4 20 



ABDOMEN 



examined. In the dissection of the perineum the student 

 saw that the lower part of the parietal pelvic fascia lined 

 the lateral wall of the ischio-rectal fossa, and that it blended, 

 immediately below the origin of the levator ani, with the 

 lower layer of the fascia of the pelvic diaphragm, which covers 

 the lower surfaces of the levator ani and the coccygeus (anal 

 fascia). He saw also that, in the anterior part of the peri- 

 neum, the parietal fascia extended medially, as the superior 

 fascia of the urogenital diaphragm, from the margin of the 

 pubic arch to the side of the urethra, where it not only 

 blended with the fascia coming from the opposite side, but 



Anal canal 



Fascia iliaca-- 

 Peritoneum - 



Obturator internus 



Levator ani, clothed on 



medial side by rectal 



fascia, and on lateral side 



by lower fascia of pelvic 



diaphragm 



Canal in obturator fascia> 



containing pudendal 



vessels and nerve 



FlG. 195. Diagram of the Endo-pelvic Fascia. The pelvis is divided in a 

 frontal plane and the pelvic fascia is represented in red. 



also became continuous, round the anterior border of the 

 levator ani, with the fascia on the upper surface of that 

 muscle, that is, with the visceral layer of the pelvic fascia. 



To display the details of the visceral layer of the fascia 

 the final stages of the dissection of the perineum must now 

 be completed. 



Dissection. The dissector must carefully define the anterior 

 borders of the levatores ani muscles, and then he must cut 

 boldly through the centre of the perineum between the bulb 

 and the anal orifice until he reaches the fascial interval between 

 the posterior surface of the prostate and the front of the lower 

 part of the rectum. When the interval is reached the knife 

 may be discarded and the forefinger introduced into the space 



