1152 



MALE GENERATIVE ORGANS. 



The whole of the structure of the corpora cavernosa contained within the 

 fibrous sheath consists, therefore, of a sponge-like tissue of areolar spaces freely 

 communicating with each other and filled with venous blood. The spaces may 

 therefore be regarded as large cavernous veins. 



The arteries bringing the blood to these spaces are the arteries of the corpora 

 cavernosa and branches from the dorsal artery of the penis, which perforate the 

 fibrous capsule, along the upper surface, especially near the fore part of the 

 organ. 



These arteries on entering the cavernous structure divide into branches which 

 are supported and enclosed by the trabeculee. Some of these terminate in a 

 capillary network, the branches of which open directly into the cavernous spaces ; 

 others assume a tendril-like appearance, and form convoluted and somewhat 

 dilated vessels, which were named by Miiller helicine arteries. 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 

 (Fig. 737). 



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 



Frc. 737. From the peripheral portion of the corpus 



(Copied from Langer.) 1". a. "Capillary network, 

 with the cavernous spaces. 



corpus cavernosum penis under a low magnifying power. 

 . Cavernous spaces. 2. Connection of the arterial twigs (a) 



converge on the dorsum of the organ to form the 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 round the sides of the penis to terminate in the dorsal 

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

 prostatic plexus. 



The Corpus Spongiosum encloses the urethra, and is situated in the groove on 

 the under surface of the corpora cavernosa. It commences posteriorly in front of 

 the deep perineal fascia, between the divei'ging crura of the corpora cavernosa. 

 where it forms a rounded enlargement, the bulb, and terminates anteriorly in 

 another expansion, the glans penis, which overlaps the anterior rounded extremity 

 of the corpora cavernosa. The central portion, or body of the corpus spongiosum, 

 is cylindrical, and tapers slightly from behind forward. 



The bulb varies in size in different subjects ; it receives a fibrous investment 

 from the anterior layer of the deep perineal fascia, and is surrounded by the 

 Accelerator urinse muscle. The urethra enters the bulb nearer its upper than its 

 lower surface, being surrounded by a layer of erectile tissue, a thin prolongation 

 of which is continued backward round the membranous and prostatic portions of 

 the canal to the neck of the bladder, lying between the two layers of muscular 

 tissue. The portion of the bulb below the urethra presents a partial division into 

 two lobes, being marked externally by a linear raphe, whilst internally there 

 projects inward, for a short distance, a thin fibrous septum, more distinct in 

 early life. 



