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Show n 't WHY WE BEHAVE LIKE HUMAN BEINGS B GEORGE DORSEY. Pa. D, LL D. tt ". ............ ,.,..f The Secret of the Thyroid yilB endocrine gland best under- stood Is the thyroid (shieldlike) astride our Adam's apple. It varies Indivldunlly and with age. It la relatively rela-tively largest In fetul life. At btrth Its welKht In proportion to the entire hody Is as 1 to 300, by the third week 1 to l.KiO, and In the adult as t to 1,8(10. It i gcnernlly larger In women than In men. Why this Is so la not yet known. The thyroid uanally consists of two equally developed lobes two Inches long, an Inch and a quarter broad. They vary greatly; one lobe may be much iarger tlmn the other, or may be quite absenf. Generally the two lobes are connected by an Isthmus; this also varies In position or may be absent. There (nay be accessory thyroids down the trachea ns far as the heart. Only In higher fishes does the .thyroid .thy-roid become a ductless gland, take on new functions, and start new career. ca-reer. In man, a duct Is sometimes found In the Isthmus vestige of a condition found In lowest fishes, echo of millions of yenrs ago. It Is prone to trouble. Children with deficient thyroids, through removal, atrophy, or Injury, become heavy-featured, gibbering, Idiotic dwarfs known as cretins; they do not metamorphose Into normal adults. These appulling results In both children chil-dren and adults have been corrected by feeding thyroid extract Knlurgement of the thyroid from whatsoever cause Is called goiter, or Derbyshire reck. But an over-developed or over-artlve thyroid produces a definite dlaeuse known as toxic or exophthalmic goiter, or Graves' dlaeuse. dla-euse. This is characterized by Increased In-creased metaholisin and blood pressure, pres-sure, rapid pulse, lax and moist skin, nervousness, and protruding eyeballs hence the name, "exophthulmlc." The remedy Is still In the bands of the surgeon. It Is believed that the activating principle of the thyroid hormone la thyroxin, lsolnted by Kendall In 1018. Thyroxin Is a crystalline compound of three molecules of Iodine fixed In a protein derivative: trl-lodo-trl-hydro-oxylndole propionic acid, or 05 per cent of Iodine. Only the thyroid secretes thyroxin, and apparently It is the Iodine in thyroxin thy-roxin that tells the story. Iodine a found In many seaweeds; Is three times more abundant In codfish than In human beings; Is found In traces In milk and In drinking water; and gets its name from Its violet (lodes) color 1 Possibly no life exists without Iodine. Io-dine. Certainly normal human life Is Impossible without one one-hundredth of a grain of thyroxin a day. Three and a half grains of thyroxin are all that stands between Intelligence and JUI1IKCUJI.Y. The adrennls, or suprarenals, get their name lroro their position Jnst above the kidneys. Normally they are of the size and shape of a large bean. But they vary: one or, In rare cases, both may be absent; there may be accessory ac-cessory adrenals varying In size from a pin head to a large pea. Removal of both glands Is fatal, often within a few hours. When death does not follow fol-low their removal it Is because accessory ac-cessory adrenals are present and can function. Adrenln Is a powerful drug and a powerful cardlo-vascular stimulant. Normally our blood contains abont eight -nlllfgrams of It, wlilcb means that the proportion of adrenln to arterial ar-terial blood is one part to a billion. It Influences some tissues when diluted di-luted to one part in lOO.OUO.OOO. It depresses de-presses the Intestinal canal when diluted di-luted to one part In 880,000,0001 Large doses are fatal. Adrenln Is a drug, one of the most potent our body concocts. Yet adrenal feeding leads to no known or proved results. The administration of the drug adrenalin does lead to profound results. re-sults. Our body blood contains this drug. Whether it is mnde by or excreted ex-creted by the adrennls Is still an open question, hut that adrenln has specific action on the vascular system, the nervous system, the blood, the alimentary ali-mentary canal, and on sugar mobilization, mobiliza-tion, there If no doubt. Nor Is there any doubt thnt when administered as a drug It Increases the action of local anesthetics by constricting the blood i vessels, thus preventing local loss of the anesthetic. And as this reduces the amount of anesthetic required. It also reduces the amount of toxin danger dan-ger from the anesthetic. It checks hemorrhages. It allays the spasms of acute bronchial asthma. It also stimulates stimu-lates weak hearts and fortifies the hearts of tlv old and Infirm against the shock of operation. In short, adrenalin exerts an Influence Influ-ence upon ail smooth muscle enervated ener-vated by flhera of the autonomic nervous nerv-ous system. Thnt mukes Its responsibility respon-sibility enormous. Its Influence on nullum nu-llum destiny second to none. Iff) by George A. Doraey. I |
