My students consistently have problems with clinical problem solving in the Introductory Pathophysiology course I teach. The first time they hit this type of problem is in the first organ system we study, hematology.
This video explains how to break down clinical problems into a manageable set of steps. Of course the hematology is much simplified, but this is the students’ first exposure to the pathophysiology of this organ system.
This Thursday’s teaching video is a primer on pedigree analysis.
Even though their use has fallen out of favor, as we begin to better understand the complexity of genetic diseases, a pedigree is still a pretty good place to start as students begin to learn the basics of Mendelian inheritance: autosomal vs sex-linked modes of inheritance, and dominant vs recessive mutations.
Sure, we know the world is a lot more complex than this. But it’s still good to start with relatively simple pedigrees, so we can build from there. Today’s video is a brief introduction to Mendelian genetics and pedigrees.
For example, in the therapeutic school called Cognitive-Behavioral Therapy, the therapist acts as neuroscientist, suggesting hypotheses and carrying out experiments in conjunction with the patient. “Let’s hypothesize that you will be harmed by snakes, Mr. Jones. Are you saying that all snakes are harmful, or just some types?”
I have taught and done outreach at all levels, from kindergardners to specialized scientists in post-graduate training. Now, I teach mostly college freshmen and sophomores.
At the university where I teach, many of our students are first-generation: that is, they are the first in their families to attend college. Our estimates are maybe 1/3 or more fit this category. Many come to college not quite prepared for college work. It’s really rewarding for me to show them some tools that bench scientists use every day. I think most scientists take some of their methods for granted, because they become so familiar that we begin to believe we’ve always known how to do them.
For example, when I sit down to calculate what I need for a 1 molar solution of sodium chloride in water, I already have memorized that the molecular weight of NaCl is 58.44 g/mole and I know exactly how to combine that with other numbers to get the amount I need to weigh out.
But I didn’t always know how to do that. It’s something that you get better at with long practice.
A shortcut of sorts that scientists use is something called “Dimensional Analysis”. I learned it as “The Factor-Label Method” but it’s the same thing with either name. You’ve got two goals: 1) make the units work out; 2) keep multiplying by things you know equal 1 until the units do work out.
This video (5:44) shows students how to approach problems using Dimensional Analysis. It’s also available at YouTube.
Every Thursday, I plan to post an “explainer”, a short video or screencast that will explain some scientific concept. The first few of these will come from my teaching vaults. After a while, I’ll run out of videos and need to make new ones, but for now, I’ll go with what I have laying around.
This week’s Teaching Thursday video is a two-fer. My students have always struggled with understanding the immune system, and the interplay between its cells.
T-cytotoxic, T-helper, T-helper, T-regulator
Back in graduate school, my major advisor was probably one of the worst human beings on earth but one of the best teachers. (I have found that teaching ability is often inversely proportional to human kindness.) He would personalize brain cells. Each one had a personality, and a backstory, so that attending his class was like having a particularly lurid soap opera plot explained to you.
It was in this spirit that I created these videos.
What if we reimagined the cells of the immune system as boys (B cells) and girls (T cells)? B cells just spit out their antibodies and leave. T cells use specialized signaling chemicals called cytokines to coordinate the immune attack.
The movie “Mean Girls” is about the interplay between young women in a high school environment, which is a lot like the immune system. That’s the basic premise I started with. That gave me a chance to throw in some random facts about the immune system based on scenes in the movie.
There’s some other little tidbits in there that I had fun with. For example, there is evidence (reviewed in Sheril Kirshenbaum’s The Science of Kissing) that one of the functions of kissing is to compare the genetically determined cell surface proteins called “major histocompatibility complex proteins” or “human leukocyte antigens”. If the match is close, then you may be kissing your sister and you should stop. If there is no match, then you are may form a child with a stronger immune system that can attack a broader variety of invaders.
There are two movies:
The first is simply the trailer for “Mean Girls” narrated to explain what it means when re-explained as a story about the immune system.