CHAPTER XV 



THE FUNCTION OF THE PITUITARY BODY 



A. Comparative Anatomy of the Pituitary Body 



1. The Mammalian Pituitary Body 



RATHKE was the first to point out the double origin of the 

 pituitary body, from the brain and from an invagination of 

 the mucous membrane of the alimentary tract. Other observers 

 of this period looked upon the body as part of the brain. 

 Luschka called the body a "nerve gland," consisting of two 

 parts, separated by pia mater ; while Ecker includes the 

 structure of both portions under the name " Blutgefassdrusen." 



Burdach regarded the nervous portion as the " filum ter- 

 minale anterius " of the cerebro- spinal canal; and Virchow 

 and others noticed in the anterior portion colloid vesicles 

 like those of the thyroid. 



The anterior lobe is admittedly glandular in its nature, 

 but the structure of the posterior lobe has been variously 

 described. Earlier writers looked upon it as a mass of con- 

 nective-tissue cells and fibres, which, during the course of 

 development, have destroyed all trace of the original nerve 

 tissue. Berkley described nerve cells and glia cells in the 

 posterior lobe. Kolliker speaks very doubtfully about the 

 matter, even about the results of investigation by the silver 

 chromate matter. 



Osborne and Swale Vincent could detect only very few 

 undoubtedly nerve cells in the infundibular portion. These 

 observers also confirmed and utilized experimentally the fact 

 that the posterior lobe has an epithelial investment. 



The pituitary body consists of three portions : (1) The 

 anterior lobe ; (2) the intermediate portion ; and (3) the 

 posterior lobe, or nervous portion. 



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