PELVIS 627 



The dissector should commence his examination of the 

 fascia by noting that the parietal part is continuous above 

 with the fascia on the psoas muscle. Traced downwards 

 from the psoas it can be followed to the level of a line 

 extending from the lower part of the back of the symphysis 

 to the spine of the ischium, i.e. to the level at which 

 the visceral layer springs from its inner surface. Traced 

 backwards it passes lateral to the hypogastric vessels 

 and then across the front of the sacrum to the opposite 

 side, concealing the sacral plexuses and the piriformis 

 muscles. 



When it is traced forwards it will be found to terminate, 

 anteriorly, along a curved line which commences at the medial 

 side of the ilio-pectineal eminence, on the medial surface 

 of the superior ramus of the pubis, descends to the lower 

 border of the symphysis pubis, and then ascends to a corre- 

 sponding point on the opposite side. The parietal fascia is 

 deficient, therefore, on the anterior boundary of the lower part 

 of the cave of Retzius. Each half of this anterior border of 

 the parietal fascia is separable into three parts : A lateral 

 part where the fascia blends with the periosteum on the inner 

 surface of the ascending ramus of the pubis ; an intermediate 

 part below the highest portion of the obturator foramen, where 

 the fascia turns over the upper border of the obturator internus 

 and runs outwards into the thigh, forming the lower wall of the 

 obturator canal ; a median part which is attached to the peri- 

 osteum on the posterior surface of the body of the pubis. 

 Turning next to the visceral layer the dissector will find as he 

 traces it medially, in the posterior part of the pelvis, that the 

 rectum sinks into its substance. In front of the rectum it is 

 carried over the upper part of the vagina on to the uterus, and 

 in front of the uterus it is lost on the bladder. Still more 

 anteriorly it can be followed across the median plane to the 

 opposite side. In this last part of its extent two thickened 

 bands of its substance, one on each side of the median plane, 

 extend from the back of the pubis to the anterior border 

 of the bladder. These bands are the medial pubo-vesical 

 ligaments or anterior true ligaments of the bladder already 

 referred to. The dissector should note that the attachment 

 of the visceral layer to the back of the body of the pubis lies 

 at a higher level than the attachment of the anterior border 

 of the parietal layer. In the space between the two lines of 



