THE MALE URETHRA. 395 



is a slight elevation of the mucous membrane, called the 

 uvula. The arteries of the bladder are derived from the 

 internal iliacs, the nerves from the hypogastric plexuses. 



THE MALE URETHRA. 



The male urethra is a canal, from eight to nine 

 inches long, which runs through the corpus spongiosum 

 of the penis. It is divided into a prostatic, membranous, 

 and spongy portion. The prostatic is the widest and 

 most dilatable part. The urethra passes through the 

 gland, in the middle line, above its centre. It meas- 

 ures about one and one-quarter inches in length ; its 

 transverse section forms a curve through the prostate, 

 the convexity being upward. The following points are 

 presented in the prostatic urethra. The veru montanum 

 is a linear elevation of the mucous membrane on the floor 

 of the prostatic portion. It becomes much distended 

 during the erection of the penis, and prevents the regur- 

 gitation of the semen. On either side of the veru mon- 

 tanum is a sinus, upon the floor of which open numerous 

 prostatic ducts. At the anterior part of the veru mon- 

 tanum is the sinus pocularis, within which open the ejacu- 

 latory ducts. The membranous portion is that part of 

 the urethra between the two layers of the deep perineal 

 fascia ; it measures three-quarters of an inch along the 

 upper and one-half of an inch along the inferior portion. 

 It is encroached upon inferiorly by the prostate, and curves 

 beneath the subpubic ligament. The spongy portion, 

 about six inches in length, terminates at the meatus 

 urinarius. The bulb of the urethra is the commence- 

 ment of the spongy portion of the canal ; it is dilated, 

 and rests on the anterior surface of the anterior leaflet 

 of the deep perineal fascia, called the triangular ligament. 

 Near the termination of the urethra is the fossa navicu- 



