GLANDULAR ABNORMALITIES
The effects of heightened or lessened secretion of the sexual glands can be easily predicted. Abundant and very active interstitial cells cause the completely masculine man or the entirely feminine woman. When these cells are greatly reduced in number or dormant in their function, the sexual types are not so pronounced and approach each other in secondary characteristics. It is not until this condition becomes complicated by derangements of other ductless glands that it becomes definitely abnormal, but any variation in any one of these other organs is more than apt to have a direct effect on the reproductive system. This is shown clearly in the case of the thymus and the pineal.
The pineal gland, as we have seen, is essentially a gland of childhood. If both his pineal and his thymus are functioning normally then a child will be like other children. He will grow and develop gradually until he reaches his teens when the more drastic changes of puberty commence. It is at this time that his pineal body should cease to function and begin to atrophy. But suppose, for some reason, it begins to atrophy when he is only about six or seven years of age. What happens then? The child begins to grow remarkably, his reproductive organs develop, his figure becomes like that of an adult and he shows a strange mental precocity. This is the classical type of the child prodigy. And it was the pineal gland about which so much was said in the Leopold-Loeb murder trial.
If the pineal body continues to function well into the teens an individual who is almost the exact opposite of the one just described develops. Puberty is delayed for a long while—probably indefinitely. The child never grows up either anatomically, sexually or mentally.
The abnormal history of the thymus gland is similar to that of the pineal, but with a few slight differences. While the pineal and the thymus both act reciprocally with the sexual glands, they also have some check upon each other. It may be said in general that while both of these glands function in lieu of sexual secretion, the thymus allows the child to grow to its full stature while the pineal protects him from growing too rapidly. (It was to be borne in mind, however, that both of these glands of childhood control growth indirectly, as we shall see when we come to study the pituitary in more detail.) Accordingly then, if a child has an insufficient thymus, his growth is stunted, his bones do not harden properly, he is subject to rickets and to malnutrition, he is apt to become either very fat or very thin; and there is a corresponding retardation of mental growth.
If the thymus continues to be active after the age at which puberty normally occurs, the results are more striking even than they are when this gland is insufficient during childhood. In this case the child proceeds to grow, but he grows only as a child. His reproductive organs do not develop and he acquires none of the characteristics which typify adolescence. Human beings of this class are not rare, but on account of the striking changes which occur when a tadpole matures, that is when its metamorphosis into a frog takes place, the result of a prolonged activity of the thymus is illustrated more clearly in the case of this animal than of any other.
Tadpoles fed upon a continual diet of thymus extract will not change into frogs. They remain tadpoles, but tadpoles of tremendous size. And a eunuch who has been castrated just before adolescence has, essentially, a tadpole personality. Because his interstitial cells never become active, no check is put upon his thymus. Instead of atrophying, it continues to enlarge. Consequently a eunuch is apt to be very tall, possibly also babyishly plump, but he undergoes none of the usual adolescent transformations. His voice remains high pitched, he does not grow a beard and all of his other characteristics remain almost completely childlike.
If thyroid extract is fed to young tadpoles an effect which is the exact opposite of that produced by thymus feeding results. The tadpoles do not grow, but metamorphosis into frogs takes place when they are still very tiny. Frogs scarcely larger than a fly can be developed in this manner. Thus it appears that not all of the processes usually associated with puberty are caused directly by the sexual glands, but rather by the internal secretions of these glands stimulating others to greater or lesser activity.
The thyroid, however, is essential to normal development in childhood and later life as well as at adolescence. In children an insufficient amount of thyroid secretion produces a state of arrested development known as cretinism. Cretins are familiar figures in all feeble-minded institutions. They are small in stature, their skin is rough and coarse, their features are flat and characterless, and their tongues large and thick. They are awkward, unkempt and lazy. Mentally they are classified as idiots. Since the discovery of the active principle of the thyroid—thyroixin—cretinous children, if treated early enough, exhibit signs of marked improvement. They grow, they become more energetic and their mentality approaches more nearly to the normal.
When an insufficiency of thyroid extract occurs after adolescence, the disease known as myxedema sets in. Persons afflicted with this malady show definite and characteristic symptoms. Their hair begins to fall out, their skin becomes moist and swollen and they suffer continually from exhaustion. Most noticeable of all is a pronounced mental deterioration. This disease is commonly caused by an abnormal growth of the tissues surrounding the thyroid. This enlarged tissue crowds in upon the gland and causes it to shrink in size. It cannot under these conditions secrete the amount of extract necessary to bodily health, and myxedema results. The disease can be helped to some extent by regular doses of thyroixin and a permanent cure can be effected by an operation through which the superfluous tissue is removed and the thyroid allowed once more to resume its natural size.
