Dining with Snakes: A Comparison Between Snakes and Human Digestion

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– To present the diversity of anatomical and physiological systems (comparative anatomy)

– To examine the structure and function relationship in the digestive system

Activity Description: In class, students watch a short video of a snake eating. They may or may not have already read an assigned article associated with this too. Students make observations about how a snake eats differently from humans and thus how its anatomy differs.

Time Needed: 15 minute class discussion (may be more in-depth if students have read the article attached)

Materials Needed: Video, notecards, and the guided reading worksheet that accompanies the “Dining with Snakes” reading

Activity Instructions:

1. Assign students the “Dining with Snakes” article and guided reading questions. The guided reading questions are meant to keep them actively engaged with the reading assignment. (If you choose not to assign the article, you can still use the activity as a quick lecture launcher.)

2. When students come to class, show a few minutes of a snake eating (without sound). You may need to find one via an internet search. If this link works, I recommend this David Attenborough one: http://www.youtube.com/watch?v=Qy67XU6xEi8. Show the first part of this without any sound so as not to guide them through the answers you are looking for them to share next.

3. Ask students to list on  paper or a notecard (without their name) three things from the video (and/or reading) that are different between how a snake and a human eat:

They might say, “A snake…”

Does not chew food.

Swallows the animal whole (not even large pieces ripped).

Takes a long time to swallow.

Has jaws that open really wide.

Doesn’t really use its teeth much.

4. Students should share their answers with a partner and then pass their paper to another and another (thus shuffling the papers anonymously). Classmates can open the class discussion by sharing what someone else wrote on the paper they have in their hand.

5. Use their ideas to bring in structure/function talk related to teeth, jaws, HCl production, ectothermy vs endothermy, etc. Use the linked article by Jared Diamond as reference. You may decide to show them the video again (with sound) if using the David Attenborough video.

6. Two clicker questions you can use post-reading or on an exam:

Which below is a difference between human and snake digestive physiology?

a) Snakes do not make saliva, only humans do.

b) Snakes do not have intestines.

c) The function of teeth differs.

d) The name of the acid produced by the stomach differs.

When a snake ingests a large meal,

a) the snake will move to a sunny spot to increase its body temperature.

b) its HCl production continues for days.

c) the intestines double or triple in size as individual cells grow.

d) its oxygen consumption increases drastically.

e) all of the above is true.

Worksheet: Guided Reading Questions for Dining With SnakesGuided Reading Questions for Dining With Snakes KEY

Applying Understanding of Female Hormones to Birth Control

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– To explain how the female hormones LH, FSH, progesterone, and estrogen change through a human female’s menstrual cycle

– To understand how the birth control pill provides negative feedback to the hypothalamus and pituitary gland

– To demonstrate the value of the application of material to students in addition to lecture/reading

Activity Description: Students are given a mini-lecture on the female cycle. They are then asked a clicker type question to test their understanding post lecture. Students apply the material through two small case-based questions about female birth control. Students are then asked the same clicker type question to see if their understanding has increased.

Time Needed: Questions and activity require approximately 15-20 minutes.

Materials Needed: Handouts, clickers if available, blank paper for students

Activity Instructions:

1. Give the students the lecture diagram (attached) that they can fill in with you as you lecture. Give a mini-lecture on the female hormone cycle, being sure to highlight how the pre-ovulation follicular phase differs from the post-ovulation luteal phase. Hormones that should be discussed include GnRH, LH, FSH, progesterone, and estrogen. How progesterone and estrogen provide negative feedback for the hypothalamus and pituitary gland are of importance to do this activity.

2. Give a post-lecture (pre-activity) clicker-type question. Have students answer independent of their classmates and don’t give them the answer yet. Collect the answers to measure the percent of students with the correct answer.

In the luteal phase (pre-ovulation) of the female cycle, the levels of _______________ remain high, inhibiting production of ________________.

a) GnRH; estrogen

b) LH and FSH; estrogen

c) progesterone; estrogen

d) estrogen; progesterone

e) None of the above. (Correct answer)

3. Give them a worksheet case study activity. Allow students to work in pairs and use their textbook images to answer the following case study questions (attached). A good way to increase discussion, even in a large class, is to have the students not put their names on their answers. You can collect them and read a few examples, letting the students decide if the answer is sufficient or not. Alternatively, you can have the students shuffle their answers among themselves and take turns reading some of the answers they have on the paper they received after the shuffle.

