MALE PERINEUM 



361 



sisting of a pelvic, a glutceal, and & perineal part. 'The perineal 

 or third part of the pudendal artery enters the perineum by 

 passing through the small sciatic foramen. At first it is 

 placed deeply ; but it is found to become more superficial, 

 as it is traced forwards, and at the same time to incline 

 medially, so that, at its termination, it lies close to the middle 

 line of the body. 



In the rectal triangle the pudendal artery is contained 



Bladder 



Pelvic fascia 



Obturator 



internus 



Prostate 



Prostatic 



urethra 



Levator ani 



Pubic arch - 



Deep perineal 



muscles 



Urogenital diaphragm _ 

 (inferior layer) 

 Crus pen 

 Ischio-cavernosus 



' Superficial peri 

 vessels and ne 



Fascia of Colles 



Upper fascia of 

 .pelvic diaphragm 

 '(O.T. visceral layer) 

 'Pelvic fascia 



Sheath of 



prostate 

 - Anal fascia 

 .Parietal pelvic 



fascia 

 '-- Obturator 



membrane 



....Urogenital diaphragm 



(superior layer), 

 ,Pudendal vessels and 

 nerve 



Crus penis covered by 

 I schio-cavernosus 



Bulbo-cavernosus covering 

 the bulb of penis 



FIG. 135. Vertical section (schematic) through the pubic arch to show the 

 two perineal compartments. 



within a sheath, termed Alcock's canal, which is formed by 

 the splitting of that part of the parietal pelvic fascia which 

 forms the lateral wall of the ischio-rectal fossa. It lies fully 

 an inch and a half above the level of the lowest part of the 

 ischial tuberosity, and is accompanied by two veins and the 

 two divisions of the pudendal nerve. Of the latter the dorsal 

 nerve of the penis lies above it and the perineal nerve below 

 it. Reaching the base of the urethral triangle, the pudendal 

 artery insinuates itself between the two fasciae of the uro- 

 genital diaphragm, and, gradually emerging from under cover 

 of the bone, proceeds forwards along the edge of the pubic 



