1392 



THE URINOGENITAL ORGANS 



On entering the cavernous structure the arteries divide into branches which are supported and 

 enclosed by the trabeculje. Some of these terminate in a capillary network, the branches of 

 which open directly into the cavernous spaces (Fig. 1143); others assume a tendril-like appear- 

 ance, and form convoluted and somewhat dilated vessels, which were named by Muller helicine 

 arteries (arteriae helicinae). They project into the spaces, and from them are given off small 

 capillary branches to supply the trabecular structure. They are bound down in the spaces by 

 fine fibrous processes, and are more abundant in the back part of the corpora cavernosa. 



CAVERNOUS 

 BRANCH 



DORSAL ARTERY 



CORPUS CAVERNOSUM 



CLANS PENIS 



INTERNAL PUDIC 

 ARTERY 



FIG. 1145. -Diagram of the arteries of the penis. (Testut.) 



The blood from the cavernous spaces is returned by a series of vessels, some of which emerge 

 in considerable numbers from the base of the glans penis and converge on the dorsum of the 

 organ to form the deep dorsal vein; others pass out on the upper surface of the corpora cavernosa 

 and join the dorsal vein; some emerge from the under surface of the corpora cavernosa, 

 and, receiving branches from the corpus spongiosum, wind around the sides of the penis to ter- 

 minate in the dorsal vein; but the greater number pass out at the root of the penis and join the 

 prostatic plexus. 



The fibrous envelope of the corpus spongiosum is thinner, whiter in color, and more elastic 

 than that of the corpora cavernosa. The trabeculse are more delicate, more nearly uniform in 

 size, and the meshes between them smaller than in the corpora cavernosa, their long diameter, 

 for the most part, corresponding with that of the penis. The external envelope or outer coat of 



the corpus spongiosum is formed partly 

 of unstriped muscle tissue, and a layer 

 of the same tissue immediately surrounds 

 the canal of the urethra. The corpus 

 spongiosum receives its blood through the 

 bulbourethral branch of the internal pudic 

 artery. 



The lymphatics of the skin of the penis 

 terminate in the inguinal nodes. The 

 lymphatics of the penile portion of the 

 urethra accompany those of the glans 

 penis and terminate with them in the deep 

 inguinal and external iliac nodes. Those 

 of the membranous and prostatic portions 

 pass to the internal iliac nodes. 



The nerves are derived from the in- 

 ternal pudic nerve and the pelvic plexus. 

 On the glans and bulb some filaments of 



the cutaneous nerves have Pacinian bodies connected with them, and, according to Krause, 

 many of them terminate in peculiar end-bulbs (see p. 821). 



Applied Anatomy. It is occasionally necessary to remove a penis for malignant disease. 

 Usually, removal of the antescrotal portion is all that is necessary, but s'ometimes it is requisite 

 to remove the whole organ from its attachment to the rami of the ossa pubis and ischia. The 

 former operation is performed either by cutting off the whole of the anterior part of the penis 

 %nth one sweep of the knife, or, what is better, cutting through the corpora cavernosa from the 

 dorsum, and then separating the corpus spongiosum from them, dividing it at a level nearer the 

 glans penis. The mucous membrane of the urethra is then slit up, and the edges of the flap 

 attached to the external skin, in order to prevent contraction of the orifice, which would other- 



SUPERFICIAL DOR- 



SAL VEIN 



DORSAL ARTERY j .DEEP DORSAL VEIN 

 CORPUS CAVERNOSUM 



SKIN -,-. 



DARTOS- , 



CAVERNOUS. 

 ARTERY 



DEEP 

 FASCIA 



BULBOCAVERNOUS ARTERY/ ._ 

 ANTERIOR BRANCH 



CORPUS 

 SPONGIOSUM 



FIG. 1146. The penis in transverse section, showing the 

 bloodvessels. (Testut.) 