4. After discussing case study answers as a class, ask the same clicker-type question again. You should see a rise in the percent of students with the correct answer and you can now have the students fill in the blanks to make a correct statement: In the luteal phase (pre-ovulation) of the female cycle, the levels of estrogen and progesterone remain high, inhibiting production of FSH and LH.

Two potential test questions related to the activity:

1. Using your knowledge of the feedback loops of human female hormones, which of the following would you predict would result if a woman was continually exposed to estrogen and progesterone?

a) increased secretion of FSH

b) increased secretion of LH

c) degeneration of the corpus luteum

d) absence of monthly ovulation (Correct answer)

e) all of the above

2.  In hormone production, how do the follicle and corpus luteum compare?

a) Both produces primarily estrogen.

b) Both produce primarily progesterone.

c)The follicle produces more estrogen than progesterone; the corpus luteum produces more progesterone than estrogen. (Correct answer)

d) The follicle produces mostly progesterone; the corpus luteum produces estrogen and progesterone.

Lecture diagram for students:

What happens if there is no successful fertilization?

 

What happens if there is a pregnancy?

 

Worksheet: Female Hormones and Birth Control WorksheetFemale Hormones and Birth Control Worksheet KEY

Collecting Student Misconceptions About the Flu Vaccine

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– For students to find out what misconceptions they have about the flu vaccine

– To learn why the flu vaccine is sometimes ineffective

Activity Description: This can be done as a lecture opener to an immunology discussion or after the adaptive immune system is discussed. Students are surveyed (through a clicker system if available) to find out how many of them received the flu vaccine in the previous or current flu season. They are asked to anonymously write reasons if they chose not to get one. A discussion follows about misconceptions based upon their answers.

Time Needed: Survey and discussion can be completed in approximately 10 minutes.

Materials Needed: Handouts, clickers if available, notecards/paper for students

Activity Instructions:

  1. Survey your students to see how many of them have had the most current flu vaccine. (If your students are like mine, the majority will not have had the vaccine.) If you are using a clicker program, you can easily survey with this. If you are not using a clicker program and have a class of less than 32 students, you can use the free version of www.polleverywhere.com to survey students and get an instant histogram like clickers (students use laptops or cell phones to answer through either a web browser or a text message). Of course, a low-tech way to survey is to count raised hands!
  2. Next, seeing that many have not gotten the vaccine, push them to give you the reasons why they chose not get one. To get better responses, use an anonymous method. Have them write on blank paper and pass forward or have them text a free response to the question you might have already set up in www.polleverywhere.com.
  3. Discuss reasons. Below I state common misconceptions that my students had:

Misconceptions:

  1. I hear I can get the flu from it.
  2. I have gotten the flu from the flu shot. The vaccine doesn’t work.
  3. I never had the shot and I never got the flu.
  4. The shot is only for babies and old people.
  5. I can get scary, severe side effects from the vaccine. Vaccines are dangerous and I would rather get the flu.

Background information to discuss their misconceptions:

(Based on CDC’s flu vaccine information;  http://www.cdc.gov/flu/protect/keyfacts.htm for more information.)

1. I hear I can get the flu from it.

The flu shot is made from a virus that has been killed. You cannot get the flu from this. There is a nasal spray version of the vaccine made with weakened, live virus. While some people will have minor side effects, runny nose or headache etc., they will not have the “flu.” People with severely compromised immune systems should not get the nasal spray, since this is a live virus.  This misconception that people will get the flu perpetuates though because someone they know got the flu after being vaccinated (see misconception number 2).

2. I had the shot once, but still got the flu. The vaccine doesn’t work.

Sometimes, people have already been exposed to the flu and are not showing symptoms yet. They receive the vaccine and then develop the flu. (They would have shown symptoms of the flu with or without the vaccine.)

Sometimes the vaccine is not effective because it doesn’t match the circulating strain of virus or there are multiple strains circulating.

“The effectiveness of inactivated influenza vaccine depends primarily on the age and immunocompetence of the vaccine recipient, and the degree of similarity between the viruses in the vaccine and those in circulation. In years when the vaccine strains are not well matched to circulating strains, vaccine effectiveness is generally lower. The vaccine may also be lower among persons with chronic medical conditions and among the elderly, as compared to healthy young adults and children. In addition, estimates of vaccine effectiveness vary, based on the specificity of the outcome that is being measured in the study.” (CDC)

3. I never had the shot and I never had the flu.

There is nothing superhuman about these people. They will likely one day get the flu and if it is bad enough, they will reconsider getting a flu shot in the future!

