THE PELVIC FASCIA. 



1071 



tance, at the side of the cavity, and to the inner surface of the bone round the 

 attachment of the Obturator internus. At the posterior border of this muscle it is 

 continued backward as a very thin membrane in front of the Pyriformis muscle 

 and sacral nerves to the front of the sacrum. In front it follows the attachment 

 of the Obturator internus to the bone, arches beneath the obturator vessels, com- 

 pleting the orifice of the obturator canal, and at the front of the pelvis is attached 

 to the lower part of the symphysis pubis. At the level of a line extending from 

 the lower part of the symphysis pubis to the spine of the ischium is a thickened 

 whitish band, termed the white line ; this marks the attachment of the Levator ani 

 muscle to the pelvic fascia, and corresponds to its point of division into two layers, 

 the obturator and recto-vesical. 



The obturator fascia descends and covers the Obturator internus muscle. It is 

 a direct continuation of the parietal pelvic fascia below the white line above men- 

 tioned, and is attached to the pelvic arch, the ischial tuberosities, and to the mar- 

 gin of the great sacro-sciatic ligaments. This fascia forms a canal for the pudic 



FIG. 595. Side view of the pelvic viscera of the male subject, showing the pelvic and perineal fasciae. 



vessels and nerve in their passage forward to the perinaeum, and gives off a thin 

 membrane which covers the perineal aspect of the Levator ani muscle, called the 

 ischio-rectal (anal) fossa. From its attachment to the rami of the os pubis and 

 ischium a process is given off which is continuous with a similar process from the 

 opposite side, so as to close the front part of the outlet of the pelvis, forming the 

 deep layer of the triangular ligament. 



The recto-vesical fascia (visceral layer of the pelvic fascia) descends into the 

 pelvis upon the upper surface of the Levator ani muscle, and invests the prostate, 

 bladder, and rectum. From the inner surface of the symphysis pubis a short 

 rounded band is continued, on each side of the middle line, to the upper surface of 

 the prostate and neck of the bladder, forming the pubo-prostatic or anterior true lig- 

 aments of the bladder. At the side this fascia is connected to the side of the pros- 

 tate, enclosing this gland and the vesico-prostatic plexus of veins, and is continued 



