several modalities of treatment: individual therapy, group therapy, couples therapy, and family therapy are the most common. In an individual therapy session, a client works one-on-one with a trained therapist. In group therapy, usually 5–10 people meet with a trained group therapist to discuss a common issue (e.g., divorce, grief, eating disorders, substance abuse, or anger management). Couples therapy involves two people in an intimate relationship who are having difficulties and are trying to resolve them. The couple may be dating, partnered, engaged, or married. The therapist helps them resolve their problems as well as implement strategies that will lead to a healthier and happier relationship. Family therapy is a special form of group therapy. The therapy group is made up of one or more families. The goal of this approach is to enhance the growth of each individual family member and the family as a whole. Review Questions A treatment modality in which 5–10 people with the same issue or concern meet together with a trained clinician is known as ________. - family therapy - couples therapy - group therapy - self-help group Hint: C What happens during an intake? - The therapist gathers specific information to address the client’s immediate needs such as the presenting problem, the client’s support system, and insurance status. The therapist informs the client about confidentiality, fees, and what to expect in a therapy session. - The therapist guides what happens in the therapy session and designs a detailed approach to resolving each member’s presenting problem. - The therapist meets with a couple to help them see how their individual backgrounds, beliefs, and actions are affecting their relationship. - The therapist examines and discusses with the family the boundaries and structure of the family: For example, who makes the rules, who sleeps in the bed with whom, and how decisions are made. Hint: A Critical Thinking Question Compare and contrast individual and group therapies. Hint: In an individual therapy session, a client works one-on-one with a trained therapist. In group therapy, usually 5–10 people meet with a trained group therapist to discuss a common issue, such as divorce, grief, eating disorder, substance abuse, or anger management. Personal Application Your best friend tells you that she is concerned about her cousin. The cousin—a teenage girl—is constantly coming home after her curfew, and your friend suspects that she has been drinking. What treatment modality would you recommend to your friend and why?	oercommons	2025-03-18T00:37:16.248865	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15394/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/15395/overview	Substance-Related and Addictive Disorders: A Special Case Overview By the end of this section, you will be able to: - Recognize the goal of substance-related and addictive disorders treatment - Discuss what makes for effective treatment - Describe how comorbid disorders are treated Addiction is often viewed as a chronic disease (Figure). The choice to use a substance is initially voluntary; however, because chronic substance use can permanently alter the neural structure in the prefrontal cortex, an area of the brain associated with decision-making and judgment, a person becomes driven to use drugs and/or alcohol (Muñoz-Cuevas, Athilingam, Piscopo, & Wilbrecht, 2013). This helps explain why relapse rates tend to be high. About 40%–60% of individuals relapse, which means they return to abusing drugs and/or alcohol after a period of improvement (National Institute on Drug Abuse [NIDA], 2008). The goal of substance-related treatment is to help an addicted person stop compulsive drug-seeking behaviors (NIDA, 2012). This means an addicted person will need long-term treatment, similar to a person battling a chronic physical disease such as hypertension or diabetes. Treatment usually includes behavioral therapy and/or medication, depending on the individual (NIDA, 2012). Specialized therapies have also been developed for specific types of substance-related disorders, including alcohol, cocaine, and opioids (McGovern & Carroll, 2003). Substance-related treatment is considered much more cost-effective than incarceration or not treating those with addictions (NIDA, 2012) (Figure). WHAT MAKES TREATMENT EFFECTIVE? Specific factors make substance-related treatment much more effective. One factor is duration of treatment. Generally, the addict needs to be in treatment for at least three months to achieve a positive outcome (Simpson, 1981; Simpson, Joe, & Bracy, 1982; NIDA, 2012). This is due to the psychological, physiological, behavioral, and social aspects of abuse (Simpson, 1981; Simpson et al., 1982; NIDA, 2012). While in treatment, an addict might receive behavior therapy, which can help motivate the addict to participate in the treatment program and teach strategies for dealing with cravings and how to prevent relapse. Also, treatment needs to be holistic and address multiple needs, not just the drug addiction. This means that treatment will address factors such as communication, stress management, relationship issues, parenting, vocational concerns, and legal concerns (McGovern & Carroll, 2003; NIDA, 2012). While individual therapy is used in the treatment of substance-related disorders, group therapy is the most widespread treatment modality (Weiss, Jaffee, de Menil, & Cogley, 2004). The rationale behind using group therapy for addiction treatment is that addicts are much more likely to maintain sobriety in a group format. It has been suggested that this is due to the rewarding and therapeutic benefits of the group, such as support, affiliation, identification, and even confrontation (Center for Substance Abuse Treatment, 2005). For teenagers, the whole family often needs to participate in treatment to address issues such as family dynamics, communication, and relapse prevention. Family involvement in teen drug addiction is vital. Research suggests that greater parental involvement is correlated with a greater reduction in use by teen substance abusers. Also, mothers who participated in treatment displayed better mental health and greater warmth toward their children (Bertrand et al., 2013). However, neither individual nor group therapy has been found to be more effective (Weiss et al., 2004). Regardless of the type of treatment service, the primary focus is on abstinence or at the very least a significant reduction in use (McGovern & Carroll, 2003). Treatment also usually involves medications to detox the addict safely after an overdose, to prevent seizures and agitation that often occur in detox, to prevent reuse of the drug, and to manage withdrawal symptoms. Getting off drugs often involves the use of drugs—some of which can be just as addictive. Detox can be difficult and dangerous. Watch this video to find out more about treating substance-related disorders using the biological, behavioral, and psychodynamic approaches. COMORBID DISORDERS Frequently, a person who is addicted to drugs and/or alcohol has an additional psychological disorder. Saying a person has comorbid disorders means the individual has two or more diagnoses. This can often be a substance-related diagnosis and another psychiatric diagnosis, such as depression, bipolar disorder, or schizophrenia. These individuals fall into the category of mentally ill and chemically addicted (MICA)—their problems are often chronic and expensive to treat, with limited success. Compared with the overall population, substance abusers are twice as likely to have a mood or anxiety disorder. Drug abuse can cause symptoms of mood and anxiety disorders and the reverse is also true—people with debilitating symptoms of a psychiatric disorder may self-medicate and abuse substances. In cases of comorbidity, the best treatment is thought to address both (or multiple) disorders simultaneously (NIDA, 2012). Behavior therapies are used to treat comorbid conditions, and in many cases, psychotropic medications are used along with psychotherapy. For example, evidence suggests that bupropion (trade names: Wellbutrin and Zyban), approved for treating depression and nicotine dependence, might also help reduce craving and use of the drug methamphetamine (NIDA, 2011). However, more research is needed to better understand how these medications work—particularly when combined in patients with comorbidities. Summary Addiction is often viewed as a chronic disease that rewires the brain. This helps explain why relapse rates tend to be high, around 40%–60% (McLellan, Lewis, & O’Brien, & Kleber, 2000). The goal of treatment is to help an addict stop compulsive drug-seeking behaviors. Treatment usually includes behavioral therapy, which can take place individually or in a group setting. Treatment may also include medication. Sometimes a person has comorbid disorders, which usually means that they have a substance-related disorder diagnosis and another psychiatric diagnosis, such as depression, bipolar disorder, or schizophrenia. The best treatment would address both problems simultaneously. Review Questions What is the minimum amount of time addicts should receive treatment if they are to achieve a desired outcome? - 3 months - 6 months - 9 months - 12 months Hint: A When an individual has two or more diagnoses, which often includes a substance-related diagnosis and another psychiatric diagnosis, this is known as ________. - bipolar disorder - comorbid disorder - codependency - bi-morbid disorder Hint: B John was drug-free for almost six months. Then he started hanging out with his addict friends, and he has now started abusing drugs again. This is an example of ________. - release - reversion - re-addiction - relapse Hint: D Critical Thinking Question You are conducting an intake assessment. Your client is a 45-year-old single, employed male with cocaine dependence. He failed a drug screen at work and is mandated to treatment by his employer if he wants to keep his job. Your client admits that he needs help. Why would you recommend group therapy for him? Hint: The rationale behind using group therapy for addiction treatment is that addicts are much more likely to maintain sobriety when treatment is in a group format. It has been suggested that it’s due to the rewarding and therapeutic benefits of the group, such as support, affiliation, identification, and even confrontation. Because this client is single, he may not have family support, so support from the group may be even more important in his ability to recover and maintain his sobriety. Personal Application Question What are some substance-related and addictive disorder treatment facilities in your community, and what types of services do they provide? Would you recommend any of them to a friend or family member with a substance abuse problem? Why or why not?	oercommons	2025-03-18T00:37:16.273774	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15395/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/15396/overview	The Sociocultural Model and Therapy Utilization Overview By the end of this section, you will be able to: - Explain how the sociocultural model is used in therapy - Discuss barriers to mental health services among ethnic minorities The sociocultural perspective looks at you, your behaviors, and your symptoms in the context of your culture and background. For example, José is an 18-year-old Hispanic male from a traditional family. José comes to treatment because of depression. During the intake session, he reveals that he is gay and is nervous about telling his family. He also discloses that he is concerned because his religious background has taught him that homosexuality is wrong. How does his religious and cultural background affect him? How might his cultural background affect how his family reacts if José were to tell them he is gay? As our society becomes increasingly multiethnic and multiracial, mental health professionals must develop cultural competence (Figure), which means they must understand and address issues of race, culture, and ethnicity. They must also develop strategies to effectively address the needs of various populations for which Eurocentric therapies have limited application (Sue, 2004). For example, a counselor whose treatment focuses on individual decision making may be ineffective at helping a Chinese client with a collectivist approach to problem solving (Sue, 2004). Multicultural counseling and therapy aims to offer both a helping role and process that uses modalities and defines goals consistent with the life experiences and cultural values of clients. It strives to recognize client identities to include individual, group, and universal dimensions, advocate the use of universal and culture-specific strategies and roles in the healing process, and balancs the importance of individualism and collectivism in the assessment, diagnosis, and treatment of client and client systems (Sue, 2001). This therapeutic perspective integrates the impact of cultural and social norms, starting at the beginning of treatment. Therapists who use this perspective work with clients to obtain and integrate information about their cultural patterns into a unique treatment approach based on their particular situation (Stewart, Simmons, & Habibpour, 2012). Sociocultural therapy can include individual, group, family, and couples treatment modalities. Watch this short video to learn more about cultural competence and sociocultural treatments. BARRIERS TO TREATMENT Statistically, ethnic minorities tend to utilize mental health services less frequently than White, middle-class Americans (Alegría et al., 2008; Richman, Kohn-Wood, & Williams, 2007). Why is this so? Perhaps the reason has to do with access and availability of mental health services. Ethnic minorities and individuals of low socioeconomic status (SES) report that barriers to services include lack of insurance, transportation, and time (Thomas & Snowden, 2002). However, researchers have found that even when income levels and insurance variables are taken into account, ethnic minorities are far less likely to seek out and utilize mental health services. And when access to mental health services is comparable across ethnic and racial groups, differences in service utilization remain (Richman et al., 2007). In a study involving thousands of women, it was found that the prevalence rate of anorexia was similar across different races, but that bulimia nervosa was more prevalent among Hispanic and African American women when compared with non-Hispanic whites (Marques et al., 2011). Although they have similar or higher rates of eating disorders, Hispanic and African American women with these disorders tend to seek and engage in treatment far less than Caucasian women. These findings suggest ethnic disparities in access to care, as well as clinical and referral practices that may prevent Hispanic and African American women from receiving care, which could include lack of bilingual treatment, stigma, fear of not being understood, family privacy, and lack of education about eating disorders. Perceptions and attitudes toward mental health services may also contribute to this imbalance. A recent study at King’s College, London, found many complex reasons why people do not seek treatment: self-sufficiency and not seeing the need for help, not seeing therapy as effective, concerns about confidentiality, and the many effects of stigma and shame (Clement et al., 2014). And in another study, African Americans exhibiting depression were less willing to seek treatment due to fear of possible psychiatric hospitalization as well as fear of the treatment itself (Sussman, Robins, & Earls, 1987). Instead of mental health treatment, many African Americans prefer to be self-reliant or use spiritual practices (Snowden, 2001; Belgrave & Allison, 2010). For example, it has been found that the Black church plays a significant role as an alternative to mental health services by providing prevention and treatment-type programs designed to enhance the psychological and physical well-being of its members (Blank, Mahmood, Fox, & Guterbock, 2002). Additionally, people belonging to ethnic groups that already report concerns about prejudice and discrimination are less likely to seek services for a mental illness because they view it as an additional stigma (Gary, 2005; Townes, Cunningham, & Chavez-Korell, 2009; Scott, McCoy, Munson, Snowden, & McMillen, 2011). For example, in one recent study of 462 older Korean Americans (over the age of 60) many participants reported suffering from depressive symptoms. However, 71% indicated they thought depression was a sign of personal weakness, and 14% reported that having a mentally ill family member would bring shame to the family (Jang, Chiriboga, & Okazaki, 2009). Language differences are a further barrier to treatment. In the previous study on Korean Americans’ attitudes toward mental health services, it was found that there were no Korean-speaking mental health professionals where the study was conducted (Orlando and Tampa, Florida) (Jang et al., 2009). Because of the growing number of people from ethnically diverse backgrounds, there is a need for therapists and psychologists to develop knowledge and skills to become culturally competent (Ahmed, Wilson, Henriksen, & Jones, 2011). Those providing therapy must approach the process from the context of the unique culture of each client (Sue & Sue, 2007). Treatment Perceptions By the time a child is a senior in high school, 20% of his classmates—that is 1 in 5—will have experienced a mental health problem (U.S. Department of Health and Human Services, 1999), and 8%—about 1 in 12—will have attempted suicide (Centers for Disease Control and Prevention, 2014). Of those classmates experiencing mental disorders, only 20% will receive professional help (U.S. Public Health Service, 2000). Why? It seems that the public has a negative perception of children and teens with mental health disorders. According to researchers from Indiana University, the University of Virginia, and Columbia University, interviews with over 1,300 U.S. adults show that they believe children with depression are prone to violence and that if a child receives treatment for a psychological disorder, then that child is more likely to be rejected by peers at school. Bernice Pescosolido, author of the study, asserts that this is a misconception. However, stigmatization of psychological disorders is one of the main reasons why young people do not get the help they need when they are having difficulties. Pescosolido and her colleagues caution that this stigma surrounding mental illness, based on misconceptions rather than facts, can be devastating to the emotional and social well-being of our nation’s children. This warning played out as a national tragedy in the 2012 shootings at Sandy Hook Elementary. In her blog, Suzy DeYoung (2013), co-founder of Sandy Hook Promise (the organization parents and concerned others set up in the wake of the school massacre) speaks to treatment perceptions and what happens when children do not receive the mental health treatment they desperately need. I've become accustomed to the reaction when I tell people where I'm from. Eleven months later, it's as consistent as it was back in January. Just yesterday, inquiring as to the availability of a rental house this holiday season, the gentleman taking my information paused to ask, “Newtown, CT? Isn't that where that...that thing happened? A recent encounter in the Massachusetts Berkshires, however, took me by surprise. It was in a small, charming art gallery. The proprietor, a woman who looked to be in her 60s, asked where we were from. My response usually depends on my present mood and readiness for the inevitable dialogue. Sometimes it's simply, Connecticut. This time, I replied, Newtown, CT. The woman's demeanor abruptly shifted from one of amiable graciousness to one of visible agitation. “Oh my god,” she said wide eyed and open mouthed. “Did you know her?” . . . . “Her?” I inquired That woman,” she replied with disdain, “that woman that raised that monster.” “That woman's” name was Nancy Lanza. Her son, Adam, killed her with a rifle blast to the head before heading out to kill 20 children and six educators at Sandy Hook Elementary School in Newtown, CT last December 14th. When Nelba Marquez Greene, whose beautiful 6-year-old daughter, Ana, was killed by Adam Lanza, was recently asked how she felt about “that woman,” this was her reply: “She's a victim herself. And it's time in America that we start looking at mental illness with compassion, and helping people who need it. “This was a family that needed help, an individual that needed help and didn't get it. And what better can come of this, of this time in America, than if we can get help to people who really need it?” (pars. 1–7, 10–15) Fortunately, we are starting to see campaigns related to the destigmatization of mental illness and an increase in public education and awareness. Join the effort by encouraging and supporting those around you to seek help if they need it. To learn more, visit the National Alliance on Mental Illness (NAMI) website (http://www.nami.org/). The nation’s largest nonprofit mental health advocacy and support organization is NAMI. Summary The sociocultural perspective looks at you, your behaviors, and your symptoms in the context of your culture and background. Clinicians using this approach integrate cultural and religious beliefs into the therapeutic process. Research has shown that ethnic minorities are less likely to access mental health services than their White middle-class American counterparts. Barriers to treatment include lack of insurance, transportation, and time; cultural views that mental illness is a stigma; fears about treatment; and language barriers. Review Questions The sociocultural perspective looks at you, your behaviors, and your symptoms in the context of your ________. - education - socioeconomic status - culture and background - age Hint: C Which of the following was not listed as a barrier to mental health treatment? - fears about treatment - language - transportation - being a member of the ethnic majority Hint: D Critical Thinking Question Lashawn is a 24-year-old African American female. For years she has been struggling with bulimia. She knows she has a problem, but she is not willing to seek mental health services. What are some reasons why she may be hesitant to get help? Hint: One reason may be that her culture views having a mental illness as a stigma. Additionally, perhaps she doesn’t have insurance and is worried about the cost of therapy. She could also be afraid that a White counselor would not understand her cultural background, so she would feel uncomfortable sharing things. Also, she may believe she is self-reliant and tell herself that she’s a strong woman who can fix this problem on her own without the help of a therapist. Personal Application Question What is your attitude toward mental health treatment? Would you seek treatment if you were experiencing symptoms or having trouble functioning in your life? Why or why not? In what ways do you think your cultural and/or religious beliefs influence your attitude toward psychological intervention?	oercommons	2025-03-18T00:37:16.298584	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15396/overview", "title": "Psychology, Therapy and Treatment", "author": null }
https://oercommons.org/courseware/lesson/67429/overview	Education Standards Teamwork! Overview This unit is for elementary students grades 3-6. Activities build on cooperation, encouraging communication, team building skills, and participation. The unit includes 4 lessons with a reflection worksheet at the end. These can be used in classroom settings, group counseling, lunch bunch groups or guidance lessons Team Building Activity Teamwork! 3rd-6th grades Lesson/Unit Topic: TEAMWORK! Subject: Elementary Guidance, School Counseling Lessons Target Grade: 3rd-6th grades Author: Loyce Ellingrod Lesson Description: This unit is for elementary students grades 3-6. Activities build on cooperation, encouraging communication, team building skills, and participation. The unit includes 4 lessons with a reflection worksheet at the end. These can be used in classroom settings, group counseling, lunch bunch groups or guidance lessons. Learning goals/outcomes: Students will define team building skills and what teamwork is. Students will participate in a variety of team building activities. Students will demonstrate using encouraging words with their team members. Students will demonstrate personal safety when participating in activities. Students will determine why listening skills are needed for effective teamwork. Wyoming Standards: Career-Vocational Standards: CV5.2.1 Students identify and practice compromise and conflict resolutions skills CV5.2.3 Students identify and participate in group roles and responstiblities while demosntrating respect and awareness of diverstiy. ASCA Behavior Standards: B-SS 6: Use effective collaboration and cooperation skills. Teacher Planning: - Equipment/materials needed: computer, TV or Smartboard; whiteboard, markers, supplies for variety of games (check each day’s activity) colored pencils, 8x11 white paper, worksheet - Time required for lesson: 4-5 days--30 minute sessions Technology Use: __X____Yes ______No Instructional Plan: Introduction: With elbow partners or assigned partners, have students list any “teams” they know. As a group they will share their lists. How do they know these are “teams”? On board, list 5 characteristics of a team (example: more than 1 person, common goal, work together to win a game, help each other etc.) - Real-World Connection: We see teams around us everywhere. We need to know how to be a successful member of a team in sports, school and in future jobs and family life. - Activities: Day 1: Watch video: T.E.A.M work TED Youth talk as a group. When finished dicuss the main points from his talk. Put the letters “T.E.A.M.” down the side of the board. Write the words that he mentioned for each letter. Discuss what each means. Play the Balloon Toss Game: Give directions: - As a whole group (may divide into 2 groups depending on the size of class-12-15 members per circle) make a circle standing around the floor. (Move all desks/chairs away from the circle’s area. Large groups may need to move to another space such as a corner of the gym or playground.) - Have a balloon ready for each circle. Explain that they have to work to keep the balloon in the air (not touch the floor, walls, chairs etc.) When they start they need to gently tap the balloon in the air to another person in their circle. They need to stay planted in their area of the circle (can’t move around). They tap the ball and count each tap. The group’s highest number of taps without stopping is the winner. If there is only one group they work to get over 100 or more taps. No jumping, running or pushing others. The teacher can remove any students who can’t follow the rules. If the balloon touches the floor etc. they start their counting the taps over. The teacher can stop the activity at any time to talk about working together, staying in the area, correct ways to tap etc. - Record the highest number of taps for each group or attempts when done. If there is more than one section of groups doing this activity, they can challenge themselves to beat another group’s total. Have the group return to their original seats. Review TEAM words. Teacher provides each student with a sheet of white paper. Draw these words on a white paper (copy from the board) with colored pencils. Draw a picture of a team. Put names on paper. Hand into the teacher. Day 2: Review TEAM words from the previous lesson. As a group: Brainstorm “encouraging” words we can use when we are working with others. List these on the board. (examples: good job!; keep trying; keep going; nice try etc.) Play the Monkey game (use Barrel of Monkeys sets-1 per set for 4-6 students). Each group of students form a circle sitting on the floor. Remind them to stay in their area and to use encouraging words. Give Directions: - As a group they are to build a chain of monkeys. The only person who can touch the monkeys is the teacher. The group can decide who starts in each group. That person will pick up a monkey and hook it to another monkey, and then pass the chain to the next team member beside them. It continues around the circle until all the monkeys are picked up. (No doubles.) If they fall off, then that member passes it on and the next member picks up one monkey to start over. They can talk during this activitiy-give suggestions, advice and encouraging words. Some students struggle with this because they are shaky or nervous. It’s okay to try and then pass it on if it gets too frustrating. They will usually try again when it is their turn. - Watch each group and record who makes the longest chain or finishes first with all of the monkeys. Have the group return to their original seats. Review encouraging words list. Teacher provides each student with a sheet of white paper. Choose one word from the board to draw on a sheet of paper with colored pencils. Add colors and draw a picture of people using these words. Put the name on the paper. Hand into teacher when done. Day 3: Review encouraging words and TEAM words. Discuss WORK. What does this look like? What is a leader? Follower? Listener? Helper? Write the letters “W.O.R.K.” on the board down the side. Brainstorm and record words from the group for each letter (example: W-we win; O-only together etc.) Decide what words they prefer and use these for the class’s example. Play build a Straw Boat to Float challenge. Divide into groups of 4-5 students or partners, depending on the size of the class, for each boat. Have them sit together facing each other. Give directions: - Give each small group a certain number of drinking straws (dollar store straws work well for this)-usually 12-15 straws per group works best. - Give masking tape strips to each group. This can be limited or not-teacher can decide how much will be used. Also scissors can be allowed if the teacher wants to have them. - Set the time for the activity. Explain they are to build a boat using straws and masking tape. It will be tested to see if it will float in a pan of water. The boat will be tested by putting coins (pennies) one at a time on the boat. The boat that holds the most coins wins. - Let the students design and make their boats together. Walk around and witness their designing, working together, encouraging words and frustrations. - When done, have a pan (old cake pan works) ½ to ¾ full of water and a jar of coins ready. Put the boat into the water for the test. Count the number of coins it holds before it sinks. The team with the most wins! Have the group return to their original seats. Review the WORK words on the board. Teacher provides each student with a sheet of white paper. Draw the words on a white paper with colored pencils. Draw a picture of people working together. Put names on papers. Hand into teacher when done. Day 4: Review TEAMWORK. Discuss how we have shown team building skills in our past lessons. Today’s focus is on communicating (using our listening and speaking skills). We will complete a challenge with talking and sharing ideas the first time and then try it again without talking. Play the Cup Stacking Challenge (this is one variation for this challenge). - Divide into partners. Give each set of partners a set of plastic drinking cups (15 works well). - Partners need to face each with the cups randomly on the table/floor in front of them. - They are going to stack the cups (5 on the bottom in a row, then 4 , 3 and so on to make a pyramid). They need to take turns putting the cups on the stack and then unstacking it. Only one cup at a time. They must wait until their partner puts a cup up before they do theirs. Each group decides who goes first. They can talk and listen to each other this round. The goal is to see how fast they can stack and unstack the cups without dropping them or knocking down the stack. The teacher can set a time limit for this. They keep stacking/unstacking until the teacher calls time. They can count the number of times they stacked & unstacked to give to the teacher. - Second round: they do it again, but this time they can’t talk while they are doing it. Start with the other partner. Again it is timed and see how many times they can stack and unstack the cups. - Following rounds: partners can be moved to new people and process repeated again. time allowed can be changed: be lengthened or shortened as the teacher prefers. Discuss how many times they had; did they get faster with practice: why is talking and listening important when working with others?; How does it help? What is a barrier to good listening? What can we do to overcome the barriers? - Closure and Check for understanding: Have students complete “My Teamwork Reflection” form about their experiences with team building during our lessons. Hand into teacher. Supplemental Information: - Modifications: Different games can be used. These are just ideas that have been used with this age group. - Safety Precautions: Always remind the group/partners of safety rules before, during and after each activity. Students can sit out if they can’t follow the rules. - Comments: These activites have been adapted for older students too. The specific requirements and follow up activities can be changed to meet the age and maturity. - All the artwork from lessons can be put together to be displayed or put onto a bulletin board promoting Teamwork. - Additional resources: 104 Activities that Build: Self-esteem, teamwork, communication, anger management, self-discovery, coping skills by Alanna Jones Activites that Teach by Tom Jackson Still More Activities that Teach by Tom Jackson	oercommons	2025-03-18T00:37:16.333582	05/27/2020	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/67429/overview", "title": "Teamwork!", "author": "Loyce Ellingrod" }
https://oercommons.org/courseware/lesson/68798/overview	Education Standards Activity 2 - Typographic Contrast Activity 3 - Text Hierarchy Calligraphr Template Evaluating Resources for OER Commons Typography - Formative Assessment Using Typography to Communicate Overview This lesson provides an introduction to the importance of typography as an element of design. Goal: The goal of this lesson is to understand that typography is everywhere. The way characters or letters are designed plays a part in the message and in creating a brand for an organization. Every font, letter, and character arrangement plays a part in determining how a message is conveyed. Understanding Basic Elements of Typography 1) Students will read articles and watch PBS video (the linked OER Commons resource). The instructor will informally assess their understanding of the information through group discussion and questioning. 2) Students will complete a short formative assessment covering information in the articles and video. Creation Date: June, 2020 Grade Level: High School - Grades 9-12 Content Area: Media Technology Goal: The goal of this lesson is to understand that typography is everywhere. The way characters or letters are designed plays a part in the message and in creating a brand for an organization. Every font, letter, and character arrangement plays a part in determining how a message is conveyed. Objectives: - To utilize type as a design element. - To differentiate between different styles of typography. - To use fonts to represent specific feelings and emotions. - To explore creative ways to layout typographic elements. Message to students: You will be designing many informational documents and title slides for video for school and community activities. An understanding of typography is imperative to any situation where you want to transmit an idea to another via text. Read these three short articles for an overview of typography: Typography Elements Everyone Needs to Understand Basic Principles for Using Typography Extra - Fonts Used in Famous Logos - Famous fonts: the typefaces behind the biggest logos Watch this PBS video: What is Typography - (this is the linked OER Resource) Activities to Demonstrate Understanding of Typography These three activities will reinforce information learned about typography. While students will be using Google Drawing for these activities, the next step will be to introduce Photoshop Elements and continuing to use the information learned on design activities for the school and community throughout the semester. Students will be using a poster printer that can print on indoor/outdoor canvas to design banners for the school and community organizations. Activity 1 - Comparing Serif, Sans-Serif and Decorative Fonts Click in each box and type your name 3 times. Each name will be put in a different font. Each font should be the type of font listed in the box. When finished, share in Google Classroom. Activity 2 - Contrast of Type Type the quote and fill the space below. Adjust words in the quote by: Size - make some words bigger than others for emphasis. Weight - create emphasis on certain words by making them bold. Color - change the color of the word this should be emphasized. Structure - choose your emphasis word and type it in a completely different typeface. Activity 3 - Typographic Hierarchy Typographic Hierarchy - distinguishes different levels of importance. Organize the information given below using contrasting typographic contrast to emphasize certain words or groups of words as more important or less important than others to capture the attention of incoming freshmen. • Emphasize levels of information through typographic contrast of size, weight, color, structure • Use spatial organization and control hierarchy in both large and small scale • Select appropriate color combinations to support organization and emphasis without reducing legibility/readability Enrichment Activity For Fun - Create Your Own Font From Your Handwriting 1) Go to calligraphr.com 2) Create an account, activate it by confirming in e-mail, log in 3) Start App 3) Create template 4) Choose minimal English, minimal Numbers, minimal Punctuation 5) Click on any characters you don't need and delete 6) Download template and print 7) Fill in each box with your handwriting 8) Take a picture or scan sheet(s) 9) Go back to calligraphr.com, choose My Fonts 9) Upload templates, choose file(s) to upload, upload 11) Preview, Build Font, Name Font 12) Make any adjustments 13) Download, open, install 14) Open new document to find and use font	oercommons	2025-03-18T00:37:16.369629	Assessment	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/68798/overview", "title": "Using Typography to Communicate", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/92850/overview	Graphic Design lesson plan Overview graphic design Lesson Plan introduction Based on the Colombian frameworks: - Competencia Tecnológica: Dentro del contexto educativo, la competencia tecnológica se puede definir como la capacidad para seleccionar y utilizar de forma pertinente, responsable y eficiente una variedad de herramientas tecnológicas entendiendo los principios que las rigen, la forma de combinarlas y las licencias que las amparan. - Competencia Comunicativa: La competencia comunicativa se puede definir como la capacidad para expresarse, establecer contacto y relacionarse en espacios virtuales y audiovisuales a través de diversos medios y con el manejo de múltiples lenguajes, de manera sincrónica y asincrónica. - Competencia Pedagógica: La competencia pedagógica se puede definir como la capacidad de utilizar las TIC para fortalecer los procesos de enseñanza y aprendizaje, reconociendo alcances y limitaciones de la incorporación de estas tecnologías en la formación integral de los estudiantes y en su propio desarrollo profesional. - Competencia de Gestión: La competencia de gestión se puede definir como la capacidad para utilizar las TIC en la planeación, organización, administración y evaluación de manera efectiva de los procesos educativos; tanto a nivel de prácticas pedagógicas como de desarrollo institucional. - Competencia Investigativa: La competencia investigativa se define como la capacidad de utilizar las TIC para la transformación del saber y la generación de nuevos conocimientos. Name of student teachers: Laura Daniela Guachetá Salinas María Fernanda Hernández Hernández Nicolás Sanchez Arguelles School/Institution: Rafael Pombo School Class/grade: Students with beginner-intermediate level of English/High School Time & Length of class: 1 hour Achievement: - Review students' knowledge and background about graphic design. - Reinforce the basics of graphic design Lesson objectives: - Define what graphic design is. - Understand the elements and principles of graphic design. - Employ the techniques of color, texture, image and typography to make a good design. Resources and materials: - video beam - pc - Digital platforms (ExeLearning, Genially). - Videos - PPT Skills Focus: - Listening - Reading Language focus: - Vocabulary: Elements of Graphic Design (Color, texture, form, space, line, size, shape) - Functional language: Answering and reading questions. Foreseeable Problems: Problems with the video beam Planned Solutions: Sharing the presentation on students' computers European Framework Digital Competence Facilitating Learners’ Digital Competence Empowering Learners: - Accessibility and inclusion: To consider and respond to learners’ (digital) expectations, abilities, uses and misconceptions, as well as contextual, physical or cognitive constraints to their use of digital technologies. - Differentiation and personalisation: To use digital technologies to address learners’ diverse learning needs, by allowing learners to advance at different levels and speeds, and to follow individual learning pathways and objectives. - Actively engaging learners: To use digital technologies to foster learners’ active and creative engagement with a subject matter. To use digital technologies within pedagogic strategies that foster learners’ transversal skills, deep thinking and creative expression. To open up learning to new, real-world contexts, which involve learners themselves in hands-on activities, scientific investigation or complex problem solving, or in other ways increase learners’ active involvement in complex subject matters. Lesson Plan Development Stage of lesson Pre-Act Time 10 min Procedure (Teacher and Student Activity) To start the lesson, a quiz will be presented in order to evaluate the students' previous knowledge and concepts about graphic design and its basic elements. For this quiz, it will be presented through an app to make it dynamic. After this, there will be a socialization of the results. With the socialization will give way to the following introductory activity to start the class in detail with the subject corresponding to graphic design. Link Activity https://quizizz.com/admin/quiz/6287ed92404f62001e48b3fd/graphic-design Interaction Students (Sts) University Supervisor’s comments Lesson Plan Development Stage of lesson While-Act Time 30 min Procedure (Teacher and Student Activity) To continue, a brainstorming session (1) will be designed in the class to socialize the key ideas or concepts that students have about graphic design and its basic elements. After this, a presentation (2) will be given with the key definitions for graphic design. Based on these key concepts, an interactive video will be presented about: - Color - Texture - Form - Space - Line - Size - Shape Students should take notes to answer the questions and develop the activities presented throughout the video. Link Activity 1. https://www.mindmeister.com/map/2299620842?t=AHSdNhvpQi 3. https://www.oercommons.org/editor/documents/12828 Interaction Teacher (Tch) Students (Sts) University Supervisor’s comments Lesson Plan Development Stage of lesson Post-Act Time 50 min Procedure (Teacher and Student Activity) Finally, an interactive image will be presented in which the students will have to design a simple card. Students will have to choose between typography, background and shape. Link Activity https://view.genial.ly/6287bb6925a6cd001848bf12/interactive-content-graphic-design Interaction Students (Sts) University Supervisor’s comments	oercommons	2025-03-18T00:37:16.394388	05/19/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/92850/overview", "title": "Graphic Design lesson plan", "author": "Daniela Guachetá" }
https://oercommons.org/courseware/lesson/123177/overview	Reviewing OER Licensing for License Compatibility Overview This mini-lesson explores how the terms Creative Commons licenses support revising or remixing OER for correct attribution. (Review and deepen knowledge) In Module 1 of this series, we reviewed a definition of open licensing. In this Module, we want to look closely at why the license matters for the processes of revision or remixing. Open licensing refers to when the author chooses terms of use that allow others to use, share or change the work with few restrictions. A non-profit called Creative Commons created a set of open licenses called the Creative Commons licenses that is a standardized way to explain how other users can re-use, redistribute, retain, revise and remix the work. When faculty are planning to revise or remix a resource, they will need to check the terms of the original license. Let's clarify the difference between revising and remixing: - revising an OER will mean making changes to the original OER to edit, adapt or modify a resource with the intent to keep the OER in it's basic orginal format. - remixing OER is when multiple OER are combined in order to create a new resource. For both of these types of iterations, faculty will need to be sure that they are following the terms of the original OER's license. The main limitations are going to be the "No Derivatives" term of use and the "Share Alike" term of use. - No Derivatives means that you cannot make changes and then distribute your changes. The work must only be distributed in its original form. - Share Alike means that you can make changes, but any changes and remixes must have the same license as the original. For example, if an infographic is licensed CC-BY-SA, then it can only be used in other resources that exactly licensed CC-BY-SA. In the chart below, you start on the left column with the OER's original license - for example a textbook licensed CC-BY. Then you use the top row to select the license of the additional material you want to add, for example, an infographic licensed CC-BY-SA that you want to modify. You can combine those two works, but the new combination would need to be licensed CC-BY-SA. Looking at an Example: - If an infographic is licensed CC-BY-NC-SA: - Can you remix the image by adding an audio description? - Yes - this license allows for derivatives - When you remix it, can you license it CC-BY? - No - Any derivatives of the original work need to be modified as CC-BY-NC-SA. - Can you include the infographic in its original form in a textbook licensed CC-BY? - Yes! The infographic must be clearly captioned and given attribution and the textbook must note "licensed CC-BY except where noted." Below are steps for checking the licensing before revising or remixing. - Find the original licensing terms for every existing resource that you wish to change or combine. - Consider finding contact information for each resource in case you need to contact the author. - Use the license compatability chart to check for license alignment. - Create appropriate attributions for each revised or adapted component. - Determine a license for the overall work. - Collaborate with a peer to check the licensing and attributions.	oercommons	2025-03-18T00:37:16.411020	12/18/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/123177/overview", "title": "OERizona Advanced OER Skills, Revise and Remix OER, Reviewing OER Licensing for License Compatibility", "author": "Peter Musser" }
https://oercommons.org/courseware/lesson/124716/overview	Fact or Fiction: Vitamin Supplements Reading Guided Notes Key - Vitamin T-Chart Guided Notes - Vitamins T-Chart Lesson Plan Outline - Like Dissolves Like Slideshow - Like Dissolves Like Station Rotation - Set Up Station Rotation - Task Cards Station Rotation - Worksheet Station Rotation - Worksheet Key Vitamins Worksheet Like Dissolves Like Lesson Plan Overview Welcome. Our goal is to design high school chemistry lesson plans that integrate fundamental organic chemisty concepts. These lessons aim to bridge the gap between introductory chemistry and organic chemistry, giving students a head start in understanding molecular structures, reactions, and more, in a way that is engaging and accessible. By connecting these core ideas with hands-on experiments, real-world applucations, and interactive learning tools, students will be better equipped to understand the relevance of organic chemistry in everyday life and future scientific studies. For additional organic chemistry lesson plans, view the following: Overview Welcome Our goal is to design high school chemistry lesson plans that integrate fundamental organic chemisty concepts. These lessons aim to bridge the gap between introductory chemistry and organic chemistry, giving students a head start in understanding molecular structures, reactions, and more, in a way that is engaging and accessible. By connecting these core ideas with hands-on experiments, real-world applucations, and interactive learning tools, students will be better equipped to understand the relevance of organic chemistry in everyday life and future scientific studies. For additional organic chemistry lesson plans, view the following: Feedback We value your feedback and would like to know how to make our lesson plans more engaging, accessible, and clear. Please take the following survey for this lesson plan, Like Dissolves Like, by using the following link: Like Dissolves Like Lesson Plan Like Dissolves Like Brief Lesson Description: \| \| Standard (from Utah SEEd Standards): Standard CHEM 2.3 \| \| Specific Learning Outcomes for This Lesson: \| Disclaimer Notice NOTICE The following information, lesson plans, demonstrations, and laboratory experiments (“Materials”) have been prepared with the objective of improving the standards and the quality of high school chemistry education. These Materials have been developed from sources that are considered to be reliable and that represent knowledgeable viewpoints of chemistry education. These Materials may involve the use of hazardous chemicals, operations, and equipment. Not all safety problems associated with the use of these methods, chemicals, and equipment may be addressed in the Materials. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before engaging in any experimental procedures described in these Materials. Consult the specific equipment or chemical user manuals for detailed precautions necessary to ensure safe handling and use. Further, it is incumbent upon instructors and those in charge to provide appropriate instruction, supervision, and laboratory conditions, including procedures for safe handling, use, and disposal of chemicals in accordance with local regulations and requirements. No warranty, guarantee, or other form of representation is made by the authors or by Brigham Young University concerning these Materials and their use. The authors and Brigham Young University hereby expressly disclaim any and all responsibility and liability concerning the use of these Materials for any purpose. This disclaimer applies to any liability that is, or may be incurred by, or on behalf of the institutions that make use of these Materials; the faculties, students, or prospective students of those institutions; and any member of the public at large; and includes, but is not limited to, a full disclaimer of any liability that may be incurred with respect to possible inadequate supervision or safety procedures taken by any individual or institution.	oercommons	2025-03-18T00:37:16.441379	Interactive	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/124716/overview", "title": "Like Dissolves Like Lesson Plan", "author": "Homework/Assignment" }
https://oercommons.org/courseware/lesson/101075/overview	Introduction to Behavioral Health & Social Services Overview In this course, you will learn about opportunities in behavioral health and human services through career explorations, self-assessments, and charting your personal academic and professional plan. You will also learn about mental health disorders and first responder skills in a mental health crisis. Introduction to Behavioral Health & Social Services In this course, you will learn about opportunities in behavioral health and human services through career explorations, self-assessments, and charting your personal academic and professional plan. You will also learn about mental health disorders and first responder skills in a mental health crisis. Course link: Canvas Commons Use this link to access this course in the Canvas Commons Course download: Common Cartridge Use the attached file to load this course into an LMS other than Canvas.	oercommons	2025-03-18T00:37:16.461578	Full Course	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/101075/overview", "title": "Introduction to Behavioral Health & Social Services", "author": "Social Work" }
https://oercommons.org/courseware/lesson/91770/overview	Life In Brazil: A Free ESL Lesson Plan Overview Brazil, the largest country in South America, also holds a large population of English Language Learners (ELLs). This free ESL lesson plan about life is Brazil is a great opportunity for students to practice using the present simple tense! It is especially useful if you are looking for a fun, light lesson to teach. You can access 150+ more free lessons like this with a free Off2Class account! Off2Class When teaching this lesson, have your student focus on speaking, not learning new grammar and vocabulary. When introducing vocabulary we recommend you encourage the student to talk about each image. Then, you can offer the vocabulary word without asking them to memorize it. The images and vocabulary are presented to encourage the student, rather than force them to learn new lexical items. You can access full teacher notes for this lesson plan by signing up for a free Off2Class account.	oercommons	2025-03-18T00:37:16.478600	04/13/2022	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/91770/overview", "title": "Life In Brazil: A Free ESL Lesson Plan", "author": "Christine Chan" }
