Monthly Archives: January 2016

Simulation as a Component of First-year Medical Physiology

cardiac simulationbIf you’ve spent any time around soon-to-retire, senior physiologists, you’ve probably heard nostalgic talk of the old dog labs.  I am a member of what may be the last generation that participated in these in a medical/graduate school environment.  The old-timers will tell you that there was no better way to teach physiology than by demonstration and experimentation with an anesthetized dog.  The experience was dramatic, and the various concepts were obviously relevant.  Nevertheless, time marches on, and with changes in economics and societal values, we are unlikely to ever see the return of the dog labs in medical or graduate school.

For the purposes of teaching physiology in a medical environment, much of the impact and value of the dog labs can be obtained through simulation.  Centers that use high-fidelity manikins and other simulation technology are becoming more and more common, and if your institution doesn’t have one yet, there is probably one in the pipeline.  However, you may be skeptical of the high-price tag that the equipment carries and its relevance to bench scientists.  After all, most of us teaching physiology aren’t clinicians, and we have neither the expertise nor the experience to teach medicine.  I was firmly of that opinion when the Texas Tech University Health Sciences Center first opened its simulation center, but I’ve tried to keep an open mind, and I’m happy to say that I’ve learned to incorporate these resources into my teaching.  More importantly, simulation works for the same reason the old dog labs worked:  it provides a clear and dramatic demonstration of fundamental physiological concepts.

Although the equipment available in most simulation centers is capable of reproducing some pretty sophisticated disorders, there is little need for such advanced capability during the pre-clinical years of medical training. The basics are more than adequate, and they can be covered adequately without obtaining a medical degree.   Cardiovascular physiology was my entry point using this new approach to teaching.  There are few things in life more fundamental than a heartbeat, and nearly every simulation center will have cardiopulmonary manikins that allow the student to practice auscultation.  This is not to say that heart sounds can’t be taught with alternatives, such as good digital recordings, but the use of manikins adds an important degree of realism.  I first ask the students to practice positioning the stethoscope for optimal detection of the various heart sounds in a healthy individual.  Demonstrating where to best hear the sound associated with pulmonary valve closure, for example, draws the connection between cardiac anatomy and physiology more closely together.  I then ask the students to explore various valve pathologies and illustrate what they would expect to see on Wiggers diagrams and pressure-volume loops.  The four murmurs that are most relevant to first-year medical students, aortic valve stenosis and regurgitation and mitral valve stenosis and regurgitation, are great starting points for illustrating the relevant changes in pressure that are associated with these defects.  For example, the combined use of auscultation and Wiggers diagrams make it easier to appreciate the excessive pressures developed in the left ventricle as a consequence of aortic valve stenosis.  It also makes it easier to understand how the high velocities of flow and resulting turbulence can cause the distinctive murmur.  In my class, I follow up the auscultation activity with standardized patients and ultrasonography, allowing the students to correlate the sounds that they hear with the coordinated movements in the heart, as visualized with the ultrasound probe.

The cardiopulmonary manikins provide a great resource for showing the practical relevance of hemodynamics to the clinical setting, but we must turn to high-fidelity manikins if we are truly to recapture the drama of the old dog labs.  I remember vividly the effects on an anesthetized dog when, as a student, I infused a sympathetic agonist or antagonist.  Now, as an instructor, I achieve a similar memorable effect with a full-blown simulation of hemorrhagic shock.  This is the capstone event in the cardiovascular physiology section of our course, when the students must recognize the problem and come up with a solution.  Our simulation center has rooms like you would find in the emergency department in which we place the manikins.  The potential “treatments” available for use by the students include a muscarinic antagonist, a sympathetic agonist, and the infusion of normal saline.  As I did with the dogs back in the day, today’s students apply various drugs or treatments to the manikin, and, from the attached control room, I can simulate the appropriate physiological response.  There are few things that bring home the importance of preload and stressed volume like the “recovery” evoked by rapid infusion of saline, especially if this follows unsuccessful attempts at treatment with various drugs.  Later in our class, we have additional simulations that illustrate fundamental principles associated with respiratory physiology and endocrinology.   I admit that it took some persuasion to convince my bench-investigator colleagues that they had sufficient experience to facilitate these activities.  However, after trying it a time or two, they usually find that the activities require more physiological knowledge and deductive reasoning than clinical skill, and, as an added bonus, they have fun.

So why not take advantage of that high-priced center that your medical school just built or is in the process of developing?  You’ll find that simulations provide hard-to-ignore demonstrations of physiology’s relevance to the clinics.  If my experience is any indication, your dean will be happy that you’re trying new things, and you’ll be rewarded by students who respond enthusiastically.

The nitty-gritty to get you started:

My colleagues and I have boiled down the use of simulation to a few key points that can provide a good start to your own efforts.

1)  Keep it simple.  You’re teaching physiology, not a subspecialty.  As described above, we require the students to recognize a loss of blood volume as the fundamental problem in hemorrhagic shock.

2)  Require a decision or intervention.  The students must follow a problem logically, putting into practice the physiology that they are learning.  In the hemorrhage scenario, they treat the “patient” with a rapid intravenous administration of saline.

3)  Provide some background material.  You’re providing a value-added experience that goes beyond simple lecture, but the students need some guidance to prepare.   For the shock simulation, they study a 20-minute online presentation focusing on low cardiac output the night before the activity.

4)  Do a debrief.  If things work well, there will be a lot of excitement and keyed-up emotion.  You’ll want to give the students a chance to talk things out and assess their performance as a team.

Good luck!

