Structure Function – The More, The Less – God and Man
The human body is a beautiful thing. Why? Because of how effectively and reliably it establishes homeostasis in an environment which is in constant flux. Most of us take our inner workings for granted, but every second of every day, our body is constantly fighting against change. Obama would be appalled. 😛
From how we metabolize food into energy (while nourished, fasted, starved, or stressed) to how our organs communicate with one another, chaos is rampant. Second messengers here, some transporters over there, and a whole barrage of neural signals all over the place. In spite of the complexity, the human body really is the quintessential example of efficiency. A very influential professor at Baylor Med summarizes histology as a sequence of “structure-function” relationships and “the more, the less” examples (in line with I.M. Pei’s creed). This is precisely what efficiency is in a more colloquial sense. Furthermore, I firmly believe in the concept of evolution and attribute our current biology solely to thousands of years of natural selection. Or as some of my classmates like to say when asked why we are what we are – “Those who did it some other way are dead.” 🙂 Structure may dictate function, but change in biology requires time… lots of time.
Medical school has also brought me closer to knowing what God and Man is. I believe that a higher power, aware of all future events, intended for Man’s biology to unfold with adaptation in mind. Every single structure (macro or microscopic) has at least one important function, and in some cases, a function vital to the survival of our species.
Take the respiratory tree – at the terminal end (alveoli), type I pneumocytes permit gas exchange at the highest possible rate. Why? Because they have an extremely thin, fused membrane with the surrounding vasculature allowing for diffusion quantified by Fick’s Law. So how about the upper respiratory tree? Do we find these thin cells in the anatomically dead areas (bronchi, bronchioles, etc.)? No, because you don’t need them there! Instead, we find several measures to prevent against infection and other damage to the alveoli using cilia, mucus, and immunological molecules (ie, sIgA). What if the respiratory tree was designed in any other way? At this point, I can’t think of a more resourceful scheme without jeopardizing oxygen exchange.
Sure it sounds like common sense, but God definitely placed emphasis on having the greatest function with the least amount of material. In other words, there’s virtually no wasted resource in the body.
Studying the human body in this much depth continues to show me how ridiculously integrated everything is. Being chased by a snarling dinosaur? Well let’s just slow down those kidneys and digestion so we can channel more resources to your leg muscles. Having an episode of high blood pressure? Well let’s let your kidney release renin, get it ultimately converted to angiotensin II in your lungs, and then release aldosterone from the zona glomerulosa of your adrenal cortex. And all of this without you having to consciously be aware of it. Now that’s positively elegant!
Winston Churchill once said “to improve is to change; to be perfect is to change often.” As a result of the body’s ability to constantly respond to both internal and external changes, I’m beginning to think that as far as perfection goes in this world, God’s most superb example is within each one of us.