OBTURATOR FASCIA PERINEAL FASCIA. 



253 



vesical plexus of veins, and forms the lateral ligaments of the blad- 

 der. A middle layer passes inwards between the base of the blad- 

 der and the upper surface of the rectum, and is named by Mr. Tyr- 

 rell the recto-vesical fascia ; and an inferior layer passes behind the 

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

 that intestine. 



The obturator fascia passes directly downwards from the splitting 

 of the layers of the pelvic fascia, and covers in the obturator inter- 

 nus 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 be- 

 tween these two layers of fascia is the levator ani muscle, .which 

 arises from their angle of separation. The levator ani is covered in 

 inferiorly by a third layer of fascia, which is given off by the obtu- 

 rator 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. 



Fig. 99 * 



In the perineum there are two fasciae of much importance, the 

 superficial and deep perineal fascia. 



The superficial perineal fascia is a thin tendino-fibro.us 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 pubic arch with the attachments of the perineal fascite. ], 1, 1. The superfi- 

 cial fascia divided by a V shaped incision into three flaps ; the lateral flaps are turned 

 over the ramus of the os pubis and ischium at each side, to which they are firmly 

 attached ; the posterior flap is continuous witli the deep perineal fascia. 2. The deep 

 perineal fascia. 3. The opening for the passage of the membranous portion of the 

 urethra, previously to entering the bulb. 4. Two projections of the anterior layer of 

 the deep perineal fascia, corresponding with Cowper's glands. 



