The Endocrine Glands - 409 



and finally death. Clinically the picture 

 includes a very high blood sugar level; per- 

 sistent glucose in the urine (sometimes ap- 

 proaching 8 percent); depletion of the gly- 

 cogen stores of the liver; and — when the 

 comatose stage is reached — a distinct acidosis, 

 with detectable amounts of acetone and re- 

 lated compounds in the blood and urine. 



All these symptoms point to a generalized 

 impairment of carbohydrate metabolism in 

 the body. In the absence of insulin the tissues 

 of the body seem to lose their capacity to 

 metabolize glucose effectively, and the liver 

 fails to store glycogen adequately. Accord- 

 ingly, glucose accumulates in the blood and 

 drains forth in the urine. Even if carbohy- 

 drates are withheld from a diabetic, glucose 

 continues to be formed and excreted. Despite 

 the fact that the tissues cannot use it, glucose 

 continues to be mobilized by an excessive 

 deamination of absorbed amino acids; and 

 even the tissue proteins are sacrificed to the 

 same quite useless end. Fats are also oxidized 

 to an excessive degree. This leads to a piling 

 up of certain acidic compounds — formed as 

 intermediary products during the excessive 

 oxidation of the fat — at the terminal stages 

 of acidosis. 



Injection of insulin alleviates the diabetic 

 symptoms, but the action only persists for 

 several hours. Consequently diabetics require 

 a daily regime of insulin injections, and the 

 maintenance of health depends upon a me- 



thodical adherence to the treatment— al- 

 though rarely the endocrine tissues of the 

 pancreas may recover their normal function. 



Hyperinsulinism. Unless accurately cali- 

 brated, an injection of insulin may overshoot 

 its mark. In this case the blood sugar level 

 sinks drastically and hypoglycemic shock (p. 

 341) ensues. Therefore, most patients take 

 precaution to have sweet drinks on hand — to 

 be taken at first sign of "postinjection shaki- 

 ness." If shock ensues and the individual be- 

 comes unconscious, the attending physician 

 may have difficulty in deciding quickly 

 whether to give sugar for shock or insulin for 

 diabetic coma. 



Insulin has proved most effective in the 

 treatment of diabetes mellitus, but there are 

 still several unsolved aspects of the problem. 

 In rare cases, for example, no appreciable 

 degeneration of the endocrine tissues of the 

 pancreas can be found at autopsy even when 

 diabetes seems to have been the cause of 

 death. Also some evidence indicates that ab- 

 normalities of anterior pituitary and the 

 adrenal cortex, as well as of the pancreas, 

 may sometimes be involved in the disease. 



THE PITUITARY 



The hypophysis, or pituitary gland, is 

 scarcely larger than a pea, and yet this gland 

 is one of the most important in the whole 

 endocrine system. The pituitary lies approxi- 



Fig. 22-8. The pituitary gland of man. Note 

 the intermediate part (stippled area, just 

 posterior to the cleft) between the principal 

 tissues of the anterior and posterior lobes. 



INFUNDIBULUM 

 CLEFT 



POSTERIOR LOBE. 



ANTERIOR LOBE 