An exophthalmic goiter produces results which are the exact opposite of those just described. In this case it is the thyroid gland, itself, which expands and therefore becomes hyperactive. The resulting excess in thyroid secretion causes the victim of the goiter to become extremely nervous and irritable (in contrast to the lassitude accompanying cretinism and myxedema). One of the most striking symptoms of this disease are the characteristic bulging, staring eyes. An operation by which the gland is cut down to its normal size alleviates the effects of the exophthalmic goiter.
When we were speaking of the growth of the skeleton, both in children and in adults, we noted that although it was influenced by the thymus, the pineal and the sexual glands, it was directly caused by another. This growth controlling organ is the pituitary. An excess of pituitary secretion in children brings about a condition known as gigantism. It is a hyperactive pituitary which is responsible for the giants to be seen in side shows, and a hypoactive one which occasions their fellow freaks, the midgets. An insufficiency of the secretion of this gland causes pronounced obesity and an unnatural craving for sweets in adults.
The pituitary, like most of the other ductless glands, is also definitely related to the reproductive organs. If for any reason its development in a child is retarded, puberty does not occur. An individual showing eunuchoid tendencies results.
An increase in the amount of sugar in the blood and a superactivity of the entire circulatory system always follows an injection of adrenalin. This is given as proof of the fact that the adrenal glands have a definite control over the emotions. A brief summary of some recent investigations will explain this statement. Cannon of Harvard working with dogs, and Watson of Johns Hopkins using human subjects, discovered that the chief characteristics of the primary emotions, such as fear and rage, were an increase in blood pressure and an unusual supply of sugar in the blood. These two conditions constitute the physiology of an emotion, whatever its mental correlate may be. Cannon found further that the adrenals, as opposed to some of the other ductless glands, are richly supplied with nerve fibers. From this and from other experimental evidence he concluded that impulses from the brain stimulating the adrenals bring about the characteristic emotional symptoms. Of course these glands are not dormant at unemotional periods but under stress of mental excitement they become superactive. If the adrenal is unusually large and consequently congenitally hyperactive, an emotional state can be induced by a very mild stimulation. Consequently persons who possess exceptionally hard working adrenals can under very ordinary conditions become keyed up to a high pitch of excitement. Their hearts pound fiercely, their nerves are taut and they are constantly ready for action. Their digestions may suffer as a result of most of their energies being turned away from normal nutritive activities, but they can accomplish a great deal as long as their health continues.
Persons with a deficiency of adrenal secretion show opposite characteristics. They tire easily, they are continually depressed and they take very little interest in life.
Each gland which we have studied has been shown to have some connection with sexual development. The adrenals form no exception to this rule but their influence in this respect is even less straightforward than that of the pituitary and thyroids. This is how Professor Berman describes the relation between the adrenal glands and sexual phenomena:
“In certain disturbances of these glands, especially when there are tumors, which supply a massive dose of the secretion to the blood presumably, peculiar sex phenomena and irregularities are produced. If the disease be present in the fetus, taking hold before birth, and so brought into the world with the child, there evolves the condition of pseudo-hermaphroditism. The individual, if a female, presents to a greater or less extent the external habits and character of the other sex. So that she is actually taken for a man, although the primary sex organs are ovaries, often not discovered to be such except when examined after an operation. How closely such an occurrence touches upon the problems of sex inversion and perversion comes at once to mind.
“If the processes involving the adrenal cortex attacks it after birth, the symmetrical correspondence and harmony of the secondary sex characters are not affected. But there follows a curious hastening of the ripening of body and mind summed up in the word puberty, a precocious puberty, with the most startling effects. A little girl of 2, 3, or 4 years of age perhaps will come to exhibit the growth and appearance of a girl of 14. She begins to menstruate, her breasts swell, she shoots up in height and weight, sprouts the hair distribution of the adult, and the mentality of the adolescent, restless, acquiring, doubting emerge. A tot bewitched into puberty! A boy of six or seven may suddenly, in the course of a few weeks or months, become a little man, robust, rather short and stocky, but moustached, with the muscular strength and sexual power of a man and thinking as a man....
“If the trouble in the adrenal cortex starts after puberty, phenomena of the same type, but of a different order, exhibit themselves. A woman, say in the thirties, becomes thus afflicted. Slowly or quickly her body will be covered by an abundant growth of hair, more or less of a beard and moustache appear upon the face, her voice will become deep and penetrating, her muscles will harden, and she will show a capacity for hard physical labor. Sexually she appears to be made over, masculinity now predominates in her make-up. Virilism is the name by which the French in particular have popularized the knowledge of the condition.”