CHAPTER I 

 THE ANATOMY OF THE PITUITARY BODY 



SPECULATIVE interest in the pituitary body has ex- 

 isted at least from Galen's time down to the present. 

 Scientific investigation of this apparently unimportant 

 structure, however, required the microscope, and began with 

 Rathke's (1838) description of some phases of its develop- 

 ment. For the next half-century the only clear-cut findings 

 were anatomical. The complex development of the pituitary 

 body as well as the histology and cytology of its main divi- 

 sions continue to be favorite subjects of anatomical investi- 

 gation. 



THE EMBRYOLOGY AND COMPARATIVE ANATOMY OF 

 THE PITUITARY BODY 



The important anatomical divisions of the pituitary body 

 are the following: 



Part Embryonic Origin 



Pars glandularis. . . .Rathke's pouch of buccal ectoderm 



Pars intermedia. . . .Superior part of caudal portion of Rathke's pouch 



Pars tuberalis Paired lateral lobes at the ventro-nasal end of 



Rathke's pouch 

 Pars neuralis Infundibular process of diencephalon 



The term "pars anterior" ordinarily refers to the pars 

 glandularis, but may include part of the pars tuberalis; the 

 term "pars buccalis" usually includes all the structures de- 

 rived from Rathke's pouch. The term "pars posterior" com- 

 monly refers to structures posterior to the residual lumen of 

 Rathke's pouch, and therefore includes the pars intermedia, 

 the pars neuralis, and often part of the pars tuberalis. 



The development of the pituitary in the cat is shown dia- 

 grammatically in Figure i. According to modern morpholo- 



[I] 