https://oercommons.org/courseware/lesson/114960/overview	Rachel Moller - Lecture Note Template Adapting OER to Incorporate UDL (Gavilan College) Overview This template supports faculty and staff as they interrogate their OER and iterate the resource. This template is part of a Canvas course titled Adapting OER to Incorporate UDL. The initial course is offered by ISKME to California Community College faculty and staff and was created with support from the Michelson Foundatin's Spark Grant Program. Background on the Resource and Collaborators Prompts are provided below. Please replace the prompts with your own information. Please note: one template will be created per team unless a team has decided that each person is interrogating a separate OER. In that instance, this section could be copied and pasted into each person's template. Please provide background information on the team members and the resource you have chosen to interrogate and adapt. - Patrick Yuh M.S. - Biology Faculty - Erik Medina M.S. - Math Faculty - Rachel Moller, Ph.D. - Chemistry Faculy - What resource did your team chose to interrogate? - What are your team's goals with interrogating and adapting this resource? - What impact do you envision this will have on students? - What impact do you envision this will have on other faculty and staff at your institution? Rachel Moller - What resource did your team chose to interrogate? - OER Organic Chemistry Textbook on OpenStax - What are your team's goals with interrogating and adapting this resource? - I am planning to make all of my courses zero cost at the begninng of the 2024 acedemic term, so I wanted to investigate the textbook I am planning on using - What impact do you envision this will have on students? - College chemistry will be acheivable and obtainable for all students - What impact do you envision this will have on other faculty and staff at your institution? - This will allow all students to get closer to their overall goals through a high quality education and at no cost. Adaptations to support Open Educational Practices Prompts are provided below. Please replace the prompts with your own information. Please refer to the Characteristics of OER tool. Based on your interrogation of your resource, please share: - What are you planning to adapt to increase the features of the open licensing on this resource? - How long will this take and who will be the main point person working on this? - How will your team keep track of the changes and future impact on students and faculty? Rachel Moller: - What are you planning to adapt to increase the features of the open licensing on this resource? - I will be focusing on backwards design using this resource and figuring out how I can incoporate baward design using this textbook when I switch over the this textbook. This year I just moved over my general chemistry material, and I would like to develop worksheets that are organic relavent to something like I use in my general chemistry courses (please see attached document). I have a lot of accessibility work to do on the note tempaltes - How long will this take and who will be the main point person working on this? - This will take a long time, I am not sure of an exact timeline, but each time I teach organic chemistry, I incorporate and remove activities that help students be more engaged with the material so they can learn the most. I would like to have the foundations (lecture videos and homework) done at the time of their course, however developing material, worksheets, and content is a labor intesive process. - How will your team keep track of the changes and future impact on students and faculty? - Every semester I have students give me feedback on what they liked, what did not serve them, and what they would do differently and have me do differently. I take ideas from what they students need so they can learn the material to the best of their ability. Adaptations to support Accessibility Prompts are provided below. Please replace the prompts with your own information. Please refer to the Characteristics of Accessibility tool. Based on your interrogation of your resource, please share: - What are you planning to adapt to increase the features of Accessibility on this resource? - How long will this take and who will be the main point person working on this? - How will your team keep track of the changes and future impact on students and faculty? Rachel Moller: - What are you planning to adapt to increase the features of Accessibility on this resource? - I have so much work to do on accessibilty. The books I use are alreacy accessible, but the corresponding worksheets I develop for the textbooks have a lot of work that needs to be done with accessabilty. Currently, I use an accessibility checker, but I am highly interested in ANDI and all that it has to offer. I had never heard of ANDI before this workshop. Right now, I make sure that I always use my accessibility checker on Canvas before I publish something. It is really hard to describe chemical structures witth a screen reader. My current videos on YouTube are closed captioned correctly, so that is a step in the accessibilty direction! - How long will this take and who will be the main point person working on this? - We are in charge of our own accessibilty; however we do have a lot of support from our distant education personelle on campus. - How will your team keep track of the changes and future impact on students and faculty? - Using ANDI is a good place to start, and no one in my cohort currently uses it. Adaptations to support UDL Prompts are provided below. Please replace the prompts with your own information. Please refer to the Characteristics of UDL tool. Based on your interrogation of your resource, please share: - What are you planning to adapt to increase the features of UDL on this resource? - DId your team identify any opportunities to co-create with students and what might that look like? - How long will this take and who will be the main point person working on this? - How will your team keep track of the changes and future impact on students and faculty? Rachel Moller - What are you planning to adapt to increase the features of UDL on this resource? - The "solutions" at the end of the textbook are lacking. Having a detailed answer is important for students to understand what could have gone wrong in their work in they do not have a detailed answer. This is one point that my current students really like about the solutions manual for the current textbook we are using. I also need to plan and discover how I can incorporate backward design from the start of switching to a new textbook. I think that this OER textbook will need some extra material to develop this well for this course. - DId your team identify any opportunities to co-create with students and what might that look like? - As mentioned above, I always ask students what worked, what did not, what they would change, how and why, and I really try and incoroprate as much as I can into the next upcoming class. - How long will this take and who will be the main point person working on this? - I will be the main person working on this. I will be asking students to help me determine what they liked, didn't, and be flexibel and fluid in the moment of teaching to accomodate the current student needs. - How will your team keep track of the changes and future impact on students and faculty? - The best resource in my students. I always check in with them multiple times throughout the semester and that will not change. Sharing your iteration Prompts are provided below. Please replace the prompts with your own information. Please attach or link your iterated resource in this section. To help make your experience visible to others who pursue similar work, please share the following: - What aspect of this process stretched your thinking about your resource? - What next steps is your team considering? Rachel Moller - What aspect of this process stretched your thinking about your resource? - I relaized in my responses that truly my best resource are the students. It really is about them and what they need. I found that all of my answers were student centered so having the best resources available to them, at no cost, is going to be hugely beneficial to them. It feels like a really long and overwhelming process, but it is about making small changes that will turn into big changes over time! And really hearing and valuing the student feedback, in the moment, is really hugely beneficial! - What next steps is your team considering?	oercommons	2025-03-18T00:37:16.510454	04/05/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/114960/overview", "title": "Adapting OER to Incorporate UDL (Gavilan College)", "author": "Rachel Moller" }
https://oercommons.org/courseware/lesson/55559/overview	Backward Design Template Class Attention Signals Class Chants Example of a completed plan - by Leta Cirigliano Example of Backward Design Example of Building Background Example of Closure Example of lesson plan with direct instruction Examples of Differentiation Formative Assessments Lesson Planning: Building Background Knowledge Lesson Planning: Closure Lesson Planning: Differentiating Instruction Lesson Planning: Direct Instruction Lesson Planning: Prior Knowledge Lesson Plans: Anticipatory Set Lesson Plans: Assessment Lesson Plans: Class Attention Getters Lesson Plans: Standards and Objectives Lesson Plan Template Lesson Plan that we do collectively Prior Knowledge Example Templates for Exit Slips Using Assessments to Make Instructional Decisions Writing Lesson Plans Overview This module will assist the pre-service teacher in writing lesson plans using the Direct Instruction method. The module is designed for Early Childhood Education, but it can easily be adapted to secondary education majors. Each section of the lesson plan is detailed and, along with his/her classroom, the instructor is encouraged to develop a group lesson plan. As each section of the lesson plan is taught, the class will add that part to the group plan. A blank template is included in the first section. Lesson Plans: Standards and Objectives In this section, you will explore the fundamentals of writing a lesson plan. Attention will be given to backward design, national and state standards, writing clear objectives, and application of writing objectives. In this module, you can develop a practice lesson plan as a class. Decide on a topic for the lesson. Then, after each section is completed, develop that part of the lesson plan as a class. At the end of the module, your class will have a completed lesson plan. After this section, add the standards and objectives to the plan. In this section, you will explore the fundamentals of writing a lesson plan. Attention will be given to backward design, national and state standards, writing clear objectives, and application of writing objectives. Lesson Plans: Assessment Students will learn about formative and summative assessments with an emphasis on formative. There is application in the PPT. When you have completed this section, add formative assessments to your group lesson plan. This section explores assessments, both formative and summative. Formative assessments are typically used in a lesson, while summative assessments are usually used at the end of a unit of learning. Therefore, more attention will be given to the formative assessments. Many examples are provided. Lesson Plans: Class Attention Getters When this section is completed, add ready position to your lesson plan. You can't teach till students are in a ready position, physically and mentally. This section will help you get their attention and get them ready to learn. Lesson Plans: Anticipatory Set When this section is completed, add the Anticipatory Set to the group plan. The Anticipatory Set gets students excited and interested to learn. Lesson Plans: Prior Knowledge and Building Background Knowledge When you have completed this section, add assessing prior knowledge and building background to your group plan. Now that you have the students' attention, you need to be sure they have the proper background knowledge for the new learning. This section will guide you through assessing prior knowledge and building background knowledge. Lesson Plans: Direct Instruction When this section is completed, add the Instruction section to your group plan. This section show the Direct Teaching Method. There is a variation called the Indirect Model, which is inquiry-based learning. This section will help you plan instruction. In the Direct Lesson plan, you will use the I DO, WE DO, YOU DO methods. Lesson Plans: Closure Add closure to your group plan. Each lesson must end with a good closure. This will summarize the lesson and assess whether students gained an understanding of the content. Lesson Plans: Differentiating Instruction Add differentiation throughout the group plan. Consider differentiating the content, process, and product. In order to meet the needs of all learners, you will need to differentiate your plans in many ways. Consider differentiation according to needs of a student with a disability, learning preferences, multiple intelligences, and Bloom's Taxonomy.	oercommons	2025-03-18T00:37:16.554586	06/20/2019	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/55559/overview", "title": "Writing Lesson Plans", "author": "Jeanne Burth" }
https://oercommons.org/courseware/lesson/113652/overview	Education Standards Fun With Words Activity Overview Ready to have a fun and learning-centered activity for your students? You've come to the right place! For this activity, we will be including physical interaction from the students. This will include attempting to form words with their bodies, and other physical movemements of your choosing. This activity comes in two parts. Most useful to students in early elementary grades, Kindergarten -- 2nd grade Word Activity Instruction Ready to have a fun and learning-centered activity for your students? You've come to the right place! For this activity, we will be including physical interaction from the students. This will include attempting to form words with their bodies, and other physical movemements of your choosing. This activity comes in two parts. The first part is an activity where students use their bodies to form words. For example, students will work together to form the word C-A-T. One student forms the letter C, one forms the letter A, and so on. This way, students get to be physical, collaberate with their peers, and learn how to spell! The next activity includes being physical as well. The educator will hold a soft ball in their hands and will either say or have a word presented on Kahoot or other platform, the student then will raise their hand and attempt to spell and pronounce the word correctly. If they get it right, the teacher will toss the lightweight ball to the student. The student will then throw it back to the teacher. Also, These activities can be used for Speech Language Pathologists as well. My Kahoot example provided shows this. For these activities you will need: - Kahoot or other platform that's similar - various sight words or any other words of choosing - a soft ball or other safe throwing object - plenty of space for students to participate! Kahoot example link : https://create.kahoot.it/details/95247f55-52f8-45cc-a362-448731c9fc70 Resources Here are links from two helpful OER activities that helped me make my own activity! "Spell And Play Lesson" - https://oercommons.org/courseware/lesson/103522/student/427100 Spell and Play is an interactive Kindergarten through 2nd grade activity. "Sight Word Spelling" - oeta.pbslearningmedia.org/resource/c1980c3e-74ab-4220-b683-549ad66544aa/sight-word-spelling/?student=true&focus=true Sight Word Spelling has four different activity ideas to help students with their spelling. I chose activity three!	oercommons	2025-03-18T00:37:16.578109	Lexie Kilhoffer	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/113652/overview", "title": "Fun With Words Activity", "author": "Activity/Lab" }
https://oercommons.org/courseware/lesson/122068/overview	OER Evaluation Tools on OER Commons Overview This resource is part of the OERizona Advanced Course and supports OERizona faculty across Arizona in using tools and rubrics to evaluate OER. Using Tools and Rubrics to Evaluate OER When faculty are analyzing OER for potentially integrating it into their courses, their pedagogical and content knowledge automatically begin noting strengths of the resource and areas that may need improvement and customization. Below are several importants points to note about analyzing and evaluating OER: - Each person's background and experiences influence how they evaluate a resource and what they see (and don't see). - Evaluting a resource can be very time-consuming. - OER are often designed to be dynamic resources that invite collaboration and iteration. - Metadata and analytics can be strong tools for helping faculty sort and curate samples that are worthy of deeper analysis. - Artificial Intellignce (AI) is a tool that can both support and hinder the curation of OER. While AI can support the creation of resources and tools, it is difficult to fact-check and give attribution. This impacts the reliability and credibility of any resources created via AI. To support faculty in curating and evaluating OER - and to support faculty who are backwards designing the creation of new OER - there are multiple tools and rubrics built into OER Commons and the OERizona Hub to leverage the collaborative power of Arizona faculty experiences and expertise. - OER Commons has partnered with Achieve to develop an OER Rubric and Evaluation Tool that is built into the platform and collects feedback to support curation and remixing. See below for two videos demonstrating how you can use the features of OER Commons to evaluate OER and add to the OER iterative community. - Video on using the Star and Comment features (___ minute watch) - Video on using the Evaluation Rubric Tool (____minute watch) - OERizona has developed their own evaluation criteria to focus on key indicators of quality for Arizona. These Standards and Criteria to support faculty in evaluating and creating OER are found on the OERizona Hub and will be demonstrated in the next section.	oercommons	2025-03-18T00:37:16.592597	11/21/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/122068/overview", "title": "OERizona Advanced OER Skills, Evaluating OER, OER Evaluation Tools on OER Commons", "author": null }
https://oercommons.org/courseware/lesson/122059/overview	Reviewing OER Licensing Overview This mini-lesson is part of the OERizona Advance Course and explores the basics of the OER Definition, the concept of open licensing and the varying Creative Commons licenses. (Review and deepen knowledge) Open Educational Resources (OER) was a term first officially coined at UNESCO's 2002 Forum on Open Courseware. OER Definition: OER are defined by UNESCO as "Open Educational Resources (OER) are learning, teaching and research materials in any format and medium that reside in the public domain or are under copyright that have been released under an open license, that permit no-cost access, re-use, re-purpose, adaptation and redistribution by others." Open Licensing Definition: - Licensing refers to the terms of use that an author places on an original work they have created. Depending on where in the world the work was created and by whom, different terms of use will indicate how openly others can use, retain, share and change the creation. - Full copyright licensing means that the creator has retained all rights and all requests to use, share or change the work must be sent to the original creator. - Open licensing refers to when the author chooses terms of use that allow others to use, share or change the work with few restrictions. A non-profit called Creative Commons created a set of open licenses called the Creative Commons licenses that is a standardized way to explain how other users can re-use, redistribute, retain, revise and remix the work. Watch the video below to hear a bit more about Creative Commons licensing. Creative Commons Licenses: - The base Creative Commons license is CC BY. - This license enables reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. - If the creator is releasing all rights, including attribution, the resource is entered into the Public Domain and best practice includes describing that as CC-0 (pronounced CC-Zero). - Additional restrictions can be added to the CC BY license and sometimes the restrictions are combined. - Share Alike (SA) - if this restriction is added, any changes to the original resource, the modified material must be given the same licensing terms as the original resource. Attribution to the original author must still be given. - Non Commercial (NC) - if this restriction is added, only non-commercial uses of the resource are allowed. Attribution to the original author must still be given. - No Derivatives (ND) - copying and distributing of the material can only occur in the original, unmodified form of the work. No derivatives or adaptations are allowed. - You may see the above combined - such as CC-BY-NC-SA or CC-BY-NC-ND. This "What are Creative Commons licenses?" video from University of Guelph McLaughlin Library walks through the main ideas of Creative Commons licenses with concrete examples. Looking at an Example: - The video above is licensed CC-BY-NC-SA 4.0. - Could you repost it on your website and remove the title and attribution? - No - the CC-BY license requires attribution. - Could you add dubbing to overlay someone speaking the text in a different language? - Yes! The CC-BY license allows modification as long as you give attribution to the original creator, use the same license and don't make any money from your derivative. - Could you play the video at an event where you have charged admission and will make a commercial profit? - No! The CC-BY-NC-SA license does not allow for commercial use.	oercommons	2025-03-18T00:37:16.609048	11/20/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/122059/overview", "title": "OERizona Advanced OER Skills, Evaluating OER, Reviewing OER Licensing", "author": null }
https://oercommons.org/courseware/lesson/123174/overview	Time to Practice - OER Evaluation Overview This resource is part of the OERizona Advanced Course. This section supports faculty in reviewing OER of their choice. In this section, the faculty will review three OER using the OERizona Network Standards. Practicing OER Evaluation In this Module, you have explored OER Commons and the OERizona Hub, which are locations to start your search for high quality OER to use in your courses. To help contribute to the OERizona community, this course will support you in evaluating three different resources. Your evaluations will help curate high quality OER while also increasing the viewpoints of instructors who share the strengths and opportunities for growth within the resources they review. For this section, please follow the below steps: - Make sure that you are logged into OER Commons. - Locate an OER of your choice that already exists on OER Commons. We suggest using the "Advanced Search" feature. - Save the resource to your "My Items" so you can find it again later. We recommend making a folder specifically for this Advanced Course. - Leave a review in the "Comment" section of the resource's landing page. Include the following four things in your comment: - An overview of the resource - One indicator from the OERizona rubric that is a strength in this resource and the specific location in the resource that is a strength. - One indicator from the OERizona rubric that is an area of growth in this resource and the specific location in the resource that is an area of growth. - A note about possible collaboration or iterations that could be made to use this resource in your specific teaching setting. - Repeat. You should review three different items. Be sure the resources are saved in your "My Items" so you can find the URLs to submit at the end of this Module.	oercommons	2025-03-18T00:37:16.622823	12/18/2024	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/123174/overview", "title": "OERizona Advanced OER Skills, Evaluating OER, Time to Practice - OER Evaluation", "author": null }
https://oercommons.org/courseware/lesson/67347/overview	How to set up a meeting in Teams Infographic Microsoft Teams 101 Overview In November 2016, Microsoft added a new tool to its already robust Office 365 suite of services – Microsoft Teams. Teams is a chat-based collaboration tool that provides global, remote, and dispersed teams with the ability to work together and share information via a common space. You can utilize cool features like document collaboration, one-on-one chat, team chat, and more. Microsoft Teams is also fully integrated with many other Office 365 services, such as Skype, SharePoint, Exchange, and Yammer. The following core capabilities are included in Teams: Chat – Enjoy public and private conversations with your teams. The deep integration of Skype video into the application brings you popular social features, such as adding emojis and custom memes to your discussions. Hub – Teams offers a shared workspace for the various applications in Microsoft Office including PowerPoint, Word, Excel, Planner, OneNote, SharePoint, Delve, and Power BI. This feature gives you and your teams the option to work natively without having to stress about toggling between applications as you try to get projects completed. Introduction The COVID-19 pandemic has shown corporations that long-term telecommuting is possible, but what if you could make it even easier? Microsoft Teams offers companies the opportunity to stay connected and still achieve their goals. Below is a storyboard of a small shipping company that could have averted their issues by using Microsift Teams. The lesson explores Microsoft Teams and how companies can benefit from Teams based on the software's features and functionality. The lesson also prepares learners for posting files and creating meetings in Microsoft Teams. Percentage of Companies Using Microsoft Teams Glossary Terms to Know Microsoft Teams \| A communication and collaboration platform that combines persistent chat capabilities, video conferencing, file storage, and integration with other Office 365 applications. \| Channels \| Dedicated sections within a team to keep conversations organized by specific topics, projects, and disciplines. \| Teams \| A collection of people, content, and tools surrounding different projects and outcomes within an organization. \| Basic Glossary Review Once reviewed, please proceed to the next section. Goals & Objectives By the end of this course you will be able to: 1. Describe the purpose of Microsoft Teams. 2. Demonstrate adding files to a Teams channel. 3. Create and schedule a meeting in Teams. To complete this lesson, you will need to: 1. Know how to use a digital device (Laptop, phone, etc.). 2. Have a general understanding of Microsoft 365. 3. Recognize and communicate your company's mission statement. 4. Have a Microsoft Teams account for your business. Success Story Schneider Electric: Schneider Electric is a worldwide energy management company that does global work. Schneider Electric used Microsoft Teams to build a successful HR marketing campaign about the importance of Diversity and Inclusion. Purpose and Benefits of Microsoft Teams Purpose: It is a communication and collaboration platform that combines persistent chat capabilities, video conferencing, file storage, and integration with other Office 365 apps. Benefits: 1. Share ideas and expertise in private, chat-based conversations. 2. Create Office Online documents within the browser. 3. Integrate internal or external content & tools with different tabs. 4. Leverage bots to support your daily activities and tasks. Self-Organization and Collaboration: Let’s get started by thinking about how Microsoft Teams allows individual teams to self-organize and collaborate across business scenarios: 1. Teams are a collection of people, content, and tools surrounding different projects and outcomes within an organization. Teams can be private or public. 2. Channels are dedicated sections within a team to keep conversations organized by specific topics, projects, disciplines—whatever works for your team! Files that you share in a channel (on the Files tab) are stored in SharePoint. 3. Meetings. Teams allows you to schedule video or audio meetings for the whole team. To assist you in Teams, Microsoft has provided a great Quick Start Guide. It's recommended to keep this at your desk. Setting up a meeting in Teams 1. Select meeting icon . 2. Then select schedule a meeting. 3. Type in a meeting title and enter a location. 4. Choose a start and end time, and add details if needed. 5. Enter names in the Invite people box to add them to the meeting or add the channel for the project. 6. See everyone's availability in the Attendees list and, if needed, choose a suggested time or select Scheduling assistant to see more available times in a calendar view. 7. Under Select a channel to meet in, select the drop-down arrow to manage your meeting's privacy settings. 8. Select None to keep your meeting private. 9. Select a channel to open the meeting to team members. 10. If your meeting gets posted in a channel, it will appear under the Posts tab. Team members can set agendas, share files, or add comments. 11. At the conclusion of the meeting the individuals can exit the meeting or the meeting organizer can End meeting from within the meeting in Teams to end it and remove all participants from it. Knowledge Check: 1. Select __________ to keep the meeting private. A) Open B) None C) Channel If you chose answer B, you are correct! Sharing files in Teams Creating a meeting and adding files to Teams: This assessment is to give you the opportunity to test your knowledge and skills in setting up a meeting in Teams and adding files to Teams. Your Project Lead or Manager will assess your ability to do the following tasks: Scheduling a meeting by complete the following items: 1. For scheduled meetings, initiate a chat before the meeting begins (to discuss the agenda, for example). - Join a meeting and test different scenarios and workloads: For example, audio only, video, desktop sharing. - Sign in to the Microsoft Teams admin center and change some of the settings for meetings (for example, disable scheduling for private meetings). How does this affect the user experience? - As the meeting organizer, end a meeting for all participants. - Adding files by completing the following items: - Drag and drop one file into your team file folder. - Upload one file into your team file folder. Drag and drop one file into your team file folder. Upload one file into your team file folder. Please download the attached assessment form to be completed and kept in employee training file. Summary Key Takeaways Microsoft Teams is a chat-based collaboration platform complete with document sharing, online meetings, and many more extremely useful features for business communications. Having an excellent team space is key to being able to make creative decisions and communicate with one another. Microsoft Teams has many core components that make it stand out from other collaboration software: - Teams and channels. Teams are made up of channels, which are conversation boards between teammates. - Conversations within channels and teams. All team members can view and add to different conversations in the General channel. - A chat function. - Document storage in SharePoint. - Online video calling and screen sharing. - Online meetings. Teams is incredibly straightforward and user-friendly. There is little to no set up required. How Teams is set up is totally up to the company or business. Assessment Creating a meeting and adding files to Teams: This assessment is to give you the opportunity to test your knowledge and skills in setting up a meeting in Teams and adding files to Teams. Your Project Lead or Manager will assess your ability to do the following tasks: Scheduling a meeting by complete the following items: 1. For scheduled meetings, initiate a chat before the meeting begins (to discuss the agenda, for example). - Join a meeting and test different scenarios and workloads: For example, audio only, video, desktop sharing. - Sign in to the Microsoft Teams admin center and change some of the settings for meetings (for example, disable scheduling for private meetings). How does this affect the user experience? - As the meeting organizer, end a meeting for all participants. - Adding files by completing the following items: - Drag and drop one file into your team file folder. - Upload one file into your team file folder. Drag and drop one file into your team file folder. Upload one file into your team file folder. Please download the attached assessment form to be completed and kept in employee training file.	oercommons	2025-03-18T00:37:16.730968	Diagram/Illustration	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/67347/overview", "title": "Microsoft Teams 101", "author": "Assessment" }
https://oercommons.org/courseware/lesson/15105/overview	Introduction The arctic fox is an example of a complex animal that has adapted to its environment and illustrates the relationships between an animal’s form and function. The structures of animals consist of primary tissues that make up more complex organs and organ systems. Homeostasis allows an animal to maintain a balance between its internal and external environments.	oercommons	2025-03-18T00:37:16.747354	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15105/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15106/overview	Animal Form and Function Overview By the end of this section, you will be able to: - Describe the various types of body plans that occur in animals - Describe limits on animal size and shape - Relate bioenergetics to body size, levels of activity, and the environment Animals vary in form and function. From a sponge to a worm to a goat, an organism has a distinct body plan that limits its size and shape. Animals’ bodies are also designed to interact with their environments, whether in the deep sea, a rainforest canopy, or the desert. Therefore, a large amount of information about the structure of an organism's body (anatomy) and the function of its cells, tissues and organs (physiology) can be learned by studying that organism's environment. Body Plans Animal body plans follow set patterns related to symmetry. They are asymmetrical, radial, or bilateral in form as illustrated in Figure. Asymmetrical animals are animals with no pattern or symmetry; an example of an asymmetrical animal is a sponge. Radial symmetry, as illustrated in Figure, describes when an animal has an up-and-down orientation: any plane cut along its longitudinal axis through the organism produces equal halves, but not a definite right or left side. This plan is found mostly in aquatic animals, especially organisms that attach themselves to a base, like a rock or a boat, and extract their food from the surrounding water as it flows around the organism. Bilateral symmetry is illustrated in the same figure by a goat. The goat also has an upper and lower component to it, but a plane cut from front to back separates the animal into definite right and left sides. Additional terms used when describing positions in the body are anterior (front), posterior (rear), dorsal (toward the back), and ventral (toward the stomach). Bilateral symmetry is found in both land-based and aquatic animals; it enables a high level of mobility. Limits on Animal Size and Shape Animals with bilateral symmetry that live in water tend to have a fusiform shape: this is a tubular shaped body that is tapered at both ends. This shape decreases the drag on the body as it moves through water and allows the animal to swim at high speeds. Table lists the maximum speed of various animals. Certain types of sharks can swim at fifty kilometers an hour and some dolphins at 32 to 40 kilometers per hour. Land animals frequently travel faster, although the tortoise and snail are significantly slower than cheetahs. Another difference in the adaptations of aquatic and land-dwelling organisms is that aquatic organisms are constrained in shape by the forces of drag in the water since water has higher viscosity than air. On the other hand, land-dwelling organisms are constrained mainly by gravity, and drag is relatively unimportant. For example, most adaptations in birds are for gravity not for drag. \| Maximum Speed of Assorted Land Marine Animals \| \|\| \|---\|---\|---\| \| Animal \| Speed (kmh) \| Speed (mph) \| \| Cheetah \| 113 \| 70 \| \| Quarter horse \| 77 \| 48 \| \| Fox \| 68 \| 42 \| \| Shortfin mako shark \| 50 \| 31 \| \| Domestic house cat \| 48 \| 30 \| \| Human \| 45 \| 28 \| \| Dolphin \| 32–40 \| 20–25 \| \| Mouse \| 13 \| 8 \| \| Snail \| 0.05 \| 0.03 \| Most animals have an exoskeleton, including insects, spiders, scorpions, horseshoe crabs, centipedes, and crustaceans. Scientists estimate that, of insects alone, there are over 30 million species on our planet. The exoskeleton is a hard covering or shell that provides benefits to the animal, such as protection against damage from predators and from water loss (for land animals); it also provides for the attachments of muscles. As the tough and resistant outer cover of an arthropod, the exoskeleton may be constructed of a tough polymer such as chitin and is often biomineralized with materials such as calcium carbonate. This is fused to the animal’s epidermis. Ingrowths of the exoskeleton, called apodemes, function as attachment sites for muscles, similar to tendons in more advanced animals (Figure). In order to grow, the animal must first synthesize a new exoskeleton underneath the old one and then shed or molt the original covering. This limits the animal’s ability to grow continually, and may limit the individual’s ability to mature if molting does not occur at the proper time. The thickness of the exoskeleton must be increased significantly to accommodate any increase in weight. It is estimated that a doubling of body size increases body weight by a factor of eight. The increasing thickness of the chitin necessary to support this weight limits most animals with an exoskeleton to a relatively small size. The same principles apply to endoskeletons, but they are more efficient because muscles are attached on the outside, making it easier to compensate for increased mass. An animal with an endoskeleton has its size determined by the amount of skeletal system it needs in order to support the other tissues and the amount of muscle it needs for movement. As the body size increases, both bone and muscle mass increase. The speed achievable by the animal is a balance between its overall size and the bone and muscle that provide support and movement. Limiting Effects of Diffusion on Size and Development The exchange of nutrients and wastes between a cell and its watery environment occurs through the process of diffusion. All living cells are bathed in liquid, whether they are in a single-celled organism or a multicellular one. Diffusion is effective over a specific distance and limits the size that an individual cell can attain. If a cell is a single-celled microorganism, such as an amoeba, it can satisfy all of its nutrient and waste needs through diffusion. If the cell is too large, then diffusion is ineffective and the center of the cell does not receive adequate nutrients nor is it able to effectively dispel its waste. An important concept in understanding how efficient diffusion is as a means of transport is the surface to volume ratio. Recall that any three-dimensional object has a surface area and volume; the ratio of these two quantities is the surface-to-volume ratio. Consider a cell shaped like a perfect sphere: it has a surface area of 4πr2, and a volume of (4/3)πr3. The surface-to-volume ratio of a sphere is 3/r; as the cell gets bigger, its surface to volume ratio decreases, making diffusion less efficient. The larger the size of the sphere, or animal, the less surface area for diffusion it possesses. The solution to producing larger organisms is for them to become multicellular. Specialization occurs in complex organisms, allowing cells to become more efficient at doing fewer tasks. For example, circulatory systems bring nutrients and remove waste, while respiratory systems provide oxygen for the cells and remove carbon dioxide from them. Other organ systems have developed further specialization of cells and tissues and efficiently control body functions. Moreover, surface-to-volume ratio applies to other areas of animal development, such as the relationship between muscle mass and cross-sectional surface area in supporting skeletons, and in the relationship between muscle mass and the generation of dissipation of heat. Link to Learning Visit this interactive site to see an entire animal (a zebrafish embryo) at the cellular and sub-cellular level. Use the zoom and navigation functions for a virtual nanoscopy exploration. Animal Bioenergetics All animals must obtain their energy from food they ingest or absorb. These nutrients are converted to adenosine triphosphate (ATP) for short-term storage and use by all cells. Some animals store energy for slightly longer times as glycogen, and others store energy for much longer times in the form of triglycerides housed in specialized adipose tissues. No energy system is one hundred percent efficient, and an animal’s metabolism produces waste energy in the form of heat. If an animal can conserve that heat and maintain a relatively constant body temperature, it is classified as a warm-blooded animal and called an endotherm. The insulation used to conserve the body heat comes in the forms of fur, fat, or feathers. The absence of insulation in ectothermic animals increases their dependence on the environment for body heat. The amount of energy expended by an animal over a specific time is called its metabolic rate. The rate is measured variously in joules, calories, or kilocalories (1000 calories). Carbohydrates and proteins contain about 4.5 to 5 kcal/g, and fat contains about 9 kcal/g. Metabolic rate is estimated as the basal metabolic rate (BMR) in endothermic animals at rest and as the standard metabolic rate (SMR) in ectotherms. Human males have a BMR of 1600 to 1800 kcal/day, and human females have a BMR of 1300 to 1500 kcal/day. Even with insulation, endothermal animals require extensive amounts of energy to maintain a constant body temperature. An ectotherm such as an alligator has an SMR of 60 kcal/day. Energy Requirements Related to Body Size Smaller endothermic animals have a greater surface area for their mass than larger ones (Figure). Therefore, smaller animals lose heat at a faster rate than larger animals and require more energy to maintain a constant internal temperature. This results in a smaller endothermic animal having a higher BMR, per body weight, than a larger endothermic animal. Energy Requirements Related to Levels of Activity The more active an animal is, the more energy is needed to maintain that activity, and the higher its BMR or SMR. The average daily rate of energy consumption is about two to four times an animal’s BMR or SMR. Humans are more sedentary than most animals and have an average daily rate of only 1.5 times the BMR. The diet of an endothermic animal is determined by its BMR. For example: the type of grasses, leaves, or shrubs that an herbivore eats affects the number of calories that it takes in. The relative caloric content of herbivore foods, in descending order, is tall grasses > legumes > short grasses > forbs (any broad-leaved plant, not a grass) > subshrubs > annuals/biennials. Energy Requirements Related to Environment Animals adapt to extremes of temperature or food availability through torpor. Torpor is a process that leads to a decrease in activity and metabolism and allows animals to survive adverse conditions. Torpor can be used by animals for long periods, such as entering a state of hibernation during the winter months, in which case it enables them to maintain a reduced body temperature. During hibernation, ground squirrels can achieve an abdominal temperature of 0° C (32° F), while a bear’s internal temperature is maintained higher at about 37° C (99° F). If torpor occurs during the summer months with high temperatures and little water, it is called estivation. Some desert animals use this to survive the harshest months of the year. Torpor can occur on a daily basis; this is seen in bats and hummingbirds. While endothermy is limited in smaller animals by surface to volume ratio, some organisms can be smaller and still be endotherms because they employ daily torpor during the part of the day that is coldest. This allows them to conserve energy during the colder parts of the day, when they consume more energy to maintain their body temperature. Animal Body Planes and Cavities A standing vertebrate animal can be divided by several planes. A sagittal plane divides the body into right and left portions. A midsagittal plane divides the body exactly in the middle, making two equal right and left halves. A frontal plane (also called a coronal plane) separates the front from the back. A transverse plane (or, horizontal plane) divides the animal into upper and lower portions. This is sometimes called a cross section, and, if the transverse cut is at an angle, it is called an oblique plane. Figure illustrates these planes on a goat (a four-legged animal) and a human being. Vertebrate animals have a number of defined body cavities, as illustrated in Figure. Two of these are major cavities that contain smaller cavities within them. The dorsal cavity contains the cranial and the vertebral (or spinal) cavities. The ventral cavity contains the thoracic cavity, which in turn contains the pleural cavity around the lungs and the pericardial cavity, which surrounds the heart. The ventral cavity also contains the abdominopelvic cavity, which can be separated into the abdominal and the pelvic cavities. Career Connections Physical AnthropologistPhysical anthropologists study the adaption, variability, and evolution of human beings, plus their living and fossil relatives. They can work in a variety of settings, although most will have an academic appointment at a university, usually in an anthropology department or a biology, genetics, or zoology department. Non-academic positions are available in the automotive and aerospace industries where the focus is on human size, shape, and anatomy. Research by these professionals might range from studies of how the human body reacts to car crashes to exploring how to make seats more comfortable. Other non-academic positions can be obtained in museums of natural history, anthropology, archaeology, or science and technology. These positions involve educating students from grade school through graduate school. Physical anthropologists serve as education coordinators, collection managers, writers for museum publications, and as administrators. Zoos employ these professionals, especially if they have an expertise in primate biology; they work in collection management and captive breeding programs for endangered species. Forensic science utilizes physical anthropology expertise in identifying human and animal remains, assisting in determining the cause of death, and for expert testimony in trials. Section Summary Animal bodies come in a variety of sizes and shapes. Limits on animal size and shape include impacts to their movement. Diffusion affects their size and development. Bioenergetics describes how animals use and obtain energy in relation to their body size, activity level, and environment. Review Questions Which type of animal maintains a constant internal body temperature? - endotherm - ectotherm - coelomate - mesoderm Hint: A The symmetry found in animals that move swiftly is ________. - radial - bilateral - sequential - interrupted Hint: B What term describes the condition of a desert mouse that lowers its metabolic rate and “sleeps” during the hot day? - turgid - hibernation - estivation - normal sleep pattern Hint: C A plane that divides an animal into equal right and left portions is ________. - diagonal - midsagittal - coronal - transverse Hint: B A plane that divides an animal into dorsal and ventral portions is ________. - sagittal - midsagittal - coronal - transverse Hint: D The pleural cavity is a part of which cavity? - dorsal cavity - thoracic cavity - abdominal cavity - pericardial cavity Hint: B Free Response How does diffusion limit the size of an organism? How is this counteracted? Hint: Diffusion is effective over a very short distance. If a cell exceeds this distance in its size, the center of the cell cannot get adequate nutrients nor can it expel enough waste to survive. To compensate for this, cells can loosely adhere to each other in a liquid medium, or develop into multi-celled organisms that use circulatory and respiratory systems to deliver nutrients and remove wastes. What is the relationship between BMR and body size? Why? Hint: Basal Metabolic Rate is an expression of the metabolic processes that occur to maintain an individual’s functioning and body temperature. Smaller bodied animals have a relatively large surface area compared to a much larger animal. The large animal’s large surface area leads to increased heat loss that the animal must compensate for, resulting in a higher BMR. A small animal, having less relative surface area, does not lose as much heat and has a correspondingly lower BMR.	oercommons	2025-03-18T00:37:16.783937	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15106/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15107/overview	Animal Primary Tissues Overview By the end of this section, you will be able to: - Describe epithelial tissues - Discuss the different types of connective tissues in animals - Describe three types of muscle tissues - Describe nervous tissue The tissues of multicellular, complex animals are four primary types: epithelial, connective, muscle, and nervous. Recall that tissues are groups of similar cells group of similar cells carrying out related functions. These tissues combine to form organs—like the skin or kidney—that have specific, specialized functions within the body. Organs are organized into organ systems to perform functions; examples include the circulatory system, which consists of the heart and blood vessels, and the digestive system, consisting of several organs, including the stomach, intestines, liver, and pancreas. Organ systems come together to create an entire organism. Epithelial Tissues Epithelial tissues cover the outside of organs and structures in the body and line the lumens of organs in a single layer or multiple layers of cells. The types of epithelia are classified by the shapes of cells present and the number of layers of cells. Epithelia composed of a single layer of cells is called simple epithelia; epithelial tissue composed of multiple layers is called stratified epithelia. Table summarizes the different types of epithelial tissues. \| Different Types of Epithelial Tissues \| \|\| \|---\|---\|---\| \| Cell shape \| Description \| Location \| \| squamous \| flat, irregular round shape \| simple: lung alveoli, capillaries stratified: skin, mouth, vagina \| \| cuboidal \| cube shaped, central nucleus \| glands, renal tubules \| \| columnar \| tall, narrow, nucleus toward base tall, narrow, nucleus along cell \| simple: digestive tract pseudostratified: respiratory tract \| \| transitional \| round, simple but appear stratified \| urinary bladder \| Squamous Epithelia Squamous epithelial cells are generally round, flat, and have a small, centrally located nucleus. The cell outline is slightly irregular, and cells fit together to form a covering or lining. When the cells are arranged in a single layer (simple epithelia), they facilitate diffusion in tissues, such as the areas of gas exchange in the lungs and the exchange of nutrients and waste at blood capillaries. Figurea illustrates a layer of squamous cells with their membranes joined together to form an epithelium. Image Figureb illustrates squamous epithelial cells arranged in stratified layers, where protection is needed on the body from outside abrasion and damage. This is called a stratified squamous epithelium and occurs in the skin and in tissues lining the mouth and vagina. Cuboidal Epithelia Cuboidal epithelial cells, shown in Figure, are cube-shaped with a single, central nucleus. They are most commonly found in a single layer representing a simple epithelia in glandular tissues throughout the body where they prepare and secrete glandular material. They are also found in the walls of tubules and in the ducts of the kidney and liver. Columnar Epithelia Columnar epithelial cells are taller than they are wide: they resemble a stack of columns in an epithelial layer, and are most commonly found in a single-layer arrangement. The nuclei of columnar epithelial cells in the digestive tract appear to be lined up at the base of the cells, as illustrated in Figure. These cells absorb material from the lumen of the digestive tract and prepare it for entry into the body through the circulatory and lymphatic systems. Columnar epithelial cells lining the respiratory tract appear to be stratified. However, each cell is attached to the base membrane of the tissue and, therefore, they are simple tissues. The nuclei are arranged at different levels in the layer of cells, making it appear as though there is more than one layer, as seen in Figure. This is called pseudostratified, columnar epithelia. This cellular covering has cilia at the apical, or free, surface of the cells. The cilia enhance the movement of mucous and trapped particles out of the respiratory tract, helping to protect the system from invasive microorganisms and harmful material that has been breathed into the body. Goblet cells are interspersed in some tissues (such as the lining of the trachea). The goblet cells contain mucous that traps irritants, which in the case of the trachea keep these irritants from getting into the lungs. Transitional Epithelia Transitional or uroepithelial cells appear only in the urinary system, primarily in the bladder and ureter. These cells are arranged in a stratified layer, but they have the capability of appearing to pile up on top of each other in a relaxed, empty bladder, as illustrated in Figure. As the urinary bladder fills, the epithelial layer unfolds and expands to hold the volume of urine introduced into it. As the bladder fills, it expands and the lining becomes thinner. In other words, the tissue transitions from thick to thin. Art Connection Which of the following statements about types of epithelial cells is false? - Simple columnar epithelial cells line the tissue of the lung. - Simple cuboidal epithelial cells are involved in the filtering of blood in the kidney. - Pseudostratisfied columnar epithilia occur in a single layer, but the arrangement of nuclei makes it appear that more than one layer is present. - Transitional epithelia change in thickness depending on how full the bladder is. Connective Tissues Connective tissues are made up of a matrix consisting of living cells and a non-living substance, called the ground substance. The ground substance is made of an organic substance (usually a protein) and an inorganic substance (usually a mineral or water). The principal cell of connective tissues is the fibroblast. This cell makes the fibers found in nearly all of the connective tissues. Fibroblasts are motile, able to carry out mitosis, and can synthesize whichever connective tissue is needed. Macrophages, lymphocytes, and, occasionally, leukocytes can be found in some of the tissues. Some tissues have specialized cells that are not found in the others. The matrix in connective tissues gives the tissue its density. When a connective tissue has a high concentration of cells or fibers, it has proportionally a less dense matrix. The organic portion or protein fibers found in connective tissues are either collagen, elastic, or reticular fibers. Collagen fibers provide strength to the tissue, preventing it from being torn or separated from the surrounding tissues. Elastic fibers are made of the protein elastin; this fiber can stretch to one and one half of its length and return to its original size and shape. Elastic fibers provide flexibility to the tissues. Reticular fibers are the third type of protein fiber found in connective tissues. This fiber consists of thin strands of collagen that form a network of fibers to support the tissue and other organs to which it is connected. The various types of connective tissues, the types of cells and fibers they are made of, and sample locations of the tissues is summarized in Table. \| Connective Tissues \| \|\|\| \|---\|---\|---\|---\| \| Tissue \| Cells \| Fibers \| Location \| \| loose/areolar \| fibroblasts, macrophages, some lymphocytes, some neutrophils \| few: collagen, elastic, reticular \| around blood vessels; anchors epithelia \| \| dense, fibrous connective tissue \| fibroblasts, macrophages, \| mostly collagen \| irregular: skin regular: tendons, ligaments \| \| cartilage \| chondrocytes, chondroblasts \| hyaline: few collagen fibrocartilage: large amount of collagen \| shark skeleton, fetal bones, human ears, intervertebral discs \| \| bone \| osteoblasts, osteocytes, osteoclasts \| some: collagen, elastic \| vertebrate skeletons \| \| adipose \| adipocytes \| few \| adipose (fat) \| \| blood \| red blood cells, white blood cells \| none \| blood \| Loose/Areolar Connective Tissue Loose connective tissue, also called areolar connective tissue, has a sampling of all of the components of a connective tissue. As illustrated in Figure, loose connective tissue has some fibroblasts; macrophages are present as well. Collagen fibers are relatively wide and stain a light pink, while elastic fibers are thin and stain dark blue to black. The space between the formed elements of the tissue is filled with the matrix. The material in the connective tissue gives it a loose consistency similar to a cotton ball that has been pulled apart. Loose connective tissue is found around every blood vessel and helps to keep the vessel in place. The tissue is also found around and between most body organs. In summary, areolar tissue is tough, yet flexible, and comprises membranes. Fibrous Connective Tissue Fibrous connective tissues contain large amounts of collagen fibers and few cells or matrix material. The fibers can be arranged irregularly or regularly with the strands lined up in parallel. Irregularly arranged fibrous connective tissues are found in areas of the body where stress occurs from all directions, such as the