Endocrine System Unit

Anatomy & Physiology 1 and 2 are structured around the different organ systems of the body. The endocrine system is the first one we cover in Anatomy & Physiology 2, and takes about a week (covered in 2 class periods and one lab period lasting 2 hours each). As one of the two control systems in the body (besides the nervous) we come back to it again and again as we go through other systems it relates to.

Topic Objectives:

Students will be able to:

  • Compare and contrast the mechanisms of action of steroid hormones with peptide based hormones and give examples of each
  • Describe factors that increase or decrease the effects of hormones on target cells and what situations might trigger these factors
  • For the various human hormones, describe where they are made and released, their target cells, their major effects, and their relationships with other hormones
  • Describe causes, symptoms, and treatments for disorders caused by hormonal imbalances and relate symptoms to cellular processes influenced by hormones.

Learning Activities and Assessments

Day 1: After going over the syllabus, course policies, and introductions, we begin with an overview of how the endocrine system. This involves lecture combined with frequent questions out to the class. Students are provided with the topic objectives, a lecture outline and pictures on slides on Canvas. Many choose to print these out and take notes on them during class.

  1. After showing the topic objectives, I display a diagram showing all the endocrine glands. Students have already talked briefly about some of these (hypothalamus, pineal, pancreas), and I point to them and ask their name, what hormone they produce, and what that hormone does. We talk about the others and ensure everyone remembers the glands we’ve already covered.
  2. I use the Interactive Physiology program to show students how steroid hormones differ from peptide hormones. I remind them how this relates to the cellular transport mechanisms they learned about in Biol 160 (a prerequisite). They should have learned that steroids are lipids, and lipids dissolve in other lipids and can therefore get through cell membranes. Then I ask students to pair up and explain the major differences between steroid and peptide hormones to each other.
  3. I hand out the Hormone Pathways worksheet, and model how to do the first page, drawing solid arrows when one hormone stimulates a particular response, and dotted arrows when it inhibits a response. This gives students a good example of how some specific hormones (the thyroid hormones) act, and how different endocrine glands stimulate each other to produce new hormones in a pathway.

Prelab Homework: Students research particular hormones and their effects to fill out some questions and a table in their lab manual. They are expected to have this finished at the beginning of lab.

Day 2: Lab

  1. I walk around the room to check that everyone has finished their prelab assignments and answer any questions students have about particular problems.
  2. I go to the board to review 2 more of the hormone pathways from the Hormone Pathways worksheet. Students should be somewhat familiar with these hormones from their prelab. We focus on the concept of negative feedback and on what might happen if particular hormones are over- or under-secreted due to disease states.
  3. Students work in groups of 2 or 3 on a case study exercise from their lab manual. Each group works on all the case studies, but each group is also assigned to present their results to the class and draw the pathways involved on the board after about 45 minutes. Anatomical models are available on the tables so that students can visualize the glands involved in each pathway. I also get out a skull and brain model so they can see where the hypothalamus and pituitary gland fit in. I walk around as the groups are working and ask them helpful questions when needed to ensure no one gets too stuck.
  4. Each student group comes up to the board in turn and draws their hormone pathway, explaining how it relates to their assigned case, which particular part of the pathway is involved in the disease state, how that affects other parts of the pathway, and how it relates to the patient symptoms and possible treatments. Classmates get a chance to ask questions.

Day 3

  1. We begin by looking at the topic objectives again. At this point we’ve completely covered the first two, and parts of the other two. I ask the class questions related to the topic objectives to make sure that they got all the information and give them ideas about what to expect on next week’s quiz. Students have an opportunity to ask questions about the topic objectives we’ve covered so far and see what we have left.
  2. We go over the different types of relationships that can exist between hormones (antagonistic, synergistic, and permissive). I draw one of the remaining pathways from the Hormone Pathways Worksheet on the board, and ask students to identify which hormones in the pathway have one of the relationships we’ve just discussed.
  3. I divide students into groups, make sure each group has a couple of copies of the textbook, and ask them to use the book to find the answers to one of the remaining two pathways from the Hormone Pathways Worksheet and then draw the pathway on the board and explain it to the class. The other groups have to ask them questions in order to fill out the rest of their own worksheet. Here are some of the drawings students made in Spring 2016: 
  4. On the board, we make a list of disorders related to hormone over- or undersecretion, along with possible causes and symptoms. I try to make sure that students relate these causes and symptoms to cellular processes they already know about, so that they are not just memorizing a list of symptoms, but that they make sense in context. I ask the students to help make the list based on what they’ve learned in class and lab. If we have time, we’ll go back to the list of topic objectives at the end and make sure students can relate all the topic objectives back to specific things we’ve covered in class.

Homework: Students have to do the last page of the Hormone Pathways Worksheet themselves – this involves hormones they were exposed to during Anatomy & Physiology 1. They have a quiz over the endocrine system the following week.

How I Have Changed the Way I Teach This Unit

The way I teach this unit has changed drastically over the past year, because I noticed that students were having an especially hard time with the content, especially the individual hormones. It felt like students were memorizing the hormones in isolation rather than thinking about how groups of hormones interacted to produce the body’s overall response. Major changes I made include:

  • Scrapping a “Hormone List” worksheet that required students to list each hormone with its source, target, and effect, and creating a “Hormone Pathways” worksheet that asks students to fill in blanks in a paragraph describing interactions between multiple hormones, then draw the pathway in a space below.
  • Creating more deliberate opportunities for scaffolding and ramping up to more difficult types of formative assessment. Previously, I asked students to spend a long chunk of time working on their hormone list worksheet in class with textbooks and small groups while I walked around, and then we went over the answers as a class. I recognized that this wasn’t helping me to accurately assess how well prepared students were for the quiz, so I broke the material and activities into smaller chunks. I provided more support and modeling during the earlier activities, and ramped up to having students work more independently and explaining their findings to classmates in the later activities.
  • In order to have enough time for more formative assessment in class, I asked students to research some of the hormones on their own for a prelab exercise and fill in the last page of the Hormone Pathways Worksheet on their own.

I do not yet have enough data to show whether the changes I’ve made have significantly impacted students’ quiz and exam scores for this unit, but the students seem far less confused about how hormones interact in groups and how hormonal signalling in cells can lead to whole-body changes and disease states.