Action Potential Tip from the Hundred Acre Wood

Last month we explained some of the outlets available with HAPS for publication. This week we are bringing you a glimpse of a Teaching Tip. The analogy provided below is a portion of a Teaching Tip recently submitted by HAPS member Micah Meltzer and his student Megan Spears. To see the full tip, visit the HAPS website

The Curriculum and Instruction Committee welcomes tip submission in all content areas; however, they are currently especially interested in tips for the following areas, which could use more tips to support our HAPS outcome guidelines.

  • Muscular system: skeletal muscle metabolism, characteristics of muscle tissue types, principles and types of whole muscle contraction (twitch, motor unit or contraction types)
  • Nervous system: neurotransmitters and their role at the synapse, sensory and motor pathways in CNS, ANS functions, body system survey
  • General A&P introduction: body cavities/regions, directional terms in A&P

Undergraduate physiology students seem to relate well to A.A. Milne’s characters Tigger & Eeyore from the Winnie-the-Pooh stories. The different behaviors of the voltage-gated Na+ & K+ channels can be likened to the personalities of Tigger & Eeyore, respectively. Tigger has a bouncy, excitable personality which is similar to the behavior of the voltage-gated Na+ channels (VGNC) responsible for rapid depolarization. In contrast, Eeyore is a mopey, sluggish character who behaves more like the voltage-gated K+ channels (VGKC) responsible for repolarization & hyperpolarization. These character associations can help students remember the differences between the two different voltage-gated ion channels involved in the generation of the neuronal action potential, which is a fundamental concept of neurophysiology.

Tigger Channels

Tigger is known for being friendly, energetic, and more than a little rambunctious. Tigger can be seen in the Hundred Acre Wood bouncing around and engaging excitedly with the world. Tigger’s exuberant and enthusiastic qualities are analogous to the rapid-open/rapid-close properties of the VGNC (Voltage-Gated Na+ Channel).

Neuronal VGNCs each contain a voltage-dependent activation gate & a time-dependent inactivation gate. The activation gate is triggered to open once a certain membrane potential, the threshold voltage, is present across the local membrane. The activation gates open rapidly allowing a significant influx of Na+ ions, causing depolarization and the rapid upstroke of an action potential, much like Tigger is known to suddenly burst into short-lived activity.  After a brief period of time (1-2 ms following activation), the inactivation gate rapidly “plugs” up the ion pore from the inside of the cell. This event abruptly stops Na+ ion influx, ending depolarization and defining the peak of the upstroke. The inactivation gate can easily be remembered by likening it to Tigger’s tail getting in the way.

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Eeyore Channels

And then there is the gloomy Eeyore. Oh bother. In this mnemonic, his tail can be thought of as the sole activation gate swinging open and closed in response to changes in voltage. Eeyore is often seen moping around or moseying behind his friends around the Hundred Acre Wood. Eeyore’s slow and deliberate manner is analogous to the slow-to-open/slow-to-close nature of the VGKC (Voltage-Gated K+ Channel).

The VGKCs contain a voltage-dependent activation gate but, unlike VGNCs, do not contain an inactivation gate. The kinetics of the VGKC activation gate are slower, responding less quickly to changes in membrane potential when compared to the VGNC’s activation gate. The repolarization phase begins at the same time as the peak of the depolarization upstroke.  It takes that long to get most of the VGKCs opened allowing for significant K+ efflux. Once the membrane potential returns toward threshold voltage, the VGKCs begin to close, also slowly. If K+ continues to exit the cell after threshold voltage has been reached there will be a hyperpolarization phase.

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Micah Meltzer M.D. is an Assistant Professor of Biology at Contra Costa Community College (CA). He teaches Human Anatomy & Physiology, through a clinical lens, to students who are interested in (mainly) pursuing careers in the healthcare field.

 

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Megan Spears is an Anatomy Teaching Assistant and student at Contra Costa College. She is on track to apply to medical school next Spring.

Publishing with HAPS

You know that old, grim academic saying, “Publish or perish”?  We at HAPS prefer to say “Publish and flourish!” While your home institution may have specific expectations regarding scholarship, we offer several options for “publishing” (in the broad sense of the word) that will make communicating with your fellow A&P professionals fulfilling and fun!  Some of these resources are only available for HAPS members (HAPS Discussion Group and Teaching Tips) while others are publicly available for the benefit of the entire A&P community (HAPS Blog and HAPS Educator). Details of each publication venue are provided below.

