COORDINATION 



445 



thetic compounds such as ephedrin produce 

 similar effects when administered to ani- 

 mals. If the medullary portion of the 

 adrenals is removed from an animal, death 

 does not follow nor is the animal markedly 

 affected by its loss. If injections of med- 

 ullary extract are given to such an animal 

 or one with intact adrenals characteristic 

 changes occur rather rapidly. The heart ac- 

 tion becomes stronger and the blood vessels 

 to the skin and viscera constrict, sending 

 most of the blood to the muscles, brain, and 

 lungs. The hair "stands on end," the pupils 

 dilate (wide-eyed), and the skin blanches. 

 The spleen constricts, forcing its reserve of 

 blood out into the general circulation, and 

 simultaneously the blood's ability to clot is 

 stepped up. More glycogen in the liver is 

 converted to glucose, so that the total 

 amount in the blood is definitely increased. 

 This chain of events prepares the body for 

 undue stress such as occurs in a fight or a 

 sudden retreat. The body is made ready to 

 function to the maximum of its ability in 

 case a sudden burst of energy is needed. 

 Provision against possible injury is afforded 

 by the increased speed of blood coagula- 

 tion. This whole series of effects is similar 

 to excitation of the sympathetic nervous 

 system. Thus, both the nervous system and 

 the adrenal medulla play an important role 

 in fear and ancrer. Knowledge of this fact 

 has lead to the so-called "emergency theory 

 of adrenal function." 



The cortex. The cortex of the adrenal is 

 essential for life, although when even such 

 a small portion as one-fifth of the total 

 gland tissue is left, life is undisturbed. Its 

 product or products are not as simple as 

 adrenalin. They are numerous; in fact, over 

 20 such compounds have been isolated in 

 recent years. The first substance, isolated 

 in 1930, was called cortin and was effective 

 in treatment of people suffering from Addi- 

 son's disease, which is the name identified 

 with a deficiency of this portion of their 

 adrenals. Since that time, many compounds 

 have been produced, the best known and 



most effective being cortisone. It is interest- 

 ing to note that all of these are steroid (fat- 

 like) compounds which are closely related 

 to the gonadal hormones, testosterone and 

 progesterone, and, as will be seen below, 

 produce some effects on the gonads as well 

 as other parts of the body. 



If the cortex fails to function, marked 

 changes occur which are fatal if uninter- 

 rupted by treatment. The carbohydrate 

 metabolism is greatly affected, as indicated 

 by a drastic drop in blood sugar, because of 

 the inability of the enzymes to convert the 

 proper amounts of proteins to carbohy- 

 drates and then to convert the latter to 

 sugar in the liver. Salt (NaCl) is lost from 

 the blood and tissues at a rapid rate which 

 reduces the entire blood volume and with 

 it the blood pressure. As Addison's disease 

 progresses, the sexual functions fail due to 

 an actual atrophy of the Graafian follicles 

 and the seminiferous tubules. 



If, on the other hand, the gland becomes 

 overactive as a result of irritation caused 

 by a tumor, changes of a different kind 

 occur. In males, the maleness is greatly en- 

 hanced, accompanied by excessive hair 

 growth. If it happens to a very young male 

 child the sex organs may become fully ma- 

 ture (except the testis) within the first or 

 second year of life, and the hair, muscula- 

 ture, and voice resemble that of an adult 

 man. These are very rare cases, fortunately. 

 In females, the situation is even worse. If 

 the overactivity occurs in an adult woman 

 the changes are all toward maleness; the 

 beard grows (the bearded lady in the cir- 

 cus ) , the body becomes more muscular, and 

 the voice deepens. Even the female sex or- 

 gans begin to atrophy and become non- 

 functional. These effects of the cortical hor- 

 mones are not well understood, in spite of 

 the sudden burst of experimentation result- 

 ing from the recent discovery that corti- 

 sone, when given in controlled doses, has 

 a beneficial effect on a large number of 

 diseases, among them arthritis. Because the 

 hormone's beneficial effects cover such a 