dermis of the skin. Regular fibrous connective tissue, shown in Figure, is found in tendons (which connect muscles to bones) and ligaments (which connect bones to bones). Cartilage Cartilage is a connective tissue with a large amount of the matrix and variable amounts of fibers. The cells, called chondrocytes, make the matrix and fibers of the tissue. Chondrocytes are found in spaces within the tissue called lacunae. A cartilage with few collagen and elastic fibers is hyaline cartilage, illustrated in Figure. The lacunae are randomly scattered throughout the tissue and the matrix takes on a milky or scrubbed appearance with routine histological stains. Sharks have cartilaginous skeletons, as does nearly the entire human skeleton during a specific pre-birth developmental stage. A remnant of this cartilage persists in the outer portion of the human nose. Hyaline cartilage is also found at the ends of long bones, reducing friction and cushioning the articulations of these bones. Elastic cartilage has a large amount of elastic fibers, giving it tremendous flexibility. The ears of most vertebrate animals contain this cartilage as do portions of the larynx, or voice box. Fibrocartilage contains a large amount of collagen fibers, giving the tissue tremendous strength. Fibrocartilage comprises the intervertebral discs in vertebrate animals. Hyaline cartilage found in movable joints such as the knee and shoulder becomes damaged as a result of age or trauma. Damaged hyaline cartilage is replaced by fibrocartilage and results in the joints becoming “stiff.” Bone Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts—mostly calcium salts—that give the tissue hardness. Without adequate organic material in the matrix, the tissue breaks; without adequate inorganic material in the matrix, the tissue bends. There are three types of cells in bone: osteoblasts, osteocytes, and osteoclasts. Osteoblasts are active in making bone for growth and remodeling. Osteoblasts deposit bone material into the matrix and, after the matrix surrounds them, they continue to live, but in a reduced metabolic state as osteocytes. Osteocytes are found in lacunae of the bone. Osteoclasts are active in breaking down bone for bone remodeling, and they provide access to calcium stored in tissues. Osteoclasts are usually found on the surface of the tissue. Bone can be divided into two types: compact and spongy. Compact bone is found in the shaft (or diaphysis) of a long bone and the surface of the flat bones, while spongy bone is found in the end (or epiphysis) of a long bone. Compact bone is organized into subunits called osteons, as illustrated in Figure. A blood vessel and a nerve are found in the center of the structure within the Haversian canal, with radiating circles of lacunae around it known as lamellae. The wavy lines seen between the lacunae are microchannels called canaliculi; they connect the lacunae to aid diffusion between the cells. Spongy bone is made of tiny plates called trabeculae these plates serve as struts to give the spongy bone strength. Over time, these plates can break causing the bone to become less resilient. Bone tissue forms the internal skeleton of vertebrate animals, providing structure to the animal and points of attachment for tendons. Adipose Tissue Adipose tissue, or fat tissue, is considered a connective tissue even though it does not have fibroblasts or a real matrix and only has a few fibers. Adipose tissue is made up of cells called adipocytes that collect and store fat in the form of triglycerides, for energy metabolism. Adipose tissues additionally serve as insulation to help maintain body temperatures, allowing animals to be endothermic, and they function as cushioning against damage to body organs. Under a microscope, adipose tissue cells appear empty due to the extraction of fat during the processing of the material for viewing, as seen in Figure. The thin lines in the image are the cell membranes, and the nuclei are the small, black dots at the edges of the cells. Blood Blood is considered a connective tissue because it has a matrix, as shown in Figure. The living cell types are red blood cells (RBC), also called erythrocytes, and white blood cells (WBC), also called leukocytes. The fluid portion of whole blood, its matrix, is commonly called plasma. The cell found in greatest abundance in blood is the erythrocyte. Erythrocytes are counted in millions in a blood sample: the average number of red blood cells in primates is 4.7 to 5.5 million cells per microliter. Erythrocytes are consistently the same size in a species, but vary in size between species. For example, the average diameter of a primate red blood cell is 7.5 µl, a dog is close at 7.0 µl, but a cat’s RBC diameter is 5.9 µl. Sheep erythrocytes are even smaller at 4.6 µl. Mammalian erythrocytes lose their nuclei and mitochondria when they are released from the bone marrow where they are made. Fish, amphibian, and avian red blood cells maintain their nuclei and mitochondria throughout the cell’s life. The principal job of an erythrocyte is to carry and deliver oxygen to the tissues. Leukocytes are the predominant white blood cells found in the peripheral blood. Leukocytes are counted in the thousands in the blood with measurements expressed as ranges: primate counts range from 4,800 to 10,800 cells per µl, dogs from 5,600 to 19,200 cells per µl, cats from 8,000 to 25,000 cells per µl, cattle from 4,000 to 12,000 cells per µl, and pigs from 11,000 to 22,000 cells per µl. Lymphocytes function primarily in the immune response to foreign antigens or material. Different types of lymphocytes make antibodies tailored to the foreign antigens and control the production of those antibodies. Neutrophils are phagocytic cells and they participate in one of the early lines of defense against microbial invaders, aiding in the removal of bacteria that has entered the body. Another leukocyte that is found in the peripheral blood is the monocyte. Monocytes give rise to phagocytic macrophages that clean up dead and damaged cells in the body, whether they are foreign or from the host animal. Two additional leukocytes in the blood are eosinophils and basophils—both help to facilitate the inflammatory response. The slightly granular material among the cells is a cytoplasmic fragment of a cell in the bone marrow. This is called a platelet or thrombocyte. Platelets participate in the stages leading up to coagulation of the blood to stop bleeding through damaged blood vessels. Blood has a number of functions, but primarily it transports material through the body to bring nutrients to cells and remove waste material from them. Muscle Tissues There are three types of muscle in animal bodies: smooth, skeletal, and cardiac. They differ by the presence or absence of striations or bands, the number and location of nuclei, whether they are voluntarily or involuntarily controlled, and their location within the body. Table summarizes these differences. \| Types of Muscles \| \|\|\|\| \|---\|---\|---\|---\|---\| \| Type of Muscle \| Striations \| Nuclei \| Control \| Location \| \| smooth \| no \| single, in center \| involuntary \| visceral organs \| \| skeletal \| yes \| many, at periphery \| voluntary \| skeletal muscles \| \| cardiac \| yes \| single, in center \| involuntary \| heart \| Smooth Muscle Smooth muscle does not have striations in its cells. It has a single, centrally located nucleus, as shown in Figure. Constriction of smooth muscle occurs under involuntary, autonomic nervous control and in response to local conditions in the tissues. Smooth muscle tissue is also called non-striated as it lacks the banded appearance of skeletal and cardiac muscle. The walls of blood vessels, the tubes of the digestive system, and the tubes of the reproductive systems are composed of mostly smooth muscle. Skeletal Muscle Skeletal muscle has striations across its cells caused by the arrangement of the contractile proteins actin and myosin. These muscle cells are relatively long and have multiple nuclei along the edge of the cell. Skeletal muscle is under voluntary, somatic nervous system control and is found in the muscles that move bones. Figure illustrates the histology of skeletal muscle. Cardiac Muscle Cardiac muscle, shown in Figure, is found only in the heart. Like skeletal muscle, it has cross striations in its cells, but cardiac muscle has a single, centrally located nucleus. Cardiac muscle is not under voluntary control but can be influenced by the autonomic nervous system to speed up or slow down. An added feature to cardiac muscle cells is a line than extends along the end of the cell as it abuts the next cardiac cell in the row. This line is called an intercalated disc: it assists in passing electrical impulse efficiently from one cell to the next and maintains the strong connection between neighboring cardiac cells. Nervous Tissues Nervous tissues are made of cells specialized to receive and transmit electrical impulses from specific areas of the body and to send them to specific locations in the body. The main cell of the nervous system is the neuron, illustrated in Figure. The large structure with a central nucleus is the cell body of the neuron. Projections from the cell body are either dendrites specialized in receiving input or a single axon specialized in transmitting impulses. Some glial cells are also shown. Astrocytes regulate the chemical environment of the nerve cell, and oligodendrocytes insulate the axon so the electrical nerve impulse is transferred more efficiently. Other glial cells that are not shown support the nutritional and waste requirements of the neuron. Some of the glial cells are phagocytic and remove debris or damaged cells from the tissue. A nerve consists of neurons and glial cells. Link to Learning Click through the interactive review to learn more about epithelial tissues. Career Connections PathologistA pathologist is a medical doctor or veterinarian who has specialized in the laboratory detection of disease in animals, including humans. These professionals complete medical school education and follow it with an extensive post-graduate residency at a medical center. A pathologist may oversee clinical laboratories for the evaluation of body tissue and blood samples for the detection of disease or infection. They examine tissue specimens through a microscope to identify cancers and other diseases. Some pathologists perform autopsies to determine the cause of death and the progression of disease. Section Summary The basic building blocks of complex animals are four primary tissues. These are combined to form organs, which have a specific, specialized function within the body, such as the skin or kidney. Organs are organized together to perform common functions in the form of systems. The four primary tissues are epithelia, connective tissues, muscle tissues, and nervous tissues. Art Connections Figure Which of the following statements about types of epithelial cells is false? - Simple columnar epithelial cells line the tissue of the lung. - Simple cuboidal epithelial cells are involved in the filtering of blood in the kidney. - Pseudostratisfied columnar epithilia occur in a single layer, but the arrangement of nuclei makes it appear that more than one layer is present. - Transitional epithelia change in thickness depending on how full the bladder is. Hint: Figure A Review Questions Which type of epithelial cell is best adapted to aid diffusion? - squamous - cuboidal - columnar - transitional Hint: C Which type of epithelial cell is found in glands? - squamous - cuboidal - columnar - transitional Hint: B Which type of epithelial cell is found in the urinary bladder? - squamous - cuboidal - columnar - transitional Hint: D Which type of connective tissue has the most fibers? - loose connective tissue - fibrous connective tissue - cartilage - bone Hint: B Which type of connective tissue has a mineralized different matrix? - loose connective tissue - fibrous connective tissue - cartilage - bone Hint: D The cell found in bone that breaks it down is called an ________. - osteoblast - osteocyte - osteoclast - osteon Hint: C The cell found in bone that makes the bone is called an ________. - osteoblast - osteocyte - osteoclast - osteon Hint: A Plasma is the ________. - fibers in blood - matrix of blood - cell that phagocytizes bacteria - cell fragment found in the tissue Hint: B The type of muscle cell under voluntary control is the ________. - smooth muscle - skeletal muscle - cardiac muscle - visceral muscle Hint: B The part of a neuron that contains the nucleus is the - cell body - dendrite - axon - glial Hint: A Free Response How can squamous epithelia both facilitate diffusion and prevent damage from abrasion? Hint: Squamous epithelia can be either simple or stratified. As a single layer of cells, it presents a very thin epithelia that minimally inhibits diffusion. As a stratified epithelia, the surface cells can be sloughed off and the cells in deeper layers protect the underlying tissues from damage. What are the similarities between cartilage and bone? Hint: Both contain cells other than the traditional fibroblast. Both have cells that lodge in spaces within the tissue called lacunae. Both collagen and elastic fibers are found in bone and cartilage. Both tissues participate in vertebrate skeletal development and formation.	oercommons	2025-03-18T00:37:16.834137	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15107/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15108/overview	Homeostasis Overview By the end of this section, you will be able to: - Define homeostasis - Describe the factors affecting homeostasis - Discuss positive and negative feedback mechanisms used in homeostasis - Describe thermoregulation of endothermic and ectothermic animals Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis (“steady state”). These changes might be in the level of glucose or calcium in blood or in external temperatures. Homeostasis means to maintain dynamic equilibrium in the body. It is dynamic because it is constantly adjusting to the changes that the body’s systems encounter. It is equilibrium because body functions are kept within specific ranges. Even an animal that is apparently inactive is maintaining this homeostatic equilibrium. Homeostatic Process The goal of homeostasis is the maintenance of equilibrium around a point or value called a set point. While there are normal fluctuations from the set point, the body’s systems will usually attempt to go back to this point. A change in the internal or external environment is called a stimulus and is detected by a receptor; the response of the system is to adjust the deviation parameter toward the set point. For instance, if the body becomes too warm, adjustments are made to cool the animal. If the blood’s glucose rises after a meal, adjustments are made to lower the blood glucose level by getting the nutrient into tissues that need it or to store it for later use. Control of Homeostasis When a change occurs in an animal’s environment, an adjustment must be made. The receptor senses the change in the environment, then sends a signal to the control center (in most cases, the brain) which in turn generates a response that is signaled to an effector. The effector is a muscle (that contracts or relaxes) or a gland that secretes. Homeostatsis is maintained by negative feedback loops. Positive feedback loops actually push the organism further out of homeostasis, but may be necessary for life to occur. Homeostasis is controlled by the nervous and endocrine system of mammals. Negative Feedback Mechanisms Any homeostatic process that changes the direction of the stimulus is a negative feedback loop. It may either increase or decrease the stimulus, but the stimulus is not allowed to continue as it did before the receptor sensed it. In other words, if a level is too high, the body does something to bring it down, and conversely, if a level is too low, the body does something to make it go up. Hence the term negative feedback. An example is animal maintenance of blood glucose levels. When an animal has eaten, blood glucose levels rise. This is sensed by the nervous system. Specialized cells in the pancreas sense this, and the hormone insulin is released by the endocrine system. Insulin causes blood glucose levels to decrease, as would be expected in a negative feedback system, as illustrated in Figure. However, if an animal has not eaten and blood glucose levels decrease, this is sensed in another group of cells in the pancreas, and the hormone glucagon is released causing glucose levels to increase. This is still a negative feedback loop, but not in the direction expected by the use of the term “negative.” Another example of an increase as a result of the feedback loop is the control of blood calcium. If calcium levels decrease, specialized cells in the parathyroid gland sense this and release parathyroid hormone (PTH), causing an increased absorption of calcium through the intestines and kidneys and, possibly, the breakdown of bone in order to liberate calcium. The effects of PTH are to raise blood levels of the element. Negative feedback loops are the predominant mechanism used in homeostasis. Positive Feedback Loop A positive feedback loop maintains the direction of the stimulus, possibly accelerating it. Few examples of positive feedback loops exist in animal bodies, but one is found in the cascade of chemical reactions that result in blood clotting, or coagulation. As one clotting factor is activated, it activates the next factor in sequence until a fibrin clot is achieved. The direction is maintained, not changed, so this is positive feedback. Another example of positive feedback is uterine contractions during childbirth, as illustrated in Figure. The hormone oxytocin, made by the endocrine system, stimulates the contraction of the uterus. This produces pain sensed by the nervous system. Instead of lowering the oxytocin and causing the pain to subside, more oxytocin is produced until the contractions are powerful enough to produce childbirth. Art Connection State whether each of the following processes is regulated by a positive feedback loop or a negative feedback loop. - A person feels satiated after eating a large meal. - The blood has plenty of red blood cells. As a result, erythropoietin, a hormone that stimulates the production of new red blood cells, is no longer released from the kidney. Set Point It is possible to adjust a system’s set point. When this happens, the feedback loop works to maintain the new setting. An example of this is blood pressure: over time, the normal or set point for blood pressure can increase as a result of continued increases in blood pressure. The body no longer recognizes the elevation as abnormal and no attempt is made to return to the lower set point. The result is the maintenance of an elevated blood pressure that can have harmful effects on the body. Medication can lower blood pressure and lower the set point in the system to a more healthy level. This is called a process of alteration of the set point in a feedback loop. Changes can be made in a group of body organ systems in order to maintain a set point in another system. This is called acclimatization. This occurs, for instance, when an animal migrates to a higher altitude than it is accustomed to. In order to adjust to the lower oxygen levels at the new altitude, the body increases the number of red blood cells circulating in the blood to ensure adequate oxygen delivery to the tissues. Another example of acclimatization is animals that have seasonal changes in their coats: a heavier coat in the winter ensures adequate heat retention, and a light coat in summer assists in keeping body temperature from rising to harmful levels. Link to Learning Feedback mechanisms can be understood in terms of driving a race car along a track: watch a short video lesson on positive and negative feedback loops. Homeostasis: Thermoregulation Body temperature affects body activities. Generally, as body temperature rises, enzyme activity rises as well. For every ten degree centigrade rise in temperature, enzyme activity doubles, up to a point. Body proteins, including enzymes, begin to denature and lose their function with high heat (around 50oC for mammals). Enzyme activity will decrease by half for every ten degree centigrade drop in temperature, to the point of freezing, with a few exceptions. Some fish can withstand freezing solid and return to normal with thawing. Link to Learning Watch this Discovery Channel video on thermoregulation to see illustrations of this process in a variety of animals. Endotherms and Ectotherms Animals can be divided into two groups: some maintain a constant body temperature in the face of differing environmental temperatures, while others have a body temperature that is the same as their environment and thus varies with the environment. Animals that do not control their body temperature are ectotherms. This group has been called cold-blooded, but the term may not apply to an animal in the desert with a very warm body temperature. In contrast to ectotherms, which rely on external temperatures to set their body temperatures, poikilotherms are animals with constantly varying internal temperatures. An animal that maintains a constant body temperature in the face of environmental changes is called a homeotherm. Endotherms are animals that rely on internal sources for body temperature but which can exhibit extremes in temperature. These animals are able to maintain a level of activity at cooler temperature, which an ectotherm cannot due to differing enzyme levels of activity. Heat can be exchanged between an animal and its environment through four mechanisms: radiation, evaporation, convection, and conduction (Figure). Radiation is the emission of electromagnetic “heat” waves. Heat comes from the sun in this manner and radiates from dry skin the same way. Heat can be removed with liquid from a surface during evaporation. This occurs when a mammal sweats. Convection currents of air remove heat from the surface of dry skin as the air passes over it. Heat will be conducted from one surface to another during direct contact with the surfaces, such as an animal resting on a warm rock. Heat Conservation and Dissipation Animals conserve or dissipate heat in a variety of ways. In certain climates, endothermic animals have some form of insulation, such as fur, fat, feathers, or some combination thereof. Animals with thick fur or feathers create an insulating layer of air between their skin and internal organs. Polar bears and seals live and swim in a subfreezing environment and yet maintain a constant, warm, body temperature. The arctic fox, for example, uses its fluffy tail as extra insulation when it curls up to sleep in cold weather. Mammals have a residual effect from shivering and increased muscle activity: arrector pili muscles cause “goose bumps,” causing small hairs to stand up when the individual is cold; this has the intended effect of increasing body temperature. Mammals use layers of fat to achieve the same end. Loss of significant amounts of body fat will compromise an individual’s ability to conserve heat. Endotherms use their circulatory systems to help maintain body temperature. Vasodilation brings more blood and heat to the body surface, facilitating radiation and evaporative heat loss, which helps to cool the body. Vasoconstriction reduces blood flow in peripheral blood vessels, forcing blood toward the core and the vital organs found there, and conserving heat. Some animals have adaptions to their circulatory system that enable them to transfer heat from arteries to veins, warming blood returning to the heart. This is called a countercurrent heat exchange; it prevents the cold venous blood from cooling the heart and other internal organs. This adaption can be shut down in some animals to prevent overheating the internal organs. The countercurrent adaption is found in many animals, including dolphins, sharks, bony fish, bees, and hummingbirds. In contrast, similar adaptations can help cool endotherms when needed, such as dolphin flukes and elephant ears. Some ectothermic animals use changes in their behavior to help regulate body temperature. For example, a desert ectothermic animal may simply seek cooler areas during the hottest part of the day in the desert to keep from getting too warm. The same animals may climb onto rocks to capture heat during a cold desert night. Some animals seek water to aid evaporation in cooling them, as seen with reptiles. Other ectotherms use group activity such as the activity of bees to warm a hive to survive winter. Many animals, especially mammals, use metabolic waste heat as a heat source. When muscles are contracted, most of the energy from the ATP used in muscle actions is wasted energy that translates into heat. Severe cold elicits a shivering reflex that generates heat for the body. Many species also have a type of adipose tissue called brown fat that specializes in generating heat. Neural Control of Thermoregulation The nervous system is important to thermoregulation, as illustrated in Figure. The processes of homeostasis and temperature control are centered in the hypothalamus of the advanced animal brain. Art Connection When bacteria are destroyed by leuckocytes, pyrogens are released into the blood. Pyrogens reset the body’s thermostat to a higher temperature, resulting in fever. How might pyrogens cause the body temperature to rise? The hypothalamus maintains the set point for body temperature through reflexes that cause vasodilation and sweating when the body is too warm, or vasoconstriction and shivering when the body is too cold. It responds to chemicals from the body. When a bacterium is destroyed by phagocytic leukocytes, chemicals called endogenous pyrogens are released into the blood. These pyrogens circulate to the hypothalamus and reset the thermostat. This allows the body’s temperature to increase in what is commonly called a fever. An increase in body temperature causes iron to be conserved, which reduces a nutrient needed by bacteria. An increase in body heat also increases the activity of the animal’s enzymes and protective cells while inhibiting the enzymes and activity of the invading microorganisms. Finally, heat itself may also kill the pathogen. A fever that was once thought to be a complication of an infection is now understood to be a normal defense mechanism. Section Summary Homeostasis is a dynamic equilibrium that is maintained in body tissues and organs. It is dynamic because it is constantly adjusting to the changes that the systems encounter. It is in equilibrium because body functions are kept within a normal range, with some fluctuations around a set point for the processes. Art Connections Figure State whether each of the following processes are regulated by a positive feedback loop or a negative feedback loop. - A person feels satiated after eating a large meal. - The blood has plenty of red blood cells. As a result, erythropoietin, a hormone that stimulates the production of new red blood cells, is no longer released from the kidney. Hint: Figure Both processes are the result of negative feedback loops. Negative feedback loops, which tend to keep a system at equilibrium, are more common than positive feedback loops. Figure When bacteria are destroyed by leuckocytes, pyrogens are released into the blood. Pyrogens reset the body’s thermostat to a higher temperature, resulting in fever. How might pyrogens cause the body temperature to rise? Hint: Figure Pyrogens increase body temperature by causing the blood vessels to constrict, inducing shivering, and stopping sweat glands from secreting fluid. Review Questions When faced with a sudden drop in environmental temperature, an endothermic animal will: - experience a drop in its body temperature - wait to see if it goes lower - increase muscle activity to generate heat - add fur or fat to increase insulation Hint: C Which is an example of negative feedback? - lowering of blood glucose after a meal - blood clotting after an injury - lactation during nursing - uterine contractions during labor Hint: A Which method of heat exchange occurs during direct contact between the source and animal? - radiation - evaporation - convection - conduction Hint: D The body’s thermostat is located in the ________. - homeostatic receptor - hypothalamus - medulla - vasodilation center Hint: B Free Response Why are negative feedback loops used to control body homeostasis? Hint: An adjustment to a change in the internal or external environment requires a change in the direction of the stimulus. A negative feedback loop accomplishes this, while a positive feedback loop would continue the stimulus and result in harm to the animal. Why is a fever a “good thing” during a bacterial infection? Hint: Mammalian enzymes increase activity to the point of denaturation, increasing the chemical activity of the cells involved. Bacterial enzymes have a specific temperature for their most efficient activity and are inhibited at either higher or lower temperatures. Fever results in an increase in the destruction of the invading bacteria by increasing the effectiveness of body defenses and an inhibiting bacterial metabolism. How is a condition such as diabetes a good example of the failure of a set point in humans? Hint: Diabetes is often associated with a lack in production of insulin. Without insulin, blood glucose levels go up after a meal, but never go back down to normal levels.	oercommons	2025-03-18T00:37:16.871978	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15108/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15109/overview	Introduction All living organisms need nutrients to survive. While plants can obtain the molecules required for cellular function through the process of photosynthesis, most animals obtain their nutrients by the consumption of other organisms. At the cellular level, the biological molecules necessary for animal function are amino acids, lipid molecules, nucleotides, and simple sugars. However, the food consumed consists of protein, fat, and complex carbohydrates. Animals must convert these macromolecules into the simple molecules required for maintaining cellular functions, such as assembling new molecules, cells, and tissues. The conversion of the food consumed to the nutrients required is a multi-step process involving digestion and absorption. During digestion, food particles are broken down to smaller components, and later, they are absorbed by the body. One of the challenges in human nutrition is maintaining a balance between food intake, storage, and energy expenditure. Imbalances can have serious health consequences. For example, eating too much food while not expending much energy leads to obesity, which in turn will increase the risk of developing illnesses such as type-2 diabetes and cardiovascular disease. The recent rise in obesity and related diseases makes understanding the role of diet and nutrition in maintaining good health all the more important.	oercommons	2025-03-18T00:37:16.888725	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15109/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15110/overview	Digestive Systems Overview By the end of this section, you will be able to: - Explain the processes of digestion and absorption - Compare and contrast different types of digestive systems - Explain the specialized functions of the organs involved in processing food in the body - Describe the ways in which organs work together to digest food and absorb nutrients Animals obtain their nutrition from the consumption of other organisms. Depending on their diet, animals can be classified into the following categories: plant eaters (herbivores), meat eaters (carnivores), and those that eat both plants and animals (omnivores). The nutrients and macromolecules present in food are not immediately accessible to the cells. There are a number of processes that modify food within the animal body in order to make the nutrients and organic molecules accessible for cellular function. As animals evolved in complexity of form and function, their digestive systems have also evolved to accommodate their various dietary needs. Herbivores, Omnivores, and Carnivores Herbivores are animals whose primary food source is plant-based. Examples of herbivores, as shown in Figure include vertebrates like deer, koalas, and some bird species, as well as invertebrates such as crickets and caterpillars. These animals have evolved digestive systems capable of handling large amounts of plant material. Herbivores can be further classified into frugivores (fruit-eaters), granivores (seed eaters), nectivores (nectar feeders), and folivores (leaf eaters). Carnivores are animals that eat other animals. The word carnivore is derived from Latin and literally means “meat eater.” Wild cats such as lions, shown in Figurea and tigers are examples of vertebrate carnivores, as are snakes and sharks, while invertebrate carnivores include sea stars, spiders, and ladybugs, shown in Figureb. Obligate carnivores are those that rely entirely on animal flesh to obtain their nutrients; examples of obligate carnivores are members of the cat family, such as lions and cheetahs. Facultative carnivores are those that also eat non-animal food in addition to animal food. Note that there is no clear line that differentiates facultative carnivores from omnivores; dogs would be considered facultative carnivores. Omnivores are animals that eat both plant- and animal-derived food. In Latin, omnivore means to eat everything. Humans, bears (shown in Figurea), and chickens are example of vertebrate omnivores; invertebrate omnivores include cockroaches and crayfish (shown in Figureb). Invertebrate Digestive Systems Animals have evolved different types of digestive systems to aid in the digestion of the different foods they consume. The simplest example is that of a gastrovascular cavity and is found in organisms with only one opening for digestion. Platyhelminthes (flatworms), Ctenophora (comb jellies), and Cnidaria (coral, jelly fish, and sea anemones) use this type of digestion. Gastrovascular cavities, as shown in Figurea, are typically a blind tube or cavity with only one opening, the “mouth”, which also serves as an “anus”. Ingested material enters the mouth and passes through a hollow, tubular cavity. Cells within the cavity secrete digestive enzymes that break down the food. The food particles are engulfed by the cells lining the gastrovascular cavity. The alimentary canal, shown in Figureb, is a more advanced system: it consists of one tube with a mouth at one end and an anus at the other. Earthworms are an example of an animal with an alimentary canal. Once the food is ingested through the mouth, it passes through the esophagus and is stored in an organ called the crop; then it passes into the gizzard where it is churned and digested. From the gizzard, the food passes through the intestine, the nutrients are absorbed, and the waste is eliminated as feces, called castings, through the anus. Vertebrate Digestive Systems Vertebrates have evolved more complex digestive systems to adapt to their dietary needs. Some animals have a single stomach, while others have multi-chambered stomachs. Birds have developed a digestive system adapted to eating unmasticated food. Monogastric: Single-chambered Stomach As the word monogastric suggests, this type of digestive system consists of one (“mono”) stomach chamber (“gastric”). Humans and many animals have a monogastric digestive system as illustrated in Figureab. The process of digestion begins with the mouth and the intake of food. The teeth play an important role in masticating (chewing) or physically breaking down food into smaller particles. The enzymes present in saliva also begin to chemically break down food. The esophagus is a long tube that connects the mouth to the stomach. Using peristalsis, or wave-like smooth muscle contractions, the muscles of the esophagus push the food towards the stomach. In order to speed up the actions of enzymes in the stomach, the stomach is an extremely acidic environment, with a pH between 1.5 and 2.5. The gastric juices, which include enzymes in the stomach, act on the food particles and continue the process of digestion. Further breakdown of food takes place in the small intestine where enzymes produced by the liver, the small intestine, and the pancreas continue the process of digestion. The nutrients are absorbed into the blood stream across the epithelial cells lining the walls of the small intestines. The waste material travels on to the large intestine where water is absorbed and the drier waste material is compacted into feces; it is stored until it is excreted through the rectum. Avian Birds face special challenges when it comes to obtaining nutrition from food. They do not have teeth and so their digestive system, shown in Figure, must be able to process un-masticated food. Birds have evolved a variety of beak types that reflect the vast variety in their diet, ranging from seeds and insects to fruits and nuts. Because most birds fly, their metabolic rates are high in order to efficiently process food and keep their body weight low. The stomach of birds has two chambers: the proventriculus, where gastric juices are produced to digest the food before it enters the stomach, and the gizzard, where the food is stored, soaked, and mechanically ground. The undigested material forms food pellets that are sometimes regurgitated. Most of the chemical digestion and absorption happens in the intestine and the waste is excreted through the cloaca. Evolution Connection Avian AdaptationsBirds have a highly efficient, simplified digestive system. Recent fossil evidence has shown that the evolutionary divergence of birds from other land animals was characterized by streamlining and simplifying the digestive system. Unlike many other animals, birds do not have teeth to chew their food. In place of lips, they have sharp pointy beaks. The horny beak, lack of jaws, and the smaller tongue of the birds can be traced back to their dinosaur ancestors. The emergence of these changes seems to coincide with the inclusion of seeds in the bird diet. Seed-eating birds have beaks that are shaped for grabbing seeds and the two-compartment stomach allows for delegation of tasks. Since birds need to remain light in order to fly, their metabolic rates are very high, which means they digest their food very quickly and need to eat often. Contrast this with the ruminants, where the digestion of plant matter takes a very long time. Ruminants Ruminants are mainly herbivores like cows, sheep, and goats, whose entire diet consists of eating large amounts of roughage or fiber. They have evolved digestive systems that help them digest vast amounts of cellulose. An interesting feature of the ruminants’ mouth is that they do not have upper incisor teeth. They use their lower teeth, tongue and lips to tear and chew their food. From the mouth, the food travels to the esophagus and on to the stomach. To help digest the large amount of plant material, the stomach of the ruminants is a multi-chambered organ, as illustrated in Figure. The four compartments of the stomach are called the rumen, reticulum, omasum, and abomasum. These chambers contain many microbes that break down cellulose and ferment ingested food. The abomasum is the “true” stomach and is the equivalent of the monogastric stomach chamber where gastric juices are secreted. The four-compartment gastric chamber provides larger space and the microbial support necessary to digest plant material in ruminants. The fermentation process produces large amounts of gas in the stomach chamber, which must be eliminated. As in other animals, the small intestine plays an important role in nutrient absorption, and the large intestine helps in the elimination of waste. Pseudo-ruminants Some animals, such as camels and alpacas, are pseudo-ruminants. They eat a lot of plant material and roughage. Digesting plant material is not easy because plant cell walls contain the polymeric sugar molecule cellulose. The digestive enzymes of these animals cannot break down cellulose, but microorganisms present in the digestive system can. Therefore, the digestive system must be able to handle large amounts of roughage and break down the cellulose. Pseudo-ruminants have a three-chamber stomach in the digestive system. However, their cecum—a pouched organ at the beginning of the large intestine containing many microorganisms that are necessary for the digestion of plant materials—is large and is the site where the roughage is fermented and digested. These animals do not have a rumen but have an omasum, abomasum, and reticulum. Parts of the Digestive System The vertebrate digestive system is designed to facilitate the transformation of food matter into the nutrient components that sustain organisms. Oral Cavity The oral cavity, or mouth, is the point of entry of food into the digestive system, illustrated in Figure. The food consumed is broken into smaller particles by mastication, the chewing action of the teeth. All mammals have teeth and can chew their food. The extensive chemical process of digestion begins in the mouth. As food is being chewed, saliva, produced by the salivary glands, mixes with the food. Saliva is a watery substance produced in the mouths of many animals. There are three major glands that secrete saliva—the parotid, the submandibular, and the sublingual. Saliva contains mucus that moistens food and buffers the pH of the food. Saliva also contains immunoglobulins and lysozymes, which have antibacterial action to reduce tooth decay by inhibiting growth of some bacteria. Saliva also contains an enzyme called salivary amylase that begins the process of converting starches in the food into a disaccharide called maltose. Another enzyme called lipase is produced by the cells in the tongue. Lipases are a class of enzymes that can break down triglycerides. The lingual lipase begins the breakdown of fat components in the food. The chewing and wetting action provided by the teeth and saliva prepare the food into a mass called the bolus for swallowing. The tongue helps in swallowing—moving the bolus from the mouth into the pharynx. The pharynx opens to two passageways: the trachea, which leads to the lungs, and the esophagus, which leads to the stomach. The trachea has an opening called the glottis, which is covered by a cartilaginous flap called the epiglottis. When swallowing, the epiglottis closes the glottis and food passes into the esophagus and not the trachea. This arrangement allows food to be kept out of the trachea. Esophagus The esophagus is a tubular organ that connects the mouth to the stomach. The chewed and softened food passes through the esophagus after being swallowed. The smooth muscles of the esophagus undergo a series of wave like movements called peristalsis that push the food toward the stomach, as illustrated in Figure. The peristalsis wave is unidirectional—it moves food from the mouth to the stomach, and reverse movement is not possible. The peristaltic movement of the esophagus is an involuntary reflex; it takes place in response to the act of swallowing. A ring-like muscle called a sphincter forms valves in the digestive system. The gastro-esophageal sphincter is located at the stomach end of the esophagus. In response to swallowing and the pressure exerted by the bolus of food, this sphincter opens, and the bolus enters the stomach. When there is no swallowing action, this sphincter is shut and prevents the contents of the stomach from traveling up the esophagus. Many animals have a true sphincter; however, in humans, there is no true sphincter, but the esophagus remains closed when there is no swallowing action. Acid reflux or “heartburn” occurs when the acidic digestive juices escape into the esophagus. Stomach A large part of digestion occurs in the stomach, shown in Figure. The stomach is a saclike organ that secretes gastric digestive juices. The pH in the stomach is between 1.5 and 2.5. This highly acidic environment is required for the chemical breakdown of food and the extraction of nutrients. When empty, the stomach is a rather small organ; however, it can expand to up to 20 times its resting size when filled with food. This characteristic is particularly useful for animals that need to eat when food is available. Art Connection Which of the following statements about the digestive system is false? - Chyme is a mixture of food and digestive juices that is produced in the stomach. - Food enters the large intestine before the small intestine. - In the small intestine, chyme mixes with bile, which emulsifies fats. - The stomach is separated from the small intestine by the pyloric sphincter. The stomach is also the major site for protein digestion in animals other than ruminants. Protein digestion is mediated by an enzyme called pepsin in the stomach chamber. Pepsin is secreted by the chief cells in the stomach in an inactive form called pepsinogen. Pepsin breaks peptide bonds and cleaves proteins into smaller polypeptides; it also helps activate more pepsinogen, starting a positive feedback mechanism that generates more pepsin. Another cell type—parietal cells—secrete hydrogen and chloride ions, which combine in the lumen to form hydrochloric acid, the primary acidic component of the stomach juices. Hydrochloric acid helps to convert the inactive pepsinogen to pepsin. The highly acidic environment also kills many microorganisms in the food and, combined with the action of the enzyme pepsin, results in the hydrolysis of protein in the food. Chemical digestion is facilitated by the churning action of the stomach. Contraction and relaxation of smooth muscles mixes the stomach contents about every 20 minutes. The partially digested food and gastric juice mixture is called chyme. Chyme passes from the stomach to the small intestine. Further protein digestion takes place in the small intestine. Gastric emptying occurs within two to six hours after a meal. Only a small amount of chyme is released into the small intestine at a time. The movement of chyme from the stomach into the small intestine is regulated by the pyloric sphincter. When digesting protein and some fats, the stomach lining must be protected from getting digested by pepsin. There are two points to consider when describing how the stomach lining is protected. First, as previously mentioned, the enzyme pepsin is synthesized in the inactive form. This protects the chief cells, because pepsinogen does not have the same enzyme functionality of pepsin. Second, the stomach has a thick mucus lining that protects the underlying tissue from the action of the digestive juices. When this mucus lining is ruptured, ulcers can form in the stomach. Ulcers are open wounds in or on an organ caused by bacteria (Helicobacter pylori) when the mucus lining is ruptured and fails to reform. Small Intestine Chyme moves from the stomach to the small intestine. The small intestine is the organ where the digestion of protein, fats, and carbohydrates is completed. The small intestine is a long tube-like organ with a highly folded surface containing finger-like projections called the villi. The apical surface of each villus has many microscopic projections called microvilli. These structures, illustrated in Figure, are lined with epithelial cells on the luminal side and allow for the nutrients to be absorbed from the digested food and absorbed into the blood stream on the other side. The villi and microvilli, with their many folds, increase the surface area of the intestine and increase absorption efficiency of the nutrients. Absorbed nutrients in the blood are carried into the hepatic portal vein, which leads to the liver. There, the liver regulates the distribution of nutrients to the rest of the body and removes toxic substances, including drugs, alcohol, and some pathogens. Art Connection Which of the following statements about the small intestine is false? - Absorptive cells that line the small intestine have microvilli, small projections that increase surface area and aid in the absorption of food. - The inside of the small intestine has many folds, called villi. - Microvilli are lined with blood vessels as well as lymphatic vessels. - The inside of the small intestine is called the lumen. The human small intestine is over 6m long and is divided into three parts: the duodenum, the jejunum, and the ileum. The “C-shaped,” fixed part of the small intestine is called the duodenum and is shown in Figure. The duodenum is separated from the stomach by the pyloric sphincter which opens to allow chyme to move from the stomach to the duodenum. In the duodenum, chyme is mixed with pancreatic juices in an alkaline solution rich in bicarbonate that neutralizes the acidity of chyme and acts as a buffer. Pancreatic juices also contain several digestive enzymes. Digestive juices from the pancreas, liver, and gallbladder, as well as from gland cells of the intestinal wall itself, enter the duodenum. Bile is produced in the liver and stored and concentrated in the gallbladder. Bile contains bile salts which emulsify lipids while the pancreas produces enzymes that catabolize starches, disaccharides, proteins, and fats. These digestive juices break down the food particles in the chyme into glucose, triglycerides, and amino acids. Some chemical digestion of food takes place in the duodenum. Absorption of fatty acids also takes place in the duodenum. The second part of the small intestine is called the jejunum, shown in Figure. Here, hydrolysis of nutrients is continued while most of the carbohydrates and amino acids are absorbed through the intestinal lining. The bulk of chemical digestion and nutrient absorption occurs in the jejunum. The ileum, also illustrated in Figure is the last part of the small intestine and here the bile salts and vitamins are absorbed into blood stream. The undigested food is sent to the colon from the ileum via peristaltic movements of the muscle. The ileum ends and the large intestine begins at the ileocecal valve. The vermiform, “worm-like,” appendix is located at the ileocecal valve. The appendix of humans secretes no enzymes and has an insignificant role in immunity. Large Intestine The large intestine, illustrated in Figure, reabsorbs the water from the undigested food material and processes the waste material. The human large intestine is much smaller in length compared to the small intestine but larger in diameter. It has three parts: the cecum, the colon, and the rectum. The cecum joins the ileum to the colon and is the receiving pouch for the waste matter. The colon is home to many bacteria or “intestinal flora” that aid in the digestive processes. The colon can be divided into four regions, the ascending colon, the transverse colon, the descending colon and the sigmoid colon. The main functions of the colon are to extract the water and mineral salts from undigested food, and to store waste material. Carnivorous mammals have a shorter large intestine compared to herbivorous mammals due to their diet. Rectum and Anus The rectum is the terminal end of the large intestine, as shown in Figure. The primary role of the rectum is to store the feces until defecation. The feces are propelled using peristaltic movements during elimination. The anus is an opening at the far-end of the digestive tract and is the exit point for the waste material. Two sphincters between the rectum and anus control elimination: the inner sphincter is involuntary and the outer sphincter is voluntary. Accessory Organs The organs discussed above are the organs of the digestive tract through which food passes. Accessory organs are organs that add secretions (enzymes) that catabolize food into nutrients. Accessory organs include salivary glands, the liver, the pancreas, and the gallbladder. The liver, pancreas, and gallbladder are regulated by hormones in response to the food consumed. The liver is the largest internal organ in humans and it plays a very important role in digestion of fats and detoxifying blood. The liver produces bile, a digestive juice that is required for the breakdown of fatty components of the food in the duodenum. The liver also processes the vitamins and fats and synthesizes many plasma proteins. The pancreas is another important gland that secretes digestive juices. The chyme produced from the stomach is highly acidic in nature; the pancreatic juices contain high levels of bicarbonate, an alkali that neutralizes the acidic chyme. Additionally, the pancreatic juices contain a large variety of enzymes that are required for the digestion of protein and carbohydrates. The gallbladder is a small organ that aids the liver by storing bile and concentrating bile salts. When chyme containing fatty acids enters the duodenum, the bile is secreted from the gallbladder into the duodenum. Section Summary Different animals have evolved different types of digestive systems specialized to meet their dietary needs. Humans and many other animals have monogastric digestive systems with a single-chambered stomach. Birds have evolved a digestive system that includes a gizzard where the food is crushed into smaller pieces. This compensates for their inability to masticate. Ruminants that consume large amounts of plant material have a multi-chambered stomach that digests roughage. Pseudo-ruminants have similar digestive processes as ruminants but do not have the four-compartment stomach. Processing food involves ingestion (eating), digestion (mechanical and enzymatic breakdown of large molecules), absorption (cellular uptake of nutrients), and elimination (removal of undigested waste as feces). Many organs work together to digest food and absorb nutrients. The mouth is the point of ingestion and the location where both mechanical and chemical breakdown of food begins. Saliva contains an enzyme called amylase that breaks down carbohydrates. The food bolus travels through the esophagus by peristaltic movements to the stomach. The stomach has an extremely acidic environment. An enzyme called pepsin digests protein in the stomach. Further digestion and absorption take place in the small intestine. The large intestine reabsorbs water from the undigested food and stores waste until elimination. Art Connections Figure Which of the following statements about the digestive system is false? - Chyme is a mixture of food and digestive juices that is produced in the stomach. - Food enters the large intestine before the small intestine. - In the small intestine, chyme mixes with bile, which emulsifies fats. - The stomach is separated from the small intestine by the pyloric sphincter. Hint: Figure B Figure Which of the following statements about the small intestine is false? - Absorptive cells that line the small intestine have microvilli, small projections that increase surface area and aid in the absorption of food. - The inside of the small intestine has many folds, called villi. - Microvilli are lined with blood vessels as well as lymphatic vessels. - The inside of the small intestine is called the lumen. Hint: Figure C Review Questions Which of the following is a pseudo-ruminant? - cow - pig - crow - horse Hint: D Which of the following statements is untrue? - Roughage takes a long time to digest. - Birds eat large quantities at one time so that they can fly long distances. - Cows do not have upper teeth. - In pseudo-ruminants, roughage is digested in the cecum. Hint: B The acidic nature of chyme is neutralized by ________. - potassium hydroxide - sodium hydroxide - bicarbonates - vinegar Hint: C The digestive juices from the liver are delivered to the ________. - stomach - liver - duodenum - colon Hint: C Free Response How does the polygastric digestive system aid in digesting roughage? Hint: Animals with a polygastric digestive system have a multi-chambered stomach. The four compartments of the stomach are called the rumen, reticulum, omasum, and abomasum. These chambers contain many microbes that break down the cellulose and ferment the ingested food. The abomasum is the “true” stomach and is the equivalent of a monogastric stomach chamber where gastric juices are secreted. The four-compartment gastric chamber provides larger space and the microbial support necessary for ruminants to digest plant material. How do birds digest their food in the absence of teeth? Hint: Birds have a stomach chamber called a gizzard. Here, the food is stored, soaked, and ground into finer particles, often using pebbles. Once this process is complete, the digestive juices take over in the proventriculus and continue the digestive process. What is the role of the accessory organs in digestion? Hint: Accessory organs play an important role in producing and delivering digestive juices to the intestine during digestion and absorption. Specifically, the salivary glands, liver, pancreas, and gallbladder play important roles. Malfunction of any of these organs can lead to disease states. Explain how the villi and microvilli aid in absorption. Hint: The villi and microvilli are folds on the surface of the small intestine. These folds increase the surface area of the intestine and provide more area for the absorption of nutrients.	