424 



The Penis 



may be guided to the pubes and there point ; the abscess should not 

 be opened by incision along the median line, as the dorsal vessels 

 might so be wounded. 



The corpus cavernosum acts as a support for the corpus 

 spongiosum, which lies in a shallow groove on its under surface. It 

 divides behind into two strong masses, the crura, which are firmly 

 attached to the inner surface of the pubic and ischial rami. The 

 anterior extremity of the crus is capped by the glans penis, which is 

 the enlarged end of the corpus spongiosum. The other end of the 

 corpus spongiosum forms an enlargement in the perineum, the bulb ; 

 it rests upon the front of the triangular ligament, where it encloses the 

 first part of the spongy urethra and is invested by the accelerator urin;c. 

 (See fig. on p. 440.) 



The corpus cavernosum is bounded by strong fibre-elastic tissue 

 which contracts as the mass empties itself 

 of blood, and which prevents distension 

 beyond a definite limit. The interior is 

 partitioned off into numberless small spaces 

 by trabeculre, which interlace between the 

 fibrous coat and the pectiniform septum. 

 Pale, muscular tissue also exists in the 

 framework. The spaces freely communicate 

 with one another, and are occupied with 

 venous dilatations, which are supplied by 

 11, urethra; v t dorsal vein branches of the dorsal artery and of the 



(single) ; a, n, dorsal artery f . _., i i j 



and nerve. artery of the corpora cavernosa. The blood 



is returned chiefly by veins, which emerge 



near the corpus spongiosum and turn round the side of the penis to 

 end in the dorsal vein. The other veins leave the root of the penis 

 as tributaries of the internal pudic vein. 



Bisecting the interior of the corpus cavernosum longitudinally is a 

 vertical fibrous partition, which is connected with the fibrous coat near 

 the dorsal and urethral grooves. The partition, which, viewed in pro- 

 file, looks like a comb, is called the pectin! form septum (pec fen, a 

 comb). This septum is incomplete towards the fore-end, in order that 

 the erectile tissue of one-half of the corpus cavernosum may be in free 

 communication with that of the other, so that, if by chance one iliac 

 or pudic artery be obstructed, distressing unilateral erection of the penis 

 may not occur. The corpus cavernosum, in rare instances, yields to 

 the blood-pressure within, and undergoes a kind of aneurismal dilata- 

 tion. 



The urethra tunnels through the corpus spongiosum. Coming 

 through the triangular ligament, it enters the bulb, where it is some- 

 what dilated, and it ends in a vertical slit in the glans, the meatus 

 urinarius (v. p. 385.) 



The structure of the corpus spongiosum resembles that of the corpus 



