PELVIC FASCIA. 



491 



of the muscle it is continuous with the general fascial lining of the pelvic cavity, 

 and gives rise to a conspicuous thickening, the tendinous arch (arcus tendineus) 

 of the pelvic fascia, which stretches like a bow-string from the back of the 

 symphysis pubis to the ischial spine. This band is related not so much to the 

 origin of the levator ani muscle, which often extends higher up external to the 

 pelvic fascia, as to the attachments of the fascial investments of the genito-urinary 

 passages, to be described below. There are sometimes additional thickenings of 

 the fascia, branching upwards from the tendinous arch towards the superior aperture 

 of the pelvis. At the insertion of the levator ani, the fascia clothing its pelvic 

 surface is attached to the perineal body, the margin of the anal canal, and the 

 ano-coccygeal body, over which it passes to be continuous, above the raphe of in- 

 sertion of the levatores ani, with the layer of the opposite side. At the antero- 



Posterior (recto-vesical) layer 

 Superior layer : lateral true ligament of the bladder , 



Suspensory ligament of the prostate gland 

 Rectal channel 





SPHINCTER URETHRA MEMBRANACE^E MTTSCLE Anal canal 



Sheath of the prostate gland 



FIG. 435. RELATIONS OP PELVIC FASCIA TO THE RECTUM AND PROSTATE 

 (Median Section of the Pelvis). 



inferior border of the muscle the fasciae enclosing it become continuous with the 

 superior fascia of the urogenital diaphragm ; at its postero-superior border they join 

 the fascia enclosing the coccygeus muscle. 



Within the pelvic basin, the walls and floor of which are thus continuously 

 invested by the pelvic fascia, are contained the rectum and bladder, and in the female 

 the uterus, suspended and maintained in position by the peritoneum, extra-peritoneal 

 tissue, and the pelvic vessels and nerves. They are essentially free to distend or 

 collapse, and are not bound down by the pelvic fascia. The rectum in both sexes 

 extends down to the floor of the pelvis, where the anal canal takes its origin. It 

 s invested by the peritoneum and extra-peritoneal tissue, and occupies a special 

 rectal channel ; this is lined by pelvic fascia, which gains an attachment to the 

 floor of the pelvis at the margin of the anal canal. 



The arrangement of the fascia in relation to the genito-urinary passages is 

 essentially different. 



Just as from the perineal aspect the inferior aperture of the pelvis is divisible 

 into two different parts, a posterior or dorsal part, comprising the ischio-rectal 



