974 



GENERATIVE APPARATUS. 



tendinous fibres, and partly concealed by the semimembranosus muscles. These 

 erector penis muscles arise from the inferior ischiaic spine, and terminate on the 

 membrane enveloping the crura of the penis, which they cover posteriorly and 

 externally. 



The anterior extremity of the corpus cavernosum forms a blunt point, and is 

 surrounded by the spongy tissue of the glans. 



Mode of attachment of the corjms cavernosum. — The chief attachment is 



constituted by the insertion of the two crura into the ischiatic arch. There is 



also a double suspensory ligament proceeding from the ischio-pubic symphysis, 



where it is confounded with the superior attachments of the short adductor of 



the thigh, and passes to the dorsal border of the corpus 



Fis:. 523. cavernosum, a little in front of the point of union of its 



crura. 



Structuee. — This erectile organ is composed, ex- 

 ternally, of a white, elastic, fibrous envelope, remarkable 

 for its thickness, especially on the dorsum ; it gives off, 

 from its inner face, a certain number of lamellar trabe- 

 culse which partition the interior of the cavity it forms. 

 One of these septa {spptum pectiniforme) is directed 

 vertically from the upper to the lower border, and di- 

 vides the corpus cavernosum into two lateral portions 

 {corpora cavernosa), which would indicate that the crura 

 are not one mass at their point of union, but merely 

 joined to each other. In the Hoise, this septum is 

 generally very incomplete, and rarely extends the whole 

 length of the organ. 



The lamellar prolongations sustain other elastic and 

 contractile bands, which circumscribe the cavities in 

 which is lodged the essential portion of the erectile 

 tissue. According to Legros, the latter is composed of 

 a network of capillaries interposed between the arterial 

 and venous twigs ; this network shows abrupt or regular dilatations of a diameter 

 varying from '0001 m. to '0015 m. These successively dilated capillaries have 

 very thin -walls, which are adherent to the contractile prolongations of the 

 envelope, and are lined by a very delicate pavement endothelium. In the areolae 

 of the cavernous tissue, particularly towards the base of the organ, the arteries 

 offer a special arrangement ; their walls are very thick, and they soon divide 

 into a bouquet of branches which enter the areola?, where they terminate either 

 by a cul-de-sac, or — which is most frequent — give off small free branches convo- 

 luted in a spiral manner. These are the arterim heUcince described by Miiller and 

 Eouget. (The walls of the cells are composed of white and yellow fibrous tissue, 

 and unstriped muscular fibres. The cells themselves are in reality venous sinuses. 

 Kolliker found a minute artery to proceed from each of the csecal terminations 

 of the helicine arteries, and terminate, like the other capillaries, in the veins. 

 The dilated vessels have been regarded by some anatomists as only vascular loops. 

 The cells, during the erection of the penis, are distended with blood.) 



The arteries of the corpus cavernosum and dorsales penis pass into the 

 erectile structure, and supply this organ with blood. The collateral veins of 

 these arteries arise near the surface. The nerves are from the internal pudic 

 and great sympathetic. 



TRANSVERSE SECTION OF 

 THE PENIS, SHOWING THE 

 RELATIONS OF THE 



URETHRA WITH THE 

 CORPUS CAVERNOSUM. 



1, Erectile tissue of the 

 corpus caveruosum ; 2, 

 envelope of ditto ; 3, 

 urethral canal; 4, erectile 

 tissue of the urethra ; 5, 

 accelerator urinae ; 6, 

 section of the suspensory 

 ligament of the penis. 



