Moist organs and kinesthetic learners

“I profess to learn and to teach anatomy not from books but from dissections, not from the tenets of Philosophers but from the fabric of Nature.” — William Harvey

Any EMS instructor who has taught for more than five minutes understands that most adults, and most especially the ones who take our EMT classes, are kinesthetic learners. They learn by doing; by putting their hands on things. As the old saying goes, “Tell me and I’ll forget, show me and I’ll remember, let me do and I’ll understand.”

Investing EMS students in their own learning

Recently, I’ve rededicated myself to making my EMT classes more interactive and engaging to the students in active learning exercises. I’m a strong speaker, and my natural tendency is to expound on a given subject at length and engage my listeners in discussions.

But while using Socratic dialogue in a conference presentation works well to engage listeners who already have some knowledge base, it falls flat when your students are hearing the information for the very first time. Sure, they’re supposed to read the chapter and do the online assignments before class, but so many of them don’t, and many more flail helplessly at the textbook and never absorb anything, simply because no one has ever taught them how to study.

Hence, my zeal at using what Dan Limmer calls “dynamic learning exercises.” Dan has a wealth of them on his website, and inspired me to make up a bunch of my own.

One thing I’ve done for the past four years is teach a pluck lab in my EMT courses. I cover anatomy – and most especially, physiology and pathophysiology – in great depth compared to most EMT classes, and it pays off later in class when we discuss various medical emergencies. When the students already have a solid understanding of how things are supposed to work, it is relatively easy to understand what happens – and what to do – when those mechanisms go wrong.

Contextualizing anatomy for EMS students

Students have a hard time contextualizing information like, “The heart is a muscular organ with four chambers whose function is to … ”

It’s just esoteric information to them. But let them put their hands on a heart – not a plastic anatomical model – and suddenly, they’re paying attention when you talk about pulmonary pumps and systemic pumps, or semilunar valves, or coronary arteries, or where the tricuspid and mitral valves get their name, or how blood can collect and clot in the atria in an atrial fibrillation patient who isn’t on anticoagulants.

“It’s so … muscular! I had in mind this sort of … bag of blood.” — EMT student

I invariably get incredulous comments like that from my students when they feel the muscularity of the left ventricle versus the right, or observe atelectasis in pig lungs and watch how we can reverse it with a BVM and peep, or feel the cartilaginous rings around a trachea.

6 steps to conducting a pluck lab

First of all, plucks are the pig or beef offal; organs and viscera not usually cooked for human consumption. Typically, the plucks are discarded at slaughterhouses, and you can get them for free for your classes. Here are 6 steps to conducting a pluck lab:

1. If you have a slaughterhouse or meat processing plant near your home or school, go visit the manager. Explain to him that you need swine hearts, kidneys and lungs with tracheas attached for an anatomy lab. He may have you sign a waiver stating that you will not be using the organs for human consumption. Explain to him that, if possible, the organs he sets aside for you remain as intact as possible, with as much of the arterial trunks attached. This usually won’t be a problem with lungs and kidneys, but FDA inspectors typically cut into pig hearts to check for signs of disease or parasitic infestations. With a little coordination, you can make sure the cuts aren’t extensive, or in some cases, the FDA inspector will cut into a few hearts from a particular lot, and you can get the undamaged ones.
2. You’ll need PPE equipment for everyone, of course, as well as plenty of chux pads. Give every student a pair of disposable forceps, a scalpel and a pair of blunt probes. To keep the mess down, I also give each student a crawfish platter to use as a dissection tray. You can get disposable ones on Amazon and assign one to each student.
3. Download dissection guides for mammal hearts, kidneys and eyes from Carolina Biological Supply. A few sets of their laminated dissection mats also make nice, reusable color photo references for identifying structures as they dissect.
4. While you dissect the organs, point out the physiology of the structures you identify, and how that relates to our assessment and care. For example, find a good specimen of the heart with coronary ostia undamaged, crack a glow stick and inject 10 mL of the fluid into the ostia with the classroom lights off, and watch the coronary arteries glow in the dark (Figure 1). Discuss with your students the coronary artery anatomy, which parts of the myocardium they perfuse, and how clinicians can localize an infarct to a particular region based upon knowledge of that anatomy. Intubate a pig trachea and ventilate the lungs with a BVM, with and without PEEP valve attached. Discuss concepts such as alveolar recruitment, pulmonary shunts and V/Q mismatch.
5. If you have a document camera, a nice touch is to hook that up to your projector or smartboard and demonstrate the dissection as students follow along.
6. Clean up after yourself. A wastebasket full of rancid meat is no way to endear yourself to the custodial staff at your school. Dispose of all sharps appropriately, and dispose of tissue and organs in the appropriate containers.

Figure 1: Engage students with glowing coronary arteries. (Courtesy/Kelly Grayson via GIPHY)

With a little planning and preparation, you can make what is often a confusing and somewhat dull part of EMT class an engaging learning experience for everyone!