PELVIC FASCIA 



447 



(Cowper's) glands, the arteries of the bulb, and the dorsal nerves and arteries of the penis. 

 In the female it is pierced by the vagina as well as by the structures mentioned above. 



Beneath the superficial layer of the fascia of the trigone, in addition to the muscles of the 

 urogenital diaphragm, there are found the membranous urethra, the bulbo-urethral glands 

 (Cowper's), the internal pudic arteries and the pudic nerves (in part). 



The deep (superior) layer of the urogenital trigone (figs. 400, 402, 403) lies between the muscles 

 of the urogenital diaphragm and the ischio-rectal fossa and levator ani. It may be looked upon 

 as a continuation of the obturator fascia across the pubic arch. Posterior to the deep transverse 

 perineal muscle it fuses with the superficial layer of the fascia of the urogenital trigone. In 

 this region in the male it fuses with a fascial membrane, the prostatico-perineal fascia, which 

 extends upward between the rectum and prostate, and is attached to the posterior wall of the 

 latter. In the female it is fused with the fibrous tissue which Lies between the vagina and the 

 rectum. 



The muscle fasciae of the pelvis (figs. 399, 400, 401, 402, 407, B) have been described in 

 various ways by different authors. Tlaey may be subdivided into parietal and diaphragmatic. 



Fig. 403. — Diagram of the Superficial and Deep Layers of the Urogenital Trigone. 



Arcuate ligament : -^a s^ 



Apertures for dorsal artery and 

 nerve of the penis 



Crus penis 

 Aperture for deep artery of penis 

 Superficial layer of urogenital 

 trigone 



Ischio-cavernosus , 

 Aperture for artery -^ 



to bulb 

 Urethral aperture' 

 Aperture for bulbo- 

 urethral duct 



Position of bulb A^ 



Apertures for peri- 

 neal vessels and 

 nerve 



Tela subcutanea of 

 perineum turned 

 backwards 



Aperture for dorsal vein of the penis 



.Dorsal nerve 



Superficial layer of urogenital 



trigone (reflected) 

 Dorsal artery of penis 



Deep layer of uro- 

 • genital trigone 



■^ — .j.*^^ Deep artery of 



^ penis 



Artery to bulb 



die veins 

 Dorsal nerve 

 Position of bulbo-ure- 

 thral gland 

 Internal pudic artery 



Junction of urogen- 

 ital trigone with 

 tela subcutanea of 

 aerineum 



The parietal fasciae (fig. 399) cover the muscles which extend from the interior of the pelvis 

 to the thigh (the obturator internus and piriformis muscles). Above, the fascia on each side 

 is attached to the linea terminalis and is continuous with the fascia transversalis and the iliac 

 fascia. It is attached to the margins of the greater and lesser sciatic notches and to the ischio- 

 pubic ramus and the body of the pubis. Between the ischio-pubic rami it is stretched across 

 the subpubic arch and forms the superior or deep laj^er of the urogenital trigone described above. 

 The portion of parietal pelvic fascia over the obturator internus muscle is called the obturator 

 fascia. 



The diaphragmatic pelvic fasciae cover both surfaces of the pelvic diaphragm and are re- 

 flected upon the viscera. The fasciae covering the two surfaces of the levator ani are attached 

 to the parietal (obturator) fascia along the line of origin of the muscle. 



The line of attachment of the levator ani divides the obturator fascia into two parts (fig. 

 399), a pelvic part above the line of attachment, covered by peritoneum, and an ischio-rectal 

 part below the line of attachment. The latter bounds the lateral wall of the ischio-rectal fossa. 

 The former part is much the thicker. It consists morphologically of two fused membranes, the 

 obturator fascia proper and the aponeurosis of the ilio-coccygeal portion of the levator ani, 

 which although usually fused with the obturator fascia, may frequently be traced to the term- 

 inal (ilio-pectineal) line from which in tailed mammals this portion of the levator takes origin. 

 The two layers of fascia also become continuous at the medial margin of the muscle where this 

 faces the urogenital passage (tig. 399). Posteriorly, the inner layer fuses with the tendinous 

 insertion of the pubo-coccygeus portion of the muscle and the fascia; of the muscles of each side 

 are continuous. It also fuses with a fascia covering the coccygeus muscle. 



The thin perineal layer of the levator fascia behind the rectum fuses with that of the opposite 

 side and is attached to the coccyx and the ano-coccygeal raphe. About the anus it helps to 

 form a covering for the external sphincter. Ventrally it is attached to the ischio-pubic rami. 

 It forms the medial wall of the ischio-rectal fossa. 



Endo-pelvic fascia (figs. 401, 402). — The peritoneum is reflected from the pelvic wall onto 

 the viscera much higher up than the level at which the viscera are attached to the pelvic dia- 

 phragm. Between the pelvic fascia covering the deep surface of the pelvic diaphragm (levator 

 ani and coccygeus muscles) and the peritoneum there is thus left a space, subperitoneal space 

 (fig. 467 B). 'In the median plane in this region in the male are found the bladder, prostate, 

 seminal vesicles, the ureter and ductus deferens in their course near the bladder, and the am- 

 pulla of the rectum. In the female we find here the bladder, the vagina, the uterus, and the arn- 

 pulla of the rectum. Between these medially placed viscera and the lateral wall of the pelvis 