oercommons	2025-03-18T00:37:16.931899	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15110/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15111/overview	Nutrition and Energy Production Overview By the end of this section, you will be able to: - Explain why an animal’s diet should be balanced and meet the needs of the body - Define the primary components of food - Describe the essential nutrients required for cellular function that cannot be synthesized by the animal body - Explain how energy is produced through diet and digestion - Describe how excess carbohydrates and energy are stored in the body Given the diversity of animal life on our planet, it is not surprising that the animal diet would also vary substantially. The animal diet is the source of materials needed for building DNA and other complex molecules needed for growth, maintenance, and reproduction; collectively these processes are called biosynthesis. The diet is also the source of materials for ATP production in the cells. The diet must be balanced to provide the minerals and vitamins that are required for cellular function. Food Requirements What are the fundamental requirements of the animal diet? The animal diet should be well balanced and provide nutrients required for bodily function and the minerals and vitamins required for maintaining structure and regulation necessary for good health and reproductive capability. These requirements for a human are illustrated graphically in Figure Link to Learning The first step in ensuring that you are meeting the food requirements of your body is an awareness of the food groups and the nutrients they provide. To learn more about each food group and the recommended daily amounts, explore this interactive site by the United States Department of Agriculture. Everyday Connection Let’s Move! CampaignObesity is a growing epidemic and the rate of obesity among children is rapidly rising in the United States. To combat childhood obesity and ensure that children get a healthy start in life, first lady Michelle Obama has launched the Let’s Move! campaign. The goal of this campaign is to educate parents and caregivers on providing healthy nutrition and encouraging active lifestyles to future generations. This program aims to involve the entire community, including parents, teachers, and healthcare providers to ensure that children have access to healthy foods—more fruits, vegetables, and whole grains—and consume fewer calories from processed foods. Another goal is to ensure that children get physical activity. With the increase in television viewing and stationary pursuits such as video games, sedentary lifestyles have become the norm. Learn more at www.letsmove.gov. Organic Precursors The organic molecules required for building cellular material and tissues must come from food. Carbohydrates or sugars are the primary source of organic carbons in the animal body. During digestion, digestible carbohydrates are ultimately broken down into glucose and used to provide energy through metabolic pathways. Complex carbohydrates, including polysaccharides, can be broken down into glucose through biochemical modification; however, humans do not produce the enzyme cellulase and lack the ability to derive glucose from the polysaccharide cellulose. In humans, these molecules provide the fiber required for moving waste through the large intestine and a healthy colon. The intestinal flora in the human gut are able to extract some nutrition from these plant fibers. The excess sugars in the body are converted into glycogen and stored in the liver and muscles for later use. Glycogen stores are used to fuel prolonged exertions, such as long-distance running, and to provide energy during food shortage. Excess glycogen can be converted to fats, which are stored in the lower layer of the skin of mammals for insulation and energy storage. Excess digestible carbohydrates are stored by mammals in order to survive famine and aid in mobility. Another important requirement is that of nitrogen. Protein catabolism provides a source of organic nitrogen. Amino acids are the building blocks of proteins and protein breakdown provides amino acids that are used for cellular function. The carbon and nitrogen derived from these become the building block for nucleotides, nucleic acids, proteins, cells, and tissues. Excess nitrogen must be excreted as it is toxic. Fats add flavor to food and promote a sense of satiety or fullness. Fatty foods are also significant sources of energy because one gram of fat contains nine calories. Fats are required in the diet to aid the absorption of fat-soluble vitamins and the production of fat-soluble hormones. Essential Nutrients While the animal body can synthesize many of the molecules required for function from the organic precursors, there are some nutrients that need to be consumed from food. These nutrients are termed essential nutrients, meaning they must be eaten, and the body cannot produce them. The omega-3 alpha-linolenic acid and the omega-6 linoleic acid are essential fatty acids needed to make some membrane phospholipids. Vitamins are another class of essential organic molecules that are required in small quantities for many enzymes to function and, for this reason, are considered to be co-enzymes. Absence or low levels of vitamins can have a dramatic effect on health, as outlined in Table and Table. Both fat-soluble and water-soluble vitamins must be obtained from food. Minerals, listed in Table, are inorganic essential nutrients that must be obtained from food. Among their many functions, minerals help in structure and regulation and are considered co-factors. Certain amino acids also must be procured from food and cannot be synthesized by the body. These amino acids are the “essential” amino acids. The human body can synthesize only 11 of the 20 required amino acids; the rest must be obtained from food. The essential amino acids are listed in Table. \| Water-soluble Essential Vitamins \| \|\|\| \|---\|---\|---\|---\| \| Vitamin \| Function \| Deficiencies Can Lead To \| Sources \| \| Vitamin B1 (Thiamine) \| Needed by the body to process lipids, proteins, and carbohydrates Coenzyme removes CO2 from organic compounds \| Muscle weakness, Beriberi: reduced heart function, CNS problems \| Milk, meat, dried beans, whole grains \| \| Vitamin B2 (Riboflavin) \| Takes an active role in metabolism, aiding in the conversion of food to energy (FAD and FMN) \| Cracks or sores on the outer surface of the lips (cheliosis); inflammation and redness of the tongue; moist, scaly skin inflammation (seborrheic dermatitis) \| Meat, eggs, enriched grains, vegetables \| \| Vitamin B3 (Niacin) \| Used by the body to release energy from carbohydrates and to process alcohol; required for the synthesis of sex hormones; component of coenzyme NAD+ and NADP+ \| Pellagra, which can result in dermatitis, diarrhea, dementia, and death \| Meat, eggs, grains, nuts, potatoes \| \| Vitamin B5 (Pantothenic acid) \| Assists in producing energy from foods (lipids, in particular); component of coenzyme A \| Fatigue, poor coordination, retarded growth, numbness, tingling of hands and feet \| Meat, whole grains, milk, fruits, vegetables \| \| Vitamin B6 (Pyridoxine) \| The principal vitamin for processing amino acids and lipids; also helps convert nutrients into energy \| Irritability, depression, confusion, mouth sores or ulcers, anemia, muscular twitching \| Meat, dairy products, whole grains, orange juice \| \| Vitamin B7 (Biotin) \| Used in energy and amino acid metabolism, fat synthesis, and fat breakdown; helps the body use blood sugar \| Hair loss, dermatitis, depression, numbness and tingling in the extremities; neuromuscular disorders \| Meat, eggs, legumes and other vegetables \| \| Vitamin B9 (Folic acid) \| Assists the normal development of cells, especially during fetal development; helps metabolize nucleic and amino acids \| Deficiency during pregnancy is associated with birth defects, such as neural tube defects and anemia \| Leafy green vegetables, whole wheat, fruits, nuts, legumes \| \| Vitamin B12 (Cobalamin) \| Maintains healthy nervous system and assists with blood cell formation; coenzyme in nucleic acid metabolism \| Anemia, neurological disorders, numbness, loss of balance \| Meat, eggs, animal products \| \| Vitamin C (Ascorbic acid) \| Helps maintain connective tissue: bone, cartilage, and dentin; boosts the immune system \| Scurvy, which results in bleeding, hair and tooth loss; joint pain and swelling; delayed wound healing \| Citrus fruits, broccoli, tomatoes, red sweet bell peppers \| \| Fat-soluble Essential Vitamins \| \|\|\| \|---\|---\|---\|---\| \| Vitamin \| Function \| Deficiencies Can Lead To \| Sources \| \| Vitamin A (Retinol) \| Critical to the development of bones, teeth, and skin; helps maintain eyesight, enhances the immune system, fetal development, gene expression \| Night-blindness, skin disorders, impaired immunity \| Dark green leafy vegetables, yellow-orange vegetables fruits, milk, butter \| \| Vitamin D \| Critical for calcium absorption for bone development and strength; maintains a stable nervous system; maintains a normal and strong heartbeat; helps in blood clotting \| Rickets, osteomalacia, immunity \| Cod liver oil, milk, egg yolk \| \| Vitamin E (Tocopherol) \| Lessens oxidative damage of cells,and prevents lung damage from pollutants; vital to the immune system \| Deficiency is rare; anemia, nervous system degeneration \| Wheat germ oil, unrefined vegetable oils, nuts, seeds, grains \| \| Vitamin K (Phylloquinone) \| Essential to blood clotting \| Bleeding and easy bruising \| Leafy green vegetables, tea \| \| Minerals and Their Function in the Human Body \| \|\|\| \|---\|---\|---\|---\| \| Mineral \| Function \| Deficiencies Can Lead To \| Sources \| \| Calcium \| Needed for muscle and neuron function; heart health; builds bone and supports synthesis and function of blood cells; nerve function \| Osteoporosis, rickets, muscle spasms, impaired growth \| Milk, yogurt, fish, green leafy vegetables, legumes \| \| Chlorine \| Needed for production of hydrochloric acid (HCl) in the stomach and nerve function; osmotic balance \| Muscle cramps, mood disturbances, reduced appetite \| Table salt \| \| Copper (trace amounts) \| Required component of many redox enzymes, including cytochrome c oxidase; cofactor for hemoglobin synthesis \| Copper deficiency is rare \| Liver, oysters, cocoa, chocolate, sesame, nuts \| \| Iodine \| Required for the synthesis of thyroid hormones \| Goiter \| Seafood, iodized salt, dairy products \| \| Iron \| Required for many proteins and enzymes, notably hemoglobin, to prevent anemia \| Anemia, which causes poor concentration, fatigue, and poor immune function \| Red meat, leafy green vegetables, fish (tuna, salmon), eggs, dried fruits, beans, whole grains \| \| Magnesium \| Required co-factor for ATP formation; bone formation; normal membrane functions; muscle function \| Mood disturbances, muscle spasms \| Whole grains, leafy green vegetables \| \| Manganese (trace amounts) \| A cofactor in enzyme functions; trace amounts are required \| Manganese deficiency is rare \| Common in most foods \| \| Molybdenum (trace amounts) \| Acts as a cofactor for three essential enzymes in humans: sulfite oxidase, xanthine oxidase, and aldehyde oxidase \| Molybdenum deficiency is rare \| \| \| Phosphorus \| A component of bones and teeth; helps regulate acid-base balance; nucleotide synthesis \| Weakness, bone abnormalities, calcium loss \| Milk, hard cheese, whole grains, meats \| \| Potassium \| Vital for muscles, heart, and nerve function \| Cardiac rhythm disturbance, muscle weakness \| Legumes, potato skin, tomatoes, bananas \| \| Selenium (trace amounts) \| A cofactor essential to activity of antioxidant enzymes like glutathione peroxidase; trace amounts are required \| Selenium deficiency is rare \| Common in most foods \| \| Sodium \| Systemic electrolyte required for many functions; acid-base balance; water balance; nerve function \| Muscle cramps, fatigue, reduced appetite \| Table salt \| \| Zinc (trace amounts) \| Required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, and carbonic anhydrase \| Anemia, poor wound healing, can lead to short stature \| Common in most foods \| \| Greater than 200mg/day required \| \| Essential Amino Acids \| \| \|---\|---\| \| Amino acids that must be consumed \| Amino acids anabolized by the body \| \| isoleucine \| alanine \| \| leucine \| selenocysteine \| \| lysine \| aspartate \| \| methionine \| cysteine \| \| phenylalanine \| glutamate \| \| tryptophan \| glycine \| \| valine \| proline \| \| histidine \| serine \| \| threonine \| tyrosine \| \| arginine* \| asparagine \| \| *The human body can synthesize histidine and arginine, but not in the quantities required, especially for growing children. \| Food Energy and ATP Animals need food to obtain energy and maintain homeostasis. Homeostasis is the ability of a system to maintain a stable internal environment even in the face of external changes to the environment. For example, the normal body temperature of humans is 37°C (98.6°F). Humans maintain this temperature even when the external temperature is hot or cold. It takes energy to maintain this body temperature, and animals obtain this energy from food. The primary source of energy for animals is carbohydrates, mainly glucose. Glucose is called the body’s fuel. The digestible carbohydrates in an animal’s diet are converted to glucose molecules through a series of catabolic chemical reactions. Adenosine triphosphate, or ATP, is the primary energy currency in cells; ATP stores energy in phosphate ester bonds. ATP releases energy when the phosphodiester bonds are broken and ATP is converted to ADP and a phosphate group. ATP is produced by the oxidative reactions in the cytoplasm and mitochondrion of the cell, where carbohydrates, proteins, and fats undergo a series of metabolic reactions collectively called cellular respiration. For example, glycolysis is a series of reactions in which glucose is converted to pyruvic acid and some of its chemical potential energy is transferred to NADH and ATP. ATP is required for all cellular functions. It is used to build the organic molecules that are required for cells and tissues; it provides energy for muscle contraction and for the transmission of electrical signals in the nervous system. When the amount of ATP is available in excess of the body’s requirements, the liver uses the excess ATP and excess glucose to produce molecules called glycogen. Glycogen is a polymeric form of glucose and is stored in the liver and skeletal muscle cells. When blood sugar drops, the liver releases glucose from stores of glycogen. Skeletal muscle converts glycogen to glucose during intense exercise. The process of converting glucose and excess ATP to glycogen and the storage of excess energy is an evolutionarily important step in helping animals deal with mobility, food shortages, and famine. Everyday Connection ObesityObesity is a major health concern in the United States, and there is a growing focus on reducing obesity and the diseases it may lead to, such as type-2 diabetes, cancers of the colon and breast, and cardiovascular disease. How does the food consumed contribute to obesity? Fatty foods are calorie-dense, meaning that they have more calories per unit mass than carbohydrates or proteins. One gram of carbohydrates has four calories, one gram of protein has four calories, and one gram of fat has nine calories. Animals tend to seek lipid-rich food for their higher energy content. The signals of hunger (“time to eat”) and satiety (“time to stop eating”) are controlled in the hypothalamus region of the brain. Foods that are rich in fatty acids tend to promote satiety more than foods that are rich only in carbohydrates. Excess carbohydrate and ATP are used by the liver to synthesize glycogen. The pyruvate produced during glycolysis is used to synthesize fatty acids. When there is more glucose in the body than required, the resulting excess pyruvate is converted into molecules that eventually result in the synthesis of fatty acids within the body. These fatty acids are stored in adipose cells—the fat cells in the mammalian body whose primary role is to store fat for later use. It is important to note that some animals benefit from obesity. Polar bears and seals need body fat for insulation and to keep them from losing body heat during Arctic winters. When food is scarce, stored body fat provides energy for maintaining homeostasis. Fats prevent famine in mammals, allowing them to access energy when food is not available on a daily basis; fats are stored when a large kill is made or lots of food is available. Section Summary Animal diet should be balanced and meet the needs of the body. Carbohydrates, proteins, and fats are the primary components of food. Some essential nutrients are required for cellular function but cannot be produced by the animal body. These include vitamins, minerals, some fatty acids, and some amino acids. Food intake in more than necessary amounts is stored as glycogen in the liver and muscle cells, and in fat cells. Excess adipose storage can lead to obesity and serious health problems. ATP is the energy currency of the cell and is obtained from the metabolic pathways. Excess carbohydrates and energy are stored as glycogen in the body. Review Questions Which of the following statements is not true? - Essential nutrients can be synthesized by the body. - Vitamins are required in small quantities for bodily function. - Some amino acids can be synthesized by the body, while others need to be obtained from diet. - Vitamins come in two categories: fat-soluble and water-soluble. Hint: A Which of the following is a water-soluble vitamin? - vitamin A - vitamin E - vitamin K - vitamin C Hint: D What is the primary fuel for the body? - carbohydrates - lipids - protein - glycogen Hint: A Excess glucose is stored as ________. - fat - glucagon - glycogen - it is not stored in the body Hint: C Free Response What are essential nutrients? Hint: Essential nutrients are those nutrients that must be obtained from the diet because they cannot be produced by the body. Vitamins and minerals are examples of essential nutrients. What is the role of minerals in maintaining good health? Hint: Minerals—such as potassium, sodium, and calcium—are required for the functioning of many cellular processes, including muscle contraction and nerve conduction. While minerals are required in trace amounts, not having minerals in the diet can be potentially harmful. Discuss why obesity is a growing epidemic. Hint: In the United States, obesity, particularly childhood obesity, is a growing concern. Some of the contributors to this situation include sedentary lifestyles and consuming more processed foods and less fruits and vegetables. As a result, even young children who are obese can face health concerns. There are several nations where malnourishment is a common occurrence. What may be some of the health challenges posed by malnutrition? Hint: Malnutrition, often in the form of not getting enough calories or not enough of the essential nutrients, can have severe consequences. Many malnourished children have vision and dental problems, and over the years may develop many serious health problems.	oercommons	2025-03-18T00:37:16.973672	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15111/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15112/overview	Digestive System Processes Overview By the end of this section, you will be able to: - Describe the process of digestion - Detail the steps involved in digestion and absorption - Define elimination - Explain the role of both the small and large intestines in absorption Obtaining nutrition and energy from food is a multi-step process. For true animals, the first step is ingestion, the act of taking in food. This is followed by digestion, absorption, and elimination. In the following sections, each of these steps will be discussed in detail. Ingestion The large molecules found in intact food cannot pass through the cell membranes. Food needs to be broken into smaller particles so that animals can harness the nutrients and organic molecules. The first step in this process is ingestion. Ingestion is the process of taking in food through the mouth. In vertebrates, the teeth, saliva, and tongue play important roles in mastication (preparing the food into bolus). While the food is being mechanically broken down, the enzymes in saliva begin to chemically process the food as well. The combined action of these processes modifies the food from large particles to a soft mass that can be swallowed and can travel the length of the esophagus. Digestion and Absorption Digestion is the mechanical and chemical break down of food into small organic fragments. It is important to break down macromolecules into smaller fragments that are of suitable size for absorption across the digestive epithelium. Large, complex molecules of proteins, polysaccharides, and lipids must be reduced to simpler particles such as simple sugar before they can be absorbed by the digestive epithelial cells. Different organs play specific roles in the digestive process. The animal diet needs carbohydrates, protein, and fat, as well as vitamins and inorganic components for nutritional balance. How each of these components is digested is discussed in the following sections. Carbohydrates The digestion of carbohydrates begins in the mouth. The salivary enzyme amylase begins the breakdown of food starches into maltose, a disaccharide. As the bolus of food travels through the esophagus to the stomach, no significant digestion of carbohydrates takes place. The esophagus produces no digestive enzymes but does produce mucous for lubrication. The acidic environment in the stomach stops the action of the amylase enzyme. The next step of carbohydrate digestion takes place in the duodenum. Recall that the chyme from the stomach enters the duodenum and mixes with the digestive secretion from the pancreas, liver, and gallbladder. Pancreatic juices also contain amylase, which continues the breakdown of starch and glycogen into maltose, a disaccharide. The disaccharides are broken down into monosaccharides by enzymes called maltases, sucrases, and lactases, which are also present in the brush border of the small intestinal wall. Maltase breaks down maltose into glucose. Other disaccharides, such as sucrose and lactose are broken down by sucrase and lactase, respectively. Sucrase breaks down sucrose (or “table sugar”) into glucose and fructose, and lactase breaks down lactose (or “milk sugar”) into glucose and galactose. The monosaccharides (glucose) thus produced are absorbed and then can be used in metabolic pathways to harness energy. The monosaccharides are transported across the intestinal epithelium into the bloodstream to be transported to the different cells in the body. The steps in carbohydrate digestion are summarized in Figure and Table. \| Digestion of Carbohydrates \| \|\|\|\| \|---\|---\|---\|---\|---\| \| Enzyme \| Produced By \| Site of Action \| Substrate Acting On \| End Products \| \| Salivary amylase \| Salivary glands \| Mouth \| Polysaccharides (Starch) \| Disaccharides (maltose), oligosaccharides \| \| Pancreatic amylase \| Pancreas \| Small intestine \| Polysaccharides (starch) \| Disaccharides (maltose), monosaccharides \| \| Oligosaccharidases \| Lining of the intestine; brush border membrane \| Small intestine \| Disaccharides \| Monosaccharides (e.g., glucose, fructose, galactose) \| Protein A large part of protein digestion takes place in the stomach. The enzyme pepsin plays an important role in the digestion of proteins by breaking down the intact protein to peptides, which are short chains of four to nine amino acids. In the duodenum, other enzymes—trypsin, elastase, and chymotrypsin—act on the peptides reducing them to smaller peptides. Trypsin elastase, carboxypeptidase, and chymotrypsin are produced by the pancreas and released into the duodenum where they act on the chyme. Further breakdown of peptides to single amino acids is aided by enzymes called peptidases (those that break down peptides). Specifically, carboxypeptidase, dipeptidase, and aminopeptidase play important roles in reducing the peptides to free amino acids. The amino acids are absorbed into the bloodstream through the small intestines. The steps in protein digestion are summarized in Figure and Table. \| Digestion of Protein \| \|\|\|\| \|---\|---\|---\|---\|---\| \| Enzyme \| Produced By \| Site of Action \| Substrate Acting On \| End Products \| \| Pepsin \| Stomach chief cells \| Stomach \| Proteins \| Peptides \| \| Pancreas \| Small intestine \| Proteins \| Peptides \| \| Carboxypeptidase \| Pancreas \| Small intestine \| Peptides \| Amino acids and peptides \| \| Lining of intestine \| Small intestine \| Peptides \| Amino acids \| Lipids Lipid digestion begins in the stomach with the aid of lingual lipase and gastric lipase. However, the bulk of lipid digestion occurs in the small intestine due to pancreatic lipase. When chyme enters the duodenum, the hormonal responses trigger the release of bile, which is produced in the liver and stored in the gallbladder. Bile aids in the digestion of lipids, primarily triglycerides by emulsification. Emulsification is a process in which large lipid globules are broken down into several small lipid globules. These small globules are more widely distributed in the chyme rather than forming large aggregates. Lipids are hydrophobic substances: in the presence of water, they will aggregate to form globules to minimize exposure to water. Bile contains bile salts, which are amphipathic, meaning they contain hydrophobic and hydrophilic parts. Thus, the bile salts hydrophilic side can interface with water on one side and the hydrophobic side interfaces with lipids on the other. By doing so, bile salts emulsify large lipid globules into small lipid globules. Why is emulsification important for digestion of lipids? Pancreatic juices contain enzymes called lipases (enzymes that break down lipids). If the lipid in the chyme aggregates into large globules, very little surface area of the lipids is available for the lipases to act on, leaving lipid digestion incomplete. By forming an emulsion, bile salts increase the available surface area of the lipids many fold. The pancreatic lipases can then act on the lipids more efficiently and digest them, as detailed in Figure. Lipases break down the lipids into fatty acids and glycerides. These molecules can pass through the plasma membrane of the cell and enter the epithelial cells of the intestinal lining. The bile salts surround long-chain fatty acids and monoglycerides forming tiny spheres called micelles. The micelles move into the brush border of the small intestine absorptive cells where the long-chain fatty acids and monoglycerides diffuse out of the micelles into the absorptive cells leaving the micelles behind in the chyme. The long-chain fatty acids and monoglycerides recombine in the absorptive cells to form triglycerides, which aggregate into globules and become coated with proteins. These large spheres are called chylomicrons. Chylomicrons contain triglycerides, cholesterol, and other lipids and have proteins on their surface. The surface is also composed of the hydrophilic phosphate "heads" of phospholipids. Together, they enable the chylomicron to move in an aqueous environment without exposing the lipids to water. Chylomicrons leave the absorptive cells via exocytosis. Chylomicrons enter the lymphatic vessels, and then enter the blood in the subclavian vein. Vitamins Vitamins can be either water-soluble or lipid-soluble. Fat soluble vitamins are absorbed in the same manner as lipids. It is important to consume some amount of dietary lipid to aid the absorption of lipid-soluble vitamins. Water-soluble vitamins can be directly absorbed into the bloodstream from the intestine. Link to Learning This website has an overview of the digestion of protein, fat, and carbohydrates. Art Connection Which of the following statements about digestive processes is true? - Amylase, maltase, and lactase in the mouth digest carbohydrates. - Trypsin and lipase in the stomach digest protein. - Bile emulsifies lipids in the small intestine. - No food is absorbed until the small intestine. Elimination The final step in digestion is the elimination of undigested food content and waste products. The undigested food material enters the colon, where most of the water is reabsorbed. Recall that the colon is also home to the microflora called “intestinal flora” that aid in the digestion process. The semi-solid waste is moved through the colon by peristaltic movements of the muscle and is stored in the rectum. As the rectum expands in response to storage of fecal matter, it triggers the neural signals required to set up the urge to eliminate. The solid waste is eliminated through the anus using peristaltic movements of the rectum. Common Problems with Elimination Diarrhea and constipation are some of the most common health concerns that affect digestion. Constipation is a condition where the feces are hardened because of excess water removal in the colon. In contrast, if enough water is not removed from the feces, it results in diarrhea. Many bacteria, including the ones that cause cholera, affect the proteins involved in water reabsorption in the colon and result in excessive diarrhea. Emesis Emesis, or vomiting, is elimination of food by forceful expulsion through the mouth. It is often in response to an irritant that affects the digestive tract, including but not limited to viruses, bacteria, emotions, sights, and food poisoning. This forceful expulsion of the food is due to the strong contractions produced by the stomach muscles. The process of emesis is regulated by the medulla. Section Summary Digestion begins with ingestion, where the food is taken in the mouth. Digestion and absorption take place in a series of steps with special enzymes playing important roles in digesting carbohydrates, proteins, and lipids. Elimination describes removal of undigested food contents and waste products from the body. While most absorption occurs in the small intestines, the large intestine is responsible for the final removal of water that remains after the absorptive process of the small intestines. The cells that line the large intestine absorb some vitamins as well as any leftover salts and water. The large intestine (colon) is also where feces is formed. Art Connections Review Questions Where does the majority of protein digestion take place? - stomach - duodenum - mouth - jejunum Hint: A Lipases are enzymes that break down ________. - disaccharides - lipids - proteins - cellulose Hint: B Free Response Explain why some dietary lipid is a necessary part of a balanced diet. Hint: Lipids add flavor to food and promote a sense of satiety or fullness. Fatty foods are sources of high energy; one gram of lipid contains nine calories. Lipids are also required in the diet to aid the absorption of lipid-soluble vitamins and for the production of lipid-soluble hormones.	oercommons	2025-03-18T00:37:17.005853	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15112/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15113/overview	Digestive System Regulation Overview By the end of this section, you will be able to: - Discuss the role of neural regulation in digestive processes - Explain how hormones regulate digestion The brain is the control center for the sensation of hunger and satiety. The functions of the digestive system are regulated through neural and hormonal responses. Neural Responses to Food In reaction to the smell, sight, or thought of food, like that shown in Figure, the first response is that of salivation. The salivary glands secrete more saliva in response to stimulation by the autonomic nervous system triggered by food in preparation for digestion. Simultaneously, the stomach begins to produce hydrochloric acid to digest the food. Recall that the peristaltic movements of the esophagus and other organs of the digestive tract are under the control of the brain. The brain prepares these muscles for movement as well. When the stomach is full, the part of the brain that detects satiety signals fullness. There are three overlapping phases of gastric control—the cephalic phase, the gastric phase, and the intestinal phase—each requires many enzymes and is under neural control as well. Digestive Phases The response to food begins even before food enters the mouth. The first phase of ingestion, called the cephalic phase, is controlled by the neural response to the stimulus provided by food. All aspects—such as sight, sense, and smell—trigger the neural responses resulting in salivation and secretion of gastric juices. The gastric and salivary secretion in the cephalic phase can also take place due to the thought of food. Right now, if you think about a piece of chocolate or a crispy potato chip, the increase in salivation is a cephalic phase response to the thought. The central nervous system prepares the stomach to receive food. The gastric phase begins once the food arrives in the stomach. It builds on the stimulation provided during the cephalic phase. Gastric acids and enzymes process the ingested materials. The gastric phase is stimulated by (1) distension of the stomach, (2) a decrease in the pH of the gastric contents, and (3) the presence of undigested material. This phase consists of local, hormonal, and neural responses. These responses stimulate secretions and powerful contractions. The intestinal phase begins when chyme enters the small intestine triggering digestive secretions. This phase controls the rate of gastric emptying. In addition to gastrin emptying, when chyme enters the small intestine, it triggers other hormonal and neural events that coordinate the activities of the intestinal tract, pancreas, liver, and gallbladder. Hormonal Responses to Food The endocrine system controls the response of the various glands in the body and the release of hormones at the appropriate times. One of the important factors under hormonal control is the stomach acid environment. During the gastric phase, the hormone gastrin is secreted by G cells in the stomach in response to the presence of proteins. Gastrin stimulates the release of stomach acid, or hydrochloric acid (HCl) which aids in the digestion of the proteins. However, when the stomach is emptied, the acidic environment need not be maintained and a hormone called somatostatin stops the release of hydrochloric acid. This is controlled by a negative feedback mechanism. In the duodenum, digestive secretions from the liver, pancreas, and gallbladder play an important role in digesting chyme during the intestinal phase. In order to neutralize the acidic chyme, a hormone called secretin stimulates the pancreas to produce alkaline bicarbonate solution and deliver it to the duodenum. Secretin acts in tandem with another hormone called cholecystokinin (CCK). Not only does CCK stimulate the pancreas to produce the requisite pancreatic juices, it also stimulates the gallbladder to release bile into the duodenum. Link to Learning Visit this website to learn more about the endocrine system. Review the text and watch the animation of how control is implemented in the endocrine system. Another level of hormonal control occurs in response to the composition of food. Foods high in lipids take a long time to digest. A hormone called gastric inhibitory peptide is secreted by the small intestine to slow down the peristaltic movements of the intestine to allow fatty foods more time to be digested and absorbed. Understanding the hormonal control of the digestive system is an important area of ongoing research. Scientists are exploring the role of each hormone in the digestive process and developing ways to target these hormones. Advances could lead to knowledge that may help to battle the obesity epidemic. Section Summary The brain and the endocrine system control digestive processes. The brain controls the responses of hunger and satiety. The endocrine system controls the release of hormones and enzymes required for digestion of food in the digestive tract. Review Questions Which hormone controls the release of bile from the gallbladder - pepsin - amylase - CCK - gastrin Hint: C Which hormone stops acid secretion in the stomach? - gastrin - somatostatin - gastric inhibitory peptide - CCK Hint: B Free Response Describe how hormones regulate digestion. Hint: Hormones control the different digestive enzymes that are secreted in the stomach and the intestine during the process of digestion and absorption. For example, the hormone gastrin stimulates stomach acid secretion in response to food intake. The hormone somatostatin stops the release of stomach acid. Describe one or more scenarios where loss of hormonal regulation of digestion can lead to diseases. Hint: There are many cases where loss of hormonal regulation can lead to illnesses. For example, the bilirubin produced by the breakdown of red blood cells is converted to bile by the liver. When there is malfunction of this process, there is excess bilirubin in the blood and bile levels are low. As a result, the body struggles with dealing with fatty food. This is why a patient suffering from jaundice is asked to eat a diet with almost zero fat.	oercommons	2025-03-18T00:37:17.029109	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15113/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15114/overview	Introduction When you’re reading this book, your nervous system is performing several functions simultaneously. The visual system is processing what is seen on the page; the motor system controls the turn of the pages (or click of the mouse); the prefrontal cortex maintains attention. Even fundamental functions, like breathing and regulation of body temperature, are controlled by the nervous system. A nervous system is an organism’s control center: it processes sensory information from outside (and inside) the body and controls all behaviors—from eating to sleeping to finding a mate.	oercommons	2025-03-18T00:37:17.047779	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15114/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15115/overview	Neurons and Glial Cells Overview By the end of this section, you will be able to: - List and describe the functions of the structural components of a neuron - List and describe the four main types of neurons - Compare the functions of different types of glial cells Nervous systems throughout the animal kingdom vary in structure and complexity, as illustrated by the variety of animals shown in Figure. Some organisms, like sea sponges, lack a true nervous system. Others, like jellyfish, lack a true brain and instead have a system of separate but connected nerve cells (neurons) called a “nerve net.” Echinoderms such as sea stars have nerve cells that are bundled into fibers called nerves. Flatworms of the phylum Platyhelminthes have both a central nervous system (CNS), made up of a small “brain” and two nerve cords, and a peripheral nervous system (PNS) containing a system of nerves that extend throughout the body. The insect nervous system is more complex but also fairly decentralized. It contains a brain, ventral nerve cord, and ganglia (clusters of connected neurons). These ganglia can control movements and behaviors without input from the brain. Octopi may have the most complicated of invertebrate nervous systems—they have neurons that are organized in specialized lobes and eyes that are structurally similar to vertebrate species. Compared to invertebrates, vertebrate nervous systems are more complex, centralized, and specialized. While there is great diversity among different vertebrate nervous systems, they all share a basic structure: a CNS that contains a brain and spinal cord and a PNS made up of peripheral sensory and motor nerves. One interesting difference between the nervous systems of invertebrates and vertebrates is that the nerve cords of many invertebrates are located ventrally whereas the vertebrate spinal cords are located dorsally. There is debate among evolutionary biologists as to whether these different nervous system plans evolved separately or whether the invertebrate body plan arrangement somehow “flipped” during the evolution of vertebrates. Link to Learning Watch this video of biologist Mark Kirschner discussing the “flipping” phenomenon of vertebrate evolution. The nervous system is made up of neurons, specialized cells that can receive and transmit chemical or electrical signals, and glia, cells that provide support functions for the neurons by playing an information processing role that is complementary to neurons. A neuron can be compared to an electrical wire—it transmits a signal from one place to another. Glia can be compared to the workers at the electric company who make sure wires go to the right places, maintain the wires, and take down wires that are broken. Although glia have been compared to workers, recent evidence suggests that also usurp some of the signaling functions of neurons. There is great diversity in the types of neurons and glia that are present in different parts of the nervous system. There are four major types of neurons, and they share several important cellular components. Neurons The nervous system of the common laboratory fly, Drosophila melanogaster, contains around 100,000 neurons, the same number as a lobster. This number compares to 75 million in the mouse and 300 million in the octopus. A human brain contains around 86 billion neurons. Despite these very different numbers, the nervous systems of these animals control many of the same behaviors—from basic reflexes to more complicated behaviors like finding food and courting mates. The ability of neurons to communicate with each other as well as with other types of cells underlies all of these behaviors. Most neurons share the same cellular components. But neurons are also highly specialized—different types of neurons have different sizes and shapes that relate to their functional roles. Parts of a Neuron Like other cells, each neuron has a cell body (or soma) that contains a nucleus, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria, and other cellular components. Neurons also contain unique structures, illustrated in Figure for receiving and sending the electrical signals that make neuronal communication possible. Dendrites are tree-like structures that extend away from the cell body to receive messages from other neurons at specialized junctions called synapses. Although some neurons do not have any dendrites, some types of neurons have multiple dendrites. Dendrites can have small protrusions called dendritic spines, which further increase surface area for possible synaptic connections. Once a signal is received by the dendrite, it then travels passively to the cell body. The cell body contains a specialized structure, the axon hillock that integrates signals from multiple synapses and serves as a junction between the cell body and an axon. An axon is a tube-like structure that propagates the integrated signal to specialized endings called axon terminals. These terminals in turn synapse on other neurons, muscle, or target organs. Chemicals released at axon terminals allow signals to be communicated to these other cells. Neurons usually have one or two axons, but some neurons, like amacrine cells in the retina, do not contain any axons. Some axons are covered with myelin, which acts as an insulator to minimize dissipation of the electrical signal as it travels down the axon, greatly increasing the speed on conduction. This insulation is important as the axon from a human motor neuron can be as long as a meter—from the base of the spine to the toes. The myelin sheath is not actually part of the neuron. Myelin is produced by glial cells. Along the axon there are periodic gaps in the myelin sheath. These gaps are called nodes of Ranvier and are sites where the signal is “recharged” as it travels along the axon. It is important to note that a single neuron does not act alone—neuronal communication depends on the connections that neurons make with one another (as well as with other cells, like muscle cells). Dendrites from a single neuron may receive synaptic contact from many other neurons. For example, dendrites from a Purkinje cell in the cerebellum are thought to receive contact from as many as 200,000 other neurons. Art Connection Which of the following statements is false? - The soma is the cell body of a nerve cell. - Myelin sheath provides an insulating layer to the dendrites. - Axons carry the signal from the soma to the target. - Dendrites carry the signal to the soma. Types of Neurons There are different types of neurons, and the functional role of a given neuron is intimately dependent on its structure. There is an amazing diversity of neuron shapes and sizes found in different parts of the nervous system (and across species), as illustrated by the neurons shown in Figure. While there are many defined neuron cell subtypes, neurons are broadly divided into four basic types: unipolar, bipolar, multipolar, and pseudounipolar. Figure illustrates these four basic neuron types. Unipolar neurons have only one structure that extends away from the soma. These neurons are not found in vertebrates but are found in insects where they stimulate muscles or glands. A bipolar neuron has one axon and one dendrite extending from the soma. An example of a bipolar neuron is a retinal bipolar cell, which receives signals from photoreceptor cells that are sensitive to light and transmits these signals to ganglion cells that carry the signal to the brain. Multipolar neurons are the most common type of neuron. Each multipolar neuron contains one axon and multiple dendrites. Multipolar neurons can be found in the central nervous system (brain and spinal cord). An example of a multipolar neuron is a Purkinje cell in the cerebellum, which has many branching dendrites but only one axon. Pseudounipolar cells share characteristics with both unipolar and bipolar cells. A pseudounipolar cell has a single process that extends from the soma, like a unipolar cell, but this process later branches into two distinct structures, like a bipolar cell. Most sensory neurons are pseudounipolar and have an axon that branches into two extensions: one connected to dendrites that receive sensory information and another that transmits this information to the spinal cord. Everyday Connection Neurogenesis At one time, scientists believed that people were born with all the neurons they would ever have. Research performed during the last few decades indicates that neurogenesis, the birth of new neurons, continues into adulthood. Neurogenesis was first discovered in songbirds that produce new neurons while learning songs. For mammals, new neurons also play an important role in learning: about 1000 new neurons develop in the hippocampus (a brain structure involved in learning and memory) each day. While most of the new neurons will die, researchers found that an increase in the number of surviving new neurons in the hippocampus correlated with how well rats learned a new task. Interestingly, both exercise and some antidepressant medications also promote neurogenesis in the hippocampus. Stress has the opposite effect. While neurogenesis is quite limited compared to regeneration in other tissues, research in this area may lead to new treatments for disorders such as Alzheimer’s, stroke, and epilepsy. How do scientists identify new neurons? A researcher can inject a compound called bromodeoxyuridine (BrdU) into the brain of an animal. While all cells will be exposed to BrdU, BrdU will only be incorporated into the DNA of newly generated cells that are in S phase. A technique called immunohistochemistry can be used to attach a fluorescent label to the incorporated BrdU, and a researcher can use fluorescent microscopy to visualize the presence of BrdU, and thus new neurons, in brain tissue. Figure is a micrograph which shows fluorescently labeled neurons in the hippocampus of a rat. Link to Learning This site contains more information about neurogenesis, including an interactive laboratory simulation and a video that explains how BrdU labels new cells. Glia While glia are often thought of as the supporting cast of the nervous system, the number of glial cells in the brain actually outnumbers the number of neurons by a factor of ten. Neurons would be unable to function without the vital roles that are fulfilled by these glial cells. Glia guide developing neurons to their destinations, buffer ions and chemicals that would otherwise harm neurons, and provide myelin sheaths around axons. Scientists have recently discovered that they also play a role in responding to nerve activity and modulating communication between nerve cells. When glia do not function properly, the result can be disastrous—most brain tumors are caused by mutations in glia. Types of Glia There are several different types of glia with different functions, two of which are shown in Figure. Astrocytes, shown in Figurea make contact with both capillaries and neurons in the CNS. They provide nutrients and other substances to neurons, regulate the concentrations of ions and chemicals in the extracellular fluid, and provide structural support for synapses. Astrocytes also form the blood-brain barrier—a structure that blocks entrance of toxic substances into the brain. Astrocytes, in particular, have been shown through calcium imaging experiments to become active in response to nerve activity, transmit calcium waves between astrocytes, and modulate the activity of surrounding synapses. Satellite glia provide nutrients and structural support for neurons in the PNS. Microglia scavenge and degrade dead cells and protect the brain from invading microorganisms. Oligodendrocytes, shown in Figureb form myelin sheaths around axons in the CNS. One axon can be myelinated by several oligodendrocytes, and one oligodendrocyte can provide myelin for multiple neurons. This is distinctive from the PNS where a single Schwann cell provides myelin for only one axon as the entire Schwann cell surrounds the axon. Radial glia serve as scaffolds for developing neurons as they migrate to their end destinations. Ependymal cells line fluid-filled ventricles of the brain and the central canal of the spinal cord. They are involved in the production of cerebrospinal fluid, which serves as a cushion for the brain, moves the fluid between the spinal cord and the brain, and is a component for the choroid plexus. Section Summary The nervous system is made up of neurons and glia. Neurons are specialized cells that are capable of sending electrical as well as chemical signals. Most neurons contain dendrites, which receive these signals, and axons that send signals to other neurons or tissues. There are four main types of neurons: unipolar, bipolar, multipolar, and pseudounipolar neurons. Glia are non-neuronal cells in the nervous system that support neuronal development and signaling. There are several types of glia that serve different functions. Art Connections Review Questions Neurons contain ________, which can receive signals from other neurons. - axons - mitochondria - dendrites - Golgi bodies Hint: C A(n) ________ neuron has one axon and one dendrite extending directly from the cell body. - unipolar - bipolar - multipolar - pseudounipolar Hint: B Glia that provide myelin for neurons in the brain are called ________. - Schwann cells - oligodendrocytes - microglia - astrocytes Hint: B Free Response How are neurons similar to other cells? How are they unique? Hint: Neurons contain organelles common to all cells, such as a nucleus and mitochondria. They are unique because they contain dendrites, which can receive signals from other neurons, and axons that can send these signals to other cells. Multiple sclerosis causes demyelination of axons in the brain and spinal cord. Why is this problematic? Hint: Myelin provides insulation for signals traveling along axons. Without myelin, signal transmission can slow down and degrade over time. This would slow down neuronal communication across the nervous system and affect all downstream functions.	