4. The shot is only for babies and old people.

Everyone 6 months and older should get a flu vaccine. It’s especially important that the following groups get vaccinated either because they are at high risk of having serious flu-related complications or because they live with or care for people at high risk for developing flu-related complications: pregnant women, children younger than 5, but especially children younger than 2 years old, people 50 years of age and older, people of any age with certain chronic medical conditions, people who live in nursing homes and other long-term care facilities, people who live with or care for those at high risk for complications from flu.

5. I can get scary, severe side effects from it.

“Almost all people who receive influenza vaccine have no serious problems from it. However, on rare occasions, flu vaccination can cause serious problems, such as severe allergic reactions.” (CDC). People with allergies to chicken eggs or other ingredients of the vaccine should not be vaccinated.

Correlation does not equal cause and effect. It is understandable that people who fall ill look for reasons behind their illness. Remind students about sample size. Just because they heard about  friend of a friend…

The CDC keeps a list of side effects from the flu shot and flu nasal spray in their vaccine adverse event reporting system (VAERS). VAERS data contains coincidental events and those truly caused by vaccines.

Guillain-Barré Syndrome (GBS) is the most commonly cited serious side effect. “The potential association between the vaccine and GBS has been an area of ongoing research.” (CDC)

“Guillain-Barré syndrome (GBS) is a rare disorder in which a person’s own immune system damages their nerve cells, causing muscle weakness and sometimes paralysis. GBS can cause symptoms that last for a few weeks. Most people recover fully from GBS, but some people have permanent nerve damage. In very rare cases, people have died of GBS, usually from difficulty breathing. In the United States, for example, an estimated 3,000 to 6,000 people develop GBS each year on average, whether or not they received a vaccination.”

There is much information to read from the CDC about this: http://www.cdc.gov/flu/professionals/acip/adversetiv.htm

Blood Flow: Following a Single Red Blood Cell

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– To learn the basic blood flow through the human circulatory system

Activity Description: Students are given a mini-lecture on how blood flows through the human circulatory system by following the diagram provided. Students will label the diagram during the lecture. Students will then be given a location in the body by you and will be asked a variety of questions. Students will work in pairs.

Time Needed: Approximately 15-20 minutes

Materials Needed: Blank diagrams for students (attached)

Activity Instructions:

  1. Deliver a mini-lecture on blood flow through the human circulatory system, allowing students to fill in the diagram as you proceed.
  2. After lecturing, have the students “pair and share” to take turns explaining the diagram to each other. This should take about 5 minutes.
  3. Randomly choose a location and ask various questions to the students. This is an activity where repetition will be useful for many students. (You may choose to set this up as a game show scenario or have the students shout out answers etc.)Have a list of these “locations” in the system either on a set of index cards or pre-loaded as a list in the “Fruit Machine.” (This is a fun way to randomly choose items or student names etc from an electronic list. Cut and paste the list of locations into: http://www.classtools.net/main_area/template_loader.php/?fruit_machine)Pulmonary arteryLeft atrium

    Superior Vena cava

    Pulmonary vein

    Capillaries of head, chest, and arms

    Aorta

    Capillaries of lungs

    Right atrium

    Left ventricle

    Right ventricle

    Capillaries of the abdomen and legs

    Inferior vena cava

  4. Ask a variety of questions such as:What’s the location the red blood cell will go to next?What’s the location the red blood cell has just come from?Will the red blood cell go through any capillary beds before reaching the left atrium? If so, how many?

    What is the most recent heart valve the red blood cell has travelled through?

    If not in the heart, describe the path how the red blood cell will get back to the heart.

 

Using Diabetes as the Story to Discuss the Secretory Pathway of Proteins

Written by Kelly A. Hogan, University of North Carolina at Chapel Hill

Learning Outcomes:

– To use insulin as an example secretory protein

– To examine an analogy that the cell is a protein factory analogous to a manufacturing factory

– To learn about an important disease students may know little about

Activity Description: Students act out an interpreted case study and discuss answers to the questions. Lecture or animations may be interspersed in the discussion.

Time Needed: Approximately 50 minutes

Materials Needed: Copies of the case study and questions, 3 x 5 index cards

Activity Instructions: Choose 6 students to play the roles. Intersperse lecture, BioFlix animations, and discussion as needed. I always play the role ofLena, so that I can still play a “teaching role” and pull up animations while I say my lines.

OPTIONAL: The animation that could be shown to the class is located at:

For question 8, I have my students write their answers on 3 x 5 index cards. I ask them to swap cards several times with classmates. When I ask for people to read from their cards, I get a much better response. We then discuss whether the analogy is a good one or not.

Worksheet: Diabetes Case Study and Role Play Worksheet