HAPS Discussion Group (HAPS-L Listserv): Maybe you don’t really want to write up anything formal — you just want to share a link to a cool news item and comment on it. Or maybe you have a question for your fellow educators.  Great for getting rapid feedback, often from experts like A&P textbook authors.  Why do some texts refer to a “dorsal body cavity” while others do not? How does pelvis shape vary according to geography?  The listserv has you covered.

Teaching Tips: As the name implies, teaching tips are concise pieces of practical teaching advice. Teaching tips can be submitted here; submitters choose appropriate learning outcome tags to assist others in locating their tip for usage in class or lab.  Each submission is reviewed by Curriculum and Instruction Committee members to assure that it is posted in an optimal location.

Blog: Want feedback during the early stages of a research project?  Want to provoke discussion that is more extensive or more timeless than the typical listserv chit-chat? The blog is the place for you. Blog posts are published once a week during the academic year and contain a wide variety of ideas from short teaching tips (see above) to descriptions of unique A&P-related experiences. Each post is edited before publication, so no need to worry about minor errors or incomplete thoughts. Ideas and drafts can be emailed to hapsblog@hapsconnect.org. Please include a headshot or other picture and a short author bio.

HAPS Educator: The most formal of these four options, but run by friendly editors! HAPS Educator aims to foster teaching excellence and pedagogical research in anatomy and physiology education.  This open-access journal publishes peer-reviewed articles under three categories. Educational Research articles discuss pedagogical research projects supported by robust data.  Perspectives on Teaching articles discuss a teaching philosophy or modality but do not require supporting data. Current Topics articles provide a state-of-the-art summary of a trending topic area relevant to A&P educators.  All submitted articles undergo peer review. Educational Research articles will additionally be reviewed for the quality of the supporting data. HAPS Educator is the official publication of the Human Anatomy and Physiology Society (HAPS) and is published online three times per year: on March 1, July 1, and November 1.

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The Rule of Threes: Self-care advice for A&P Instructors

For most instructors, the Fall term brings a fresh start with our courses. It also tends to bring a sense of feeling overwhelmed with all the things we could be doing. As much as I enjoy and look forward to the HAPS annual conference every year, I usually leave filled with motivation and self-doubt in equal measure. It is all too easy to forget that every university, college, and department will vary, whether in funding, faculty to student ratio, program focus, or appreciation for quality A&P education. Many of us simply cannot execute a number of the innovations we see at HAPS. Some activities require a great deal of extra work on top of our already full plates, and at the end of the day, we can’t quite motivate ourselves to go those extra miles. Could there be a middle ground?

Over the summer, I was making a long list of new strategies to try in my courses, both in and out of class. Shamefully, I was “multitasking”,  watching “The Crown” on Netflix at the same time. In the episode I was watching, the queen was feeling overwhelmed by criticism, and unsure how to address it to regain public favor. In an unprecedented move, she met with an outspoken critic to hear his thoughts on the public image of the monarchy. To keep things simple, he suggested “three things to start, and three things to stop.” Perhaps it is my obsession with British history, or maybe it was just what I needed to hear at that moment, but for whatever reason, I stopped writing my list. I realized that if I did all of the things I listed, I would never know what actually worked and didn’t work well in my class. I threw out that list, and pulled out two fresh pieces of paper. After some non-distracted reflection I wrote three things to start and three things to stop on each of these papers. Since I’ve always been the “bad news first” type, in this post, I share my three things to stop.

My Three Things to Stop:

It’s in the syllabus” and other associated phrases

I have to admit, I never said these phrases often at all, but I’ve decided that they are all officially on my do not say list. Jokes, sarcasm and a variety of venting sessions abound in academia about this topic. We are easily frustrated when students bombard us with questions that we have already answered (often in obvious places), or questions they could have easily answered for themselves with a little effort. Other tempting phrases include; “as I said earlier”, “per my email”, or anything else referencing the fact that students should already know the answer to the question, or could easily find it. I encourage all teachers to take a moment to ask yourself four questions, before hitting that reply button:

  1. What harm does it really do to just answer their question?
  2. is using one of my phrases just going to embarrass them?
  3. Will it take me just as long to respond that they should have already known the answer, as it will to answer the question
  4. Honestly, how often do carefully read directions?

I think if we are honest with ourselves, this simply stems from annoyance that we wasted our own precious time on something that was either unnoticed or ignored by the students. Or, perhaps this triggers a fear of what other questions are to come and an immediate assumption that the students will struggle in the class if they are this “helpless” already. This is making assumptions we have no business making. Instead, answer their question and simply add, “if you need more information later and I am unavailable….” while referring them to whatever they should have read in the first place. They’ll get the message and won’t be afraid to approach you again.

