CHAPTER VIII. 

 PATHOLOGY OF THE PITUITARY. 



FUNCTIONS OF THE PITUITARY. 



The pituitary is a gland or organ located at the base of 

 the skull, in the cavity of the sella tursica. It is com- 

 posed of two lobes; a large anterior lobe and a smaller 

 posterior lobe. The latter, an invagination of the inter- 

 mediary brain of the embryo, is still called nervous lobe. 

 It is made up of a loose stroma, containing connective 

 tissue and capillary blood vessels. 



The anterior or epithelial lobe is a derivative of the 

 bucco-pharyngeal ectoderm. It is made up of an anterior 

 and posterior part separated by a hilum. 



The anterior or glandular portion is made up of alve- 

 oli of variable sizes, containing cells which have various 

 affinities for certain dyes, placed in a vascular network 

 very well developed. 



The posterior part, not very noticeable in man, consists 

 of a layer of cylindrical cells or a ciliated epithelium, or of 

 vesicles looking something like those of the thyroid and 

 made up of a thick connective tissue wall line by cylin- 

 drical or ciliated epithelium. 



The pituitary secretes substances brought in evidence 

 by histology. They consist of fats, a coloidal material 

 which is found between the strands of connective tissue, 

 or in the vesicles. Experimentation also reveals the 

 presence of a hormone in the posterior lobe called pitu- 

 itrin or hypophysin, the action of which is comparable to 

 that of suprarenalin. 



The physiological action of the pituitary is obscure. 



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