CHAPTER II 



THE EFFECTS OF HYPOPHYSECTOMY (WITH 



REMARKS ON THE EFFECTS OF LESIONS 



OF THE HYPOTHALAMUS)^ 



THE observation of the effects of the removal of a 

 gland of internal secretion is generally the most im- 

 portant step in the elucidation of the gland's func- 

 tion. In this respect the pituitary body has presented unusu- 

 al difficulties. In the first place, in mammals at least, the 

 gland is shielded by bone against experimental insults on al- 

 most all sides; in addition, it is surrounded laterally by a rich 

 venous sinus. Second, the pituitary body is in intimate rela- 

 tion to the hypothalamus; not only is the infundibular part 

 of the tuber cinereum continuous with the pars neuralis, but 

 a portion of the pars buccalis — usually the pars tuberalis — 

 may also be attached to the floor of the tuber cinereum, espe- 

 cially on the nasal side. Therefore, removal of the gland, so 

 complete that no remnants of pituitary tissue can be found 

 histologically, is almost inevitably complicated by injury to 

 the basal part of the hypothalamus (tuber cinereum). Even 

 the incomplete extirpation of the pituitary body may be at- 

 tended by injury of the tuber cinereum. Although our knowl- 

 edge of the physiology of the hypothalamus is very imperfect, 

 there can be little doubt but that it is of decisive importance 

 in some phases of the metabolism of water, fat, and carbohy- 

 drates, probably in the regulation of the temperature, and, 

 less directly perhaps, in the nervous control of the respiratory 

 movements and the cardiac rate. 



It is therefore not surprising that the literature on hypo- 



' For references to the older literature the reader is referred to the books or arti- 

 cles of Aschner (1912); Gushing (1912); Biedl (1913); Leschke (1919); and Bailey 

 and Bremer (1921). 



[34I 



