I AM A PINKISH, pea-size nubbin of tissue. I hang, like a cherry, on a tiny stem from the underside of your brain. I weigh only about 1/50 of an ounce-and 85 percent of that is water. But after your brain I am probably the most complex organ in your body. I play a key role in almost everything that you are or do.
The all-important hormones that I secrete can work wonders or wreak havoc. I can let you live a perfectly normal existence, I can make you sick with a bizarre spectrum of diseases-or I can kill you. It was one of my hormones that gave you that initial push into the world: oxytocin started the contractions of your mother's womb. It was I who decided that you should be of normal size, rather than a three-foot midget or an eight-foot giant. I can shrink your sexual organs back to child's size, or so hasten your aging process that you will be old in a few months. I am your pituitary gland.
I have been described as your master gland, the conductor of your endocrine symphony. I take my orders straight from that prune-size section of your brain called the hypothalamus, from which I hang. It is my job to monitor the activity of other glands, to see that they produce exactly the right amounts of their hormones. I suppose you could call me the chemical boss of your body. And I'm not bragging when I call myself the earth's most compact and intricate chemical plant.
I am divided into two lobes. My small posterior lobe stores two hormones produced by the hypothalamus. My much larger anterior lobe produces most probable ten hormones or more-no one is quite sure. These hormones are among the most complex substances known to man. My total daily output, however, is less than 1/1,000,000 of a gram.
It took a long time to pry the first of my secrets from me. For centuries, doctors thought my function a lowly one: I was believed to be the source of nasal mucus! My elusive secretions were present in far too small quantities to be detected until the advent of modern chemistry. Now they are being found by accumulating large quantities of different animal and human pituitaries.
One of my hormones manages the thyroid gland in your neck. If I should secrete too much of this thyrotropic hormone, thereby setting too fast a pace for the thyroid, you would almost literally burn up. Your appetite would be wolfish, yet you would remain rail-thin. On the other hand, if I were to produce too little of this hormone, you would be sluggish, puffy, dim-witted. Fortunately, I have a built-in feedback mechanism to prevent either of these things from happening.
Much of the same situation exists with testicles. I have two hormones, which govern these glands - one by stimulating production of sperm cells and male hormone, the other by promoting growth of the duct system to transport the sperm or to nudge along development of ovaries and production of eggs. Thus, fertility - and life - depend on me.
For Females, I normally secrete only enough follicle stimulating hormone (FSH) and interstitial-cell stimulating hormone (ICSH) to produce a single mature egg a month. If I we're to go on a spree and produce too much FSH and ICSH, five or more eggs might ripen in a single month and this could result in quintuplets. It's the same with testes too little FSH and ICSH and he would become a fretful, whining and sexually apathetic; too much, and he might well become a snorting bull.