34 SOURCES OF KINETIC AND METABOLIC HORMONES 



.Nucleus porQventricuiaris 



Tractus suproopticohypophyseus 

 Optic 

 chiosmo 



Accumulation of 

 neurosecretory 

 material 



Plane of 

 stalk section. 



Fig. 2-10. Diagram of the pituitary body of a dog, Cams; (a) 

 before and (b) after the pituitary stalk has been cut. Neuro- 

 secretory cells in the paraventricular and supraoptic nuclei of the 

 hypothalamus of the brain pass secretory granules down their 

 axons to the neural lobe of the neurohypophysis (pars nervosa), 

 where they are stored in Herring bodies, or swollen axon endings, 

 and thence pass into the surrounding blood vessels (Fig. 2-12). 

 After cutting across the stalk, the neurosecretion accumulates 

 in the proximal part of the axons and the supply previously 

 accumulated in the neurohypophysis becomes depleted after a time 

 and is not replenished. The pars distalis of the adenohypophysis 

 (and pars tuberalis) lie in front of the pars nervosa, separated from it 

 by the pars intermedia (from Scharrer and Scharrer, 1954a). 



