436 



HISTOLOGY 



the pineal body from its resemblance to a pine cone, and according to Hyrtl the hypo- 

 physis below, being a round structure attached to a stem, was named the "rose hip" 

 by the Mohammedan physician Avicenna (ca. A. D. 1000). Vesalius introduced 

 the name pituitary gland. The pituita or phlegm was believed to be excrementitious 

 material, eliminated by the brain and received by the naso-pharynx, and its possible 

 origin by way of the olfactory nerves had been discussed. Vesalius and his followers 

 believed that it was collected by the infundibular funnel and eliminated by the pituitary 

 gland. If the sella turcica of a prepared skull is examined, four grooves may be traced 

 from it, two passing forward to the optic foramina, and two passing backward to the 

 lacerated foramina. Vesalius pictured these four channels as outlets for the pituitary 

 gland, the two latter (which in life are closed by cartilage) being in relation with the 

 naso-pharynx. Bartholin recorded another function of the pituitary gland, namely, 

 "to close the infundibulum lest vital spirits should escape," and finally V. C. Schneider 

 showed conclusively that the pituitary gland is not the source of phlegm. According 

 to Hyrtl this was accomplished in five classic but lengthy books, De catarrhis, 1640- 

 1642, and he adds "No physician and no anatomist should leave this fundamental 

 and learned work unread if he has time for it." 



The anterior lobe consists of solid branched epithelial cords, of irregular 

 caliber, connected with one another by frequent anastomoses. Between 



Portion of th< 

 anterior lobe. 



Epithelial cord. 



Epithelial follicle. 



Blood vessel con- 

 taining blood 

 corpuscles. 



Portion of the 

 posterior lobe. 



Multipolar cell. 



Connective tissue 

 fibers. 



FIG. 448. PORTION OF A HORIZONTAL SECTION OF A HUMAN HYPOPHYSIS, showing the boundary line 

 between the anterior and the posterior lobes. Twp gland follicles on the left each contain a dark 

 epithelial cell. X 220. 



the cords and in close relation with them, there are wide lacunar capil- 

 laries derived from several arterioles which descend along the stalk of the 

 infundibulum. The wide terminal vessels are arterio-venous connections 

 having a sinusoidal structure. Along their margins, especially in the 

 central part of the lobe, the cords are covered with eosinophilic cells, 

 having round nuclei; the axial cells of the cords are neutrophilic and less 

 granular. Although the nature of the marginal cells has not been 

 fully determined, they are usually described as glandular, and their gran- 

 ules presumably represent an internal secretion which is discharged into 

 the adjacent vessels. At the periphery of the anterior lobe, basophile 

 cells occur. 



