486 ABDOMEN 



of the urethra, and that its posterior fibres pass over the wall 

 of the vagina. Above the sphincter urethrae membranaceae 

 lies the upper fascia of the urogenital diaphragm, which is now 

 seen from the front. Pass a finger into the vagina, and note 

 that both the urethra and the vagina pass through the upper 

 fascia of the urogenital diaphragm, which is reflected up- 

 wards along their borders. 



Divide the upper fascia of the urogenital diaphragm on both 

 sides, and again note that, at the sides of the urethra and the 

 vagina, it is continuous round the anterior border of the levator 

 ani with the visceral layer of the pelvic fascia. 



Divide the pubes on each side, with the saw, along a line 

 commencing on the margin of the pubic arch, below the attach- 

 ment of the arcuate ligament, and terminating above at the lateral 

 border of the tubercle of the pubis. Pass the knife behind the 

 pubis and separate the visceral layer of the pelvic fascia from its 

 attachment to the bone between the saw cuts. The separated 

 piece of bone may now be removed and should be kept for the 

 examination of the ligaments of the symphysis (see pp. 474, 

 475). If necessary, a further portion of the margin of the pubic 

 arch may be removed, on each side, to give room for the examina- 

 tion of the relations of the vagina and the urethra. 



The dissector should now make his final examination of the 

 pelvic fascia. Tracing the upper surface of the visceral layer medi- 

 ally, he will find that it spreads out on the infero-lateral surfaces 

 and anterior border of the urinary bladder, and that, below the 

 bladder, it covers the front of the urethra and the vagina. The 

 latter part presents a free border where it was detached from 

 the back of the pubes, and beneath that border the dorsal vein 

 of the clitoris can be traced towards the bladder, where it joins 

 the vesical plexus. In that part of the fascia the two thickened 

 bands which form the medial pubo-vesical ligaments will be 

 noted. If the dissector next traces the fascia medially, follow- 

 ing its lower surface, he will find that it passes behind the rectum, 

 and he will thus demonstrate that the visceral layer of the 

 pelvic fascia splits as it passes towards the median plane, one 

 layer, the vesical, passing on to the bladder and in front of the 

 urethra and vagina, and a second layer, the rectal, which passes 

 behind the rectum. There is, however, a third layer, the recto- 

 vaginal, which crosses between the rectum and the vagina. To 

 demonstrate that layer the dissector should divide the vesical 

 layer in the median plane in front of the bladder, and turn the 

 lateral halves towards the side walls of the pelvis. In that 

 way he will expose the urethra and the anterior wall of the 

 vagina, the two being closely bound together, and when the 

 lateral border of the vagina is reached he will find that the 

 vesical layer of the fascia blends with a deeper layer which passes 

 behind the vagina ; that layer is the recto-vaginal layer. On 

 the anterior wall of the vagina, and, more particularly, along its 

 lateral border, the dissector should note a plexus of veins, the 

 vaginal plexus. 



The recto-vaginal layer of the pelvic fascia should be dis- 

 played from below also. To do that the dissector must cut 

 transversely through the tissue of the perineal body, which lies 

 in front of the anal orifice, until he reaches the junction of the 

 anal passage with the rectum. When that point is attained he 