oercommons	2025-03-18T00:37:17.077926	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15115/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15116/overview	How Neurons Communicate Overview By the end of this section, you will be able to: - Describe the basis of the resting membrane potential - Explain the stages of an action potential and how action potentials are propagated - Explain the similarities and differences between chemical and electrical synapses - Describe long-term potentiation and long-term depression All functions performed by the nervous system—from a simple motor reflex to more advanced functions like making a memory or a decision—require neurons to communicate with one another. While humans use words and body language to communicate, neurons use electrical and chemical signals. Just like a person in a committee, one neuron usually receives and synthesizes messages from multiple other neurons before “making the decision” to send the message on to other neurons. Nerve Impulse Transmission within a Neuron For the nervous system to function, neurons must be able to send and receive signals. These signals are possible because each neuron has a charged cellular membrane (a voltage difference between the inside and the outside), and the charge of this membrane can change in response to neurotransmitter molecules released from other neurons and environmental stimuli. To understand how neurons communicate, one must first understand the basis of the baseline or ‘resting’ membrane charge. Neuronal Charged Membranes The lipid bilayer membrane that surrounds a neuron is impermeable to charged molecules or ions. To enter or exit the neuron, ions must pass through special proteins called ion channels that span the membrane. Ion channels have different configurations: open, closed, and inactive, as illustrated in Figure. Some ion channels need to be activated in order to open and allow ions to pass into or out of the cell. These ion channels are sensitive to the environment and can change their shape accordingly. Ion channels that change their structure in response to voltage changes are called voltage-gated ion channels. Voltage-gated ion channels regulate the relative concentrations of different ions inside and outside the cell. The difference in total charge between the inside and outside of the cell is called the membrane potential. Link to Learning This video discusses the basis of the resting membrane potential. Resting Membrane Potential A neuron at rest is negatively charged: the inside of a cell is approximately 70 millivolts more negative than the outside (−70 mV, note that this number varies by neuron type and by species). This voltage is called the resting membrane potential; it is caused by differences in the concentrations of ions inside and outside the cell. If the membrane were equally permeable to all ions, each type of ion would flow across the membrane and the system would reach equilibrium. Because ions cannot simply cross the membrane at will, there are different concentrations of several ions inside and outside the cell, as shown in Table. The difference in the number of positively charged potassium ions (K+) inside and outside the cell dominates the resting membrane potential (Figure). When the membrane is at rest, K+ ions accumulate inside the cell due to a net movement with the concentration gradient. The negative resting membrane potential is created and maintained by increasing the concentration of cations outside the cell (in the extracellular fluid) relative to inside the cell (in the cytoplasm). The negative charge within the cell is created by the cell membrane being more permeable to potassium ion movement than sodium ion movement. In neurons, potassium ions are maintained at high concentrations within the cell while sodium ions are maintained at high concentrations outside of the cell. The cell possesses potassium and sodium leakage channels that allow the two cations to diffuse down their concentration gradient. However, the neurons have far more potassium leakage channels than sodium leakage channels. Therefore, potassium diffuses out of the cell at a much faster rate than sodium leaks in. Because more cations are leaving the cell than are entering, this causes the interior of the cell to be negatively charged relative to the outside of the cell. The actions of the sodium potassium pump help to maintain the resting potential, once established. Recall that sodium potassium pumps brings two K+ ions into the cell while removing three Na+ ions per ATP consumed. As more cations are expelled from the cell than taken in, the inside of the cell remains negatively charged relative to the extracellular fluid. It should be noted that chloride ions (Cl–) tend to accumulate outside of the cell because they are repelled by negatively-charged proteins within the cytoplasm. \| Ion Concentration Inside and Outside Neurons \| \|\|\| \|---\|---\|---\|---\| \| Ion \| Extracellular concentration (mM) \| Intracellular concentration (mM) \| Ratio outside/inside \| \| Na+ \| 145 \| 12 \| 12 \| \| K+ \| 4 \| 155 \| 0.026 \| \| Cl− \| 120 \| 4 \| 30 \| \| Organic anions (A−) \| — \| 100 \| Action Potential A neuron can receive input from other neurons and, if this input is strong enough, send the signal to downstream neurons. Transmission of a signal between neurons is generally carried by a chemical called a neurotransmitter. Transmission of a signal within a neuron (from dendrite to axon terminal) is carried by a brief reversal of the resting membrane potential called an action potential. When neurotransmitter molecules bind to receptors located on a neuron’s dendrites, ion channels open. At excitatory synapses, this opening allows positive ions to enter the neuron and results in depolarization of the membrane—a decrease in the difference in voltage between the inside and outside of the neuron. A stimulus from a sensory cell or another neuron depolarizes the target neuron to its threshold potential (-55 mV). Na+ channels in the axon hillock open, allowing positive ions to enter the cell (Figure and Figure). Once the sodium channels open, the neuron completely depolarizes to a membrane potential of about +40 mV. Action potentials are considered an "all-or nothing" event, in that, once the threshold potential is reached, the neuron always completely depolarizes. Once depolarization is complete, the cell must now "reset" its membrane voltage back to the resting potential. To accomplish this, the Na+ channels close and cannot be opened. This begins the neuron's refractory period, in which it cannot produce another action potential because its sodium channels will not open. At the same time, voltage-gated K+ channels open, allowing K+ to leave the cell. As K+ ions leave the cell, the membrane potential once again becomes negative. The diffusion of K+ out of the cell actually hyperpolarizes the cell, in that the membrane potential becomes more negative than the cell's normal resting potential. At this point, the sodium channels will return to their resting state, meaning they are ready to open again if the membrane potential again exceeds the threshold potential. Eventually the extra K+ ions diffuse out of the cell through the potassium leakage channels, bringing the cell from its hyperpolarized state, back to its resting membrane potential. Art Connection Potassium channel blockers, such as amiodarone and procainamide, which are used to treat abnormal electrical activity in the heart, called cardiac dysrhythmia, impede the movement of K+ through voltage-gated K+ channels. Which part of the action potential would you expect potassium channels to affect? Link to Learning This video presents an overview of action potential. Myelin and the Propagation of the Action Potential For an action potential to communicate information to another neuron, it must travel along the axon and reach the axon terminals where it can initiate neurotransmitter release. The speed of conduction of an action potential along an axon is influenced by both the diameter of the axon and the axon’s resistance to current leak. Myelin acts as an insulator that prevents current from leaving the axon; this increases the speed of action potential conduction. In demyelinating diseases like multiple sclerosis, action potential conduction slows because current leaks from previously insulated axon areas. The nodes of Ranvier, illustrated in Figure are gaps in the myelin sheath along the axon. These unmyelinated spaces are about one micrometer long and contain voltage gated Na+ and K+ channels. Flow of ions through these channels, particularly the Na+ channels, regenerates the action potential over and over again along the axon. This ‘jumping’ of the action potential from one node to the next is called saltatory conduction. If nodes of Ranvier were not present along an axon, the action potential would propagate very slowly since Na+ and K+ channels would have to continuously regenerate action potentials at every point along the axon instead of at specific points. Nodes of Ranvier also save energy for the neuron since the channels only need to be present at the nodes and not along the entire axon. Synaptic Transmission The synapse or “gap” is the place where information is transmitted from one neuron to another. Synapses usually form between axon terminals and dendritic spines, but this is not universally true. There are also axon-to-axon, dendrite-to-dendrite, and axon-to-cell body synapses. The neuron transmitting the signal is called the presynaptic neuron, and the neuron receiving the signal is called the postsynaptic neuron. Note that these designations are relative to a particular synapse—most neurons are both presynaptic and postsynaptic. There are two types of synapses: chemical and electrical. Chemical Synapse When an action potential reaches the axon terminal it depolarizes the membrane and opens voltage-gated Na+ channels. Na+ ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated Ca2+ channels to open. Calcium ions entering the cell initiate a signaling cascade that causes small membrane-bound vesicles, called synaptic vesicles, containing neurotransmitter molecules to fuse with the presynaptic membrane. Synaptic vesicles are shown in Figure, which is an image from a scanning electron microscope. Fusion of a vesicle with the presynaptic membrane causes neurotransmitter to be released into the synaptic cleft, the extracellular space between the presynaptic and postsynaptic membranes, as illustrated in Figure. The neurotransmitter diffuses across the synaptic cleft and binds to receptor proteins on the postsynaptic membrane. The binding of a specific neurotransmitter causes particular ion channels, in this case ligand-gated channels, on the postsynaptic membrane to open. Neurotransmitters can either have excitatory or inhibitory effects on the postsynaptic membrane, as detailed in Table. For example, when acetylcholine is released at the synapse between a nerve and muscle (called the neuromuscular junction) by a presynaptic neuron, it causes postsynaptic Na+ channels to open. Na+ enters the postsynaptic cell and causes the postsynaptic membrane to depolarize. This depolarization is called an excitatory postsynaptic potential (EPSP) and makes the postsynaptic neuron more likely to fire an action potential. Release of neurotransmitter at inhibitory synapses causes inhibitory postsynaptic potentials (IPSPs), a hyperpolarization of the presynaptic membrane. For example, when the neurotransmitter GABA (gamma-aminobutyric acid) is released from a presynaptic neuron, it binds to and opens Cl- channels. Cl- ions enter the cell and hyperpolarizes the membrane, making the neuron less likely to fire an action potential. Once neurotransmission has occurred, the neurotransmitter must be removed from the synaptic cleft so the postsynaptic membrane can “reset” and be ready to receive another signal. This can be accomplished in three ways: the neurotransmitter can diffuse away from the synaptic cleft, it can be degraded by enzymes in the synaptic cleft, or it can be recycled (sometimes called reuptake) by the presynaptic neuron. Several drugs act at this step of neurotransmission. For example, some drugs that are given to Alzheimer’s patients work by inhibiting acetylcholinesterase, the enzyme that degrades acetylcholine. This inhibition of the enzyme essentially increases neurotransmission at synapses that release acetylcholine. Once released, the acetylcholine stays in the cleft and can continually bind and unbind to postsynaptic receptors. \| Neurotransmitter Function and Location \| \|\| \|---\|---\|---\| \| Neurotransmitter \| Example \| Location \| \| Acetylcholine \| — \| CNS and/or PNS \| \| Biogenic amine \| Dopamine, serotonin, norepinephrine \| CNS and/or PNS \| \| Amino acid \| Glycine, glutamate, aspartate, gamma aminobutyric acid \| CNS \| \| Neuropeptide \| Substance P, endorphins \| CNS and/or PNS \| Electrical Synapse While electrical synapses are fewer in number than chemical synapses, they are found in all nervous systems and play important and unique roles. The mode of neurotransmission in electrical synapses is quite different from that in chemical synapses. In an electrical synapse, the presynaptic and postsynaptic membranes are very close together and are actually physically connected by channel proteins forming gap junctions. Gap junctions allow current to pass directly from one cell to the next. In addition to the ions that carry this current, other molecules, such as ATP, can diffuse through the large gap junction pores. There are key differences between chemical and electrical synapses. Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is unidirectional. Signaling in electrical synapses, in contrast, is virtually instantaneous (which is important for synapses involved in key reflexes), and some electrical synapses are bidirectional. Electrical synapses are also more reliable as they are less likely to be blocked, and they are important for synchronizing the electrical activity of a group of neurons. For example, electrical synapses in the thalamus are thought to regulate slow-wave sleep, and disruption of these synapses can cause seizures. Signal Summation Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron, but often multiple presynaptic inputs must create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. This process is called summation and occurs at the axon hillock, as illustrated in Figure. Additionally, one neuron often has inputs from many presynaptic neurons—some excitatory and some inhibitory—so IPSPs can cancel out EPSPs and vice versa. It is the net change in postsynaptic membrane voltage that determines whether the postsynaptic cell has reached its threshold of excitation needed to fire an action potential. Together, synaptic summation and the threshold for excitation act as a filter so that random “noise” in the system is not transmitted as important information. Everyday Connection Brain-computer interface Amyotrophic lateral sclerosis (ALS, also called Lou Gehrig’s Disease) is a neurological disease characterized by the degeneration of the motor neurons that control voluntary movements. The disease begins with muscle weakening and lack of coordination and eventually destroys the neurons that control speech, breathing, and swallowing; in the end, the disease can lead to paralysis. At that point, patients require assistance from machines to be able to breathe and to communicate. Several special technologies have been developed to allow “locked-in” patients to communicate with the rest of the world. One technology, for example, allows patients to type out sentences by twitching their cheek. These sentences can then be read aloud by a computer. A relatively new line of research for helping paralyzed patients, including those with ALS, to communicate and retain a degree of self-sufficiency is called brain-computer interface (BCI) technology and is illustrated in Figure. This technology sounds like something out of science fiction: it allows paralyzed patients to control a computer using only their thoughts. There are several forms of BCI. Some forms use EEG recordings from electrodes taped onto the skull. These recordings contain information from large populations of neurons that can be decoded by a computer. Other forms of BCI require the implantation of an array of electrodes smaller than a postage stamp in the arm and hand area of the motor cortex. This form of BCI, while more invasive, is very powerful as each electrode can record actual action potentials from one or more neurons. These signals are then sent to a computer, which has been trained to decode the signal and feed it to a tool—such as a cursor on a computer screen. This means that a patient with ALS can use e-mail, read the Internet, and communicate with others by thinking of moving his or her hand or arm (even though the paralyzed patient cannot make that bodily movement). Recent advances have allowed a paralyzed locked-in patient who suffered a stroke 15 years ago to control a robotic arm and even to feed herself coffee using BCI technology. Despite the amazing advancements in BCI technology, it also has limitations. The technology can require many hours of training and long periods of intense concentration for the patient; it can also require brain surgery to implant the devices. Link to Learning Watch this video in which a paralyzed woman use a brain-controlled robotic arm to bring a drink to her mouth, among other images of brain-computer interface technology in action. Synaptic Plasticity Synapses are not static structures. They can be weakened or strengthened. They can be broken, and new synapses can be made. Synaptic plasticity allows for these changes, which are all needed for a functioning nervous system. In fact, synaptic plasticity is the basis of learning and memory. Two processes in particular, long-term potentiation (LTP) and long-term depression (LTD) are important forms of synaptic plasticity that occur in synapses in the hippocampus, a brain region that is involved in storing memories. Long-term Potentiation (LTP) Long-term potentiation (LTP) is a persistent strengthening of a synaptic connection. LTP is based on the Hebbian principle: cells that fire together wire together. There are various mechanisms, none fully understood, behind the synaptic strengthening seen with LTP. One known mechanism involves a type of postsynaptic glutamate receptor, called NMDA (N-Methyl-D-aspartate) receptors, shown in Figure. These receptors are normally blocked by magnesium ions; however, when the postsynaptic neuron is depolarized by multiple presynaptic inputs in quick succession (either from one neuron or multiple neurons), the magnesium ions are forced out allowing Ca ions to pass into the postsynaptic cell. Next, Ca2+ ions entering the cell initiate a signaling cascade that causes a different type of glutamate receptor, called AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, to be inserted into the postsynaptic membrane, since activated AMPA receptors allow positive ions to enter the cell. So, the next time glutamate is released from the presynaptic membrane, it will have a larger excitatory effect (EPSP) on the postsynaptic cell because the binding of glutamate to these AMPA receptors will allow more positive ions into the cell. The insertion of additional AMPA receptors strengthens the synapse and means that the postsynaptic neuron is more likely to fire in response to presynaptic neurotransmitter release. Some drugs of abuse co-opt the LTP pathway, and this synaptic strengthening can lead to addiction. Long-term Depression (LTD) Long-term depression (LTD) is essentially the reverse of LTP: it is a long-term weakening of a synaptic connection. One mechanism known to cause LTD also involves AMPA receptors. In this situation, calcium that enters through NMDA receptors initiates a different signaling cascade, which results in the removal of AMPA receptors from the postsynaptic membrane, as illustrated in Figure. The decrease in AMPA receptors in the membrane makes the postsynaptic neuron less responsive to glutamate released from the presynaptic neuron. While it may seem counterintuitive, LTD may be just as important for learning and memory as LTP. The weakening and pruning of unused synapses allows for unimportant connections to be lost and makes the synapses that have undergone LTP that much stronger by comparison. Section Summary Neurons have charged membranes because there are different concentrations of ions inside and outside of the cell. Voltage-gated ion channels control the movement of ions into and out of a neuron. When a neuronal membrane is depolarized to at least the threshold of excitation, an action potential is fired. The action potential is then propagated along a myelinated axon to the axon terminals. In a chemical synapse, the action potential causes release of neurotransmitter molecules into the synaptic cleft. Through binding to postsynaptic receptors, the neurotransmitter can cause excitatory or inhibitory postsynaptic potentials by depolarizing or hyperpolarizing, respectively, the postsynaptic membrane. In electrical synapses, the action potential is directly communicated to the postsynaptic cell through gap junctions—large channel proteins that connect the pre-and postsynaptic membranes. Synapses are not static structures and can be strengthened and weakened. Two mechanisms of synaptic plasticity are long-term potentiation and long-term depression. Art Connections Figure Potassium channel blockers, such as amiodarone and procainamide, which are used to treat abnormal electrical activity in the heart, called cardiac dysrhythmia, impede the movement of K+ through voltage-gated K+ channels. Which part of the action potential would you expect potassium channels to affect? Hint: Figure Potassium channel blockers slow the repolarization phase, but have no effect on depolarization. Review Questions For a neuron to fire an action potential, its membrane must reach ________. - hyperpolarization - the threshold of excitation - the refractory period - inhibitory postsynaptic potential Hint: B After an action potential, the opening of additional voltage-gated ________ channels and the inactivation of sodium channels, cause the membrane to return to its resting membrane potential. - sodium - potassium - calcium - chloride Hint: B What is the term for protein channels that connect two neurons at an electrical synapse? - synaptic vesicles - voltage-gated ion channels - gap junction protein - sodium-potassium exchange pumps Hint: C Free Response How does myelin aid propagation of an action potential along an axon? How do the nodes of Ranvier help this process? Hint: Myelin prevents the leak of current from the axon. Nodes of Ranvier allow the action potential to be regenerated at specific points along the axon. They also save energy for the cell since voltage-gated ion channels and sodium-potassium transporters are not needed along myelinated portions of the axon. What are the main steps in chemical neurotransmission? Hint: An action potential travels along an axon until it depolarizes the membrane at an axon terminal. Depolarization of the membrane causes voltage-gated Ca2+ channels to open and Ca2+ to enter the cell. The intracellular calcium influx causes synaptic vesicles containing neurotransmitter to fuse with the presynaptic membrane. The neurotransmitter diffuses across the synaptic cleft and binds to receptors on the postsynaptic membrane. Depending on the specific neurotransmitter and postsynaptic receptor, this action can cause positive (excitatory postsynaptic potential) or negative (inhibitory postsynaptic potential) ions to enter the cell.	oercommons	2025-03-18T00:37:17.118234	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15116/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15117/overview	The Central Nervous System Overview By the end of this section, you will be able to: - Identify the spinal cord, cerebral lobes, and other brain areas on a diagram of the brain - Describe the basic functions of the spinal cord, cerebral lobes, and other brain areas The central nervous system (CNS) is made up of the brain, a part of which is shown in Figure and spinal cord and is covered with three layers of protective coverings called meninges (from the Greek word for membrane). The outermost layer is the dura mater (Latin for “hard mother”). As the Latin suggests, the primary function for this thick layer is to protect the brain and spinal cord. The dura mater also contains vein-like structures that carry blood from the brain back to the heart. The middle layer is the web-like arachnoid mater. The last layer is the pia mater (Latin for “soft mother”), which directly contacts and covers the brain and spinal cord like plastic wrap. The space between the arachnoid and pia maters is filled with cerebrospinal fluid (CSF). CSF is produced by a tissue called choroid plexus in fluid-filled compartments in the CNS called ventricles. The brain floats in CSF, which acts as a cushion and shock absorber and makes the brain neutrally buoyant. CSF also functions to circulate chemical substances throughout the brain and into the spinal cord. The entire brain contains only about 8.5 tablespoons of CSF, but CSF is constantly produced in the ventricles. This creates a problem when a ventricle is blocked—the CSF builds up and creates swelling and the brain is pushed against the skull. This swelling condition is called hydrocephalus (“water head”) and can cause seizures, cognitive problems, and even death if a shunt is not inserted to remove the fluid and pressure. Brain The brain is the part of the central nervous system that is contained in the cranial cavity of the skull. It includes the cerebral cortex, limbic system, basal ganglia, thalamus, hypothalamus, and cerebellum. There are three different ways that a brain can be sectioned in order to view internal structures: a sagittal section cuts the brain left to right, as shown in Figureb, a coronal section cuts the brain front to back, as shown in Figurea, and a horizontal section cuts the brain top to bottom. Cerebral Cortex The outermost part of the brain is a thick piece of nervous system tissue called the cerebral cortex, which is folded into hills called gyri (singular: gyrus) and valleys called sulci (singular: sulcus). The cortex is made up of two hemispheres—right and left—which are separated by a large sulcus. A thick fiber bundle called the corpus callosum (Latin: “tough body”) connects the two hemispheres and allows information to be passed from one side to the other. Although there are some brain functions that are localized more to one hemisphere than the other, the functions of the two hemispheres are largely redundant. In fact, sometimes (very rarely) an entire hemisphere is removed to treat severe epilepsy. While patients do suffer some deficits following the surgery, they can have surprisingly few problems, especially when the surgery is performed on children who have very immature nervous systems. In other surgeries to treat severe epilepsy, the corpus callosum is cut instead of removing an entire hemisphere. This causes a condition called split-brain, which gives insights into unique functions of the two hemispheres. For example, when an object is presented to patients’ left visual field, they may be unable to verbally name the object (and may claim to not have seen an object at all). This is because the visual input from the left visual field crosses and enters the right hemisphere and cannot then signal to the speech center, which generally is found in the left side of the brain. Remarkably, if a split-brain patient is asked to pick up a specific object out of a group of objects with the left hand, the patient will be able to do so but will still be unable to vocally identify it. Link to Learning See this website to learn more about split-brain patients and to play a game where you can model the split-brain experiments yourself. Each cortical hemisphere contains regions called lobes that are involved in different functions. Scientists use various techniques to determine what brain areas are involved in different functions: they examine patients who have had injuries or diseases that affect specific areas and see how those areas are related to functional deficits. They also conduct animal studies where they stimulate brain areas and see if there are any behavioral changes. They use a technique called transmagnetic stimulation (TMS) to temporarily deactivate specific parts of the cortex using strong magnets placed outside the head; and they use functional magnetic resonance imaging (fMRI) to look at changes in oxygenated blood flow in particular brain regions that correlate with specific behavioral tasks. These techniques, and others, have given great insight into the functions of different brain regions but have also showed that any given brain area can be involved in more than one behavior or process, and any given behavior or process generally involves neurons in multiple brain areas. That being said, each hemisphere of the mammalian cerebral cortex can be broken down into four functionally and spatially defined lobes: frontal, parietal, temporal, and occipital. Figure illustrates these four lobes of the human cerebral cortex. The frontal lobe is located at the front of the brain, over the eyes. This lobe contains the olfactory bulb, which processes smells. The frontal lobe also contains the motor cortex, which is important for planning and implementing movement. Areas within the motor cortex map to different muscle groups, and there is some organization to this map, as shown in Figure. For example, the neurons that control movement of the fingers are next to the neurons that control movement of the hand. Neurons in the frontal lobe also control cognitive functions like maintaining attention, speech, and decision-making. Studies of humans who have damaged their frontal lobes show that parts of this area are involved in personality, socialization, and assessing risk. The parietal lobe is located at the top of the brain. Neurons in the parietal lobe are involved in speech and also reading. Two of the parietal lobe’s main functions are processing somatosensation—touch sensations like pressure, pain, heat, cold—and processing proprioception—the sense of how parts of the body are oriented in space. The parietal lobe contains a somatosensory map of the body similar to the motor cortex. The occipital lobe is located at the back of the brain. It is primarily involved in vision—seeing, recognizing, and identifying the visual world. The temporal lobe is located at the base of the brain by your ears and is primarily involved in processing and interpreting sounds. It also contains the hippocampus (Greek for “seahorse”)—a structure that processes memory formation. The hippocampus is illustrated in Figure. The role of the hippocampus in memory was partially determined by studying one famous epileptic patient, HM, who had both sides of his hippocampus removed in an attempt to cure his epilepsy. His seizures went away, but he could no longer form new memories (although he could remember some facts from before his surgery and could learn new motor tasks). Evolution Connection Cerebral Cortex Compared to other vertebrates, mammals have exceptionally large brains for their body size. An entire alligator’s brain, for example, would fill about one and a half teaspoons. This increase in brain to body size ratio is especially pronounced in apes, whales, and dolphins. While this increase in overall brain size doubtlessly played a role in the evolution of complex behaviors unique to mammals, it does not tell the whole story. Scientists have found a relationship between the relatively high surface area of the cortex and the intelligence and complex social behaviors exhibited by some mammals. This increased surface area is due, in part, to increased folding of the cortical sheet (more sulci and gyri). For example, a rat cortex is very smooth with very few sulci and gyri. Cat and sheep cortices have more sulci and gyri. Chimps, humans, and dolphins have even more. Basal Ganglia Interconnected brain areas called the basal ganglia (or basal nuclei), shown in Figureb, play important roles in movement control and posture. Damage to the basal ganglia, as in Parkinson’s disease, leads to motor impairments like a shuffling gait when walking. The basal ganglia also regulate motivation. For example, when a wasp sting led to bilateral basal ganglia damage in a 25-year-old businessman, he began to spend all his days in bed and showed no interest in anything or anybody. But when he was externally stimulated—as when someone asked to play a card game with him—he was able to function normally. Interestingly, he and other similar patients do not report feeling bored or frustrated by their state. Thalamus The thalamus (Greek for “inner chamber”), illustrated in Figure, acts as a gateway to and from the cortex. It receives sensory and motor inputs from the body and also receives feedback from the cortex. This feedback mechanism can modulate conscious awareness of sensory and motor inputs depending on the attention and arousal state of the animal. The thalamus helps regulate consciousness, arousal, and sleep states. A rare genetic disorder called fatal familial insomnia causes the degeneration of thalamic neurons and glia. This disorder prevents affected patients from being able to sleep, among other symptoms, and is eventually fatal. Hypothalamus Below the thalamus is the hypothalamus, shown in Figure. The hypothalamus controls the endocrine system by sending signals to the pituitary gland, a pea-sized endocrine gland that releases several different hormones that affect other glands as well as other cells. This relationship means that the hypothalamus regulates important behaviors that are controlled by these hormones. The hypothalamus is the body’s thermostat—it makes sure key functions like food and water intake, energy expenditure, and body temperature are kept at appropriate levels. Neurons within the hypothalamus also regulate circadian rhythms, sometimes called sleep cycles. Limbic System The limbic system is a connected set of structures that regulates emotion, as well as behaviors related to fear and motivation. It plays a role in memory formation and includes parts of the thalamus and hypothalamus as well as the hippocampus. One important structure within the limbic system is a temporal lobe structure called the amygdala (Greek for “almond”), illustrated in Figure. The two amygdala are important both for the sensation of fear and for recognizing fearful faces. The cingulate gyrus helps regulate emotions and pain. Cerebellum The cerebellum (Latin for “little brain”), shown in Figure, sits at the base of the brain on top of the brainstem. The cerebellum controls balance and aids in coordinating movement and learning new motor tasks. Brainstem The brainstem, illustrated in Figure, connects the rest of the brain with the spinal cord. It consists of the midbrain, medulla oblongata, and the pons. Motor and sensory neurons extend through the brainstem allowing for the relay of signals between the brain and spinal cord. Ascending neural pathways cross in this section of the brain allowing the left hemisphere of the cerebrum to control the right side of the body and vice versa. The brainstem coordinates motor control signals sent from the brain to the body. The brainstem controls several important functions of the body including alertness, arousal, breathing, blood pressure, digestion, heart rate, swallowing, walking, and sensory and motor information integration. Spinal Cord Connecting to the brainstem and extending down the body through the spinal column is the spinal cord, shown in Figure. The spinal cord is a thick bundle of nerve tissue that carries information about the body to the brain and from the brain to the body. The spinal cord is contained within the bones of the vertebrate column but is able to communicate signals to and from the body through its connections with spinal nerves (part of the peripheral nervous system). A cross-section of the spinal cord looks like a white oval containing a gray butterfly-shape, as illustrated in Figure. Myelinated axons make up the “white matter” and neuron and glial cell bodies make up the “gray matter.” Gray matter is also composed of interneurons, which connect two neurons each located in different parts of the body. Axons and cell bodies in the dorsal (facing the back of the animal) spinal cord convey mostly sensory information from the body to the brain. Axons and cell bodies in the ventral (facing the front of the animal) spinal cord primarily transmit signals controlling movement from the brain to the body. The spinal cord also controls motor reflexes. These reflexes are quick, unconscious movements—like automatically removing a hand from a hot object. Reflexes are so fast because they involve local synaptic connections. For example, the knee reflex that a doctor tests during a routine physical is controlled by a single synapse between a sensory neuron and a motor neuron. While a reflex may only require the involvement of one or two synapses, synapses with interneurons in the spinal column transmit information to the brain to convey what happened (the knee jerked, or the hand was hot). In the United States, there around 10,000 spinal cord injuries each year. Because the spinal cord is the information superhighway connecting the brain with the body, damage to the spinal cord can lead to paralysis. The extent of the paralysis depends on the location of the injury along the spinal cord and whether the spinal cord was completely severed. For example, if the spinal cord is damaged at the level of the neck, it can cause paralysis from the neck down, whereas damage to the spinal column further down may limit paralysis to the legs. Spinal cord injuries are notoriously difficult to treat because spinal nerves do not regenerate, although ongoing research suggests that stem cell transplants may be able to act as a bridge to reconnect severed nerves. Researchers are also looking at ways to prevent the inflammation that worsens nerve damage after injury. One such treatment is to pump the body with cold saline to induce hypothermia. This cooling can prevent swelling and other processes that are thought to worsen spinal cord injuries. Section Summary The vertebrate central nervous system contains the brain and the spinal cord, which are covered and protected by three meninges. The brain contains structurally and functionally defined regions. In mammals, these include the cortex (which can be broken down into four primary functional lobes: frontal, temporal, occipital, and parietal), basal ganglia, thalamus, hypothalamus, limbic system, cerebellum, and brainstem—although structures in some of these designations overlap. While functions may be primarily localized to one structure in the brain, most complex functions, like language and sleep, involve neurons in multiple brain regions. The spinal cord is the information superhighway that connects the brain with the rest of the body through its connections with peripheral nerves. It transmits sensory and motor input and also controls motor reflexes. Review Questions The ________ lobe contains the visual cortex. - frontal - parietal - temporal - occipital Hint: D The ________ connects the two cerebral hemispheres. - limbic system - corpus callosum - cerebellum - pituitary Hint: B Neurons in the ________ control motor reflexes. - thalamus - spinal cord - parietal lobe - hippocampus Hint: B Free Response What methods can be used to determine the function of a particular brain region? Hint: To determine the function of a specific brain area, scientists can look at patients who have damage in that brain area and see what symptoms they exhibit. Researchers can disable the brain structure temporarily using transcranial magnetic stimulation. They can disable or remove the area in an animal model. fMRI can be used to correlate specific functions with increased blood flow to brain regions. What are the main functions of the spinal cord? Hint: The spinal cord transmits sensory information from the body to the brain and motor commands from the brain to the body through its connections with peripheral nerves. It also controls motor reflexes.	oercommons	2025-03-18T00:37:17.150911	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15117/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15118/overview	The Peripheral Nervous System Overview By the end of this section, you will be able to: - Describe the organization and functions of the sympathetic and parasympathetic nervous systems - Describe the organization and function of the sensory-somatic nervous system The peripheral nervous system (PNS) is the connection between the central nervous system and the rest of the body. The CNS is like the power plant of the nervous system. It creates the signals that control the functions of the body. The PNS is like the wires that go to individual houses. Without those “wires,” the signals produced by the CNS could not control the body (and the CNS would not be able to receive sensory information from the body either). The PNS can be broken down into the autonomic nervous system, which controls bodily functions without conscious control, and the sensory-somatic nervous system, which transmits sensory information from the skin, muscles, and sensory organs to the CNS and sends motor commands from the CNS to the muscles. Autonomic Nervous System Art Connection Which of the following statements is false? - The parasympathetic pathway is responsible for resting the body, while the sympathetic pathway is responsible for preparing for an emergency. - Most preganglionic neurons in the sympathetic pathway originate in the spinal cord. - Slowing of the heartbeat is a parasympathetic response. - Parasympathetic neurons are responsible for releasing norepinephrine on the target organ, while sympathetic neurons are responsible for releasing acetylcholine. The autonomic nervous system serves as the relay between the CNS and the internal organs. It controls the lungs, the heart, smooth muscle, and exocrine and endocrine glands. The autonomic nervous system controls these organs largely without conscious control; it can continuously monitor the conditions of these different systems and implement changes as needed. Signaling to the target tissue usually involves two synapses: a preganglionic neuron (originating in the CNS) synapses to a neuron in a ganglion that, in turn, synapses on the target organ, as illustrated in Figure. There are two divisions of the autonomic nervous system that often have opposing effects: the sympathetic nervous system and the parasympathetic nervous system. Sympathetic Nervous System The sympathetic nervous system is responsible for the “fight or flight” response that occurs when an animal encounters a dangerous situation. One way to remember this is to think of the surprise a person feels when encountering a snake (“snake” and “sympathetic” both begin with “s”). Examples of functions controlled by the sympathetic nervous system include an accelerated heart rate and inhibited digestion. These functions help prepare an organism’s body for the physical strain required to escape a potentially dangerous situation or to fend off a predator. Most preganglionic neurons in the sympathetic nervous system originate in the spinal cord, as illustrated in Figure. The axons of these neurons release acetylcholine on postganglionic neurons within sympathetic ganglia (the sympathetic ganglia form a chain that extends alongside the spinal cord). The acetylcholine activates the postganglionic neurons. Postganglionic neurons then release norepinephrine onto target organs. As anyone who has ever felt a rush before a big test, speech, or athletic event can attest, the effects of the sympathetic nervous system are quite pervasive. This is both because one preganglionic neuron synapses on multiple postganglionic neurons, amplifying the effect of the original synapse, and because the adrenal gland also releases norepinephrine (and the closely related hormone epinephrine) into the blood stream. The physiological effects of this norepinephrine release include dilating the trachea and bronchi (making it easier for the animal to breathe), increasing heart rate, and moving blood from the skin to the heart, muscles, and brain (so the animal can think and run). The strength and speed of the sympathetic response helps an organism avoid danger, and scientists have found evidence that it may also increase LTP—allowing the animal to remember the dangerous situation and avoid it in the future. Parasympathetic Nervous System While the sympathetic nervous system is activated in stressful situations, the parasympathetic nervous system allows an animal to “rest and digest.” One way to remember this is to think that during a restful situation like a picnic, the parasympathetic nervous system is in control (“picnic” and “parasympathetic” both start with “p”). Parasympathetic preganglionic neurons have cell bodies located in the brainstem and in the sacral (toward the bottom) spinal cord, as shown in Figure. The axons of the preganglionic neurons release acetylcholine on the postganglionic neurons, which are generally located very near the target organs. Most postganglionic neurons release acetylcholine onto target organs, although some release nitric oxide. The parasympathetic nervous system resets organ function after the sympathetic nervous system is activated (the common adrenaline dump you feel after a ‘fight-or-flight’ event). Effects of acetylcholine release on target organs include slowing of heart rate, lowered blood pressure, and stimulation of digestion. Sensory-Somatic Nervous System The sensory-somatic nervous system is made up of cranial and spinal nerves and contains both sensory and motor neurons. Sensory neurons transmit sensory information from the skin, skeletal muscle, and sensory organs to the CNS. Motor neurons transmit messages about desired movement from the CNS to the muscles to make them contract. Without its sensory-somatic nervous system, an animal would be unable to process any information about its environment (what it sees, feels, hears, and so on) and could not control motor movements. Unlike the autonomic nervous system, which has two synapses between the CNS and the target organ, sensory and motor neurons have only one synapse—one ending of the neuron is at the organ and the other directly contacts a CNS neuron. Acetylcholine is the main neurotransmitter released at these synapses. Humans have 12 cranial nerves, nerves that emerge from or enter the skull (cranium), as opposed to the spinal nerves, which emerge from the vertebral column. Each cranial nerve is accorded a name, which are detailed in Figure. Some cranial nerves transmit only sensory information. For example, the olfactory nerve transmits information about smells from the nose to the brainstem. Other cranial nerves transmit almost solely motor information. For example, the oculomotor nerve controls the opening and closing of the eyelid and some eye movements. Other cranial nerves contain a mix of sensory and motor fibers. For example, the glossopharyngeal nerve has a role in both taste (sensory) and swallowing (motor). Spinal nerves transmit sensory and motor information between the spinal cord and the rest of the body. Each of the 31 spinal nerves (in humans) contains both sensory and motor axons. The sensory neuron cell bodies are grouped in structures called dorsal root ganglia and are shown in Figure. Each sensory neuron has one projection—with a sensory receptor ending in skin, muscle, or sensory organs—and another that synapses with a neuron in the dorsal spinal cord. Motor neurons have cell bodies in the ventral gray matter of the spinal cord that project to muscle through the ventral root. These neurons are usually stimulated by interneurons within the spinal cord but are sometimes directly stimulated by sensory neurons. Section Summary The peripheral nervous system contains both the autonomic and sensory-somatic nervous systems. The autonomic nervous system provides unconscious control over visceral functions and has two divisions: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is activated in stressful situations to prepare the animal for a “fight or flight” response. The parasympathetic nervous system is active during restful periods. The sensory-somatic nervous system is made of cranial and spinal nerves that transmit sensory information from skin and muscle to the CNS and motor commands from the CNS to the muscles. Art Connections Figure Which of the following statements is false? - The parasympathetic pathway is responsible for relaxing the body, while the sympathetic pathway is responsible for preparing for an emergency. - Most preganglionic neurons in the sympathetic pathway originate in the spinal cord. - Slowing of the heartbeat is a parasympathetic response. - Parasympathetic neurons are responsible for releasing norepinephrine on the target organ, while sympathetic neurons are responsible for releasing acetylcholine. Hint: Figure D Review Questions Activation of the sympathetic nervous system causes: - increased blood flow into the skin - a decreased heart rate - an increased heart rate - increased digestion Hint: C Where are parasympathetic preganglionic cell bodies located? - cerebellum - brainstem - dorsal root ganglia - skin Hint: B ________ is released by motor nerve endings onto muscle. - Acetylcholine - Norepinephrine - Dopamine - Serotonin Hint: A Free Response What are the main differences between the sympathetic and parasympathetic branches of the autonomic nervous system? Hint: The sympathetic nervous system prepares the body for “fight or flight,” whereas the parasympathetic nervous system allows the body to “rest and digest.” Sympathetic neurons release norepinephrine onto target organs; parasympathetic neurons release acetylcholine. Sympathetic neuron cell bodies are located in sympathetic ganglia. Parasympathetic neuron cell bodies are located in the brainstem and sacral spinal cord. Activation of the sympathetic nervous system increases heart rate and blood pressure and decreases digestion and blood flow to the skin. Activation of the parasympathetic nervous system decreases heart rate and blood pressure and increases digestion and blood flow to the skin. What are the main functions of the sensory-somatic nervous system? Hint: The sensory-somatic nervous system transmits sensory information from the skin, muscles, and sensory organs to the CNS. It also sends motor commands from the CNS to the muscles, causing them to contract.	oercommons	2025-03-18T00:37:17.180094	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15118/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15119/overview	Nervous System Disorders Overview By the end of this section, you will be able to: - Describe the symptoms, potential causes, and treatment of several examples of nervous system disorders A nervous system that functions correctly is a fantastically complex, well-oiled machine—synapses fire appropriately, muscles move when needed, memories are formed and stored, and emotions are well regulated. Unfortunately, each year millions of people in the United States deal with some sort of nervous system disorder. While scientists have discovered potential causes of many of these diseases, and viable treatments for some, ongoing research seeks to find ways to better prevent and treat all of these disorders. Neurodegenerative Disorders Neurodegenerative disorders are illnesses characterized by a loss of nervous system functioning that are usually caused by neuronal death. These diseases generally worsen over time as more and more neurons die. The symptoms of a particular neurodegenerative disease are related to where in the nervous system the death of neurons occurs. Spinocerebellar ataxia, for example, leads to neuronal death in the cerebellum. The death of these neurons causes problems in balance and walking. Neurodegenerative disorders include Huntington’s disease, amyotrophic lateral sclerosis, Alzheimer’s disease and other types of dementia disorders, and Parkinson’s disease. Here, Alzheimer’s and Parkinson’s disease will be discussed in more depth. Alzheimer’s Disease Alzheimer’s disease is the most common cause of dementia in the elderly. In 2012, an estimated 5.4 million Americans suffered from Alzheimer’s disease, and payments for their care are estimated at $200 billion. Roughly one in every eight people age 65 or older has the disease. Due to the aging of the baby-boomer generation, there are projected to be as many as 13 million Alzheimer’s patients in the United States in the year 2050. Symptoms of Alzheimer’s disease include disruptive memory loss, confusion about time or place, difficulty planning or executing tasks, poor judgment, and personality changes. Problems smelling certain scents can also be indicative of Alzheimer’s disease and may serve as an early warning sign. Many of these symptoms are also common in people who are aging normally, so it is the severity and longevity of the symptoms that determine whether a person is suffering from Alzheimer’s. Alzheimer’s disease was named for Alois Alzheimer, a German psychiatrist who published a report in 1911 about a woman who showed severe dementia symptoms. Along with his colleagues, he examined the woman’s brain following her death and reported the presence of abnormal clumps, which are now called amyloid plaques, along with tangled brain fibers called neurofibrillary tangles. Amyloid plaques, neurofibrillary tangles, and an overall shrinking of brain volume are commonly seen in the brains of Alzheimer’s patients. Loss of neurons in the hippocampus is especially severe in advanced Alzheimer’s patients. Figure compares a normal brain to the brain of an Alzheimer’s patient. Many research groups are examining the causes of these hallmarks of the disease. One form of the disease is usually caused by mutations in one of three known genes. This rare form of early onset Alzheimer’s disease affects fewer than five percent of patients with the disease and causes dementia beginning between the ages of 30 and 60. The more prevalent, late-onset form of the disease likely also has a genetic component. One particular gene, apolipoprotein E (APOE) has a variant (E4) that increases a carrier’s likelihood of getting the disease. Many other genes have been identified that might be involved in the pathology. Link to Learning Visit this website for video links discussing genetics and Alzheimer’s disease. Unfortunately, there is no cure for Alzheimer’s disease. Current treatments focus on managing the symptoms of the disease. Because decrease in the activity of cholinergic neurons (neurons that use the neurotransmitter acetylcholine) is common in Alzheimer’s disease, several drugs used to treat the disease work by increasing acetylcholine neurotransmission, often by inhibiting the enzyme that breaks down acetylcholine in the synaptic cleft. Other clinical interventions focus on behavioral therapies like psychotherapy, sensory therapy, and cognitive exercises. Since Alzheimer’s disease appears to hijack the normal aging process, research into prevention is prevalent. Smoking, obesity, and cardiovascular problems may be risk factors for the disease, so treatments for those may also help to prevent Alzheimer’s disease. Some studies have shown that people who remain intellectually active by playing games, reading, playing musical instruments, and being socially active in later life have a reduced risk of developing the disease. Parkinson’s Disease Like Alzheimer’s disease, Parkinson’s disease is a neurodegenerative disease. It was first characterized by James Parkinson in 1817. Each year, 50,000-60,000 people in the United States are diagnosed with the disease. Parkinson’s disease causes the loss of dopamine neurons in the substantia nigra, a midbrain structure that regulates movement. Loss of these neurons causes many symptoms including tremor (shaking of fingers or a limb), slowed movement, speech changes, balance and posture problems, and rigid muscles. The combination of these symptoms often causes a characteristic slow hunched shuffling walk, illustrated in Figure. Patients with Parkinson’s disease can also exhibit psychological symptoms, such as dementia or emotional problems. Although some patients have a form of the disease known to be caused by a single mutation, for most patients the exact causes of Parkinson’s disease remain unknown: the disease likely results from a combination of genetic and environmental factors (similar to Alzheimer’s disease). Post-mortem analysis of brains from Parkinson’s patients shows the presence of Lewy bodies—abnormal protein clumps—in dopaminergic neurons. The prevalence of these Lewy bodies often correlates with the severity of the disease. There is no cure for Parkinson’s disease, and treatment is focused on easing symptoms. One of the most commonly prescribed drugs for Parkinson’s is L-DOPA, which is a chemical that is converted into dopamine by neurons in the brain. This conversion increases the overall level of dopamine neurotransmission and can help compensate for the loss of dopaminergic neurons in the substantia nigra. Other drugs work by inhibiting the enzyme that breaks down dopamine. Neurodevelopmental Disorders Neurodevelopmental disorders occur when the development of the nervous system is disturbed. There are several different classes of neurodevelopmental disorders. Some, like Down Syndrome, cause intellectual deficits. Others specifically affect communication, learning, or the motor system. Some disorders like autism spectrum disorder and attention deficit/hyperactivity disorder have complex symptoms. Autism Autism spectrum disorder (ASD) is a neurodevelopmental disorder. Its severity differs from person to person. Estimates for the prevalence of the disorder have changed rapidly in the past few decades. Current estimates suggest that one in 88 children will develop the disorder. ASD is four times more prevalent in males than females. Link to Learning This video discusses possible reasons why there has been a recent increase in the number of people diagnosed with autism. A characteristic symptom of ASD is impaired social skills. Children with autism may have difficulty making and maintaining eye contact and reading social cues. They also may have problems feeling empathy for others. Other symptoms of ASD include repetitive motor behaviors (such as rocking back and forth), preoccupation with specific subjects, strict adherence to certain rituals, and unusual language use. Up to 30 percent of patients with ASD develop epilepsy, and patients with some forms of the disorder (like Fragile X) also have intellectual disability. Because it is a spectrum disorder, other ASD patients are very functional and have good-to-excellent language skills. Many of these patients do not feel that they suffer from a disorder and instead think that their brains just process information differently. Except for some well-characterized, clearly genetic forms of autism (like Fragile X and Rett’s Syndrome), the causes of ASD are largely unknown. Variants of several genes correlate with the presence of ASD, but for any given patient, many different mutations in different genes may be required for the disease to develop. At a general level, ASD is thought to be a disease of “incorrect” wiring. Accordingly, brains of some ASD patients lack the same level of synaptic pruning that occurs in non-affected people. In the 1990s, a research paper linked autism to a common vaccine given to children. This paper was retracted when it was discovered that the author falsified data, and follow-up studies showed no connection between vaccines and autism. Treatment for autism usually combines behavioral therapies and interventions, along with medications to treat other disorders common to people with autism (depression, anxiety, obsessive compulsive disorder). Although early interventions can help mitigate the effects of the disease, there is currently no cure for ASD. Attention Deficit Hyperactivity Disorder (ADHD) Approximately three to five percent of children and adults are affected by attention deficit/hyperactivity disorder (ADHD). Like ASD, ADHD is more prevalent in males than females. Symptoms of the disorder include inattention (lack of focus), executive functioning