500 THE EEPEODUCTIVE SYSTEM 



lamellated appearance. Prostatic concretions may occur at all ages but 

 increase both in number and size in later life. Occasionally they attain 

 a large size and may become encysted. 



The prostatic ducts are lined by either a single or a pseudo-stratified 

 layer of columnar epithelium, and, except for their narrower caliber 

 and more regular contour, they closely resemble the secreting tubules. 

 As the ducts approach their termination their epithelium increases 

 the number of its cell layers. The larger ducts, just prior to their 



FIG. 443. PROSTATIC GENITAL CORPUSCLES. 



a, axial nerve fiber; 6, peri-axial nerve fiber. . Methylene blue. Moderately 

 magnified. (After Timofejew.) 



termination, are lined by transitional epithelium similar to that of the 

 urethra, into which they open. 



BLOOD AND LYMPH SUPPLY. The prostate gland possesses a rich 

 blood supply. Its larger vessels are found in the capsule, whence 

 they send branches into all portions of the fibromuscular stroma, and 

 form a rich capillary plexus in the connective tissue layer about the 

 epithelium of the secreting alveoli, and a second plexus in the substance 

 of the stroma itself. The prostate is abundantly supplied, also, with 

 lymphatic vessels, which are connected with the deep pelvic lymph 

 nodes. 



The capsule of the prostate, as also the neighboring connective tissue, 

 both in relation with this organ and with the adjacent seminal vesicles, 

 contains many nerve trunks, chiefly sympathetic, and small ganglia. 

 The latter are especially numerous. In this region a peculiar variety 

 of special nerve ending is found. It was formerly regarded as a Pa- 



