THE ABDOMEN 



613 



formed by the skin and fascia which extend between the tuber 

 ischii and anus. The roof is just below the white line, where the 

 anal fascia springs from the obturator fascia. Anteriorly the fossa 

 is partially limited by the reflection of the fascia of Colles round 

 the posterior border of the superficial transverse perineal muscle to 

 join the base of the triangular ligament of the urethra. Abov^e this 

 junction there is a forward prolongation of the fossa, called the 

 anterior diverticulum, which extends almost to the symphysis pubis. 

 It lies between the postero-superior layer of the triangular ligament 

 and the inferior surface of the anterior part of the levator ani muscle. 



Scrotum 



Fascia of Colles 

 (right halO 



Superficial Perineal/ 

 Nerves 1 



f 



Long Pudendal Nerve of -Cii 



Scemmering 



Superficial Transverse -/ 



Perineal Muscle //^ 



Inferior Hemorrhoidal 



Nerve 



Gluteal Cutaneotis .«-■ 

 Branches of Small 

 Sciatic Ner\'e 



Perforating Cutaneous Nerve ' 



- Central Tendinous Point 



Superficial Perineal Artery 



- Transverse Perineal Artery 



Internal Pudic Artery in 



Alcock's Canal 

 Inferior Hemorrhoidal 



Artery 

 Gluteal Cutaneous Branches 



of Sciatic Artery 



Hemoirhoidal or Perineal Brandi 

 of 4th Sacral Nerve 



Fig. 274. — Dissection of the Male Perineum 



(On the left side the bulbo-cavemosus has been removed, and the cms 



penis cut). 



and its lateral limits are the prostate gland and pubo-prostatic 

 ligament internally, and the ischio - pubic ramus externally. 

 Posteriorly the fossa is partially limited by the margin of the great 

 sacro-sciatic ligament and the lower border of the gluteus maximus 

 muscle. Between these two structures it is prolonged backwards 

 for a short distance in the form of a posterior diverticulum, which 

 extends outwards towards the tuber ischii, and inwards towards 

 the upper part of the coccyx. 



Position of Contents. — ^The internal pudic vessels and the perineal 

 and dorsalis penis branches of the pudic nerve lie upon the outer 