difficulties, impulsivity, and hyperactivity beyond what is characteristic of the normal developmental stage. Some patients do not have the hyperactive component of symptoms and are diagnosed with a subtype of ADHD: attention deficit disorder (ADD). Many people with ADHD also show comorbitity, in that they develop secondary disorders in addition to ADHD. Examples include depression or obsessive compulsive disorder (OCD). Figure provides some statistics concerning comorbidity with ADHD. The cause of ADHD is unknown, although research points to a delay and dysfunction in the development of the prefrontal cortex and disturbances in neurotransmission. According to studies of twins, the disorder has a strong genetic component. There are several candidate genes that may contribute to the disorder, but no definitive links have been discovered. Environmental factors, including exposure to certain pesticides, may also contribute to the development of ADHD in some patients. Treatment for ADHD often involves behavioral therapies and the prescription of stimulant medications, which paradoxically cause a calming effect in these patients. Career Connection Neurologist Neurologists are physicians who specialize in disorders of the nervous system. They diagnose and treat disorders such as epilepsy, stroke, dementia, nervous system injuries, Parkinson’s disease, sleep disorders, and multiple sclerosis. Neurologists are medical doctors who have attended college, medical school, and completed three to four years of neurology residency. When examining a new patient, a neurologist takes a full medical history and performs a complete physical exam. The physical exam contains specific tasks that are used to determine what areas of the brain, spinal cord, or peripheral nervous system may be damaged. For example, to check whether the hypoglossal nerve is functioning correctly, the neurologist will ask the patient to move his or her tongue in different ways. If the patient does not have full control over tongue movements, then the hypoglossal nerve may be damaged or there may be a lesion in the brainstem where the cell bodies of these neurons reside (or there could be damage to the tongue muscle itself). Neurologists have other tools besides a physical exam they can use to diagnose particular problems in the nervous system. If the patient has had a seizure, for example, the neurologist can use electroencephalography (EEG), which involves taping electrodes to the scalp to record brain activity, to try to determine which brain regions are involved in the seizure. In suspected stroke patients, a neurologist can use a computerized tomography (CT) scan, which is a type of X-ray, to look for bleeding in the brain or a possible brain tumor. To treat patients with neurological problems, neurologists can prescribe medications or refer the patient to a neurosurgeon for surgery. Link to Learning This website allows you to see the different tests a neurologist might use to see what regions of the nervous system may be damaged in a patient. Mental Illnesses Mental illnesses are nervous system disorders that result in problems with thinking, mood, or relating with other people. These disorders are severe enough to affect a person’s quality of life and often make it difficult for people to perform the routine tasks of daily living. Debilitating mental disorders plague approximately 12.5 million Americans (about 1 in 17 people) at an annual cost of more than $300 billion. There are several types of mental disorders including schizophrenia, major depression, bipolar disorder, anxiety disorders and phobias, post-traumatic stress disorders, and obsessive-compulsive disorder (OCD), among others. The American Psychiatric Association publishes the Diagnostic and Statistical Manual of Mental Disorders (or DSM), which describes the symptoms required for a patient to be diagnosed with a particular mental disorder. Each newly released version of the DSM contains different symptoms and classifications as scientists learn more about these disorders, their causes, and how they relate to each other. A more detailed discussion of two mental illnesses—schizophrenia and major depression—is given below. Schizophrenia Schizophrenia is a serious and often debilitating mental illness affecting one percent of people in the United States. Symptoms of the disease include the inability to differentiate between reality and imagination, inappropriate and unregulated emotional responses, difficulty thinking, and problems with social situations. People with schizophrenia can suffer from hallucinations and hear voices; they may also suffer from delusions. Patients also have so-called “negative” symptoms like a flattened emotional state, loss of pleasure, and loss of basic drives. Many schizophrenic patients are diagnosed in their late adolescence or early 20s. The development of schizophrenia is thought to involve malfunctioning dopaminergic neurons and may also involve problems with glutamate signaling. Treatment for the disease usually requires antipsychotic medications that work by blocking dopamine receptors and decreasing dopamine neurotransmission in the brain. This decrease in dopamine can cause Parkinson’s disease-like symptoms in some patients. While some classes of antipsychotics can be quite effective at treating the disease, they are not a cure, and most patients must remain medicated for the rest of their lives. Depression Major depression affects approximately 6.7 percent of the adults in the United States each year and is one of the most common mental disorders. To be diagnosed with major depressive disorder, a person must have experienced a severely depressed mood lasting longer than two weeks along with other symptoms including a loss of enjoyment in activities that were previously enjoyed, changes in appetite and sleep schedules, difficulty concentrating, feelings of worthlessness, and suicidal thoughts. The exact causes of major depression are unknown and likely include both genetic and environmental risk factors. Some research supports the “classic monoamine hypothesis,” which suggests that depression is caused by a decrease in norepinephrine and serotonin neurotransmission. One argument against this hypothesis is the fact that some antidepressant medications cause an increase in norepinephrine and serotonin release within a few hours of beginning treatment—but clinical results of these medications are not seen until weeks later. This has led to alternative hypotheses: for example, dopamine may also be decreased in depressed patients, or it may actually be an increase in norepinephrine and serotonin that causes the disease, and antidepressants force a feedback loop that decreases this release. Treatments for depression include psychotherapy, electroconvulsive therapy, deep-brain stimulation, and prescription medications. There are several classes of antidepressant medications that work through different mechanisms. For example, monoamine oxidase inhibitors (MAO inhibitors) block the enzyme that degrades many neurotransmitters (including dopamine, serotonin, norepinephrine), resulting in increased neurotransmitter in the synaptic cleft. Selective serotonin reuptake inhibitors (SSRIs) block the reuptake of serotonin into the presynaptic neuron. This blockage results in an increase in serotonin in the synaptic cleft. Other types of drugs such as norepinephrine-dopamine reuptake inhibitors and norepinephrine-serotonin reuptake inhibitors are also used to treat depression. Other Neurological Disorders There are several other neurological disorders that cannot be easily placed in the above categories. These include chronic pain conditions, cancers of the nervous system, epilepsy disorders, and stroke. Epilepsy and stroke are discussed below. Epilepsy Estimates suggest that up to three percent of people in the United States will be diagnosed with epilepsy in their lifetime. While there are several different types of epilepsy, all are characterized by recurrent seizures. Epilepsy itself can be a symptom of a brain injury, disease, or other illness. For example, people who have intellectual disability or ASD can experience seizures, presumably because the developmental wiring malfunctions that caused their disorders also put them at risk for epilepsy. For many patients, however, the cause of their epilepsy is never identified and is likely to be a combination of genetic and environmental factors. Often, seizures can be controlled with anticonvulsant medications. However, for very severe cases, patients may undergo brain surgery to remove the brain area where seizures originate. Stroke A stroke results when blood fails to reach a portion of the brain for a long enough time to cause damage. Without the oxygen supplied by blood flow, neurons in this brain region die. This neuronal death can cause many different symptoms—depending on the brain area affected— including headache, muscle weakness or paralysis, speech disturbances, sensory problems, memory loss, and confusion. Stroke is often caused by blood clots and can also be caused by the bursting of a weak blood vessel. Strokes are extremely common and are the third most common cause of death in the United States. On average one person experiences a stroke every 40 seconds in the United States. Approximately 75 percent of strokes occur in people older than 65. Risk factors for stroke include high blood pressure, diabetes, high cholesterol, and a family history of stroke. Smoking doubles the risk of stroke. Because a stroke is a medical emergency, patients with symptoms of a stroke should immediately go to the emergency room, where they can receive drugs that will dissolve any clot that may have formed. These drugs will not work if the stroke was caused by a burst blood vessel or if the stroke occurred more than three hours before arriving at the hospital. Treatment following a stroke can include blood pressure medication (to prevent future strokes) and (sometimes intense) physical therapy. Section Summary Some general themes emerge from the sampling of nervous system disorders presented above. The causes for most disorders are not fully understood—at least not for all patients—and likely involve a combination of nature (genetic mutations that become risk factors) and nurture (emotional trauma, stress, hazardous chemical exposure). Because the causes have yet to be fully determined, treatment options are often lacking and only address symptoms. Review Questions Parkinson’s disease is a caused by the degeneration of neurons that release ________. - serotonin - dopamine - glutamate - norepinephrine Hint: B ________ medications are often used to treat patients with ADHD. - Tranquilizer - Antibiotic - Stimulant - Anti-seizure Hint: C Strokes are often caused by ________. - neurodegeneration - blood clots or burst blood vessels - seizures - viruses Hint: B Free Response What are the main symptoms of Alzheimer’s disease? Hint: Symptoms of Alzheimer’s disease include disruptive memory loss, confusion about time or place, difficulties planning or executing tasks, poor judgment, and personality changes. What are possible treatments for patients with major depression? Hint: Possible treatments for patients with major depression include psychotherapy and prescription medications. MAO inhibitor drugs inhibit the breakdown of certain neurotransmitters (including dopamine, serotonin, norepinephrine) in the synaptic cleft. SSRI medications inhibit the reuptake of serotonin into the presynaptic neuron.	oercommons	2025-03-18T00:37:17.211918	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15119/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15120/overview	Introduction In more advanced animals, the senses are constantly at work, making the animal aware of stimuli—such as light, or sound, or the presence of a chemical substance in the external environment—and monitoring information about the organism’s internal environment. All bilaterally symmetric animals have a sensory system, and the development of any species’ sensory system has been driven by natural selection; thus, sensory systems differ among species according to the demands of their environments. The shark, unlike most fish predators, is electrosensitive—that is, sensitive to electrical fields produced by other animals in its environment. While it is helpful to this underwater predator, electrosensitivity is a sense not found in most land animals.	oercommons	2025-03-18T00:37:17.230636	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15120/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15121/overview	Sensory Processes Overview By the end of this section, you will be able to: - Identify the general and special senses in humans - Describe three important steps in sensory perception - Explain the concept of just-noticeable difference in sensory perception Senses provide information about the body and its environment. Humans have five special senses: olfaction (smell), gustation (taste), equilibrium (balance and body position), vision, and hearing. Additionally, we possess general senses, also called somatosensation, which respond to stimuli like temperature, pain, pressure, and vibration. Vestibular sensation, which is an organism’s sense of spatial orientation and balance, proprioception (position of bones, joints, and muscles), and the sense of limb position that is used to track kinesthesia (limb movement) are part of somatosensation. Although the sensory systems associated with these senses are very different, all share a common function: to convert a stimulus (such as light, or sound, or the position of the body) into an electrical signal in the nervous system. This process is called sensory transduction. There are two broad types of cellular systems that perform sensory transduction. In one, a neuron works with a sensory receptor, a cell, or cell process that is specialized to engage with and detect a specific stimulus. Stimulation of the sensory receptor activates the associated afferent neuron, which carries information about the stimulus to the central nervous system. In the second type of sensory transduction, a sensory nerve ending responds to a stimulus in the internal or external environment: this neuron constitutes the sensory receptor. Free nerve endings can be stimulated by several different stimuli, thus showing little receptor specificity. For example, pain receptors in your gums and teeth may be stimulated by temperature changes, chemical stimulation, or pressure. Reception The first step in sensation is reception, which is the activation of sensory receptors by stimuli such as mechanical stimuli (being bent or squished, for example), chemicals, or temperature. The receptor can then respond to the stimuli. The region in space in which a given sensory receptor can respond to a stimulus, be it far away or in contact with the body, is that receptor’s receptive field. Think for a moment about the differences in receptive fields for the different senses. For the sense of touch, a stimulus must come into contact with body. For the sense of hearing, a stimulus can be a moderate distance away (some baleen whale sounds can propagate for many kilometers). For vision, a stimulus can be very far away; for example, the visual system perceives light from stars at enormous distances. Transduction The most fundamental function of a sensory system is the translation of a sensory signal to an electrical signal in the nervous system. This takes place at the sensory receptor, and the change in electrical potential that is produced is called the receptor potential. How is sensory input, such as pressure on the skin, changed to a receptor potential? In this example, a type of receptor called a mechanoreceptor (as shown in Figure) possesses specialized membranes that respond to pressure. Disturbance of these dendrites by compressing them or bending them opens gated ion channels in the plasma membrane of the sensory neuron, changing its electrical potential. Recall that in the nervous system, a positive change of a neuron’s electrical potential (also called the membrane potential), depolarizes the neuron. Receptor potentials are graded potentials: the magnitude of these graded (receptor) potentials varies with the strength of the stimulus. If the magnitude of depolarization is sufficient (that is, if membrane potential reaches a threshold), the neuron will fire an action potential. In most cases, the correct stimulus impinging on a sensory receptor will drive membrane potential in a positive direction, although for some receptors, such as those in the visual system, this is not always the case. Sensory receptors for different senses are very different from each other, and they are specialized according to the type of stimulus they sense: they have receptor specificity. For example, touch receptors, light receptors, and sound receptors are each activated by different stimuli. Touch receptors are not sensitive to light or sound; they are sensitive only to touch or pressure. However, stimuli may be combined at higher levels in the brain, as happens with olfaction, contributing to our sense of taste. Encoding and Transmission of Sensory Information Four aspects of sensory information are encoded by sensory systems: the type of stimulus, the location of the stimulus in the receptive field, the duration of the stimulus, and the relative intensity of the stimulus. Thus, action potentials transmitted over a sensory receptor’s afferent axons encode one type of stimulus, and this segregation of the senses is preserved in other sensory circuits. For example, auditory receptors transmit signals over their own dedicated system, and electrical activity in the axons of the auditory receptors will be interpreted by the brain as an auditory stimulus—a sound. The intensity of a stimulus is often encoded in the rate of action potentials produced by the sensory receptor. Thus, an intense stimulus will produce a more rapid train of action potentials, and reducing the stimulus will likewise slow the rate of production of action potentials. A second way in which intensity is encoded is by the number of receptors activated. An intense stimulus might initiate action potentials in a large number of adjacent receptors, while a less intense stimulus might stimulate fewer receptors. Integration of sensory information begins as soon as the information is received in the CNS, and the brain will further process incoming signals. Perception Perception is an individual’s interpretation of a sensation. Although perception relies on the activation of sensory receptors, perception happens not at the level of the sensory receptor, but at higher levels in the nervous system, in the brain. The brain distinguishes sensory stimuli through a sensory pathway: action potentials from sensory receptors travel along neurons that are dedicated to a particular stimulus. These neurons are dedicated to that particular stimulus and synapse with particular neurons in the brain or spinal cord. All sensory signals, except those from the olfactory system, are transmitted though the central nervous system and are routed to the thalamus and to the appropriate region of the cortex. Recall that the thalamus is a structure in the forebrain that serves as a clearinghouse and relay station for sensory (as well as motor) signals. When the sensory signal exits the thalamus, it is conducted to the specific area of the cortex (Figure) dedicated to processing that particular sense. How are neural signals interpreted? Interpretation of sensory signals between individuals of the same species is largely similar, owing to the inherited similarity of their nervous systems; however, there are some individual differences. A good example of this is individual tolerances to a painful stimulus, such as dental pain, which certainly differ. Scientific Method Connection Just-Noticeable DifferenceIt is easy to differentiate between a one-pound bag of rice and a two-pound bag of rice. There is a one-pound difference, and one bag is twice as heavy as the other. However, would it be as easy to differentiate between a 20- and a 21-pound bag? Question: What is the smallest detectible weight difference between a one-pound bag of rice and a larger bag? What is the smallest detectible difference between a 20-pound bag and a larger bag? In both cases, at what weights are the differences detected? This smallest detectible difference in stimuli is known as the just-noticeable difference (JND). Background: Research background literature on JND and on Weber’s Law, a description of a proposed mathematical relationship between the overall magnitude of the stimulus and the JND. You will be testing JND of different weights of rice in bags. Choose a convenient increment that is to be stepped through while testing. For example, you could choose 10 percent increments between one and two pounds (1.1, 1.2, 1.3, 1.4, and so on) or 20 percent increments (1.2, 1.4, 1.6, and 1.8). Hypothesis: Develop a hypothesis about JND in terms of percentage of the whole weight being tested (such as “the JND between the two small bags and between the two large bags is proportionally the same,” or “. . . is not proportionally the same.”) So, for the first hypothesis, if the JND between the one-pound bag and a larger bag is 0.2 pounds (that is, 20 percent; 1.0 pound feels the same as 1.1 pounds, but 1.0 pound feels less than 1.2 pounds), then the JND between the 20-pound bag and a larger bag will also be 20 percent. (So, 20 pounds feels the same as 22 pounds or 23 pounds, but 20 pounds feels less than 24 pounds.) Test the hypothesis: Enlist 24 participants, and split them into two groups of 12. To set up the demonstration, assuming a 10 percent increment was selected, have the first group be the one-pound group. As a counter-balancing measure against a systematic error, however, six of the first group will compare one pound to two pounds, and step down in weight (1.0 to 2.0, 1.0 to 1.9, and so on.), while the other six will step up (1.0 to 1.1, 1.0 to 1.2, and so on). Apply the same principle to the 20-pound group (20 to 40, 20 to 38, and so on, and 20 to 22, 20 to 24, and so on). Given the large difference between 20 and 40 pounds, you may wish to use 30 pounds as your larger weight. In any case, use two weights that are easily detectable as different. Record the observations: Record the data in a table similar to the table below. For the one-pound and 20-pound groups (base weights) record a plus sign (+) for each participant that detects a difference between the base weight and the step weight. Record a minus sign (-) for each participant that finds no difference. If one-tenth steps were not used, then replace the steps in the “Step Weight” columns with the step you are using. \| Results of JND Testing (+ = difference; – = no difference) \| \|\|\| \|---\|---\|---\|---\| \| Step Weight \| One pound \| 20 pounds \| Step Weight \| \| 1.1 \| 22 \| \|\| \| 1.2 \| 24 \| \|\| \| 1.3 \| 26 \| \|\| \| 1.4 \| 28 \| \|\| \| 1.5 \| 30 \| \|\| \| 1.6 \| 32 \| \|\| \| 1.7 \| 34 \| \|\| \| 1.8 \| 36 \| \|\| \| 1.9 \| 38 \| \|\| \| 2.0 \| 40 \| Analyze the data/report the results: What step weight did all participants find to be equal with one-pound base weight? What about the 20-pound group? Draw a conclusion: Did the data support the hypothesis? Are the final weights proportionally the same? If not, why not? Do the findings adhere to Weber’s Law? Weber’s Law states that the concept that a just-noticeable difference in a stimulus is proportional to the magnitude of the original stimulus. Section Summary A sensory activation occurs when a physical or chemical stimulus is processed into a neural signal (sensory transduction) by a sensory receptor. Perception is an individual interpretation of a sensation and is a brain function. Humans have special senses: olfaction, gustation, equilibrium, and hearing, plus the general senses of somatosensation. Sensory receptors are either specialized cells associated with sensory neurons or the specialized ends of sensory neurons that are a part of the peripheral nervous system, and they are used to receive information about the environment (internal or external). Each sensory receptor is modified for the type of stimulus it detects. For example, neither gustatory receptors nor auditory receptors are sensitive to light. Each sensory receptor is responsive to stimuli within a specific region in space, which is known as that receptor’s receptive field. The most fundamental function of a sensory system is the translation of a sensory signal to an electrical signal in the nervous system. All sensory signals, except those from the olfactory system, enter the central nervous system and are routed to the thalamus. When the sensory signal exits the thalamus, it is conducted to the specific area of the cortex dedicated to processing that particular sense. Review Questions Where does perception occur? - spinal cord - cerebral cortex - receptors - thalamus Hint: B If a person’s cold receptors no longer convert cold stimuli into sensory signals, that person has a problem with the process of ________. - reception - transmission - perception - transduction Hint: D After somatosensory transduction, the sensory signal travels through the brain as a(n) _____ signal. - electrical - pressure - optical - thermal Hint: A Free Response If a person sustains damage to axons leading from sensory receptors to the central nervous system, which step or steps of sensory perception will be affected? Hint: Transmission of sensory information from the receptor to the central nervous system will be impaired, and thus, perception of stimuli, which occurs in the brain, will be halted. In what way does the overall magnitude of a stimulus affect the just-noticeable difference in the perception of that stimulus? Hint: The just-noticeable difference is a fraction of the overall magnitude of the stimulus and seems to be a relatively fixed proportion (such as 10 percent) whether the stimulus is large (such as a very heavy object) or small (such as a very light object).	oercommons	2025-03-18T00:37:17.260761	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15121/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15122/overview	Somatosensation Overview By the end of this section, you will be able to: - Describe four important mechanoreceptors in human skin - Describe the topographical distribution of somatosensory receptors between glabrous and hairy skin - Explain why the perception of pain is subjective Somatosensation is a mixed sensory category and includes all sensation received from the skin and mucous membranes, as well from as the limbs and joints. Somatosensation is also known as tactile sense, or more familiarly, as the sense of touch. Somatosensation occurs all over the exterior of the body and at some interior locations as well. A variety of receptor types—embedded in the skin, mucous membranes, muscles, joints, internal organs, and cardiovascular system—play a role. Recall that the epidermis is the outermost layer of skin in mammals. It is relatively thin, is composed of keratin-filled cells, and has no blood supply. The epidermis serves as a barrier to water and to invasion by pathogens. Below this, the much thicker dermis contains blood vessels, sweat glands, hair follicles, lymph vessels, and lipid-secreting sebaceous glands (Figure). Below the epidermis and dermis is the subcutaneous tissue, or hypodermis, the fatty layer that contains blood vessels, connective tissue, and the axons of sensory neurons. The hypodermis, which holds about 50 percent of the body’s fat, attaches the dermis to the bone and muscle, and supplies nerves and blood vessels to the dermis. Somatosensory Receptors Sensory receptors are classified into five categories: mechanoreceptors, thermoreceptors, proprioceptors, pain receptors, and chemoreceptors. These categories are based on the nature of stimuli each receptor class transduces. What is commonly referred to as “touch” involves more than one kind of stimulus and more than one kind of receptor. Mechanoreceptors in the skin are described as encapsulated (that is, surrounded by a capsule) or unencapsulated (a group that includes free nerve endings). A free nerve ending, as its name implies, is an unencapsulated dendrite of a sensory neuron. Free nerve endings are the most common nerve endings in skin, and they extend into the middle of the epidermis. Free nerve endings are sensitive to painful stimuli, to hot and cold, and to light touch. They are slow to adjust to a stimulus and so are less sensitive to abrupt changes in stimulation. There are three classes of mechanoreceptors: tactile, proprioceptors, and baroreceptors. Mechanoreceptors sense stimuli due to physical deformation of their plasma membranes. They contain mechanically gated ion channels whose gates open or close in response to pressure, touch, stretching, and sound.” There are four primary tactile mechanoreceptors in human skin: Merkel’s disks, Meissner’s corpuscles, Ruffini endings, and Pacinian corpuscle; two are located toward the surface of the skin and two are located deeper. A fifth type of mechanoreceptor, Krause end bulbs, are found only in specialized regions. Merkel’s disks (shown in Figure) are found in the upper layers of skin near the base of the epidermis, both in skin that has hair and on glabrous skin, that is, the hairless skin found on the palms and fingers, the soles of the feet, and the lips of humans and other primates. Merkel’s disks are densely distributed in the fingertips and lips. They are slow-adapting, encapsulated nerve endings, and they respond to light touch. Light touch, also known as discriminative touch, is a light pressure that allows the location of a stimulus to be pinpointed. The receptive fields of Merkel’s disks are small with well-defined borders. That makes them finely sensitive to edges and they come into use in tasks such as typing on a keyboard. Art Connection Which of the following statements about mechanoreceptors is false? - Pacini corpuscles are found in both glabrous and hairy skin. - Merkel’s disks are abundant on the fingertips and lips. - Ruffini endings are encapsulated mechanoreceptors. - Meissner’s corpuscles extend into the lower dermis. Meissner’s corpuscles, (shown in Figure) also known as tactile corpuscles, are found in the upper dermis, but they project into the epidermis. They, too, are found primarily in the glabrous skin on the fingertips and eyelids. They respond to fine touch and pressure, but they also respond to low-frequency vibration or flutter. They are rapidly adapting, fluid-filled, encapsulated neurons with small, well-defined borders and are responsive to fine details. Like Merkel’s disks, Meissner’s corpuscles are not as plentiful in the palms as they are in the fingertips. Deeper in the epidermis, near the base, are Ruffini endings, which are also known as bulbous corpuscles. They are found in both glabrous and hairy skin. These are slow-adapting, encapsulated mechanoreceptors that detect skin stretch and deformations within joints, so they provide valuable feedback for gripping objects and controlling finger position and movement. Thus, they also contribute to proprioception and kinesthesia. Ruffini endings also detect warmth. Note that these warmth detectors are situated deeper in the skin than are the cold detectors. It is not surprising, then, that humans detect cold stimuli before they detect warm stimuli. Pacinian corpuscles (seen in Figure) are located deep in the dermis of both glabrous and hairy skin and are structurally similar to Meissner’s corpuscles; they are found in the bone periosteum, joint capsules, pancreas and other viscera, breast, and genitals. They are rapidly adapting mechanoreceptors that sense deep transient (but not prolonged) pressure and high-frequency vibration. Pacinian receptors detect pressure and vibration by being compressed, stimulating their internal dendrites. There are fewer Pacinian corpuscles and Ruffini endings in skin than there are Merkel’s disks and Meissner’s corpuscles. In proprioception, proprioceptive and kinesthetic signals travel through myelinated afferent neurons running from the spinal cord to the medulla. Neurons are not physically connected, but communicate via neurotransmitters secreted into synapses or “gaps” between communicating neurons. Once in the medulla, the neurons continue carrying the signals to the thalamus. Muscle spindles are stretch receptors that detect the amount of stretch, or lengthening of muscles. Related to these are Golgi tendon organs, which are tension receptors that detect the force of muscle contraction. Proprioceptive and kinesthetic signals come from limbs. Unconscious proprioceptive signals run from the spinal cord to the cerebellum, the brain region that coordinates muscle contraction, rather than to the thalamus, like most other sensory information. Barorecptors detect pressure changes in an organ. They are found in the walls of the carotid artery and the aorta where they monitor blood pressure, and in the lungs where they detect the degree of lung expansion. Stretch receptors are found at various sites in the digestive and urinary systems. In addition to these two types of deeper receptors, there are also rapidly adapting hair receptors, which are found on nerve endings that wrap around the base of hair follicles. There are a few types of hair receptors that detect slow and rapid hair movement, and they differ in their sensitivity to movement. Some hair receptors also detect skin deflection, and certain rapidly adapting hair receptors allow detection of stimuli that have not yet touched the skin. Integration of Signals from Mechanoreceptors The configuration of the different types of receptors working in concert in human skin results in a very refined sense of touch. The nociceptive receptors—those that detect pain—are located near the surface. Small, finely calibrated mechanoreceptors—Merkel’s disks and Meissner’s corpuscles—are located in the upper layers and can precisely localize even gentle touch. The large mechanoreceptors—Pacinian corpuscles and Ruffini endings—are located in the lower layers and respond to deeper touch. (Consider that the deep pressure that reaches those deeper receptors would not need to be finely localized.) Both the upper and lower layers of the skin hold rapidly and slowly adapting receptors. Both primary somatosensory cortex and secondary cortical areas are responsible for processing the complex picture of stimuli transmitted from the interplay of mechanoreceptors. Density of Mechanoreceptors The distribution of touch receptors in human skin is not consistent over the body. In humans, touch receptors are less dense in skin covered with any type of hair, such as the arms, legs, torso, and face. Touch receptors are denser in glabrous skin (the type found on human fingertips and lips, for example), which is typically more sensitive and is thicker than hairy skin (4 to 5 mm versus 2 to 3 mm). How is receptor density estimated in a human subject? The relative density of pressure receptors in different locations on the body can be demonstrated experimentally using a two-point discrimination test. In this demonstration, two sharp points, such as two thumbtacks, are brought into contact with the subject’s skin (though not hard enough to cause pain or break the skin). The subject reports if he or she feels one point or two points. If the two points are felt as one point, it can be inferred that the two points are both in the receptive field of a single sensory receptor. If two points are felt as two separate points, each is in the receptive field of two separate sensory receptors. The points could then be moved closer and re-tested until the subject reports feeling only one point, and the size of the receptive field of a single receptor could be estimated from that distance. Thermoreception In addition to Krause end bulbs that detect cold and Ruffini endings that detect warmth, there are different types of cold receptors on some free nerve endings: thermoreceptors, located in the dermis, skeletal muscles, liver, and hypothalamus, that are activated by different temperatures. Their pathways into the brain run from the spinal cord through the thalamus to the primary somatosensory cortex. Warmth and cold information from the face travels through one of the cranial nerves to the brain. You know from experience that a tolerably cold or hot stimulus can quickly progress to a much more intense stimulus that is no longer tolerable. Any stimulus that is too intense can be perceived as pain because temperature sensations are conducted along the same pathways that carry pain sensations Pain Pain is the name given to nociception, which is the neural processing of injurious stimuli in response to tissue damage. Pain is caused by true sources of injury, such as contact with a heat source that causes a thermal burn or contact with a corrosive chemical. But pain also can be caused by harmless stimuli that mimic the action of damaging stimuli, such as contact with capsaicins, the compounds that cause peppers to taste hot and which are used in self-defense pepper sprays and certain topical medications. Peppers taste “hot” because the protein receptors that bind capsaicin open the same calcium channels that are activated by warm receptors. Nociception starts at the sensory receptors, but pain, inasmuch as it is the perception of nociception, does not start until it is communicated to the brain. There are several nociceptive pathways to and through the brain. Most axons carrying nociceptive information into the brain from the spinal cord project to the thalamus (as do other sensory neurons) and the neural signal undergoes final processing in the primary somatosensory cortex. Interestingly, one nociceptive pathway projects not to the thalamus but directly to the hypothalamus in the forebrain, which modulates the cardiovascular and neuroendocrine functions of the autonomic nervous system. Recall that threatening—or painful—stimuli stimulate the sympathetic branch of the visceral sensory system, readying a fight-or-flight response. Link to Learning View this video that animates the five phases of nociceptive pain. Section Summary Somatosensation includes all sensation received from the skin and mucous membranes, as well as from the limbs and joints. Somatosensation occurs all over the exterior of the body and at some interior locations as well, and a variety of receptor types, embedded in the skin and mucous membranes, play a role. There are several types of specialized sensory receptors. Rapidly adapting free nerve endings detect nociception, hot and cold, and light touch. Slowly adapting, encapsulated Merkel’s disks are found in fingertips and lips, and respond to light touch. Meissner’s corpuscles, found in glabrous skin, are rapidly adapting, encapsulated receptors that detect touch, low-frequency vibration, and flutter. Ruffini endings are slowly adapting, encapsulated receptors that detect skin stretch, joint activity, and warmth. Hair receptors are rapidly adapting nerve endings wrapped around the base of hair follicles that detect hair movement and skin deflection. Finally, Pacinian corpuscles are encapsulated, rapidly adapting receptors that detect transient pressure and high-frequency vibration. Art Connections Figure Which of the following statements about mechanoreceptors is false? - Pacini corpuscles are found in both glabrous and hairy skin. - Merkel’s disks are abundant on the fingertips and lips. - Ruffini endings are encapsulated mechanoreceptors. - Meissner’s corpuscles extend into the lower dermis. Hint: Figure D Review Questions _____ are found only in _____ skin, and detect skin deflection. - Meissner’s corpuscles: hairy - Merkel’s disks: glabrous - hair receptors: hairy - Krause end bulbs: hairy Hint: B If you were to burn your epidermis, what receptor type would you most likely burn? - free nerve endings - Ruffini endings - Pacinian corpuscle - hair receptors Hint: A Free Response What can be inferred about the relative sizes of the areas of cortex that process signals from skin not densely innervated with sensory receptors and skin that is densely innervated with sensory receptors? Hint: The cortical areas serving skin that is densely innervated likely are larger than those serving skin that is less densely innervated.	oercommons	2025-03-18T00:37:17.290559	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15122/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15123/overview	Taste and Smell Overview By the end of this section, you will be able to: - Explain in what way smell and taste stimuli differ from other sensory stimuli - Identify the five primary tastes that can be distinguished by humans - Explain in anatomical terms why a dog’s sense of smell is more acute than a human’s Taste, also called gustation, and smell, also called olfaction, are the most interconnected senses in that both involve molecules of the stimulus entering the body and bonding to receptors. Smell lets an animal sense the presence of food or other animals—whether potential mates, predators, or prey—or other chemicals in the environment that can impact their survival. Similarly, the sense of taste allows animals to discriminate between types of foods. While the value of a sense of smell is obvious, what is the value of a sense of taste? Different tasting foods have different attributes, both helpful and harmful. For example, sweet-tasting substances tend to be highly caloric, which could be necessary for survival in lean times. Bitterness is associated with toxicity, and sourness is associated with spoiled food. Salty foods are valuable in maintaining homeostasis by helping the body retain water and by providing ions necessary for cells to function. Tastes and Odors Both taste and odor stimuli are molecules taken in from the environment. The primary tastes detected by humans are sweet, sour, bitter, salty and umami. The first four tastes need little explanation. The identification of umami as a fundamental taste occurred fairly recently—it was identified in 1908 by Japanese scientist Kikunae Ikeda while he worked with seaweed broth, but it was not widely accepted as a taste that could be physiologically distinguished until many years later. The taste of umami, also known as savoriness, is attributable to the taste of the amino acid L-glutamate. In fact, monosodium glutamate, or MSG, is often used in cooking to enhance the savory taste of certain foods. What is the adaptive value of being able to distinguish umami? Savory substances tend to be high in protein. All odors that we perceive are molecules in the air we breathe. If a substance does not release molecules into the air from its surface, it has no smell. And if a human or other animal does not have a receptor that recognizes a specific molecule, then that molecule has no smell. Humans have about 350 olfactory receptor subtypes that work in various combinations to allow us to sense about 10,000 different odors. Compare that to mice, for example, which have about 1,300 olfactory receptor types, and therefore probably sense more odors. Both odors and tastes involve molecules that stimulate specific chemoreceptors. Although humans commonly distinguish taste as one sense and smell as another, they work together to create the perception of flavor. A person’s perception of flavor is reduced if he or she has congested nasal passages. Reception and Transduction Odorants (odor molecules) enter the nose and dissolve in the olfactory epithelium, the mucosa at the back of the nasal cavity (as illustrated in Figure). The olfactory epithelium is a collection of specialized olfactory receptors in the back of the nasal cavity that spans an area about 5 cm2 in humans. Recall that sensory cells are neurons. An olfactory receptor, which is a dendrite of a specialized neuron, responds when it binds certain molecules inhaled from the environment by sending impulses directly to the olfactory bulb of the brain. Humans have about 12 million olfactory receptors, distributed among hundreds of different receptor types that respond to different odors. Twelve million seems like a large number of receptors, but compare that to other animals: rabbits have about 100 million, most dogs have about 1 billion, and bloodhounds—dogs selectively bred for their sense of smell—have about 4 billion. The overall size of the olfactory epithelium also differs between species, with that of bloodhounds, for example, being many times larger than that of humans. Olfactory neurons are bipolar neurons (neurons with two processes from the cell body). Each neuron has a single dendrite buried in the olfactory epithelium, and extending from this dendrite are 5 to 20 receptor-laden, hair-like cilia that trap odorant molecules. The sensory receptors on the cilia are proteins, and it is the variations in their amino acid chains that make the receptors sensitive to different odorants. Each olfactory sensory neuron has only one type of receptor on its cilia, and the receptors are specialized to detect specific odorants, so the bipolar neurons themselves are specialized. When an odorant binds with a receptor that recognizes it, the sensory neuron associated with the receptor is stimulated. Olfactory stimulation is the only sensory information that directly reaches the cerebral cortex, whereas other sensations are relayed through the thalamus. Evolution Connection PheromonesA pheromone is a chemical released by an animal that affects the behavior or physiology of animals of the same species. Pheromonal signals can have profound effects on animals that inhale them, but pheromones apparently are not consciously perceived in the same way as other odors. There are several different types of pheromones, which are released in urine or as glandular secretions. Certain pheromones are attractants to potential mates, others are repellants to potential competitors of the same sex, and still others play roles in mother-infant attachment. Some pheromones can also influence the timing of puberty, modify reproductive cycles, and even prevent embryonic implantation. While the roles of pheromones in many nonhuman species are important, pheromones have become less important in human behavior over evolutionary time compared to their importance to organisms with more limited behavioral repertoires. The vomeronasal organ (VNO, or Jacobson’s organ) is a tubular, fluid-filled, olfactory organ present in many vertebrate animals that sits adjacent to the nasal cavity. It is very sensitive to pheromones and is connected to the nasal cavity by a duct. When molecules dissolve in the mucosa of the nasal cavity, they then enter the VNO where the pheromone molecules among them bind with specialized pheromone receptors. Upon exposure to pheromones from their own species or others, many animals, including cats, may display the flehmen response (shown in Figure), a curling of the upper lip that helps pheromone molecules enter the VNO. Pheromonal signals are sent, not to the main olfactory bulb, but to a different neural structure that projects directly to the amygdala (recall that the amygdala is a brain center important in emotional reactions, such as fear). The pheromonal signal then continues to areas of the hypothalamus that are key to reproductive physiology and behavior. While some scientists assert that the VNO is apparently functionally vestigial in humans, even though there is a similar structure located near human nasal cavities, others are researching it as a possible functional system that may, for example, contribute to synchronization of menstrual cycles in women living in close proximity. Taste Detecting a taste (gustation) is fairly similar to detecting an odor (olfaction), given that both taste and smell rely on chemical receptors being stimulated by certain molecules. The primary organ of taste is the taste bud. A taste bud is a cluster of gustatory receptors (taste cells) that are located within the bumps on the tongue called papillae (singular: papilla) (illustrated in Figure). There are several structurally distinct papillae. Filiform papillae, which are located across the tongue, are tactile, providing friction that helps the tongue move substances, and contain no taste cells. In contrast, fungiform papillae, which are located mainly on the anterior two-thirds of the tongue, each contain one to eight taste buds and also have receptors for pressure and temperature. The large circumvallate papillae contain up to 100 taste buds and form a V near the posterior margin of the tongue. In addition to those two types of chemically and mechanically sensitive papillae are foliate papillae—leaf-like papillae located in parallel folds along the edges and toward the back of the tongue, as seen in the Figure micrograph. Foliate papillae contain about 1,300 taste buds within their folds. Finally, there are circumvallate papillae, which are wall-like papillae in the shape of an inverted “V” at the back of the tongue. Each of these papillae is surrounded by a groove and contains about 250 taste buds. Each taste bud’s taste cells are replaced every 10 to 14 days. These are elongated cells with hair-like processes called microvilli at the tips that extend into the taste bud pore (illustrate in Figure). Food molecules (tastants) are dissolved in saliva, and they bind with and stimulate the receptors on the microvilli. The receptors for tastants are located across the outer portion and front of the tongue, outside of the middle area where the filiform papillae are most prominent. In humans, there are five primary tastes, and each taste has only one corresponding type of receptor. Thus, like olfaction, each receptor is specific to its stimulus (tastant). Transduction of the five tastes happens through different mechanisms that reflect the molecular composition of the tastant. A salty tastant (containing NaCl) provides the sodium ions (Na+) that enter the taste neurons and excite them directly. Sour tastants are acids and belong to the thermoreceptor protein family. Binding of an acid or other sour-tasting molecule triggers a change in the ion channel and these increase hydrogen ion (H+) concentrations in the taste neurons, thus depolarizing them. Sweet, bitter, and umami tastants require a G-protein coupled receptor. These tastants bind to their respective receptors, thereby exciting the specialized neurons associated with them. Both tasting abilities and sense of smell change with age. In humans, the senses decline dramatically by age 50 and continue to decline. A child may find a food to be too spicy, whereas an elderly person may find the same food to be bland and unappetizing. Link to Learning View this animation that shows how the sense of taste works. Smell and Taste in the Brain Olfactory neurons project from the olfactory epithelium to the olfactory bulb as thin, unmyelinated axons. The olfactory bulb is composed of neural clusters called glomeruli, and each glomerulus receives signals from one type of olfactory receptor, so each glomerulus is specific to one odorant. From glomeruli, olfactory signals travel directly to the olfactory cortex and then to the frontal cortex and the thalamus. Recall that this is a different path from most other sensory information, which is sent directly to the thalamus before ending up in the cortex. Olfactory signals also travel directly to the amygdala, thereafter reaching the hypothalamus, thalamus, and frontal cortex. The last structure that olfactory signals directly travel to is a cortical center in the temporal lobe structure important in spatial, autobiographical, declarative, and episodic memories. Olfaction is finally processed by areas of the brain that deal with memory, emotions, reproduction, and thought. Taste neurons project from taste cells in the tongue, esophagus, and palate to the medulla, in the brainstem. From the medulla, taste signals travel to the thalamus and then to the primary gustatory cortex. Information from different regions of the tongue is segregated in the medulla, thalamus, and cortex. Section Summary There are five primary tastes in humans: sweet, sour, bitter, salty, and umami. Each taste has its own receptor type that responds only to that taste. Tastants enter the body and are dissolved in saliva. Taste cells are located within taste buds, which are found on three of the four types of papillae in the mouth. Regarding olfaction, there are many thousands of odorants, but humans detect only about 10,000. Like taste receptors, olfactory receptors are each responsive to only one odorant. Odorants dissolve in nasal mucosa, where they excite their corresponding olfactory sensory cells. When these cells detect an odorant, they send their signals to the main olfactory bulb and then to other locations in the brain, including the olfactory cortex. Review Questions Which of the following has the fewest taste receptors? - fungiform papillae - circumvallate papillae - foliate papillae - filiform papillae Hint: D How many different taste molecules do taste cells each detect? - one - five - ten - It depends on the spot on the tongue Hint: A Salty foods activate the taste cells by _____. - exciting the taste cell directly - causing hydrogen ions to enter the cell - causing sodium channels to close - binding directly to the receptors Hint: A All sensory signals except _____ travel to the _____ in the brain before the cerebral cortex. - vision; thalamus - olfaction; thalamus - vision; cranial nerves - olfaction; cranial nerves Hint: B Free Response From the perspective of the recipient of the signal, in what ways do pheromones differ from other odorants? Hint: Pheromones may not be consciously perceived, and pheromones can have direct physiological and behavioral effects on their recipients. What might be the effect on an animal of not being able to perceive taste? Hint: The animal might not be able to recognize the differences in food sources and thus might not be able to discriminate between spoiled food and safe food or between foods that contain necessary nutrients, such as proteins, and foods that do not.	oercommons	2025-03-18T00:37:17.364233	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15123/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15124/overview	Hearing and Vestibular Sensation Overview By the end of this section, you will be able to: - Describe the relationship of amplitude and frequency of a sound wave to attributes of sound - Trace the path of sound through the auditory system to the site of transduction of sound - Identify the structures of the vestibular system that respond to gravity Audition, or hearing, is important to humans and to other animals for many different interactions. It enables an organism to detect and receive information about danger, such as an approaching predator, and to participate in communal exchanges like those concerning territories or mating. On the other hand, although it is physically linked to the auditory system, the vestibular system is not involved in hearing. Instead, an animal’s vestibular system detects its own movement, both linear and angular acceleration and deceleration, and balance. Sound Auditory stimuli are sound waves, which are mechanical, pressure waves that move through a medium, such as air or water. There are no sound waves in a vacuum since there are no air molecules to move in waves. The speed of sound waves differs, based on altitude, temperature, and medium, but at sea level and a temperature of 20º C (68º F), sound waves travel in the air at about 343 meters per second. As is true for all waves, there are four main characteristics of a sound wave: frequency, wavelength, period, and amplitude. Frequency is the number of waves per unit of time, and in sound is heard as pitch. High-frequency (≥15.000Hz) sounds are higher-pitched (short wavelength) than low-frequency (long wavelengths; ≤100Hz) sounds. Frequency is measured in cycles per second, and for sound, the most commonly used unit is hertz (Hz), or cycles per second. Most humans can perceive sounds with frequencies between 30 and 20,000 Hz. Women are typically better at hearing high frequencies, but everyone’s ability to hear high frequencies decreases with age. Dogs detect up to about 40,000 Hz; cats, 60,000 Hz; bats, 100,000 Hz; and dolphins 150,000 Hz, and American shad (Alosa sapidissima), a fish, can hear 180,000 Hz. Those frequencies above the human range are called ultrasound. Amplitude, or the dimension of a wave from peak to trough, in sound is heard as volume and is illustrated in Figure. The sound waves of louder sounds have greater amplitude than those of softer sounds. For sound, volume is measured in decibels (dB). The softest sound that a human