THE PITUITARY BODY 



pulses from certain nuclei in the hypothalamus to the neural 

 lobe. (The most complete experiments have been performed 

 in cats by Fisher, Ingram, and Ranson.) The important nu- 

 clei are the paired supraoptic nuclei which supply most of the 

 nerve fibers of the pars neuralis as well as a few fibers to the 

 different divisions of the pars buccalis. Both of the nuclei 

 must be destroyed or cut off' from the pars neuralis before the 

 latter undergoes atrophy and ceases to elaborate its hor- 

 mones. The neurones of the supraoptic nuclei degenerate and 



Fig. 4. — Diagram of hypothalamico-hypophysial fiber system of the monkey. 

 (From Ingram, Fisher, and Ranson, Arch, intern. Med., 57, 1067-80 [1936].) Diabe- 

 tes insipidus can be produced by lesions in the circumscribed region L. IS: stalk; 

 M: mammillary body; OC; optic chiasm; P/^.- pars glandularis; PP; pars neuralis; 

 PT: pars tuberalis; SHT: supraoptico-hypophysial tract; SO: supraoptic nucleus; 

 VM: ventromedial component of supraoptic nucleus; TC: tuber cinereum; THT: 

 tubero-hypophysial tract. As indicated by a broken Hne, it is possible that fibers 

 of the supraoptico-hypophysial tract pass through the optic chiasm. 



disappear after hypophysectomy — i.e., in the dog or rat 

 (Hare, 1937; Rasmussen, 1937) or after interruption of the 

 supraoptico-hypophysial tract. The filiform or paraventricu- 

 lar nuclei perhaps also directly or indirectly — i.e., by way of 

 interposed synapses with neurones of other nuclei — innervate 

 the pars neuralis. The morphological evidence for this inter- 

 pretation is, however, better than the neurological.-' 



3 The following are recently published references to authors who have made ob- 

 servations on other parts of the pituitary and its possible central connections: Col- 

 lin (1935), Collin and Fontaine (1936), Collin and Hennequin (1936), and Roussy 

 and Mosinger (1935-36). 



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