Pressley head shot


Thomas A Pressley is a Professor in the Department of Medical Education at Texas Tech University Health Sciences Center. After earning his undergraduate degree at Johns Hopkins University, he entered the graduate program in biochemistry at the Medical University of South Carolina. His postdoctoral training was in the College of Physicians and Surgeons at Columbia University. He was recruited by the University of Texas Medical School in Houston in 1987, and he transferred to Texas Tech in 1995. Tom has served as an interim dean, a visiting professor at multiple institutions, a member of grant review committees, and the chair of the Education Committee of the American Physiological Society. He is the current chair of the APS Career Opportunities in Physiology Committee. He has also developed numerous courses, and he has reviewed degree programs at several institutions.

How Much Material Should We Cover?

womanedhatI’m not sure where the phrase “the tyranny of content” was first coined, but picturing this bloated and oppressive ruler issuing dictates from on high does seem apt at times. Now, of course, there is no one telling us[1] that we have to cover every last bit of Physiology, but yet we often end up trying to do just that. This is in spite of numerous articles and publications telling us and showing us that trying to cover less is more effective[2].

Last spring I taught a 300 level[3] physiology course at my previous institution, and this course is their first and usually only exposure to physiology while the students are undergraduates. I thought I had finally put together a pretty awesome course. I reorganized the material in a manner similar to Carnegie Mellon’s Open Learning Initiative A&P course[4] which has a structure that seems to reflect the 5 Core Concepts in Biology and “Core Principles” of Physiology[5]. I mapped out all of my learning outcomes for each unit and aligned my activities and assessments. It wasn’t until after the semester that I happened to put all of the learning outcomes into a single spreadsheet and realized I had 105!

I had the good fortune of moving into a new position right after that semester, one where I am responsible for training and mentoring graduate students and post-docs who are developing and teaching a course for the first time[6]. Sadly, this means I don’t get to teach Physiology any more[7] – but it has allowed me to really reflect on how I approach teaching. This one big question keeps popping back up for me: How much material is the right amount of material to cover?[8]

In preparation for a workshop here at UW-Madison, I went through all of those learning outcomes and pared the list down to ~50. Is that still too many or too few? At the risk of mixing metaphors, am I preventing my students from being buried under this mountain of information or am I just dooming them to being buried later when they go on to professional school?

I think that this gets to one of the big underlying issues associated with managing course content, and that is maybe more important than counting learning objectives – What do I want my students to be able to do once the course is over? My initial response is a partially tongue-in-cheek “understand physiology.” But, even if I was being completely serious that is still a really vague idea. So where to, from here?

A colleague recently related a story to me about a teaching talk that they had heard once upon a time. In it the faculty member discussed how they had for years taught all of these molecular structures, which students would promptly forget as soon as they were out the door after an exam. This faculty member then decided to really focus on 1-2 structures and work with students to make sure that they really understood those structures and the rules that govern them. This would then give them the skills to figure out other structures. Great! What are those handful of things that we could focus on in a human physiology course though?

The “Core Principles” that I mentioned earlier emphasized the following concepts: the importance/function of the cell membrane, homeostasis, cell-to-cell communications, interdependence between cells/structures/organs, and flow down gradients. If a student understands those principles, it would definitely give them the tools to figure out what is going on behind many physiological processes. Obviously a physiology course would need to cover more than just those five areas though, but what? And maybe more importantly, how?

As someone who now mentors first time college science instructors, it has become even more apparent to me that we tend to default to teaching the way we were taught, but all it takes is the right example or the right conversation to spark an entirely new approach to a course. So, this is the point in the process where I want to hear ideas. You can comment on these blog posts, and I’d like to see comments about ideas that you’ve had in terms of focusing your content for human physiology/A&P courses, as well as ideas on making these courses more conceptual/skill-based.  Thanks for your input.


[1] For most of us at least

[2]Brewer, C. A., & Smith, D. (2011). Vision and change in undergraduate biology education: a call to action. American Association for the Advancement of Science, Washington, DC.

Association of American Colleges and Universities (AAC&U). (2007). College Learning for the New

Global Century. Washington, D.C.: AAC& U.

Handelsman, J., Ebert-May, D., Beichner, R., Bruns, P., Chang, A., DeHaan, R., & Wood, W. B. (2004).

Scientific teaching. Science, 304(5670), 521-522.

National Research Council. (2003) BIO 2010: Transforming Undergraduate Education for Future

Research Biologists Washington, DC: National Academies Press.

Schwab, J. J. (1962). The Teaching of Science as Enquiry. Cambridge, Mass.: Harvard University Press.

Schatz, G. (2012). The endangered bond. Science. doi:10.1126/science.1219756


[3] So, sophomore & juniors mostly. Almost all ‘pre-health’ of some sort.


[5] Michael, J., Modell, H., McFarland, J., & Cliff, W. (2009). The “core principles” of physiology: what should students understand? Advances in Physiology Education, 33(1), 10–16. doi:10.1152/advan.90139.2008 – AND –

Michael, J., & McFarland, J. (2011). The core principles (“big ideas”) of physiology: results of faculty surveys. Advances in Physiology Education,35(4), 336–341. doi:10.1152/advan.00004.2011

[6] Sorry…shameless plug

[7] At least for the time being

[8] Spoiler Alert! I don’t have the answer, or even AN answer. I am mostly ruminating on this idea.

PECOP Trimby picture 2




Chris Trimby is the (Interim) Director of the Teaching Fellows Program and Pre-Faculty Development for WISCIENCE at University of Wisconsin-Madison. As part of this position he mentors graduate students and post-docs while they gain experience teaching and developing course materials. Chris’s research background was in gene therapy and neurotrauma, but that focus has shifted to education practice. He did his Ph.D. in Physiology at University of Kentucky.