can hear is the zero point. Humans speak normally at 60 decibels. Reception of Sound In mammals, sound waves are collected by the external, cartilaginous part of the ear called the pinna, then travel through the auditory canal and cause vibration of the thin diaphragm called the tympanum or ear drum, the innermost part of the outer ear (illustrated in Figure). Interior to the tympanum is the middle ear. The middle ear holds three small bones called the ossicles, which transfer energy from the moving tympanum to the inner ear. The three ossicles are the malleus (also known as the hammer), the incus (the anvil), and stapes (the stirrup). The aptly named stapes looks very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in hearing. The malleus attaches at three points to the interior surface of the tympanic membrane. The incus attaches the malleus to the stapes. In humans, the stapes is not long enough to reach the tympanum. If we did not have the malleus and the incus, then the vibrations of the tympanum would never reach the inner ear. These bones also function to collect force and amplify sounds. The ear ossicles are homologous to bones in a fish mouth: the bones that support gills in fish are thought to be adapted for use in the vertebrate ear over evolutionary time. Many animals (frogs, reptiles, and birds, for example) use the stapes of the middle ear to transmit vibrations to the middle ear. Transduction of Sound Vibrating objects, such as vocal cords, create sound waves or pressure waves in the air. When these pressure waves reach the ear, the ear transduces this mechanical stimulus (pressure wave) into a nerve impulse (electrical signal) that the brain perceives as sound. The pressure waves strike the tympanum, causing it to vibrate. The mechanical energy from the moving tympanum transmits the vibrations to the three bones of the middle ear. The stapes transmits the vibrations to a thin diaphragm called the oval window, which is the outermost structure of the inner ear. The structures of the inner ear are found in the labyrinth, a bony, hollow structure that is the most interior portion of the ear. Here, the energy from the sound wave is transferred from the stapes through the flexible oval window and to the fluid of the cochlea. The vibrations of the oval window create pressure waves in the fluid (perilymph) inside the cochlea. The cochlea is a whorled structure, like the shell of a snail, and it contains receptors for transduction of the mechanical wave into an electrical signal (as illustrated in Figure). Inside the cochlea, the basilar membrane is a mechanical analyzer that runs the length of the cochlea, curling toward the cochlea’s center. The mechanical properties of the basilar membrane change along its length, such that it is thicker, tauter, and narrower at the outside of the whorl (where the cochlea is largest), and thinner, floppier, and broader toward the apex, or center, of the whorl (where the cochlea is smallest). Different regions of the basilar membrane vibrate according to the frequency of the sound wave conducted through the fluid in the cochlea. For these reasons, the fluid-filled cochlea detects different wave frequencies (pitches) at different regions of the membrane. When the sound waves in the cochlear fluid contact the basilar membrane, it flexes back and forth in a wave-like fashion. Above the basilar membrane is the tectorial membrane. Art Connection Cochlear implants can restore hearing in people who have a nonfunctional cochlear. The implant consists of a microphone that picks up sound. A speech processor selects sounds in the range of human speech, and a transmitter converts these sounds to electrical impulses, which are then sent to the auditory nerve. Which of the following types of hearing loss would not be restored by a cochlear implant? - Hearing loss resulting from absence or loss of hair cells in the organ of Corti. - Hearing loss resulting from an abnormal auditory nerve. - Hearing loss resulting from fracture of the cochlea. - Hearing loss resulting from damage to bones of the middle ear. The site of transduction is in the organ of Corti (spiral organ). It is composed of hair cells held in place above the basilar membrane like flowers projecting up from soil, with their exposed short, hair-like stereocilia contacting or embedded in the tectorial membrane above them. The inner hair cells are the primary auditory receptors and exist in a single row, numbering approximately 3,500. The stereocilia from inner hair cells extend into small dimples on the tectorial membrane’s lower surface. The outer hair cells are arranged in three or four rows. They number approximately 12,000, and they function to fine tune incoming sound waves. The longer stereocilia that project from the outer hair cells actually attach to the tectorial membrane. All of the stereocilia are mechanoreceptors, and when bent by vibrations they respond by opening a gated ion channel (refer to ). As a result, the hair cell membrane is depolarized, and a signal is transmitted to the chochlear nerve. Intensity (volume) of sound is determined by how many hair cells at a particular location are stimulated. The hair cells are arranged on the basilar membrane in an orderly way. The basilar membrane vibrates in different regions, according to the frequency of the sound waves impinging on it. Likewise, the hair cells that lay above it are most sensitive to a specific frequency of sound waves. Hair cells can respond to a small range of similar frequencies, but they require stimulation of greater intensity to fire at frequencies outside of their optimal range. The difference in response frequency between adjacent inner hair cells is about 0.2 percent. Compare that to adjacent piano strings, which are about six percent different. Place theory, which is the model for how biologists think pitch detection works in the human ear, states that high frequency sounds selectively vibrate the basilar membrane of the inner ear near the entrance port (the oval window). Lower frequencies travel farther along the membrane before causing appreciable excitation of the membrane. The basic pitch-determining mechanism is based on the location along the membrane where the hair cells are stimulated. The place theory is the first step toward an understanding of pitch perception. Considering the extreme pitch sensitivity of the human ear, it is thought that there must be some auditory “sharpening” mechanism to enhance the pitch resolution. When sound waves produce fluid waves inside the cochlea, the basilar membrane flexes, bending the stereocilia that attach to the tectorial membrane. Their bending results in action potentials in the hair cells, and auditory information travels along the neural endings of the bipolar neurons of the hair cells (collectively, the auditory nerve) to the brain. When the hairs bend, they release an excitatory neurotransmitter at a synapse with a sensory neuron, which then conducts action potentials to the central nervous system. The cochlear branch of the vestibulocochlear cranial nerve sends information on hearing. The auditory system is very refined, and there is some modulation or “sharpening” built in. The brain can send signals back to the cochlea, resulting in a change of length in the outer hair cells, sharpening or dampening the hair cells’ response to certain frequencies. Link to Learning Watch an animation of sound entering the outer ear, moving through the ear structure, stimulating cochlear nerve impulses, and eventually sending signals to the temporal lobe. Higher Processing The inner hair cells are most important for conveying auditory information to the brain. About 90 percent of the afferent neurons carry information from inner hair cells, with each hair cell synapsing with 10 or so neurons. Outer hair cells connect to only 10 percent of the afferent neurons, and each afferent neuron innervates many hair cells. The afferent, bipolar neurons that convey auditory information travel from the cochlea to the medulla, through the pons and midbrain in the brainstem, finally reaching the primary auditory cortex in the temporal lobe. Vestibular Information The stimuli associated with the vestibular system are linear acceleration (gravity) and angular acceleration and deceleration. Gravity, acceleration, and deceleration are detected by evaluating the inertia on receptive cells in the vestibular system. Gravity is detected through head position. Angular acceleration and deceleration are expressed through turning or tilting of the head. The vestibular system has some similarities with the auditory system. It utilizes hair cells just like the auditory system, but it excites them in different ways. There are five vestibular receptor organs in the inner ear: the utricle, the saccule, and three semicircular canals. Together, they make up what’s known as the vestibular labyrinth that is shown in Figure. The utricle and saccule respond to acceleration in a straight line, such as gravity. The roughly 30,000 hair cells in the utricle and 16,000 hair cells in the saccule lie below a gelatinous layer, with their stereocilia projecting into the gelatin. Embedded in this gelatin are calcium carbonate crystals—like tiny rocks. When the head is tilted, the crystals continue to be pulled straight down by gravity, but the new angle of the head causes the gelatin to shift, thereby bending the stereocilia. The bending of the stereocilia stimulates the neurons, and they signal to the brain that the head is tilted, allowing the maintenance of balance. It is the vestibular branch of the vestibulocochlear cranial nerve that deals with balance. The fluid-filled semicircular canals are tubular loops set at oblique angles. They are arranged in three spatial planes. The base of each canal has a swelling that contains a cluster of hair cells. The hairs project into a gelatinous cap called the cupula and monitor angular acceleration and deceleration from rotation. They would be stimulated by driving your car around a corner, turning your head, or falling forward. One canal lies horizontally, while the other two lie at about 45 degree angles to the horizontal axis, as illustrated in Figure. When the brain processes input from all three canals together, it can detect angular acceleration or deceleration in three dimensions. When the head turns, the fluid in the canals shifts, thereby bending stereocilia and sending signals to the brain. Upon cessation accelerating or decelerating—or just moving—the movement of the fluid within the canals slows or stops. For example, imagine holding a glass of water. When moving forward, water may splash backwards onto the hand, and when motion has stopped, water may splash forward onto the fingers. While in motion, the water settles in the glass and does not splash. Note that the canals are not sensitive to velocity itself, but to changes in velocity, so moving forward at 60mph with your eyes closed would not give the sensation of movement, but suddenly accelerating or braking would stimulate the receptors. Higher Processing Hair cells from the utricle, saccule, and semicircular canals also communicate through bipolar neurons to the cochlear nucleus in the medulla. Cochlear neurons send descending projections to the spinal cord and ascending projections to the pons, thalamus, and cerebellum. Connections to the cerebellum are important for coordinated movements. There are also projections to the temporal cortex, which account for feelings of dizziness; projections to autonomic nervous system areas in the brainstem, which account for motion sickness; and projections to the primary somatosensory cortex, which monitors subjective measurements of the external world and self-movement. People with lesions in the vestibular area of the somatosensory cortex see vertical objects in the world as being tilted. Finally, the vestibular signals project to certain optic muscles to coordinate eye and head movements. Link to Learning Click through this interactive tutorial to review the parts of the ear and how they function to process sound. Section Summary Audition is important for territory defense, predation, predator defense, and communal exchanges. The vestibular system, which is not auditory, detects linear acceleration and angular acceleration and deceleration. Both the auditory system and vestibular system use hair cells as their receptors. Auditory stimuli are sound waves. The sound wave energy reaches the outer ear (pinna, canal, tympanum), and vibrations of the tympanum send the energy to the middle ear. The middle ear bones shift and the stapes transfers mechanical energy to the oval window of the fluid-filled inner ear cochlea. Once in the cochlea, the energy causes the basilar membrane to flex, thereby bending the stereocilia on receptor hair cells. This activates the receptors, which send their auditory neural signals to the brain. The vestibular system has five parts that work together to provide the sense of direction, thus helping to maintain balance. The utricle and saccule measure head orientation: their calcium carbonate crystals shift when the head is tilted, thereby activating hair cells. The semicircular canals work similarly, such that when the head is turned, the fluid in the canals bends stereocilia on hair cells. The vestibular hair cells also send signals to the thalamus and to somatosensory cortex, but also to the cerebellum, the structure above the brainstem that plays a large role in timing and coordination of movement. Art Connections Figure Cochlear implants can restore hearing in people who have a nonfunctional cochlear. The implant consists of a microphone that picks up sound. A speech processor selects sounds in the range of human speech, and a transmitter converts these sounds to electrical impulses, which are then sent to the auditory nerve. Which of the following types of hearing loss would not be restored by a cochlear implant? - Hearing loss resulting from absence or loss of hair cells in the organ of Corti. - Hearing loss resulting from an abnormal auditory nerve. - Hearing loss resulting from fracture of the cochlea. - Hearing loss resulting from damage to bones of the middle ear. Hint: Figure B Review Questions In sound, pitch is measured in _____, and volume is measured in _____. - nanometers (nm); decibels (dB) - decibels (dB); nanometers (nm) - decibels (dB); hertz (Hz) - hertz (Hz); decibels (dB) Hint: D Auditory hair cells are indirectly anchored to the _____. - basilar membrane - oval window - tectorial membrane - ossicles Hint: A Which of the following are found both in the auditory system and the vestibular system? - basilar membrane - hair cells - semicircular canals - ossicles Hint: B Free Response How would a rise in altitude likely affect the speed of a sound transmitted through air? Why? Hint: The sound would slow down, because it is transmitted through the particles (gas) and there are fewer particles (lower density) at higher altitudes. How might being in a place with less gravity than Earth has (such as Earth’s moon) affect vestibular sensation, and why? Hint: Because vestibular sensation relies on gravity’s effects on tiny crystals in the inner ear, a situation of reduced gravity would likely impair vestibular sensation.	oercommons	2025-03-18T00:37:17.398777	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15124/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15125/overview	Vision Overview By the end of this section, you will be able to: - Explain how electromagnetic waves differs from sound waves - Trace the path of light through the eye to the point of the optic nerve - Explain tonic activity as it is manifested in photoreceptors in the retina Vision is the ability to detect light patterns from the outside environment and interpret them into images. Animals are bombarded with sensory information, and the sheer volume of visual information can be problematic. Fortunately, the visual systems of species have evolved to attend to the most-important stimuli. The importance of vision to humans is further substantiated by the fact that about one-third of the human cerebral cortex is dedicated to analyzing and perceiving visual information. Light As with auditory stimuli, light travels in waves. The compression waves that compose sound must travel in a medium—a gas, a liquid, or a solid. In contrast, light is composed of electromagnetic waves and needs no medium; light can travel in a vacuum (Figure). The behavior of light can be discussed in terms of the behavior of waves and also in terms of the behavior of the fundamental unit of light—a packet of electromagnetic radiation called a photon. A glance at the electromagnetic spectrum shows that visible light for humans is just a small slice of the entire spectrum, which includes radiation that we cannot see as light because it is below the frequency of visible red light and above the frequency of visible violet light. Certain variables are important when discussing perception of light. Wavelength (which varies inversely with frequency) manifests itself as hue. Light at the red end of the visible spectrum has longer wavelengths (and is lower frequency), while light at the violet end has shorter wavelengths (and is higher frequency). The wavelength of light is expressed in nanometers (nm); one nanometer is one billionth of a meter. Humans perceive light that ranges between approximately 380 nm and 740 nm. Some other animals, though, can detect wavelengths outside of the human range. For example, bees see near-ultraviolet light in order to locate nectar guides on flowers, and some non-avian reptiles sense infrared light (heat that prey gives off). Wave amplitude is perceived as luminous intensity, or brightness. The standard unit of intensity of light is the candela, which is approximately the luminous intensity of a one common candle. Light waves travel 299,792 km per second in a vacuum, (and somewhat slower in various media such as air and water), and those waves arrive at the eye as long (red), medium (green), and short (blue) waves. What is termed “white light” is light that is perceived as white by the human eye. This effect is produced by light that stimulates equally the color receptors in the human eye. The apparent color of an object is the color (or colors) that the object reflects. Thus a red object reflects the red wavelengths in mixed (white) light and absorbs all other wavelengths of light. Anatomy of the Eye The photoreceptive cells of the eye, where transduction of light to nervous impulses occurs, are located in the retina (shown in Figure) on the inner surface of the back of the eye. But light does not impinge on the retina unaltered. It passes through other layers that process it so that it can be interpreted by the retina (Figureb). The cornea, the front transparent layer of the eye, and the crystalline lens, a transparent convex structure behind the cornea, both refract (bend) light to focus the image on the retina. The iris, which is conspicuous as the colored part of the eye, is a circular muscular ring lying between the lens and cornea that regulates the amount of light entering the eye. In conditions of high ambient light, the iris contracts, reducing the size of the pupil at its center. In conditions of low light, the iris relaxes and the pupil enlarges. Art Connection Which of the following statements about the human eye is false? - Rods detect color, while cones detect only shades of gray. - When light enters the retina, it passes the ganglion cells and bipolar cells before reaching photoreceptors at the rear of the eye. - The iris adjusts the amount of light coming into the eye. - The cornea is a protective layer on the front of the eye. The main function of the lens is to focus light on the retina and fovea centralis. The lens is dynamic, focusing and re-focusing light as the eye rests on near and far objects in the visual field. The lens is operated by muscles that stretch it flat or allow it to thicken, changing the focal length of light coming through it to focus it sharply on the retina. With age comes the loss of the flexibility of the lens, and a form of farsightedness called presbyopia results. Presbyopia occurs because the image focuses behind the retina. Presbyopia is a deficit similar to a different type of farsightedness called hyperopia caused by an eyeball that is too short. For both defects, images in the distance are clear but images nearby are blurry. Myopia (nearsightedness) occurs when an eyeball is elongated and the image focus falls in front of the retina. In this case, images in the distance are blurry but images nearby are clear. There are two types of photoreceptors in the retina: rods and cones, named for their general appearance as illustrated in Figure. Rods are strongly photosensitive and are located in the outer edges of the retina. They detect dim light and are used primarily for peripheral and nighttime vision. Cones are weakly photosensitive and are located near the center of the retina. They respond to bright light, and their primary role is in daytime, color vision. The fovea is the region in the center back of the eye that is responsible for acute vision. The fovea has a high density of cones. When you bring your gaze to an object to examine it intently in bright light, the eyes orient so that the object’s image falls on the fovea. However, when looking at a star in the night sky or other object in dim light, the object can be better viewed by the peripheral vision because it is the rods at the edges of the retina, rather than the cones at the center, that operate better in low light. In humans, cones far outnumber rods in the fovea. Link to Learning Review the anatomical structure of the eye, clicking on each part to practice identification. Transduction of Light The rods and cones are the site of transduction of light to a neural signal. Both rods and cones contain photopigments. In vertebrates, the main photopigment, rhodopsin, has two main parts Figure): an opsin, which is a membrane protein (in the form of a cluster of α-helices that span the membrane), and retinal—a molecule that absorbs light. When light hits a photoreceptor, it causes a shape change in the retinal, altering its structure from a bent (cis) form of the molecule to its linear (trans) isomer. This isomerization of retinal activates the rhodopsin, starting a cascade of events that ends with the closing of Na+ channels in the membrane of the photoreceptor. Thus, unlike most other sensory neurons (which become depolarized by exposure to a stimulus) visual receptors become hyperpolarized and thus driven away from threshold (Figure). Trichromatic Coding There are three types of cones (with different photopsins), and they differ in the wavelength to which they are most responsive, as shown in Figure. Some cones are maximally responsive to short light waves of 420 nm, so they are called S cones (“S” for “short”); others respond maximally to waves of 530 nm (M cones, for “medium”); a third group responds maximally to light of longer wavelengths, at 560 nm (L, or “long” cones). With only one type of cone, color vision would not be possible, and a two-cone (dichromatic) system has limitations. Primates use a three-cone (trichromatic) system, resulting in full color vision. The color we perceive is a result of the ratio of activity of our three types of cones. The colors of the visual spectrum, running from long-wavelength light to short, are red (700 nm), orange (600 nm), yellow (565 nm), green (497 nm), blue (470 nm), indigo (450 nm), and violet (425 nm). Humans have very sensitive perception of color and can distinguish about 500 levels of brightness, 200 different hues, and 20 steps of saturation, or about 2 million distinct colors. Retinal Processing Visual signals leave the cones and rods, travel to the bipolar cells, and then to ganglion cells. A large degree of processing of visual information occurs in the retina itself, before visual information is sent to the brain. Photoreceptors in the retina continuously undergo tonic activity. That is, they are always slightly active even when not stimulated by light. In neurons that exhibit tonic activity, the absence of stimuli maintains a firing rate at a baseline; while some stimuli increase firing rate from the baseline, and other stimuli decrease firing rate. In the absence of light, the bipolar neurons that connect rods and cones to ganglion cells are continuously and actively inhibited by the rods and cones. Exposure of the retina to light hyperpolarizes the rods and cones and removes their inhibition of bipolar cells. The now active bipolar cells in turn stimulate the ganglion cells, which send action potentials along their axons (which leave the eye as the optic nerve). Thus, the visual system relies on change in retinal activity, rather than the absence or presence of activity, to encode visual signals for the brain. Sometimes horizontal cells carry signals from one rod or cone to other photoreceptors and to several bipolar cells. When a rod or cone stimulates a horizontal cell, the horizontal cell inhibits more distant photoreceptors and bipolar cells, creating lateral inhibition. This inhibition sharpens edges and enhances contrast in the images by making regions receiving light appear lighter and dark surroundings appear darker. Amacrine cells can distribute information from one bipolar cell to many ganglion cells. You can demonstrate this using an easy demonstration to “trick” your retina and brain about the colors you are observing in your visual field. Look fixedly at Figure for about 45 seconds. Then quickly shift your gaze to a sheet of blank white paper or a white wall. You should see an afterimage of the Norwegian flag in its correct colors. At this point, close your eyes for a moment, then reopen them, looking again at the white paper or wall; the afterimage of the flag should continue to appear as red, white, and blue. What causes this? According to an explanation called opponent process theory, as you gazed fixedly at the green, black, and yellow flag, your retinal ganglion cells that respond positively to green, black, and yellow increased their firing dramatically. When you shifted your gaze to the neutral white ground, these ganglion cells abruptly decreased their activity and the brain interpreted this abrupt downshift as if the ganglion cells were responding now to their “opponent” colors: red, white, and blue, respectively, in the visual field. Once the ganglion cells return to their baseline activity state, the false perception of color will disappear. Higher Processing The myelinated axons of ganglion cells make up the optic nerves. Within the nerves, different axons carry different qualities of the visual signal. Some axons constitute the magnocellular (big cell) pathway, which carries information about form, movement, depth, and differences in brightness. Other axons constitute the parvocellular (small cell) pathway, which carries information on color and fine detail. Some visual information projects directly back into the brain, while other information crosses to the opposite side of the brain. This crossing of optical pathways produces the distinctive optic chiasma (Greek, for “crossing”) found at the base of the brain and allows us to coordinate information from both eyes. Once in the brain, visual information is processed in several places, and its routes reflect the complexity and importance of visual information to humans and other animals. One route takes the signals to the thalamus, which serves as the routing station for all incoming sensory impulses except olfaction. In the thalamus, the magnocellular and parvocellular distinctions remain intact, and there are different layers of the thalamus dedicated to each. When visual signals leave the thalamus, they travel to the primary visual cortex at the rear of the brain. From the visual cortex, the visual signals travel in two directions. One stream that projects to the parietal lobe, in the side of the brain, carries magnocellular (“where”) information. A second stream projects to the temporal lobe and carries both magnocellular (“where”) and parvocellular (“what”) information. Another important visual route is a pathway from the retina to the superior colliculus in the midbrain, where eye movements are coordinated and integrated with auditory information. Finally, there is the pathway from the retina to the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is a cluster of cells that is considered to be the body’s internal clock, which controls our circadian (day-long) cycle. The SCN sends information to the pineal gland, which is important in sleep/wake patterns and annual cycles. Link to Learning View this interactive presentation to review what you have learned about how vision functions. Section Summary Vision is the only photo responsive sense. Visible light travels in waves and is a very small slice of the electromagnetic radiation spectrum. Light waves differ based on their frequency (wavelength = hue) and amplitude (intensity = brightness). In the vertebrate retina, there are two types of light receptors (photoreceptors): cones and rods. Cones, which are the source of color vision, exist in three forms—L, M, and S—and they are differentially sensitive to different wavelengths. Cones are located in the retina, along with the dim-light, achromatic receptors (rods). Cones are found in the fovea, the central region of the retina, whereas rods are found in the peripheral regions of the retina. Visual signals travel from the eye over the axons of retinal ganglion cells, which make up the optic nerves. Ganglion cells come in several versions. Some ganglion cell axons carry information on form, movement, depth, and brightness, while other axons carry information on color and fine detail. Visual information is sent to the superior colliculi in the midbrain, where coordination of eye movements and integration of auditory information takes place. Visual information is also sent to the suprachiasmatic nucleus (SCN) of the hypothalamus, which plays a role in the circadian cycle. Art Connections Figure Which of the following statements about the human eye is false? - Rods detect color, while cones detect only shades of gray. - When light enters the retina, it passes the ganglion cells and bipolar cells before reaching photoreceptors at the rear of the eye. - The iris adjusts the amount of light coming into the eye. - The cornea is a protective layer on the front of the eye. Hint: Figure A Review Questions Why do people over 55 often need reading glasses? - Their cornea no longer focuses correctly. - Their lens no longer focuses correctly. - Their eyeball has elongated with age, causing images to focus in front of their retina. - Their retina has thinned with age, making vision more difficult. Hint: B Why is it easier to see images at night using peripheral, rather than the central, vision? - Cones are denser in the periphery of the retina. - Bipolar cells are denser in the periphery of the retina. - Rods are denser in the periphery of the retina. - The optic nerve exits at the periphery of the retina. Hint: C A person catching a ball must coordinate her head and eyes. What part of the brain is helping to do this? - hypothalamus - pineal gland - thalamus - superior colliculus Hint: D Free Response How could the pineal gland, the brain structure that plays a role in annual cycles, use visual information from the suprachiasmatic nucleus of the hypothalamus? Hint: The pineal gland could use length-of-day information to determine the time of year, for example. Day length is shorter in the winter than it is in the summer. For many animals and plants, photoperiod cues them to reproduce at a certain time of year. How is the relationship between photoreceptors and bipolar cells different from other sensory receptors and adjacent cells? Hint: The photoreceptors tonically inhibit the bipolar cells, and stimulation of the receptors turns this inhibition off, activating the bipolar cells.	oercommons	2025-03-18T00:37:17.432532	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15125/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15126/overview	Introduction An animal’s endocrine system controls body processes through the production, secretion, and regulation of hormones, which serve as chemical “messengers” functioning in cellular and organ activity and, ultimately, maintaining the body’s homeostasis. The endocrine system plays a role in growth, metabolism, and sexual development. In humans, common endocrine system diseases include thyroid disease and diabetes mellitus. In organisms that undergo metamorphosis, the process is controlled by the endocrine system. The transformation from tadpole to frog, for example, is complex and nuanced to adapt to specific environments and ecological circumstances.	oercommons	2025-03-18T00:37:17.450819	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15126/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15127/overview	Types of Hormones Overview By the end of this section, you will be able to: - List the different types of hormones - Explain their role in maintaining homeostasis Maintaining homeostasis within the body requires the coordination of many different systems and organs. Communication between neighboring cells, and between cells and tissues in distant parts of the body, occurs through the release of chemicals called hormones. Hormones are released into body fluids (usually blood) that carry these chemicals to their target cells. At the target cells, which are cells that have a receptor for a signal or ligand from a signal cell, the hormones elicit a response. The cells, tissues, and organs that secrete hormones make up the endocrine system. Examples of glands of the endocrine system include the adrenal glands, which produce hormones such as epinephrine and norepinephrine that regulate responses to stress, and the thyroid gland, which produces thyroid hormones that regulate metabolic rates. Although there are many different hormones in the human body, they can be divided into three classes based on their chemical structure: lipid-derived, amino acid-derived, and peptide (peptide and proteins) hormones. One of the key distinguishing features of lipid-derived hormones is that they can diffuse across plasma membranes whereas the amino acid-derived and peptide hormones cannot. Lipid-Derived Hormones (or Lipid-soluble Hormones) Most lipid hormones are derived from cholesterol and thus are structurally similar to it, as illustrated in Figure. The primary class of lipid hormones in humans is the steroid hormones. Chemically, these hormones are usually ketones or alcohols; their chemical names will end in “-ol” for alcohols or “-one” for ketones. Examples of steroid hormones include estradiol, which is an estrogen, or female sex hormone, and testosterone, which is an androgen, or male sex hormone. These two hormones are released by the female and male reproductive organs, respectively. Other steroid hormones include aldosterone and cortisol, which are released by the adrenal glands along with some other types of androgens. Steroid hormones are insoluble in water, and they are transported by transport proteins in blood. As a result, they remain in circulation longer than peptide hormones. For example, cortisol has a half-life of 60 to 90 minutes, while epinephrine, an amino acid derived-hormone, has a half-life of approximately one minute. Amino Acid-Derived Hormones The amino acid-derived hormones are relatively small molecules that are derived from the amino acids tyrosine and tryptophan, shown in Figure. If a hormone is amino acid-derived, its chemical name will end in “-ine”. Examples of amino acid-derived hormones include epinephrine and norepinephrine, which are synthesized in the medulla of the adrenal glands, and thyroxine, which is produced by the thyroid gland. The pineal gland in the brain makes and secretes melatonin which regulates sleep cycles. Peptide Hormones The structure of peptide hormones is that of a polypeptide chain (chain of amino acids). The peptide hormones include molecules that are short polypeptide chains, such as antidiuretic hormone and oxytocin produced in the brain and released into the blood in the posterior pituitary gland. This class also includes small proteins, like growth hormones produced by the pituitary, and large glycoproteins such as follicle-stimulating hormone produced by the pituitary. Figure illustrates these peptide hormones. Secreted peptides like insulin are stored within vesicles in the cells that synthesize them. They are then released in response to stimuli such as high blood glucose levels in the case of insulin. Amino acid-derived and polypeptide hormones are water-soluble and insoluble in lipids. These hormones cannot pass through plasma membranes of cells; therefore, their receptors are found on the surface of the target cells. Career Connection EndocrinologistAn endocrinologist is a medical doctor who specializes in treating disorders of the endocrine glands, hormone systems, and glucose and lipid metabolic pathways. An endocrine surgeon specializes in the surgical treatment of endocrine diseases and glands. Some of the diseases that are managed by endocrinologists: disorders of the pancreas (diabetes mellitus), disorders of the pituitary (gigantism, acromegaly, and pituitary dwarfism), disorders of the thyroid gland (goiter and Graves’ disease), and disorders of the adrenal glands (Cushing’s disease and Addison’s disease). Endocrinologists are required to assess patients and diagnose endocrine disorders through extensive use of laboratory tests. Many endocrine diseases are diagnosed using tests that stimulate or suppress endocrine organ functioning. Blood samples are then drawn to determine the effect of stimulating or suppressing an endocrine organ on the production of hormones. For example, to diagnose diabetes mellitus, patients are required to fast for 12 to 24 hours. They are then given a sugary drink, which stimulates the pancreas to produce insulin to decrease blood glucose levels. A blood sample is taken one to two hours after the sugar drink is consumed. If the pancreas is functioning properly, the blood glucose level will be within a normal range. Another example is the A1C test, which can be performed during blood screening. The A1C test measures average blood glucose levels over the past two to three months by examining how well the blood glucose is being managed over a long time. Once a disease has been diagnosed, endocrinologists can prescribe lifestyle changes and/or medications to treat the disease. Some cases of diabetes mellitus can be managed by exercise, weight loss, and a healthy diet; in other cases, medications may be required to enhance insulin release. If the disease cannot be controlled by these means, the endocrinologist may prescribe insulin injections. In addition to clinical practice, endocrinologists may also be involved in primary research and development activities. For example, ongoing islet transplant research is investigating how healthy pancreas islet cells may be transplanted into diabetic patients. Successful islet transplants may allow patients to stop taking insulin injections. Section Summary There are three basic types of hormones: lipid-derived, amino acid-derived, and peptide. Lipid-derived hormones are structurally similar to cholesterol and include steroid hormones such as estradiol and testosterone. Amino acid-derived hormones are relatively small molecules and include the adrenal hormones epinephrine and norepinephrine. Peptide hormones are polypeptide chains or proteins and include the pituitary hormones, antidiuretic hormone (vasopressin), and oxytocin. Review Questions A newly discovered hormone contains four amino acids linked together. Under which chemical class would this hormone be classified? - lipid-derived hormone - amino acid-derived hormone - peptide hormone - glycoprotein Hint: C Which class of hormones can diffuse through plasma membranes? - lipid-derived hormones - amino acid-derived hormones - peptide hormones - glycoprotein hormones Hint: A Free Response Although there are many different hormones in the human body, they can be divided into three classes based on their chemical structure. What are these classes and what is one factor that distinguishes them? Hint: Although there are many different hormones in the human body, they can be divided into three classes based on their chemical structure: lipid-derived, amino acid-derived, and peptide hormones. One of the key distinguishing features of the lipid-derived hormones is that they can diffuse across plasma membranes whereas the amino acid-derived and peptide hormones cannot. Where is insulin stored, and why would it be released? Hint: Secreted peptides such as insulin are stored within vesicles in the cells that synthesize them. They are then released in response to stimuli such as high blood glucose levels in the case of insulin.	oercommons	2025-03-18T00:37:17.474125	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15127/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15128/overview	How Hormones Work Overview By the end of this section, you will be able to: - Explain how hormones work - Discuss the role of different types of hormone receptors Hormones mediate changes in target cells by binding to specific hormone receptors. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Cells can have many receptors for the same hormone but often also possess receptors for different types of hormones. The number of receptors that respond to a hormone determines the cell’s sensitivity to that hormone, and the resulting cellular response. Additionally, the number of receptors that respond to a hormone can change over time, resulting in increased or decreased cell sensitivity. In up-regulation, the number of receptors increases in response to rising hormone levels, making the cell more sensitive to the hormone and allowing for more cellular activity. When the number of receptors decreases in response to rising hormone levels, called down-regulation, cellular activity is reduced. Receptor binding alters cellular activity and results in an increase or decrease in normal body processes. Depending on the location of the protein receptor on the target cell and the chemical structure of the hormone, hormones can mediate changes directly by binding to intracellular hormone receptors and modulating gene transcription, or indirectly by binding to cell surface receptors and stimulating signaling pathways. Intracellular Hormone Receptors Lipid-derived (soluble) hormones such as steroid hormones diffuse across the membranes of the endocrine cell. Once outside the cell, they bind to transport proteins that keep them soluble in the bloodstream. At the target cell, the hormones are released from the carrier protein and diffuse across the lipid bilayer of the plasma membrane of cells. The steroid hormones pass through the plasma membrane of a target cell and adhere to intracellular receptors residing in the cytoplasm or in the nucleus. The cell signaling pathways induced by the steroid hormones regulate specific genes on the cell's DNA. The hormones and receptor complex act as transcription regulators by increasing or decreasing the synthesis of mRNA molecules of specific genes. This, in turn, determines the amount of corresponding protein that is synthesized by altering gene expression. This protein can be used either to change the structure of the cell or to produce enzymes that catalyze chemical reactions. In this way, the steroid hormone regulates specific cell processes as illustrated in Figure. Art Connection Heat shock proteins (HSP) are so named because they help refold misfolded proteins. In response to increased temperature (a “heat shock”), heat shock proteins are activated by release from the NR/HSP complex. At the same time, transcription of HSP genes is activated. Why do you think the cell responds to a heat shock by increasing the activity of proteins that help refold misfolded proteins? Other lipid-soluble hormones that are not steroid hormones, such as vitamin D and thyroxine, have receptors located in the nucleus. The hormones diffuse across both the plasma membrane and the nuclear envelope, then bind to receptors in the nucleus. The hormone-receptor complex stimulates transcription of specific genes. Plasma Membrane Hormone Receptors Amino acid derived hormones and polypeptide hormones are not lipid-derived (lipid-soluble) and therefore cannot diffuse through the plasma membrane of cells. Lipid insoluble hormones bind to receptors on the outer surface of the plasma membrane, via plasma membrane hormone receptors. Unlike steroid hormones, lipid insoluble hormones do not directly affect the target cell because they cannot enter the cell and act directly on DNA. Binding of these hormones to a cell surface receptor results in activation of a signaling pathway; this triggers intracellular activity and carries out the specific effects associated with the hormone. In this way, nothing passes through the cell membrane; the hormone that binds at the surface remains at the surface of the cell while the intracellular product remains inside the cell. The hormone that initiates the signaling pathway is called a first messenger, which activates a second messenger in the cytoplasm, as illustrated in Figure. One very important second messenger is cyclic AMP (cAMP). When a hormone binds to its membrane receptor, a G-protein that is associated with the receptor is activated; G-proteins are proteins separate from receptors that are found in the cell membrane. When a hormone is not bound to the receptor, the G-protein is inactive and is bound to guanosine diphosphate, or GDP. When a hormone binds to the receptor, the G-protein is activated by binding guanosine triphosphate, or GTP, in place of GDP. After binding, GTP is hydrolysed by the G-protein into GDP and becomes inactive. The activated G-protein in turn activates a membrane-bound enzyme called adenylyl cyclase. Adenylyl cyclase catalyzes the conversion of ATP to cAMP. cAMP, in turn, activates a group of proteins called protein kinases, which transfer a phosphate group from ATP to a substrate molecule in a process called phosphorylation. The phosphorylation of a substrate molecule changes its structural orientation, thereby activating it. These activated molecules can then mediate changes in cellular processes. The effect of a hormone is amplified as the signaling pathway progresses. The binding of a hormone at a single receptor causes the activation of many G-proteins, which activates adenylyl cyclase. Each molecule of adenylyl cyclase then triggers the formation of many molecules of cAMP. Further amplification occurs as protein kinases, once activated by cAMP, can catalyze many reactions. In this way, a small amount of hormone can trigger the formation of a large amount of cellular product. To stop hormone activity, cAMP is deactivated by the cytoplasmic enzyme phosphodiesterase, or PDE. PDE is always present in the cell and breaks down cAMP to control hormone activity, preventing overproduction of cellular products. The specific response of a cell to a lipid insoluble hormone depends on the type of receptors that are present on the cell membrane and the substrate molecules present in the cell cytoplasm. Cellular responses to hormone binding of a receptor include altering membrane permeability and metabolic pathways, stimulating synthesis of proteins and enzymes, and activating hormone release. Section Summary Hormones cause cellular changes by binding to receptors on target cells. The number of receptors on a target cell can increase or decrease in response to hormone activity. Hormones can affect cells directly through intracellular hormone receptors or indirectly through plasma membrane hormone receptors. Lipid-derived (soluble) hormones can enter the cell by diffusing across the plasma membrane and binding to DNA to regulate gene transcription and to change the cell’s activities by inducing production of proteins that affect, in general, the long-term structure and function of the cell. Lipid insoluble hormones bind to receptors on the plasma membrane surface and trigger a signaling pathway to change the cell’s activities by inducing production of various cell products that affect the cell in the short-term. The hormone is called a first messenger and the cellular component is called a second messenger. G-proteins activate the second messenger (cyclic AMP), triggering the cellular response. Response to hormone binding is amplified as the signaling pathway progresses. Cellular responses to hormones include the production of proteins and enzymes and altered membrane permeability. Art Connections Figure Heat shock proteins (HSP) are so named because they help refold mis-folded proteins. In response to increased temperature (a “heat shock”), heat shock proteins are activated by release from the NR/HSP complex. At the same time, transcription of HSP genes is activated. Why do you think the cell responds to a heat shock by increasing the activity of proteins that help refold misfolded proteins? Hint: Figure Proteins unfold, or denature, at higher temperatures. Review Questions A new antagonist molecule has been discovered that binds to and blocks plasma membrane receptors. What effect will this antagonist have on testosterone, a steroid hormone? - It will block testosterone from binding to its receptor. - It will block testosterone from activating cAMP signaling. - It will increase testosterone-mediated signaling. - It will not affect testosterone-mediated signaling. Hint: D What effect will a cAMP inhibitor have on a peptide hormone-mediated signaling pathway? - It will prevent the hormone from binding its receptor. - It will prevent activation of a G-protein. - It will prevent activation of adenylate cyclase. - It will prevent activation of protein kinases. Hint: D Free Response Name two important functions of hormone receptors. Hint: The number of receptors that respond to a hormone can change, resulting in increased or decreased cell sensitivity. The number of receptors can increase in response to rising hormone levels, called up-regulation, making the cell more sensitive to the hormone and allowing for more cellular activity. The number of receptors can also decrease in response to rising hormone levels, called down-regulation, leading to reduced cellular activity. How can hormones mediate changes? Hint: Depending on the location of the protein receptor on the target cell and the chemical structure of the hormone, hormones can mediate changes directly by binding to intracellular receptors and modulating gene transcription, or indirectly by binding to cell surface receptors and stimulating signaling pathways.	oercommons	2025-03-18T00:37:17.499726	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15128/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15129/overview	Regulation of Body Processes Overview By the end of this section, you will be able to: - Explain how hormones regulate the excretory system - Discuss the role of hormones in the reproductive system - Describe how hormones regulate metabolism - Explain the role of hormones in different diseases Hormones have a wide range of effects and modulate many different body processes. The key regulatory processes that will be examined here are those affecting the excretory system, the reproductive system, metabolism, blood calcium concentrations, growth, and the stress response. Hormonal Regulation of the Excretory System Maintaining a proper water balance in the body is important to avoid dehydration or over-hydration (hyponatremia). The water concentration of the body is monitored by osmoreceptors in the hypothalamus, which detect the concentration of electrolytes in the extracellular fluid. The concentration of electrolytes in the blood rises when there is water loss caused by excessive perspiration, inadequate water intake, or low blood volume due to blood loss. An increase in blood electrolyte levels results in a neuronal signal being sent from the osmoreceptors in hypothalamic nuclei. The pituitary gland has two components: anterior and posterior. The anterior pituitary is composed of glandular cells that secrete protein hormones. The posterior pituitary is an extension of the hypothalamus. It is composed largely of neurons that are continuous with the hypothalamus. The hypothalamus produces a polypeptide hormone known as antidiuretic hormone (ADH), which is transported to and released from the posterior pituitary gland. The principal action of ADH is to regulate the amount of water excreted by the kidneys. As ADH (which is also known as vasopressin) causes direct water reabsorption from the kidney tubules, salts and wastes are concentrated in what will eventually be excreted as urine. The hypothalamus controls the mechanisms of ADH secretion, either by regulating blood volume or the concentration of water in the blood. Dehydration or physiological stress can cause an increase of osmolarity above 300 mOsm/L, which in turn, raises ADH secretion and water will be retained, causing an increase in blood pressure. ADH travels in the bloodstream to the kidneys. Once at the kidneys, ADH changes the kidneys to become more permeable to water by temporarily inserting water channels, aquaporins, into the kidney tubules. Water moves out of the kidney tubules through the aquaporins, reducing urine volume. The water is reabsorbed into the capillaries lowering blood osmolarity back toward normal. As blood osmolarity decreases, a negative feedback mechanism reduces osmoreceptor activity in the hypothalamus, and ADH secretion is reduced. ADH release can be reduced by certain substances, including alcohol, which can cause increased urine production and dehydration. Chronic underproduction of ADH or a mutation in the ADH receptor results in diabetes insipidus. If the posterior pituitary does not release enough ADH, water cannot be retained by the kidneys and is lost as urine. This causes increased thirst, but water taken in is lost again and must be continually consumed. If the condition is not severe, dehydration may not occur, but severe cases can lead to electrolyte imbalances due to dehydration. Another hormone responsible for maintaining electrolyte concentrations in extracellular fluids is aldosterone, a steroid hormone that is produced by the adrenal cortex. In contrast to ADH, which promotes the reabsorption of water to maintain proper water balance, aldosterone maintains proper water balance by enhancing Na+ reabsorption and K+ secretion from extracellular fluid of the cells in kidney tubules. Because it is produced in the cortex of the adrenal gland and affects the concentrations of minerals Na+ and K+, aldosterone is referred to as a mineralocorticoid, a corticosteroid that affects ion and water balance. Aldosterone release is stimulated by a decrease in blood sodium levels, blood volume, or blood pressure, or an increase in blood potassium levels. It also prevents the loss of Na+ from sweat, saliva, and gastric juice. The reabsorption of Na+ also results in the osmotic reabsorption of water, which alters blood volume and blood pressure. Aldosterone production can be stimulated by low blood pressure, which triggers a sequence of chemical release, as illustrated in Figure. When blood pressure drops, the renin-angiotensin-aldosterone system (RAAS) is activated. Cells in the juxtaglomerular apparatus, which regulates the functions of the nephrons of the kidney, detect this and release renin. Renin, an enzyme, circulates in the blood and reacts with a plasma protein produced by the liver called angiotensinogen. When angiotensinogen is cleaved by renin, it produces angiotensin I, which is then converted into angiotensin II in the lungs. Angiotensin II functions as a hormone and then causes the release of the hormone aldosterone by the adrenal cortex, resulting in increased Na+ reabsorption, water retention, and an increase in blood pressure. Angiotensin II in addition to being a potent vasoconstrictor also causes an increase in ADH and increased thirst, both of which help to raise blood pressure. Hormonal Regulation of the Reproductive System Regulation of the reproductive system is a process that requires the action of hormones from the pituitary gland, the adrenal cortex, and the gonads. During puberty in both males and females, the hypothalamus produces gonadotropin-releasing hormone (GnRH), which stimulates the production and release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland. These hormones regulate the gonads (testes in males and ovaries in females) and therefore are called gonadotropins. In both males and females, FSH stimulates gamete production and LH stimulates production of hormones by the gonads. An increase in gonad hormone levels inhibits GnRH production through a negative feedback loop. Regulation of the Male Reproductive System In males, FSH stimulates the maturation of sperm cells. FSH production is inhibited by the hormone inhibin, which is released by the testes. LH stimulates production of the sex hormones (androgens) by the interstitial cells of the testes and therefore is also called interstitial cell-stimulating hormone. The most widely known androgen in males is testosterone. Testosterone promotes the production of sperm and masculine characteristics. The adrenal cortex also produces small amounts of testosterone precursor, although the role of this additional hormone production is not fully understood. Everyday Connection The Dangers of Synthetic Hormones Some athletes attempt to boost their performance by using artificial hormones that enhance muscle performance. Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. Steroids are used to help build muscle mass. Other hormones that are used to enhance athletic performance include erythropoietin, which triggers the production of red blood cells, and human growth hormone, which can help in building muscle mass. Most performance enhancing drugs are illegal for non-medical purposes. They are also banned by national and international governing bodies including the International Olympic Committee, the U.S. Olympic Committee, the National Collegiate Athletic Association, the Major League Baseball, and the National Football League. The side effects of synthetic hormones are often significant and non-reversible, and in some cases, fatal. Androgens produce several complications such as liver dysfunctions and liver tumors, prostate gland enlargement, difficulty urinating, premature closure of epiphyseal cartilages, testicular atrophy, infertility, and immune system depression. The physiological strain caused by these substances is often greater than what the body can handle, leading to unpredictable and dangerous effects and linking their use to heart attacks, strokes, and impaired cardiac function. Regulation of the Female Reproductive System In females, FSH stimulates development of egg cells, called ova, which develop in structures called follicles. Follicle cells produce the hormone inhibin, which inhibits FSH production. LH also plays a role in the development of ova, induction of ovulation, and stimulation of estradiol and progesterone production by the ovaries, as illustrated in Figure. Estradiol and progesterone are steroid hormones that prepare the body for pregnancy. Estradiol produces secondary sex characteristics in females, while both estradiol and progesterone regulate the menstrual cycle. In addition to producing FSH and LH, the anterior portion of the pituitary gland also produces the hormone prolactin (PRL) in females. Prolactin stimulates the production of milk by the mammary glands following childbirth. Prolactin levels are regulated by the hypothalamic hormones prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH), which is now known to be dopamine. PRH stimulates the release of prolactin and PIH inhibits it. The posterior pituitary releases the hormone oxytocin, which stimulates uterine contractions during childbirth. The uterine smooth muscles are not very sensitive to oxytocin until late in pregnancy when the number of oxytocin receptors in the uterus peaks. Stretching of tissues in the uterus and cervix stimulates oxytocin release during childbirth. Contractions increase in intensity as blood levels of oxytocin rise via a positive feedback mechanism until the birth is complete. Oxytocin also stimulates the contraction of myoepithelial cells around the milk-producing mammary glands. As these cells contract, milk is forced from the secretory alveoli into milk ducts and is ejected from the breasts in milk ejection (“let-down”) reflex. Oxytocin release is stimulated by the suckling of an infant, which triggers the synthesis of oxytocin in the hypothalamus and its release into circulation at the posterior pituitary. Hormonal Regulation of Metabolism Blood glucose levels vary widely over the course of a day as periods of food consumption alternate with periods of fasting. Insulin and glucagon are the two hormones primarily responsible for maintaining homeostasis of blood glucose levels. Additional regulation is mediated by the thyroid hormones. Regulation of Blood Glucose Levels by Insulin and Glucagon Cells of the body require nutrients in order to function, and these nutrients are obtained through feeding. In order to manage nutrient intake, storing excess intake and utilizing reserves when necessary, the body uses hormones to moderate energy stores. Insulin is produced by the beta cells of the pancreas, which are stimulated to release insulin as blood glucose levels rise (for example, after a meal is consumed). Insulin lowers blood glucose levels by enhancing the rate of glucose uptake and utilization by target cells, which use glucose for ATP production. It also stimulates the liver to convert glucose to glycogen, which is then stored by cells for later use. Insulin also increases glucose transport into certain cells, such as muscle cells and the liver. This results from an insulin-mediated increase in the number of glucose transporter proteins in cell membranes, which remove glucose from circulation by facilitated diffusion. As insulin binds to its target cell via insulin receptors and signal transduction, it triggers the cell to incorporate glucose transport proteins into its membrane. This allows glucose to enter the cell, where it can be used as an energy source. However, this does not occur in all cells: some cells, including those in the kidneys and brain, can access glucose without the use of insulin. Insulin also stimulates the conversion of glucose to fat in adipocytes and the synthesis of proteins. These actions mediated by insulin cause blood glucose concentrations to fall, called a hypoglycemic “low sugar” effect, which inhibits further insulin release from beta cells through a negative feedback loop. Link to Learning This animation describe the role of insulin and the pancreas in diabetes. Impaired insulin function can lead to a condition called diabetes mellitus, the main symptoms of which are illustrated in Figure. This can be caused by low levels of insulin production by the beta cells of the pancreas, or by reduced sensitivity of tissue cells to insulin. This prevents glucose from being absorbed by cells, causing high levels of blood glucose, or hyperglycemia (high sugar). High blood glucose levels make it difficult for the kidneys to recover all the glucose from nascent urine, resulting in glucose being lost in urine. High glucose levels also result in less water being reabsorbed by the kidneys, causing high amounts of urine to be produced; this may result in dehydration. Over time, high blood glucose levels can cause nerve damage to the eyes and peripheral body tissues, as well as damage to the kidneys and cardiovascular system. Oversecretion of insulin can cause hypoglycemia, low blood glucose levels. This causes insufficient glucose availability to cells, often leading to muscle weakness, and can sometimes cause unconsciousness or death if left untreated. When blood glucose levels decline below normal levels, for example between meals or when glucose is utilized rapidly during exercise, the hormone glucagon is released from the alpha cells of the pancreas. Glucagon raises blood glucose levels, eliciting what is called a hyperglycemic effect, by stimulating the breakdown of glycogen to glucose in skeletal muscle cells and liver cells in a process called glycogenolysis. Glucose can then be utilized as energy by muscle cells and released into circulation by the liver cells. Glucagon also stimulates absorption of amino acids from the blood by the liver, which then converts them to glucose. This process of glucose synthesis is called gluconeogenesis. Glucagon also stimulates adipose cells to release fatty acids into the blood. These actions mediated by glucagon result in an increase in blood glucose levels to normal homeostatic levels. Rising blood glucose levels inhibit further glucagon release by the pancreas via a negative feedback mechanism. In this way, insulin and glucagon work together to maintain homeostatic glucose levels, as shown in Figure. Art Connection Pancreatic tumors may cause excess secretion of glucagon. Type I diabetes results from the failure of the pancreas to produce insulin. Which of the following statement about these two conditions is true? - A pancreatic tumor and type I diabetes will have the opposite effects on blood sugar levels. - A pancreatic tumor and type I diabetes will both cause hyperglycemia. - A pancreatic tumor and type I diabetes will both cause hypoglycemia. - Both pancreatic tumors and type I diabetes result in the inability of cells to take up glucose. Regulation of Blood Glucose Levels by Thyroid Hormones The basal metabolic rate, which is the amount of calories required by the body at rest, is determined by two hormones produced by the thyroid gland: thyroxine, also known as tetraiodothyronine or T4, and triiodothyronine, also known as T3. These hormones affect nearly every cell in the body except for the adult brain, uterus, testes, blood cells, and spleen. They are transported across the plasma membrane of target cells and bind to receptors on the mitochondria resulting in increased ATP production. In the nucleus, T3 and T4 activate genes involved in energy production and glucose oxidation. This results in increased rates of metabolism and body heat production, which is known as the hormone’s calorigenic effect. T3 and T4 release from the thyroid gland is stimulated by thyroid-stimulating hormone (TSH), which is produced by the anterior pituitary. TSH binding at the receptors of the follicle of the thyroid triggers the production of T3 and T4 from a glycoprotein called thyroglobulin. Thyroglobulin is present in the follicles of the thyroid, and is converted into thyroid hormones with the addition of iodine. Iodine is formed from iodide ions that are actively transported into the thyroid follicle from the bloodstream. A peroxidase enzyme then attaches the iodine to the tyrosine amino acid found in thyroglobulin. T3 has three iodine ions attached, while T4 has four iodine ions attached. T3 and T4 are then released into the bloodstream, with T4 being released in much greater amounts than T3. As T3 is more active than T4 and is responsible for most of the effects of thyroid hormones, tissues of the body convert T4 to T3 by the removal of an iodine ion. Most of the released T3 and T4 becomes attached to transport proteins in the bloodstream and is unable to cross the plasma membrane of cells. These protein-bound molecules are only released when blood levels of the unattached hormone begin to decline. In this way, a week’s worth of reserve hormone is maintained in the blood. Increased T3 and T4 levels in the blood inhibit the release of TSH, which results in lower T3 and T4 release from the thyroid. The follicular cells of the thyroid require iodides (anions of iodine) in order to synthesize T3 and T4. Iodides obtained from the diet are actively transported into follicle cells resulting in a concentration that is approximately 30 times higher than in blood. The typical diet in North America provides more iodine than required due to the addition of iodide to table salt. Inadequate iodine intake, which occurs in many developing countries, results in an inability to synthesize T3 and T4 hormones. The thyroid gland enlarges in a condition called goiter, which is caused by overproduction of TSH without the formation of thyroid hormone. Thyroglobulin is contained in a fluid called colloid, and TSH stimulation results in higher levels of colloid accumulation in the thyroid. In the absence of iodine, this is not converted to thyroid hormone, and colloid begins to accumulate more and more in the thyroid gland, leading to goiter. Disorders can arise from both the underproduction and overproduction of thyroid hormones. Hypothyroidism, underproduction of the thyroid hormones, can cause a low metabolic rate leading to weight gain, sensitivity to cold, and reduced mental activity, among other symptoms. In children, hypothyroidism can cause cretinism, which can lead to mental retardation and growth defects. Hyperthyroidism, the overproduction of thyroid hormones, can lead to an increased metabolic rate and its effects: weight loss, excess heat production, sweating, and an increased heart rate. Graves’ disease is one example of a hyperthyroid condition. Hormonal Control of Blood Calcium Levels Regulation of blood calcium concentrations is important for generation of muscle contractions and nerve impulses, which are electrically stimulated. If calcium levels get too high, membrane permeability to sodium decreases and membranes become less responsive. If calcium levels get too low, membrane permeability to sodium increases and convulsions or muscle spasms can result. Blood calcium levels are regulated by parathyroid hormone (PTH), which is produced by the parathyroid glands, as illustrated in Figure. PTH is released in response to low blood Ca2+ levels. PTH increases Ca2+ levels by targeting the skeleton, the kidneys, and the intestine. In the skeleton, PTH stimulates osteoclasts, which causes bone to be reabsorbed, releasing Ca2+ from bone into the blood. PTH also inhibits osteoblasts, reducing Ca2+ deposition in bone. In the intestines, PTH increases dietary Ca2+ absorption, and in the kidneys, PTH stimulates reabsorption of the CA2+. While PTH acts directly on the kidneys to increase Ca2+ reabsorption, its effects on the intestine are indirect. PTH triggers the formation of calcitriol, an active form of vitamin D, which acts on the intestines to increase absorption of dietary calcium. PTH release is inhibited by rising blood calcium levels. Hyperparathyroidism results from an overproduction of parathyroid hormone. This results in excessive calcium being removed from bones and introduced into blood circulation, producing structural weakness of the bones, which can lead to deformation and fractures, plus nervous system impairment due to high blood calcium levels. Hypoparathyroidism, the underproduction of PTH, results in extremely low levels of blood calcium, which causes impaired muscle function and may result in tetany (severe sustained muscle contraction). The hormone calcitonin, which is produced by the parafollicular or C cells of the thyroid, has the opposite effect on blood calcium levels as does PTH. Calcitonin decreases blood calcium levels by inhibiting osteoclasts, stimulating osteoblasts, and stimulating calcium excretion by the kidneys. This results in calcium being added to the bones to promote structural integrity. Calcitonin is most important in children (when it stimulates bone growth), during pregnancy (when it reduces maternal bone loss), and during prolonged starvation (because it reduces bone mass loss). In healthy nonpregnant, unstarved adults, the role of calcitonin is unclear. Hormonal Regulation of Growth Hormonal regulation is required for the growth and replication of most cells in the body. Growth hormone (GH), produced by the anterior portion of the pituitary gland, accelerates the rate of protein synthesis, particularly in skeletal muscle and bones. Growth hormone has direct and indirect mechanisms of action. The first direct action of GH is stimulation of triglyceride breakdown (lipolysis) and release into the blood by adipocytes. This results in a switch by most tissues from utilizing glucose as an energy source to utilizing fatty acids. This process is called a glucose-sparing effect. In another direct mechanism, GH stimulates glycogen breakdown in the liver; the glycogen is then released into the blood as glucose. Blood glucose levels increase as most tissues are utilizing fatty acids instead of glucose for their energy needs. The GH mediated increase in blood glucose levels is called a diabetogenic effect because it is similar to the high blood glucose levels seen in diabetes mellitus. The indirect mechanism of GH action is mediated by insulin-like growth factors (IGFs) or somatomedins, which are a family of growth-promoting proteins produced by the liver, which stimulates tissue growth. IGFs stimulate the uptake of amino acids from the blood, allowing the formation of new proteins, particularly in skeletal muscle cells, cartilage cells, and other target cells, as shown in Figure. This is especially important after a meal, when glucose and amino acid concentration levels are high in the blood. GH levels are regulated by two hormones produced by the hypothalamus. GH release is stimulated by growth hormone-releasing hormone (GHRH) and is inhibited by growth hormone-inhibiting hormone (GHIH), also called somatostatin. A balanced production of growth hormone is critical for proper development. Underproduction of GH in adults does not appear to cause any abnormalities, but in children it can result in pituitary dwarfism, in which growth is reduced. Pituitary dwarfism is characterized by symmetric body formation. In some cases, individuals are under 30 inches in height. Oversecretion of growth hormone can lead to gigantism in children, causing excessive growth. In some documented cases, individuals can reach heights of over eight feet. In adults, excessive GH can lead to acromegaly, a condition in which there is enlargement of bones in the face, hands, and feet that are still capable of growth. Hormonal Regulation of Stress When a threat or danger is perceived, the body responds by releasing hormones that will ready it for the “fight-or-flight” response. The effects of this response are familiar to anyone who has been in a stressful situation: increased heart rate, dry mouth, and hair standing up. Evolution Connection Fight-or-Flight ResponseInteractions of the endocrine hormones have evolved to ensure the body’s internal environment remains stable. Stressors are stimuli that disrupt homeostasis. The sympathetic division of the vertebrate autonomic nervous system has evolved the fight-or-flight response to counter stress-induced disruptions of homeostasis. In the initial alarm phase, the sympathetic nervous system stimulates an increase in energy levels through increased blood glucose levels. This prepares the body for physical activity that may be required to respond to stress: to either fight for survival or to flee from danger. However, some stresses, such as illness or injury, can last for a long time. Glycogen reserves, which provide energy in the short-term response to stress, are exhausted after several hours and cannot meet long-term energy needs. If glycogen reserves were the only energy source available, neural functioning could not be maintained once the reserves became depleted due to the nervous system’s high requirement for glucose. In this situation, the body has evolved a response to counter long-term stress through the actions of the glucocorticoids, which ensure that long-term energy requirements can be met. The glucocorticoids mobilize lipid and protein reserves, stimulate gluconeogenesis, conserve glucose for use by neural tissue, and stimulate the conservation of salts and water. The mechanisms to maintain homeostasis that are described here are those observed in the human body. However, the fight-or-flight response exists in some form in all vertebrates. The sympathetic nervous system regulates the stress response via the hypothalamus. Stressful stimuli cause the hypothalamus to signal the adrenal medulla (which mediates short-term stress responses) via nerve impulses, and the adrenal cortex, which mediates long-term stress responses, via the hormone adrenocorticotropic hormone (ACTH), which is produced by the anterior pituitary. Short-term Stress Response When presented with a stressful situation, the body responds by calling for the release of hormones that provide a burst of energy. The hormones epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline) are released by the adrenal medulla. How do these hormones provide a burst of energy? Epinephrine and norepinephrine increase blood glucose levels by stimulating the liver and skeletal muscles to break down glycogen and by stimulating glucose release by liver cells. Additionally, these hormones increase oxygen availability to cells by increasing the heart rate and dilating the bronchioles. The hormones also prioritize body function by increasing blood supply to essential organs such as the heart, brain, and skeletal muscles, while restricting blood flow to organs not in immediate need, such as the skin, digestive system, and kidneys. Epinephrine and norepinephrine are collectively called catecholamines. Link to Learning Watch this Discovery Channel animation describing the flight-or-flight response. Long-term Stress Response Long-term stress response differs from short-term stress response. The body cannot sustain the bursts of energy mediated by epinephrine and norepinephrine for long times. Instead, other hormones come into play. In a long-term stress response, the hypothalamus triggers the release of ACTH from the anterior pituitary gland. The adrenal cortex is stimulated by ACTH to release steroid hormones called corticosteroids. Corticosteroids turn on transcription of certain genes in the nuclei of target cells. They change enzyme concentrations in the cytoplasm and affect cellular metabolism. There are two main corticosteroids: glucocorticoids such as cortisol, and mineralocorticoids such as aldosterone. These hormones target the breakdown of fat into fatty acids in the adipose tissue. The fatty acids are released into the bloodstream for other tissues to use for ATP production. The glucocorticoids primarily affect glucose metabolism by stimulating glucose synthesis. Glucocorticoids also have anti-inflammatory properties through inhibition of the immune system. For example, cortisone is used as an anti-inflammatory medication; however, it cannot be used long term as it increases susceptibility to disease due to its immune-suppressing effects. Mineralocorticoids function to regulate ion and water balance of the body. The hormone aldosterone stimulates the reabsorption of water and sodium ions in the kidney, which results in increased blood pressure and volume. Hypersecretion of glucocorticoids can cause a condition known as Cushing’s disease, characterized by a shifting of fat storage areas of the body. This can cause the accumulation of adipose tissue in the face and neck, and excessive glucose in the blood. Hyposecretion of the corticosteroids can cause Addison’s disease, which may result in bronzing of the skin, hypoglycemia, and low electrolyte levels in the blood. Section Summary Water levels in the body are controlled by antidiuretic hormone (ADH), which is produced in the hypothalamus and triggers the reabsorption of water by the kidneys. Underproduction of ADH can cause diabetes insipidus. Aldosterone, a hormone produced by the adrenal cortex of the kidneys, enhances Na+ reabsorption from the extracellular fluids and subsequent water reabsorption by diffusion. The renin-angiotensin-aldosterone system is one way that aldosterone release is controlled. The reproductive system is controlled by the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are produced by the pituitary gland. Gonadotropin release is controlled by the hypothalamic hormone gonadotropin-releasing hormone (GnRH). FSH stimulates the maturation of sperm cells in males and is inhibited by the hormone inhibin, while LH stimulates the production of the androgen testosterone. FSH stimulates egg maturation in females, while LH stimulates the production of estrogens and progesterone. Estrogens are a group of steroid hormones produced by the ovaries that trigger the development of secondary sex characteristics in females as well as control the maturation of the ova. In females, the pituitary also produces prolactin, which stimulates milk production after childbirth, and oxytocin, which stimulates uterine contraction during childbirth and milk let-down during suckling. Insulin is produced by the pancreas in response to rising blood glucose levels and allows cells to utilize blood glucose and store excess glucose for later use. Diabetes mellitus is caused by reduced insulin activity and causes high blood glucose levels, or hyperglycemia. Glucagon is released by the pancreas in response to low blood glucose levels and stimulates the breakdown of glycogen into glucose, which can be used by the body. The body’s basal metabolic rate is controlled by the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The anterior pituitary produces thyroid stimulating hormone (TSH), which controls the release of T3 and T4 from the thyroid gland. Iodine is necessary in the production of thyroid hormone, and the lack of iodine can lead to a condition called goiter. Parathyroid hormone (PTH) is produced by the parathyroid glands in response to low blood Ca2+ levels. The parafollicular cells of the thyroid produce calcitonin, which reduces blood Ca2+ levels. Growth hormone (GH) is produced by the anterior pituitary and controls the growth rate of muscle and bone. GH action is indirectly mediated by insulin-like growth factors (IGFs). Short-term stress causes the hypothalamus to trigger the adrenal medulla to release epinephrine and norepinephrine, which trigger the fight or flight response. Long-term stress causes the hypothalamus to trigger the anterior pituitary to release adrenocorticotropic hormone (ACTH), which causes the release of corticosteroids, glucocorticoids, and mineralocorticoids, from the adrenal cortex. Art Connections Figure Pancreatic tumors may cause excess secretion of glucagon. Type I diabetes results from the failure of the pancreas to produce insulin. Which of the following statement about these two conditions is true? - A pancreatic tumor and type I diabetes will have the opposite effects on blood sugar levels. - A pancreatic tumor and type I diabetes will both cause hyperglycemia. - A pancreatic tumor and type I diabetes will both cause hypoglycemia. - Both pancreatic tumors and type I diabetes result in the inability of cells to take up glucose. Hint: Figure B Review Questions Drinking alcoholic beverages causes an increase in urine output. This most likely occurs because alcohol: - inhibits ADH release - stimulates ADH release - inhibits TSH release - stimulates TSH release Hint: A FSH and LH release from the anterior pituitary is stimulated by ________. - TSH - GnRH - T3 - PTH Hint: B What hormone is produced by beta cells of the pancreas? - T3 - glucagon - insulin - T4 Hint: C When blood calcium levels are low, PTH stimulates: - excretion of calcium from the kidneys - excretion of calcium from the intestines - osteoblasts - osteoclasts Hint: D Free Response Name and describe a function of one hormone produced by the anterior pituitary and one hormone produced by the posterior pituitary. Hint: In addition to producing FSH and LH, the anterior pituitary also produces the hormone prolactin (PRL) in females. Prolactin stimulates the production of milk by the mammary glands following childbirth. Prolactin levels are regulated by the hypothalamic hormones prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH) which is now known to be dopamine. PRH stimulates the release of prolactin and PIH inhibits it. The posterior pituitary releases the hormone oxytocin, which stimulates contractions during childbirth. The uterine smooth muscles are not very sensitive to oxytocin until late in pregnancy when the number of oxytocin receptors in the uterus peaks. Stretching of tissues in the uterus and vagina stimulates oxytocin release in childbirth. Contractions increase in intensity as blood levels of oxytocin rise until the birth is complete. Describe one direct action of growth hormone (GH). Hint: Hormonal regulation is required for the growth and replication of most cells in the body. Growth hormone (GH), produced by the anterior pituitary, accelerates the rate of protein synthesis, particularly in skeletal muscles and bones. Growth hormone has direct and indirect mechanisms of action. The direct actions of GH include: 1) stimulation of fat breakdown (lipolysis) and release into the blood by adipocytes. This results in a switch by most tissues from utilizing glucose as an energy source to utilizing fatty acids. This process is called a glucose-sparing effect. 2) In the liver, GH stimulates glycogen breakdown, which is then released into the blood as glucose. Blood glucose levels increase as most tissues are utilizing fatty acids instead of glucose for their energy needs. The GH mediated increase in blood glucose levels is called a diabetogenic effect because it is similar to the high blood glucose levels seen in diabetes mellitus.	oercommons	2025-03-18T00:37:17.544746	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15129/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15130/overview	Regulation of Hormone Production Overview By the end of this section, you will be able to: - Explain how hormone production is regulated - Discuss the different stimuli that control hormone levels in the body Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus elicits the release of a substance; once the substance reaches a certain level, it sends a signal that stops further release of the substance. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood then give feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland, as illustrated in Figure. There are three mechanisms by which endocrine glands are stimulated to synthesize and release hormones: humoral stimuli, hormonal stimuli, and neural stimuli. Art Connection Hyperthyroidism is a condition in which the thyroid gland is overactive. Hypothyroidism is a condition in which the thyroid gland is underactive. Which of the conditions are the following two patients most likely to have? Patient A has symptoms including weight gain, cold sensitivity, low heart rate and fatigue. Patient B has symptoms including weight loss, profuse sweating, increased heart rate and difficulty sleeping. Humoral Stimuli The term “humoral” is derived from the term “humor,” which refers to bodily fluids such as blood. A humoral stimulus refers to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood. For example, a rise in blood glucose levels triggers the pancreatic release of insulin. Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop. Hormonal Stimuli Hormonal stimuli refers to the release of a hormone in response to another hormone. A number of endocrine glands release hormones when stimulated by hormones released by other endocrine glands. For example, the hypothalamus produces hormones that stimulate the anterior portion of the pituitary gland. The anterior pituitary in turn releases hormones that regulate hormone production by other endocrine glands. The anterior pituitary releases the thyroid-stimulating hormone, which then stimulates the thyroid gland to produce the hormones T3 and T4. As blood concentrations of T3 and T4 rise, they inhibit both the pituitary and the hypothalamus in a negative feedback loop. Neural Stimuli In some cases, the nervous system directly stimulates endocrine glands to release hormones, which is referred to as neural stimuli. Recall that in a short-term stress response, the hormones epinephrine and norepinephrine are important for providing the bursts of energy required for the body to respond. Here, neuronal signaling from the sympathetic nervous system directly stimulates the adrenal medulla to release the hormones epinephrine and norepinephrine in response to stress. Section Summary Hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its further release. The three mechanisms of hormonal release are humoral stimuli, hormonal stimuli, and neural stimuli. Humoral stimuli refers to the control of hormonal release in response to changes in extracellular fluid levels or ion levels. Hormonal stimuli refers to the release of hormones in response to hormones released by other endocrine glands. Neural stimuli refers to the release of hormones in response to neural stimulation. Art Connections Figure Hyperthyroidism is a condition in which the thyroid gland is overactive. Hypothyroidism is a condition in which the thyroid gland is underactive. Which of the conditions are the following two patients most likely to have? Patient A has symptoms including weight gain, cold sensitivity, low heart rate and fatigue. Patient B has symptoms including weight loss, profuse sweating, increased heart rate and difficulty sleeping. Hint: Figure Patient A has symptoms associated with decreased metabolism, and may be suffering from hypothyroidism. Patient B has symptoms associated with increased metabolism, and may be suffering from hyperthyroidism. Review Questions A rise in blood glucose levels triggers release of insulin from the pancreas. This mechanism of hormone production is stimulated by: - humoral stimuli - hormonal stimuli - neural stimuli - negative stimuli Hint: A Which mechanism of hormonal stimulation would be affected if signaling and hormone release from the hypothalamus was blocked? - humoral and hormonal stimuli - hormonal and neural stimuli - neural and humoral stimuli - hormonal and negative stimuli Hint: B Free Response How is hormone production and release primarily controlled? Hint: Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects then inhibit further release. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood then feed back to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Compare and contrast hormonal and humoral stimuli. Hint: The term humoral is derived from the term humor, which refers to bodily fluids such as blood. Humoral stimuli refer to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood. For example, a rise in blood glucose levels triggers the pancreatic release of insulin. Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop. Hormonal stimuli refer to the release of a hormone in response to another hormone. A number of endocrine glands release hormones when stimulated by hormones released by other endocrine organs. For example, the hypothalamus produces hormones that stimulate the anterior pituitary. The anterior pituitary in turn releases hormones that regulate hormone production by other endocrine glands. For example, the anterior pituitary releases thyroid-stimulating hormone, which stimulates the thyroid gland to produce the hormones T3 and T4. As blood concentrations of T3 and T4 rise they inhibit both the pituitary and the hypothalamus in a negative feedback loop.	oercommons	2025-03-18T00:37:17.570779	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15130/overview", "title": "Biology, Animal Structure and Function", "author": null }
https://oercommons.org/courseware/lesson/15131/overview	Endocrine Glands Overview By the end of this section, you will be able to: - Describe the role of different glands in the endocrine system - Explain how the different glands work together to maintain homeostasis Both the endocrine and nervous systems use chemical signals to communicate and regulate the body's physiology. The endocrine system releases hormones that act on target cells to regulate development, growth, energy metabolism, reproduction, and many behaviors. The nervous system releases neurotransmitters or neurohormones that regulate neurons, muscle cells, and endocrine cells. Because the neurons can regulate the release of hormones, the nervous and endocrine systems work in a coordinated manner to regulate the body's physiology. Hypothalamic-Pituitary Axis The hypothalamus in vertebrates integrates the endocrine and nervous systems. The hypothalamus is an endocrine organ located in the diencephalon of the brain. It receives input from the body and other brain areas and initiates endocrine responses to environmental changes. The hypothalamus acts as an endocrine organ, synthesizing hormones and transporting them along axons to the posterior pituitary gland. It synthesizes and secretes regulatory hormones that control the endocrine cells in the anterior pituitary gland. The hypothalamus contains autonomic centers that control endocrine cells in the adrenal medulla via neuronal control. The pituitary gland, sometimes called the hypophysis or “master gland” is located at the base of the brain in the sella turcica, a groove of the sphenoid bone of the skull, illustrated in Figure. It is attached to the hypothalamus via a stalk called the pituitary stalk (or infundibulum). The anterior portion of the pituitary gland is regulated by releasing or release-inhibiting hormones produced by the hypothalamus, and the posterior pituitary receives signals via neurosecretory cells to release hormones produced by the hypothalamus. The pituitary has two distinct regions—the anterior pituitary and the posterior pituitary—which between them secrete nine different peptide or protein hormones. The posterior lobe of the pituitary gland contains axons of the hypothalamic neurons. Anterior Pituitary The anterior pituitary gland, or adenohypophysis, is surrounded by a capillary network that extends from the hypothalamus, down along the infundibulum, and to the anterior pituitary. This capillary network is a part of the hypophyseal portal system that carries substances from the hypothalamus to the anterior pituitary and hormones from the anterior pituitary into the circulatory system. A portal system carries blood from one capillary network to another; therefore, the hypophyseal portal system allows hormones produced by the hypothalamus to be carried directly to the anterior pituitary without first entering the circulatory system. The anterior pituitary produces seven hormones: growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), melanin-stimulating hormone (MSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Anterior pituitary hormones are sometimes referred to as tropic hormones, because they control the functioning of other organs. While these hormones are produced by the anterior pituitary, their production is controlled by regulatory hormones produced by the hypothalamus. These regulatory hormones can be releasing hormones or inhibiting hormones, causing more or less of the anterior pituitary hormones to be secreted. These travel from the hypothalamus through the hypophyseal portal system to the anterior pituitary where they exert their effect. Negative feedback then regulates how much of these regulatory hormones are released and how much anterior pituitary hormone is secreted. Posterior Pituitary The posterior pituitary is significantly different in structure from the anterior pituitary. It is a part of the brain, extending down from the hypothalamus, and contains mostly nerve fibers and neuroglial cells, which support axons that extend from the hypothalamus to the posterior pituitary. The posterior pituitary and the infundibulum together are referred to as the neurohypophysis. The hormones antidiuretic hormone (ADH), also known as vasopressin, and oxytocin are produced by neurons in the hypothalamus and transported within these axons along the infundibulum to the posterior pituitary. They are released into the circulatory system via neural signaling from the hypothalamus. These hormones are considered to be posterior pituitary hormones, even though they are produced by the hypothalamus, because that is where they are released into the circulatory system. The posterior pituitary itself does not produce hormones, but instead stores hormones produced by the hypothalamus and releases them into the blood stream. Thyroid Gland The thyroid gland is located in the neck, just below the larynx and in front of the trachea, as shown in Figure. It is a butterfly-shaped gland with two lobes that are connected by the isthmus. It has a dark red color due to its extensive vascular system. When the thyroid swells due to dysfunction, it can be felt under the skin of the neck. The thyroid gland is made up of many spherical thyroid follicles, which are lined with a simple cuboidal epithelium. These follicles contain a viscous fluid, called colloid, which stores the glycoprotein thyroglobulin, the precursor to the thyroid hormones. The follicles produce hormones that can be stored in the colloid or released into the surrounding capillary network for transport to the rest of the body via the circulatory system. Thyroid follicle cells synthesize the hormone thyroxine, which is also known as T4 because it contains four atoms of iodine, and triiodothyronine, also known as T3 because it contains three atoms of iodine. Follicle cells are stimulated to release stored T3 and T4 by thyroid stimulating hormone (TSH), which is produced by the anterior pituitary. These thyroid hormones increase the rates of mitochondrial ATP production. A third hormone, calcitonin, is produced by parafollicular cells of the thyroid either releasing hormones or inhibiting hormones. Calcitonin release is not controlled by TSH, but instead is released when calcium ion concentrations in the blood rise. Calcitonin functions to help regulate calcium concentrations in body fluids. It acts in the bones to inhibit osteoclast activity and in the kidneys to stimulate excretion of calcium. The combination of these two events lowers body fluid levels of calcium. Parathyroid Glands Most people have four parathyroid glands; however, the number can vary from two to six. These glands are located on the posterior surface of the thyroid gland, as shown in Figure. Normally, there is a superior gland and an inferior gland associated with each of the thyroid’s two lobes. Each parathyroid gland is covered by connective tissue and contains many secretory cells that are associated with a capillary network. The parathyroid glands produce parathyroid hormone (PTH). PTH increases blood calcium concentrations when calcium ion levels fall below normal. PTH (1) enhances reabsorption of Ca2+ by the kidneys, (2) stimulates osteoclast activity and inhibits osteoblast activity, and (3) it stimulates synthesis and secretion of calcitriol by the kidneys, which enhances Ca2+ absorption by the digestive system. PTH is produced by chief cells of the parathyroid. PTH and calcitonin work in opposition to one another to maintain homeostatic Ca2+ levels in body fluids. Another type of cells, oxyphil cells, exist in the parathyroid but their function is not known. These hormones encourage bone growth, muscle mass, and blood cell formation in children and women. Adrenal Glands The adrenal glands are associated with the kidneys; one gland is located on top of each kidney as illustrated in Figure. The adrenal glands consist of an outer adrenal cortex and an inner adrenal medulla. These regions secrete different hormones. Adrenal Cortex The adrenal cortex is made up of layers of epithelial cells and associated capillary networks. These layers form three distinct regions: an outer zona glomerulosa that produces mineralocorticoids, a middle zona fasciculata that produces glucocorticoids, and an inner zona reticularis that produces androgens. The main mineralocorticoid is aldosterone, which regulates the concentration of Na+ ions in urine, sweat, pancreas, and saliva. Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or by an increase in blood potassium levels. The three main glucocorticoids are cortisol, corticosterone, and cortisone. The glucocorticoids stimulate the synthesis of glucose and gluconeogenesis (converting a non-carbohydrate to glucose) by liver cells and they promote the release of fatty acids from adipose tissue. These hormones increase blood glucose levels to maintain levels within a normal range between meals. These hormones are secreted in response to ACTH and levels are regulated by negative feedback. Androgens are sex hormones that promote masculinity. They are produced in small amounts by the adrenal cortex in both males and females. They do not affect sexual characteristics and may supplement sex hormones released from the gonads. Adrenal Medulla The adrenal medulla contains large, irregularly shaped cells that are closely associated with blood vessels. These cells are innervated by preganglionic autonomic nerve fibers from the central nervous system. The adrenal medulla contains two types of secretory cells: one that produces epinephrine (adrenaline) and another that produces norepinephrine (noradrenaline). Epinephrine is the primary adrenal medulla hormone accounting for 75 to 80 percent of its secretions. Epinephrine and norepinephrine increase heart rate, breathing rate, cardiac muscle contractions, blood pressure, and blood glucose levels. They also accelerate the breakdown of glucose in skeletal muscles and stored fats in adipose tissue. The release of epinephrine and norepinephrine is stimulated by neural impulses from the sympathetic nervous system. Secretion of these hormones is stimulated by acetylcholine release from preganglionic sympathetic fibers innervating the adrenal medulla. These neural impulses originate from the hypothalamus in response to stress to prepare the body for the fight-or-flight response. Pancreas The pancreas, illustrated in Figure, is an elongated organ that is located between the stomach and the proximal portion of the small intestine. It contains both exocrine cells that excrete digestive enzymes and endocrine cells that release hormones. It is sometimes referred to as a heterocrine gland because it has both endocrine and exocrine functions. The endocrine cells of the pancreas form clusters called pancreatic islets or the islets of Langerhans, as visible in the micrograph shown in Figure. The pancreatic islets contain two primary cell types: alpha cells, which produce the hormone glucagon, and beta cells, which produce the hormone insulin. These hormones regulate blood glucose levels. As blood glucose levels decline, alpha cells release glucagon to raise the blood glucose levels by increasing rates of glycogen breakdown and glucose release by the liver. When blood glucose levels rise, such as after a meal, beta cells release insulin to lower blood glucose levels by increasing the rate of glucose uptake in most body cells, and by increasing glycogen synthesis in skeletal muscles and the liver. Together, glucagon and insulin regulate blood glucose levels. Pineal Gland The pineal gland produces melatonin. The rate of melatonin production is affected by the photoperiod. Collaterals from the visual pathways innervate the pineal gland. During the day photoperiod, little melatonin is produced; however, melatonin production increases during the dark photoperiod (night). In some mammals, melatonin has an inhibitory affect on reproductive functions by decreasing production and maturation of sperm, oocytes, and reproductive organs. Melatonin is an effective antioxidant, protecting the CNS from free radicals such as nitric oxide and hydrogen peroxide. Lastly, melatonin is involved in biological rhythms, particularly circadian rhythms such as the sleep-wake cycle and eating habits. Gonads The gonads—the male testes and female ovaries—produce steroid hormones. The testes produce androgens, testosterone being the most prominent, which allow for the development of secondary sex characteristics and the production of sperm cells. The ovaries produce estradiol and progesterone, which cause secondary sex characteristics and prepare the body for childbirth. \| Endocrine Glands and their Associated Hormones \| \|\| \|---\|---\|---\| \| Endocrine Gland \| Associated Hormones \| Effect \| \| Hypothalamus \| releasing and inhibiting hormones \| regulate hormone release from pituitary gland; produce oxytocin; produce uterine contractions and milk secretion in females \| \| antidiuretic hormone (ADH) \| water reabsorption from kidneys; vasoconstriction to increase blood pressure \| \| \| Pituitary (Anterior) \| growth hormone (GH) \| promotes growth of body tissues, protein synthesis; metabolic functions \| \| prolactin (PRL) \| promotes milk production \| \| \| thyroid stimulating hormone (TSH) \| stimulates thyroid hormone release \| \| \| adrenocorticotropic hormone (ACTH) \| stimulates hormone release by adrenal cortex, glucocorticoids \| \| \| follicle-stimulating hormone (FSH) \| stimulates gamete production (both ova and sperm); secretion of estradiol \| \| \| luteinizing hormone (LH) \| stimulates androgen production by gonads; ovulation, secretion of progesterone \| \| \| melanocyte-stimulating hormone (MSH) \| stimulates melanocytes of the skin increasing melanin pigment production. \| \| \| Pituitary (Posterior) \| antidiuretic hormone (ADH) \| stimulates water reabsorption by kidneys \| \| oxytocin \| stimulates uterine contractions during childbirth; milk ejection; stimulates ductus deferens and prostate gland contraction during emission \| \| \| Thyroid \| thyroxine, triiodothyronine \| stimulate and maintain metabolism; growth and development \| \| calcitonin \| reduces blood Ca2+ levels \| \| \| Parathyroid \| parathyroid hormone (PTH) \| increases blood Ca2+ levels \| \| Adrenal (Cortex) \| aldosterone \| increases blood Na+ levels; increase K+ secretion \| \| cortisol, corticosterone, cortisone \| increase blood glucose levels; anti-inflammatory effects \| \| \| Adrenal (Medulla) \| epinephrine, norepinephrine \| stimulate fight-or-flight response; increase blood gluclose levels; increase metabolic activities \| \| Pancreas \| insulin \| reduces blood glucose levels \| \| glucagon \| increases blood glucose levels \| \| \| Pineal gland \| melatonin \| regulates some biological rhythms and protects CNS from free radicals \| \| Testes \| androgens \| regulate, promote, increase or maintain sperm production; male secondary sexual characteristics \| \| Ovaries \| estrogen \| promotes uterine lining growth; female secondary sexual characteristics \| \| progestins \| promote and maintain uterine lining growth \| Organs with Secondary Endocrine Functions There are several organs whose primary functions are non-endocrine but that also possess endocrine functions. These include the heart, kidneys, intestines, thymus, gonads, and adipose tissue. The heart possesses endocrine cells in the walls of the atria that are specialized cardiac muscle cells. These cells release the hormone atrial natriuretic peptide (ANP) in response to increased blood volume. High blood volume causes the cells to be stretched, resulting in hormone release. ANP acts on the kidneys to reduce the reabsorption of Na+, causing Na+ and water to be excreted in the urine. ANP also reduces the amounts of renin released by the kidneys and aldosterone released by the adrenal cortex, further preventing the retention of water. In this way, ANP causes a reduction in blood volume and blood pressure, and reduces the concentration of Na+ in the blood. The gastrointestinal tract produces several hormones that aid in digestion. The endocrine cells are located in the mucosa of the GI tract throughout the stomach and small intestine. Some of the hormones produced include gastrin, secretin, and cholecystokinin, which are secreted in the presence of food, and some of which act on other organs such as the pancreas, gallbladder, and liver. They trigger the release of gastric juices, which help to break down and digest food in the GI tract. While the adrenal glands associated with the kidneys are major endocrine glands, the kidneys themselves also possess endocrine function. Renin is released in response to decreased blood volume or pressure and is part of the renin-angiotensin-aldosterone system that leads to the release of aldosterone. Aldosterone then causes the retention of Na+ and water, raising blood volume. The kidneys also release calcitriol, which aids in the absorption of Ca2+ and phosphate ions. Erythropoietin (EPO) is a protein hormone that triggers the formation of red blood cells in the bone marrow. EPO is released in response to low oxygen levels. Because red blood cells are oxygen carriers, increased production results in greater oxygen delivery throughout the body. EPO has been used by athletes to improve performance, as greater oxygen delivery to muscle cells allows for greater endurance. Because red blood cells increase the viscosity of blood, artificially high levels of EPO can cause severe health risks. The thymus is found behind the sternum; it is most prominent in infants, becoming smaller in size through adulthood. The thymus produces hormones referred to as thymosins, which contribute to the development of the immune response. Adipose tissue is a connective tissue found throughout the body. It produces the hormone leptin in response to food intake. Leptin increases the activity of anorexigenic neurons and decreases that of orexigenic neurons, producing a feeling of satiety after eating, thus affecting appetite and reducing the urge for further eating. Leptin is also associated with reproduction. It must be present for GnRH and gonadotropin synthesis to occur. Extremely thin females may enter puberty late; however, if adipose levels increase, more leptin will be produced, improving fertility. Section Summary The pituitary gland is located at the base of the brain and is attached to the hypothalamus by the infundibulum. The anterior pituitary receives products from the hypothalamus by the hypophyseal portal system and produces six hormones. The posterior pituitary is an extension of the brain and releases hormones (antidiuretic hormone and oxytocin) produced by the hypothalamus. The thyroid gland is located in the neck and is composed of two lobes connected by the isthmus. The thyroid is made up of follicle cells that produce the hormones thyroxine and triiodothyronine. Parafollicular cells of the thyroid produce calcitonin. The parathyroid glands lie on the posterior surface of the thyroid gland and produce parathyroid hormone. The adrenal glands are located on top of the kidneys and consist of the renal cortex and renal medulla. The adrenal cortex is the outer part of the adrenal gland and produces the corticosteroids, glucocorticoids, and mineralocorticoids. The adrenal medulla is the inner part of the adrenal gland and produces the catecholamines epinephrine and norepinephrine. The pancreas lies in the abdomen between the stomach and the small intestine. Clusters of endocrine cells in the pancreas form the islets of Langerhans, which are composed of alpha cells that release glucagon and beta cells that release insulin. Some organs possess endocrine activity as a secondary function but have another primary function. The heart produces the hormone atrial natriuretic peptide, which functions to reduce blood volume, pressure, and Na+ concentration. The gastrointestinal tract produces various hormones that aid in digestion. The kidneys produce renin, calcitriol, and erythropoietin. Adipose tissue produces leptin, which promotes satiety signals in the brain. Review Questions Which endocrine glands are associated with the kidneys? - thyroid glands - pituitary glands - adrenal glands - gonads Hint: C Which of the following hormones is not produced by the anterior pituitary? - oxytocin - growth hormone - prolactin - thyroid-stimulating hormone Hint: A Free Response What does aldosterone regulate, and how is it stimulated? Hint: The main mineralocorticoid is aldosterone, which regulates the concentration of ions in urine, sweat, and saliva. Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or an increase in blood potassium levels. The adrenal medulla contains two types of secretory cells, what are they and what are their functions? Hint: The adrenal medulla contains two types of secretory cells, one that produces epinephrine (adrenaline) and another that produces norepinephrine (noradrenaline). Epinephrine is the primary adrenal medulla hormone accounting for 75–80 percent of its secretions. Epinephrine and norepinephrine increase heart rate, breathing rate, cardiac muscle contractions, and blood glucose levels. They also accelerate the breakdown of glucose in skeletal muscles and stored fats in adipose tissue. The release of epinephrine and norepinephrine is stimulated by neural impulses from the sympathetic nervous system. These neural impulses originate from the hypothalamus in response to stress to prepare the body for the fight-or-flight response.	oercommons	2025-03-18T00:37:17.608965	null	{ "license": "Creative Commons - Attribution - https://creativecommons.org/licenses/by/4.0/", "url": "https://oercommons.org/courseware/lesson/15131/overview", "title": "Biology, Animal Structure and Function", "author": null }

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.