GRAM FOR GRAM, I pack more dynamite than any other organ in your body. I can cripple you, make you sick, send you to the Looney Bin even kill you. I haven't done any of these things, of course. In fact, I have behaved so well that you are barely aware of my existence.
I am your adrenal gland that perches on top of your right kidney. Like a little jockey, my twin partner rides the other. I am roughly the shape of a tricorne hat, not much larger than the tip of a finger; I weigh about as much as a nickel. But my talents are immense: it would take acres of chemical plant to synthesize the 5O odd hormones or hormone like substances that I manufacture. Although I produce less than a thousandth of an ounce of them a day, they play key roles in just about everything you do.
I am absolutely essential to life. Remove my partner and me, and you would be dead in a day or so - unless your doctor started feeding you artificial hormones in a hurry. Slow down our work, and watch your life slow down too. Soon you would become weak, debilitated - a mere shell of your former self.
Had a portion of me become overactive when you were a boy, the results would have been similarly striking. The little lad would have become a little man. Your voice would have deepened, your beard sprouted, your sexual apparatus taken on manly proportions. Bone ends, which should remain open and soft until full growth is reached, would have closed prematurely. And you would have gone through life as a runty fellow.
For a long time I was the mystery organ of your body. No one knew what I did - only that my removal meant death. As chemists began to pry out my secrets, they discovered my virtuosity. When they learned of my cortisone like hormones, for instance, they were truly astonished - for these substances alone are useful in treating upward of 100 diseases, ranging from gout to ulcerative colitis to asthma.
And consider my architecture. I have one of the richest networks of blood vessels found in the body. Each minute, six times my weight of blood passes through me. I also have a big reserve capacity. Ten percent of my tissue is sufficient to meet your normal needs for my hormones. However, if I were to dwindle down to the ten percent level, and you faced a really big stress - a severe illness, say, or major surgery - it would very likely kill you. You wouldn't have enough of my protective hormones to save you.
Actually, I produce two basic sets of hormones. My medulla, or core, makes one set; my cortex, or rind, the other. My core has a unique feature: its own hot line to your brain. Any strong emotion - a sudden rage, an overwhelming fear - and my medulla gets the information instantly. Obviously, I don't know the nature of the emergency. So I prepare you for either fight or flight. My medulla starts pouring two hormones - adrenalin and nor adrenalin - into your blood.
The response of your body is extraordinary. Your liver immediately releases stored sugar instant energy into the bloodstream. My hormones shut down skin blood vessels - you go pale - and start sluicing this extra blood into muscles and internal organs. Your heart speeds up, and arteries tighten to hoist blood pressure. Digestion comes to a halt - no time to worry about that detail right now - and the clotting time of your blood is quickened, in case of injury.