PELVIC FASCIA. 



1209 



centre runs the transverse perineal septum, which is of great strength in women, 

 and forms on either side, behind the posterior commissure, a hard, ill-defined body, 

 consisting of connective tissue, with much yellow elastic tissue and interlacing 

 bundles of involuntary muscular fibres, in which the voluntary muscles of the 

 perinseum are inserted. 



PELVIC FASCIA. 



The Pelvic fascia (Fig. 772) is a thin membrane which lines the whole of the 

 cavity of the pelvis and is continuous with the transversalis and iliac fasciae. It is 

 attached to the brim of the pelvis, for a short distance, 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, completing 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 



FIG. 772. Side view of the pelvic viscera of the male subject, showing the pelvic and perineal fasciae. 



spine of the ischium is a thickened whitish band ; 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 pelvic fascia below the white line above mentioned, 

 and is attached to the pubic arch and to the margin of the great sacro-sciatic liga- 

 ment. From its attachment to the rami of the os pubis and ischium a process is 

 given off Avhich 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 superior layer of 

 the triangular ligament. This fascia forms a canal for the pudic vessels and 

 nerve in their passage forward to the perineum, and. gives off a thin membrane 