The candy shop effect

When treating a condition, the best course of action is to add one new medication or make one change at a time, see the effects, and gradually add another. Otherwise, any changes to your well-being cannot be attributed to any one new variable. The challenge I face every fall is wanting to add everything I think will help my students. While this sounds fine at face value, there are pitfalls. First, exhaustion on my part! Second, the risk of overwhelming my students. Third, I cannot attribute any changes in my students’ outcomes directly to one, or a combination of the changes I made. For example, in the 2017 school year, we decided to add weekly quizzes for retrieval practice that were open book, 2 attempts, highest grade kept. This year, we are also adding an adaptive reading assignment to increase metacognition. By waiting a year and doing the quizzes first, we will be able to see if that made a difference and if there is a need for any more retrieval practice. In an effort to remain a reflective teacher I will examine if these changes made any meaningful difference, or if they were just more work in a student’s already very demanding schedule.

“Just being grateful”

Just being grateful to have your job goes by many names. More and more often, it is being called by its true name: Impostor Syndrome. In the past year, I have seen more and more instructors in the A&P field be vocal about this. One of my favorite HAPS moments of 2018 was during the Women in Anatomy panel, when an attendee asked (the one and only) Dee Silverthorn, “How did you deal with impostor syndrome?” and her response was “stay tuned” (or something to that effect). The rest of the panel then chimed in that this is a very real feeling, no matter what stage you are at in your career. In all of my work positions, I spent years not standing up for what I felt was best, or changes that should be made, because I thought I needed to just be agreeable. I was afraid to rock the boat because I was just “so grateful” to have my job. In truth, I am very grateful, but not that someone gave me a job; I am grateful that in all my years of teaching I have never questioned whether or not I’m doing exactly what I’m meant to do with my life. However, my “just so grateful” attitude was conveying that I didn’t believe I deserved or earned every opportunity I had. We all have to be our own biggest advocates. While external validation and recognition feel wonderful, at the end of the day, if we don’t own our accomplishments, who will?

Fellow A&P educators, I urge you to consider this exercise, especially if you are feeling like work-life balance is always out of reach or you’re never quite sure if your actions and outcomes line up. It might help you become a more balanced educator, family member, and friend. Your three things to start and stop will certainly vary, but feel free to steal mine! The most important thing is that the “three things to stop” addresses the behaviors you do or choices you make that most often that lead to undesirable outcomes. Be on the lookout for the next post, “three things to start”!


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Krista Rompolski is an Assistant Professor in the Health Sciences Department at Drexel University, Philadelphia, PA. She is an active member of the Human Anatomy and Physiology Society and the American Academy of Anatomists. Her teaching interests include pathophysiology, gross anatomy, and anatomy and physiology.

Would you be ready?

Imagine that while preparing those last few materials for the start of the semester you receive a call from Disability Support Services indicating that you will have a student with total blindness in your A&P class. The semester begins in two days.

Would you be ready?

To be accessible for students with disabilities, here are some things you can address:

  • PowerPoint slides need to have high contrast between the background and font colors. The reading order of each slide must be verified, and font sizes should be at least 24 point. Additionally, all visuals must have Alternative Text (aka Alt Text or Alt Tags). Alternative Text is a description that enables an individual with a visual impairment to learn what a sighted person would learn from the image. However, they should not be so detailed as to further increase the amount of time the student would need to acquire the information. Alt Tags for STEM images may require two parts.
  • Word documents must be written in a sans-serif font and be organized with headers. Tables require a repeating header and an Alt Tag. Further, because screen readers pronounce non-printing characters, the document shouldn’t have unnecessary spaces or tabs. If you don’t know what it sounds like to hear text verbalized by a screen reader, listen to Accessible vs. Inaccessible.
  • The physical laboratory space must accommodate students with disabilities, and there must be accessible versions of the lab materials and equipment. Institutions should have policies regarding guide dogs and students requiring wheelchairs and scooters in the science laboratory. A discussion on preparing for students with disabilities in the science lab would require a separate blog post. In the meantime, my website has a link to a study I conducted in 2016 evaluating accommodations provided for students with visual impairments in college biology laboratories. It contains information on accommodations for science labs, and those which study participants found helpful and not so helpful.
  • Textbooks are another consideration. Publishers are working toward full accessibility, but there’s a lot of work yet to be done. Check with the publisher about your textbook’s accessibility. Ask a lot of questions. Some publishers honestly believe they have accessible versions of their texts, when in fact they do not.

