PERINEAL FASCIA. 



269 



of the bladder and the upper surface o the rectum, and was named by 

 Mr. Tyrrell the recto-vesical fascia ; and an inferior layer passes behind 

 the rectum, and, with the layer of the opposite side, completely invests 

 that intestine 



Fig. 141 * 



The obturator fascia passes directly downwards from the splitting of 

 the layers of the pelvic fascia, and covers in the obturator internus muscle 

 and the internal pudic vessels and nerve ; it is attached to the ramus of 

 the os pubis and ischium in front, and below to the falciform margin of 

 the great sacro-ischiatic ligament. Lying between these two layers of 

 fascia is the levator ani muscle, which arises from their angle of separa 

 tion. The levator ani is covered in inferiorly by a third layer of fascia, 

 which is given off by the obturator fascia, and is continued downwards 

 upon the inferior surface of the muscle to the extremity of the rectum, 

 where it is lost. This layer may be named, from its position and inferior 

 attachment, the anal fascia. 



PERINEAL FASCUS. In the perineum there are two fasciaB of much im- 

 portance, the superficial and deep perineal fascia. 



The superficial perineal fascia is a thin aponeurotic layer, which covers 

 in the muscles of the genital portion of the perineum and the root of the 

 penis. It is firmly attached at each side to the ramus of the os pubis and 

 ischium ; posteriorly it is reflected backwards beneath the transversi perinei 

 muscles, to become connected with the deep perineal fascia ; while ante- 

 riorly it is continuous with the dartos of the scrotum. 



The deep perineal fascia (Camper's ligament, triangular ligament) is 

 situated behind the root of the penis, and is firmly stretched across be- 

 tween the ramus of the os pubis and ischium of each side, so as to con- 

 stitute a strong septum of defence to the outlet of the pelvis. At its infe- 



* A transverse section of the pelvis, showing the distribution of the pelvic fascia. 

 1. The bladder. 2. The vesicula seminalis of one side, divided across. 3. The rectum. 

 4. The iliac fascia, covering in the iliacus and psoas muscles (5) ; and forming a sheath 

 for the external iliac vessels (6). 7. The anterior crural nerve, excluded from tho 

 sheath. 8. The pelvic fascia. 9. Its ascending layer, forming the lateral ligament of 

 the bladder of one side, and a sheath to the vesical plexus of veins. 10. The recto 

 vesical fascia of Mr. Tyrrell, formed by the middle layer. 11. The inferior layer sur- 

 rounding the rectum and meeting at the middle line with the fascia of the opposite side. 

 12. The levator ani muscle. 13. The obturator internus muscle, covered in by the ob 

 turator fascia, which also forms a sheath for the internal pudic vessels and nerve (14) 

 15. The layer of fascia which invests the under surface of the levator ani muscle, ih 

 anal fascia. 



23* 



