MALE URETHRA. 



283 



ducts, surrounded by thin rings of smooth muscles, consist of simple low 

 epithelium. They may connect directly with the end pieces, or a secre- 

 tory duct may intervene. 



The muscularis of the prostatic part of the urethra consists of an 

 inner longitudinal and an outer circular layer of smooth muscles. Both 

 layers continue throughout the membranous part; the circular layer ends 

 in the beginning of the cavernous urethra leaving only oblique and lon- 

 gitudinal bundles in its distal part. 



Mucous membrane of the urethra. 



Epithelium. Tunica propria. Urethral glands. Submucosa. 



\ 



Tunica 

 albuginea. 



Arteries. Connective tissue Bundle of smooth Cavernous spaces, 

 trabeculae. muscle. 



FIG. 322. TRANSVERSE SECTION OP THE PARS CAVERNOSA URETHRAE OP MAN. X 28. 



Corpus cavernosum nrcthrae. In the submucosa of the cavernous 

 urethra there are many veins (Fig. 322) which become larger and more 

 numerous in and beyond the muscularis. This vascular tissue which 

 surrounds the urethra is limited by a dense elastic connective tissue layer, 

 the tunica albuginea, and the structure which is thus bounded is the corpus % 

 cavernosum urcthrae. Toward the perineum it ends in a round enlarge- 

 ment, the bulbits iirethrac, and distally it terminates in the glans penis. The 

 urethra enters" the upper surface of this corpus cavernosum near the bulbus. 

 Branches of the internal pudendal [pudic] artery, namely, the arteriae 

 bulbi and the urethral arteries, penetrate the albuginea, and the for- 



