5 6 4 



ABDOMEN 



it enters into intimate relationship with the pelvic viscera. 

 The visceral part stretches across the cavity and helps to 

 separate the perineum from the remainder of the pelvis. If 

 the upper part of the parietal layer is examined it will be found 

 that it is continuous at the pelvic brim with the fascia 

 on the psoas magnus muscle, from which it descends to the 

 level of a line drawn from the lower part of the back of 

 the body of the pubis to the spine of the ischium. At this 

 level the visceral layer springs from the parietal, its origin 

 serving to separate the latter into lower and upper parts. 

 If the upper part of the parietal portion is traced backwards 

 it will be found to extend round the lateral side of the hypo- 

 gastric vessels and across the front of the sacrum, behind the 



pelvic meso-colon and the 

 rectum, to theopposite side. 

 If it is traced forwards a 

 short distance below the 

 brim, it will be found to 

 blend with the periosteum 

 on the back of the superior 

 ramus of the pubis, along 

 an oblique line which de- 

 scends from the junction 

 of the middle with the 

 lower third of the external 

 iliac artery to the upper 

 margin of the obturator 

 foramen. Below the 



superior ramus of the pubis it forms a distinct thickened 

 border which bridges across the upper part of the obturator 

 foramen, and forms the lower boundary of the commence- 

 ment of the obturator canal, by which the obturator artery 

 and nerve leave the pelvis. To the medial side of the 

 obturator foramen the parietal fascia blends with the 

 periosteum on the back of the body of the pubis, along a 

 line which descends towards the apex of the pubic arch and 

 passes below the line of attachment of the visceral layer. The 

 parietal layer is deficient, therefore, in the region of the upper 

 part of the anterior wall of the pelvis, and as its anterior 

 margin blends with the periosteum on the pubis any effusion 

 lying external to the fascia will be prevented from extending 

 forwards to the anterior part of the pelvis. 



Peritoneum 



Endo-pelvic 



fascia 



Pelvic wall - 



Levator ani 



Perineum 



FIG. 217. Diagram of the Pelvic Wall 

 and Pelvic Floor. 



