42 



SOURCES OF KINETIC AND METABOLIC HORMONES 



Fig. 2-12. Diagrammatic sagittal section of the pituitary gland and 

 hypothalamus of a rabbit, Oryctolagiis, with the circulation super- 

 imposed and simplified. The neurosecretory cells (NS^ and NS") 

 have been disproportionately magnified to show their axons con- 

 necting with the primary plexus of veins (VP) in the median 

 eminence (ME) and (VI) in the neural lobe (NL). The only other 

 nerves are sympathetic vasomotor fibres (S^, S^ and S^). Blood 

 comes from the internal carotids (IC) by hypophysial arteries; the 

 upper right (HY^) takes an independent supply to the neural 

 LOBE (NL), which is drained by the main vein (V). The pars 

 INTERMEDIA (PIN) lias practically no circulation. The upper left 

 hypophysial artery (HY-) supplies the primary venous plexus in 