Several resources exist to help create accessible course materials. I maintain a website, Accessible Science, that has numerous resources on accessibility and other information you may find useful. Newer versions of Microsoft® Office have built-in accessibility checkers, PC Accessibility Checker and Mac Accessibility Checker, that scan for accessibility issues and indicate how to fix any problems they identify. PowerPoint Accessibility and Screen Reader Accessibility in Word demonstrate how to create accessible PowerPoint slides and documents.

New courses should be developed according to the tenets of Universal Instructional Design (UID), which recommends that accessibility be integrated into courses as they are developed. Adhering to the principles of UID helps students even if you never have a student with a disability in your class. Foreign language students benefit from subtitles on videos, for example, and larger font sizes on PowerPoint slides benefit students seated farther from the screen.

For existing courses, it takes an incredible amount of time to retrofit a laboratory science class so that it is fully accessible. Since increasing numbers of students with disabilities are attending college, my suggestion is to start preparing now so you don’t panic when you get that call. Feel free to email me if I can help.

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Dr. Barbara R. Heard is an associate professor of biology at a community college in NJ. She is interested in supporting students with disabilities in science, especially students with visual disabilities.

ABC’s of A&P

It is the ultimate challenge and lifelong pursuit of educators to facilitate learning among students with different educational backgrounds, first languages, and learning styles.  Concurrently, we work to foster individual strengths and ideas that each student brings to our classroom. With no single right way to get through to everyone, each class presents us with the awesome challenge of a lifetime!

So how can we assess our teaching methods and students’ knowledge acquisition without a test? Or better yet, before the test they will ultimately have to take? And how can we make the learning fun?

For me, one answer is a creative project.  Students in Human Anatomy and Physiology spend much of their time memorizing copious facts hoping to apply them at exam time. The act of creating something from those facts is an enjoyable way for students to take material that is complex, break it down into digestible components, tap into their creative side and ultimately ignite different aspects of their brain into flames of learning. One of my favorite creative assignments calls upon students to write a children’s storybook based on a topic we have covered.  Students must capture the big picture and then focus on filling in the details that are most relevant to their own particular stories.

Recently, three of my students created a children’s story after learning about the kidneys.  The title of their story was The Mighty KidneysWheres Sodium?  The “Kid”neys are a group of three friends (shaped like kidneys) who help the kidneys work properly. In the episode Wheres Sodium? there is a problem in the distal convoluted tubule (DCT).  As the “Kid”neys get filtered, and wind their way through a nephron they finally make it to the DCT where they encounter the villain: Caffeine (da da dum). In their story, Caffeine has somehow banished the friendly Al Dosterone.  The students were clever enough to make the shape of Caffeine and Al Dosterone similar enough so that readers could imagine how caffeine might interfere with aldosterone’s action. In the end, the “Kid”neys save the day by contacting the brain’s thirst centers.

In this story, AL Dosterone is the hero!
In this story, AL Dosterone is the hero!

Similar children’s stories submitted for this assignment also show how creative work engages and helps students personally assimilate an overarching theme in Human Anatomy and Physiology. Then the added nuances, unique to each students’ work, display knowledge of details that make the stories informative, engaging and interesting. Usually the illustrations are adorable. Creating a children’s story allows students to assess their understanding by breaking down the material, rebuilding it and adding their own unique subset of details with personal creative essence. Those students who can do this demonstrate their understanding of learning objectives.

Feedback from students who engage in this type of assignment is very positive, initiating comments such as, “We had a lot of fun with this project and hope you enjoy it as much as we did.” As a teacher, reading the stories of my students makes me happy because I know I got through to them with the core material; but then to watch them interact with that material in their own unique way makes me a very proud professor.


Bridgit Goldman has been teaching college level biology since 1998.  She has a Ph.D. in Cellular, Molecular, and Developmental Biology from The Graduate School and University Center of The City University of New York.  Since 2007 she has designed, developed and taught all the lecture and laboratory classes in Human Anatomy and Physiology at Siena College. 

“The Wave” – Neuron Action Potential Propagation

Some of our most popular blog posts describe teaching tips developed by HAPS members. We choose a handful of these to publish on the blog, but there are hundreds of tips that have been collected over the years. These little snippets are being linked to the HAPS A&P learning outcomes and posted to the HAPS website, for members only. So join HAPS now, and get access to many more teaching tips like this one.

Enjoy this teaching tip from HAPS Past President, Terry Thompson.

Objectives:

  1. Engage students with a kinesthetic demonstration of the action potential “wave” with ions moving in or out of membrane channels
  2. Generate visual memory tools to help students’ learning and long-term understanding
  3. Motivate critical thinking by having students analyze and evaluate various components of the activity as a model of the physiological events

Materials:

  • Color-coded cards: multiple cards with Na+/K+ on opposite sides; one card with ACh/Ca2+ on opposite sides; one card with neuron cell body/synaptic end bulb on opposite sides. Can use cardstock or plastic protective sleeves. Use large font to fill single page.

