THE PITUITARY BODY 



almost independent of those of the anterior lobe. These ves- 

 sels enter and leave by the posterior pole of the pars neuralis. 

 Contrary to Popa and Fielding, as well as many other in- 

 vestigators, the authors concluded that the hypophysio-por- 

 tal veins receive no blood from the anterior or posterior lobes 

 and that the hypothalamus in a vascular sense is inde- 

 pendent of the pituitary body. On the other hand, the ter- 

 minal basal portion of the tuber cinereum — the eminentia 

 saccularis — appears from its vascular supply as well as from 

 the readiness with which it takes up vital dyes to be one part 

 of a unit composed of the eminentia saccularis, the stalk, and 

 the pars neuralis. In respect of their avidity for vital dyes 

 and their unusually rich and complex blood supply, the 

 supraoptic region of the diencephalon and the area postrema 

 of the "hindbrain" also appear to be tissues similar to those 

 of the unit just described. 



It is emphasized by Wislocki and King that the foregoing 

 description is particularly true of the monkey (and probably 

 human)' pituitary and hypothalamus. It should again be em- 

 phasized that their results indicate that blood flows from the 

 hypophysio-portal vessels to the pars glandularis and not in 

 the reverse direction, as was the contention of Popa and Field- 

 ing as well as others. The description of Wislocki and King, 

 moreover, denies the assumption of many authors that secre- 

 tions of the pituitary body have ready access to and specifi- 

 cally affect hypothalamic "vegetative centers." 



The blood vessels of the diencephalic-hypophysial region 

 in the cat are, in most respects, like those in the monkey; 

 however, the eminentia saccularis is less well vascularized in 

 the cat (Wislocki, 1937). In the cat, also, Stevens (1937) 

 measured the total lengths and average diameters of the 

 capillaries per unit volume of tissue of the various parts of 

 the pituitary body. She concluded that the pars tuberalis is 

 supplied with sinusoids even more richly than the pars glan- 

 dularis. The latter was found to have a vascular bed about 



' See also the report of Wislocki (1937). 



[4I 



