The more physiology I learned, the more I realized that I needed to learn a lot more physiology. I had a reasonable understanding of applied physiology between having worked on an ambulance to help pay for college and my experience as an athletic trainer, and my bachelor’s in chemistry gave me a solid foundation in science. But the integration of these disciplines was something that needed a lot of thought and work. Physiology is the synthesis of all the body’s processes from chemistry to behavior. Taking classes and learning about the details of the inner workings of the human body became very exciting. Now I was able to understand in great detail why an athlete’s ankle would swell after it had been twisted or broken, and what the colors of a bruise meant in that athlete’s ankle. I also learned why a person in shock sweats and has a fast heart rate. I knew the facts from my previous work and now I was learning the reasons behind those facts.

We were learning about the nose. Nose physiology may be boring or uninteresting and as the pun goes, it “smells.” but the nose does more than sense odors. We learned that the membranes in the nose humidify and warm air as it is coming in. When we inhale the dry outside air is humidified and warmed to body temperature. This particular lesson was taught in late February in Michigan; so believe me inhaled air is warmed by the human nose! Hairs in the nose also catch debris and prevent solid particles from reaching the lungs. When it is cold out, if we exhale from our mouths we see our breath, which is the water condensing as it hits the cold air after leaving our warm bodies. Every kid knows that you can see your breath better if you exhale out your mouth. This is because exhaling out your mouth allows more heat and humidity to be lost as opposed to exhaling from the nose.

When I learned the difference between the air coming in the nose and out the mouth it made perfect sense to me as an athletic trainer. We have taught athletes for years to inhale through the nose and exhale through the mouth when training. Now that training lesson had a physiological reason. The air coming in through the nose was better for the lungs and was better able to cool the body. But the fastest way to release heat in an exercising athlete is to exhale through the mouth. This was a great epiphany for me, linking my previous life as a trainer to my new life as a physiologist.

I also had an equally solid understanding of muscle physiology thanks to all the athletic training and exercise physiology I had learned previously. This was a tremendous help with advanced muscle physiology, which included learning a lot about heart muscle and smooth muscle. There are three main types of muscle in humans. Skeletal muscle is the bulging leg muscles we see on football players. Heart muscle is what makes the heart contract and pump blood. Smooth muscle is sometimes called involuntary muscle, because these are the muscles we do not consciously control. The muscles of the stomach, intestines, uterus, and arteries are all smooth muscle. They are called smooth muscle because under a microscope they look smooth, whereas skeletal muscle and heart muscle look striped. There are lots of diseases of smooth muscle, and opportunities for doing research that could help people whose smooth muscle is diseased.

Smooth muscle is very different from skeletal muscle. Skeletal muscle will grow and get thicker and stronger because of exercise and conditioning. That is why those football players have big arms and legs, from the muscles that have built up in size. But smooth muscle needs no exercise to get bigger and stronger. For example the uterus; the muscular part of the womb, gets bigger and stronger during pregnancy, but not by working harder. It gets bigger because of chemical signals from the mother and the baby. So, with chemical signaling being so important, my chemistry training was important too. Arteries and other smooth muscles grow a lot too if a person gains weight or grows. I kept thinking of the athletes who took steroids to enhance muscle growth. They would get big muscles, but only when training very hard. But the uterus will grow and get stronger because of estrogen stimulation during pregnancy. Interestingly estrogen is a steroid chemical, but not a steroid like the anabolic steroids that some athletes take.

As a graduate assistant in a Ph.D. program in physiology I had to take classes, start working on a research project and help teach. My research would be with Dr. Dillon and that project was being discussed. Dr. Dillon was somewhat of an old school advisor in that he said that I was to call him Dr. Dillon until I received my Ph.D., a tradition that is coming out of favor, but not unheard of in the field. My teaching was pretty much assigned to me and the classes were all requirements for the physiology graduate students.