 Procedure:

  1. Line students up facing class (or each other if using two lines). Explain that students will represent the axolemma: phosphate “head”, lipid “legs”, voltage-gated channels “arms”.
  2. Give each student a Na+/K+ card and review relative concentration of each ion extracellular and intracellular. Designate: above “heads” as extracellular and floor as intracellular; right hand as voltage-gated Na+ channel and left hand as voltage-gated K+ channel. Start with Na+ card held toward observers, above their heads, in right hand.
  3. Demonstrate the depolarization/repolarization cycle by bringing Na+ card down in front of body, flipping K+ side toward observers as pass to left hand, then move above head.  Have all the students practice this synchronously until they feel comfortable, saying “depolarize” and “repolarize” out loud to help.  Discuss the electrogenic activity of the Na+/K+-ATPase pump as it relates to this kinesthetic demonstration.
  4. Review continuous conduction and challenge them to now complete the same movements but this time in sequence, like the “wave” in a stadium.  Show the “neuron cell body” and “ACh” cards and discuss what initiates the impulse.  Can elaborate on difference between ligand-gated and voltage-gated channels; graded potential, threshold, and action potential; neurotransmitter for motor neuron or other neurons; dendrites, soma and axon hillock; etc.  Students will often come up with ideas of ways you could include other elements in the demonstration, or at least evaluate and understand what this particular activity as a model is NOT showing.
  5. “Start” the first person in line by saying “threshold”, and allow the “wave” to progress down the axon.  This usually elicits lots of laughing and suggestions from the audience.  Allow them to repeat until they produce a reasonable “wave”, starting each with a threshold stimulus.
  6. Finally as a reasonable “wave” is progressing down the line, run to the other end and flip your cards to show synaptic end bulb and hold the Ca2+ card above your head.  When the wave reaches you, bring the Ca2+ down and flip to ACh, passing it above your head for release of neurotransmitter at synapse with muscle or another neuron.  Discuss this added activity to the model as a way to summarize the activity.
  7. Extensions can include discussing what parts of this demonstration could be improved on or don’t accurately reflect the physiology.  Can also discuss what would need to be changed to demonstrate saltatory conduction instead of continuous conduction.

NOTE: This activity was also presented by Terry Thompson at 2016 HAPS Atlanta Conference as part of the group workshop entitled “Add Drama to Your Classroom – Great Kinesthetic Activities for Students.”

Quick analogy for subclavian artery name changes

Although it is not a particularly difficult concept, sometimes students have trouble remembering the different names that the subclavian artery takes on as it passes through the superior mediastinum and base of the neck into the axilla (as the axillary artery) and arm (as the brachial artery), or they don’t quite get that it is the same vessel with three different names.

Every one of my students has to drive along these roads to get to school.
Every one of my students has to drive along these roads to get to school.

One thing I do in lecture and lab is to analogize this name change using name changes for streets in town. Fortunately, I work at a university (Benedictine University in Lisle, IL) that is situated on a road (College Road) that changes name to the north (Yackley Avenue) and to the south (Wehrli Road) without changing direction appreciably. Every student has to drive along these roads to get to school. I tell my students that the subclavian artery is like Yackley Avenue, and when it crosses the lateral edge of the first rib (in this analogy, Maple Avenue, see Figure), it changes name to the axillary artery (College Avenue); it changes name again after crossing the inferior margin of the teres major muscle (Hobson Road, see Figure), at which point it becomes the brachial artery (Wehrli Road). I would wager that many (most?) towns in the United States have roads that change names in the same way, so that the analogy could be adapted to local conditions. A particularly good example, in Washington, DC, is Constitution Avenue, which starts as I-66E, changes to US-50E/Constitution Avenue after crossing Roosevelt Bridge, and then turns into Maryland Avenue after crossing 2nd Street NE.

Of course, every semester the students and I question the sanity of anatomists and city planners alike for changing a perfectly good name again and again. I wonder how many students, driving home from my anatomy class, are thinking about the different names for the main artery of the upper limb as they drive along Yackley Avenue/College Road/Wehrli Road?


Robert McCarthy is an assistant professor in the Department of Biological Sciences at Benedictine University in Lisle, IL, where he teaches human anatomy and evolution to undergraduate biology and health science students. Robert is a biological anthropologist who studies the evolution of speech and language, the primate skull, hominin evolution, and human anatomic variation.