I have to admit that detailed chemistry and physiology has never been my strong suite. Not only did I have to take physiology, embryonology, and chemistry courses to get my degrees, at least one third of my psychology classes also included biology, biochemistry, and brain physiology components, and I even had to teach much of it when I was teaching entry-level college courses - and I still can't explain most of what I've learned, because I forgot it the minute I didn't need it any more (I even had to re-study those subjects before teaching them).
For example, I remember the mnemonic acronym for the cranial nerves (On Old Olympus' Towering Top, A Finn And German Viewed Some Hops), but I only can ever remember the Olfactory nerve, the Occular nerve, the Trigeminal nerve and the Vagus nerve.
I can understand a lot of the medical terminology, and can read medical journal articles without too much trouble, but remembering it or understanding it well enough to explain it.... not so much.
What I do find astonishing is that there are some rather significant ways in which people can differ on even basic physiological processes though.
I saw an extreme example on a television show about the genetic factors in both obesity and slimness. Featured on the show was a little boy who doctors believed had a genetic condition similar to the dogs and cows shown on this page:
http://www.environmentalgraffiti.com...ws-ripped/2780
The conditon makes it easier for him to build muscle and very difficult for him to store fat.
In the program, they discussed the possibility of developing a drug that could mimic this disorder as a means for treating muscle wasting diseases and obesity by producing the myostatin deficiency that results in the extraordinary muscle development.
There is another genetic condition and other illnesses that prevent a person from gaining fat. They can eat 20,000 calories a day, and still not be able to gain weight.
Even though these conditions (at least those in the extremes) are incredibly rare, it's still amazing to me that they exist at all... that there can be so much variability in the metabolic process from one person to another.