THE PEOSTATE GLAXD 



389 



which are the glandular alveoli. These septa converge toward the 

 urethra, which penetrates the ventral portion of the organ, their 

 muscular fibres finally blending with the sphincter fibres of the 

 prostatic portion of this canal. 



The stroma consists of smooth mus- 

 cle and connective tissue; their fibres 

 are intimately blended. The muscle 

 cells form either groups or bundles of 

 variable size, or are frequently isolated 

 within the meshes of the connective 

 tissue. Their extreme abundance in 

 some parts exceeding the connective 

 tissue in volume is characteristic of 

 the prostatic stroma. The connective 

 tissue, which is sparingly supplied with 

 elastic fibres, is rich in cells. Near the 

 secreting alveoli, which possess no true 

 wall other than their epithelium, the 

 muscle fibres are absent and the cellular 

 connective tissue becomes more promi- 

 nent, thus forming a sort of tunica 

 propria for the tubular alveoli. 



The secreting epithelium is of the 

 tall columnar type, sometimes forming 

 a single, sometimes a multiple cell layer. 

 Its cells possess spherical or ovoid nuclei 

 which lie in their deepest third. Their 

 cytoplasm is finely granular and often 

 contains small yellowish granules. The 

 epithelium rests directly upon the 

 underlying connective tissue, the base- 

 ment membrane being absent or but 

 poorly developed. Wherever it is pos- 

 sible to demonstrate a membrana pro- 

 pria, it consists either of elastic fibres or 

 of flattened connective tissue cells which 

 are closely applied to the attached sur- ^ 

 face of the epithelium. 



The epithelium is remarkably folded upon itself, the narrow 

 interval between the two layers of the epithelial folds being always 

 occupied by delicate extensions of the connective tissue stroma. 



FIG. 315. MODEL OF A RECON- 

 STKUCTED PROSTATE GLAND 



OF MAN. 



The figure includes one lobule. 

 The narrow duct expands and 

 terminates in a large number of 

 alveoli of very varied size and 



