HORMONAL CONTROL 



557 



NEUROHYPOPHYSIS. Several of the hypothalamic nuclei are made up of 

 typical neuro -secretory cells for which the posterior lobe of the pituitary 

 body (pars nervosa) and the median eminence of the pituitary stalk serve 

 as a storage -release organ (Fig. 727) (Scharrer and Scharrer, 1945 ; Weiss 

 and Hiscoe, 1948 ; S. W. Smith, 1951 ; Zuckerman, 1954 ; van Dyke et al., 

 1955 ; and others). The posterior lobe of the pituitary is thus homologous 

 with the corpus cardiacum of Insects, the anterior (non-nervous) lobe with 

 the corpus allatum. In Fishes the essential centres of this endocrine function 

 are two paired nuclei — the nucleus pre -opticus and the nucleus lateralis 



-Pf^Rf^BNTRICULAR NUCLEUS 

 ■ SUPRA-OPTIC NUCLEUS 



Fig. 727.- 



PROCESSUS 

 INFUNDieULARfS 



POSTAL VESSELS 



-The Neuro-endocrine System of a Primate. 



Diagram to indicate the relations of the pituitary gland to the hypothalamus (after 



Zuckerman). 



tuberis (E. Scharrer, 1928 ; Palay, 1943-45) ; in Amphibia the nucleus 

 pre-opticus alone (E. Scharrer, 1933 ; Gaupp and Scharrer, 1935) ; in 

 Reptiles the two divisions of the nucleus pre-opticus are involved — the 

 supra-optic and paraventricular nuclei (Gaupp and Scharrer, 1935) ; and in 

 Mammals to these may possibly be added a third group of cells, the mammillo- 

 infundibular nucleus ^ (S. W. Smith, 1951 ; Hanstrom, 1952-53 ; Zetler, 

 1953 ; and others) ; all of these are connected to the pars nervosa of the 

 pituitary and the cells of the median eminence of the stalk by the hypo- 

 thalamo -hypophyseal tract to form the neurohypophysis. The possibility 

 of the existence of secretory cells in the posterior lobe of this composite 

 organ, either in the pars nervosa or the pars intermedia, is a matter which 



^ These three nuclear masses, made up of large vacuolated cells with eccentric nuclei, 

 form the anterior group of hypothalamic nuclei. The supra-optic nucleus lies close to the 

 pituitary stalk immediately above the optic chiasma at the anterior end of the optic tract 

 and projects a sliort distance along the anterior aspect of the tuber cinereum. The neighbour- 

 ing paraventricular nucleus is a flat plate lying close against the ependymal lining of the 

 thircl ventricle. The mammiUo-infundihular nucleus is close to the cephalic end of the supra- 

 optic nucleus. 



