350 ABDOMEN 



!a. M. superficialis transversus 

 b. M. P Bu!bo-cavernosus. 

 c. M. Ischio-cavernosus. 

 iragm. 



6. The internal pudendal vessels and the pudendal nerve and their 



branches. 



7. M. transversus perinei profundus and M. sphincter urethrse mem- 



branacese. 



8. Cowper's glands. 



9. The membranous portion of the urethra. 

 10. Superior fascia of urogenital diaphragm. 



Superficial Perineal Vessels and Scrotal Nerves (O.T. 

 Perineal). The superficial perineal vessels and the scrotal 

 nerves must now be followed out : 



. . f i. The perineal artery. 



' \ 2. The transverse branch of the perineal artery. 



( i. The scrotal nerves. 



Nerves, -j 2. The long perineal branch of the posterior cutaneous nerve 

 ( of the thigh. 



The perineal artery, a branch of the pudendal, first pierces 

 the medial wall of Alcock's canal, and then the base of the 

 urogenital diaphragm, so as to gain the interior of the perineal 

 pouch of fascia. It now crosses the superficial transversus 

 perinei muscle, and is continued anteriorly, in the interval 

 between the bulbo-cavernosus and ischio-cavernosus, to the 

 scrotum, to the dartos muscle and integuments to which it is 

 distributed in the form of numerous long, slender branches, 

 the posterior scrotal arteries. Before it reaches the scrotum, 

 it supplies twigs to the superficial perineal muscles. It is 

 accompanied by the posterior scrotal branches of the perineal 

 nerve. 



The transverse perineal artery is a small vessel which usually 

 springs from the preceding. It pierces the base of the fascia 

 of the urogenital diaphragm, and, gaining the surface of the 

 transversus perinei superficialis muscle, proceeds transversely 

 and medially to the interval between the rectum and the 

 bulb, where it ends by supplying the parts in this locality, 

 and by anastomosing with the corresponding vessel of the 

 opposite side. 



The posterior scrotal nerves are branches of the perineal 

 division of the pudendal nerve. They appear in the anterior 

 part of the ischio-rectal fossa after piercing the fascia on its 

 lateral wall. They leave the fossa by piercing the base of 



