ANATOMY OF THE PITUITARY BODY 



did not regard them as cells typical of that part which he 

 described as being made up of numerous blood vessels, much 

 connective tissue, as well as small cells with pyknotic nuclei 

 and a cytoplasm containing minute basophihc granules. 



The pars neuralis. — The pars neuralis is perhaps the least 

 homogeneous part of the pituitary body. It is composed of 

 non-myelinated nerve fibers, neuroglia-like cells, and baso- 

 philic cells (rarely oxyphils) as islets or cords of cells growing 

 from the pars intermedia or the pars glandularis. The inva- 

 sion of the part by basophils, whether originating from the 

 pars intermedia or the pars glandularis, appears to be more 

 frequent in the pituitary of man and the primates than in 

 that of lower animals. "Hyaline material," thought by Her- 

 ring, Gushing, and others to represent the true secretions of 

 the pars neuralis and to be derived from basophils (holocrine 

 secretion) or colloid, can also be observed. 



Various neuroglia-like cells peculiar to the pars neuralis 

 have been described in the pituitary of the ox by Bucy (1930), 

 who named them "pituicytes." Their staining reactions may 

 be similar to those of true neuroglia. Some of these cells con- 

 tain granules of pigment resembling a lipochrome rather than 

 melanin. xAmong recent descriptions of the similar cells of the 

 human pars neuralis are those of Hoenig (1922) and Scheele 

 (1929). Stern (1932) believed that a melanin-like pigment 

 could be found among the cell processes in the pars neuralis 

 of many human pituitary bodies. 



True nerve cells have not been demonstrated in the pars 

 neuralis. 



The nature and significance of the basophilic cells in the 

 pars neuralis are still subjects of controversy. Many doubt 

 the existence of a true pars intermedia in the adult human 

 pituitary, and consider that the basophils, often infiltrating 

 into the pars neuralis from the site of the juvenile pars inter- 

 media, are basophils like those of the pars glandularis. In 

 lower mammals, invasion of the pars neuralis by basophilic 



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