482 ABDOMEN 



wall of the pelvis minor to the rectum. When that has been 

 done and the extra-peritoneal fat has been dissected away, the 

 ureter, the divisions and branches of the hypogastric artery, 

 the accompanying veins, and the pelvic plexuses of the sym- 

 pathetic nerves passing forwards at the sides of the rectum, 

 will be exposed. Whilst this stage of the dissection is proceed- 

 ing care must be taken to avoid injuring the parietal or the 

 visceral pelvic fascia. The hypogastric vessels lie inside the 

 fascia, and their visceral branches pierce the visceral layer, 

 whilst the parietal branches pierce the parietal layer. The 

 main nerve trunks and the trunks of the sympathetic are outside 

 the parietal fascia ; therefore their branches do not pierce the 

 fascia as they pass out of the pelvis. The obturator nerve, how- 

 . ever, pierces the parietal pelvic fascia, from without inwards, 

 at the posterior part of the pelvis, and runs forwards, lateral 

 to the hypogastric vessels and below the pelvic brim, to the 

 upper part of the obturator foramen, where it enters the ob- 

 turator canal, through which it passes into the thigh. 



When the extra-peritoneal fat has been removed, the 

 general positions of the structures behind the broad ligament 

 should be noted (Figs. 224, 225). The hypogastric artery 

 serves as a prominent landmark as it descends at the junction 

 of the side wall with the posterior wall of the pelvis. In 

 front of the hypogastric artery the ureter runs downwards till 

 it reaches the level of the visceral layer of the pelvic fascia ; 

 then it turns forwards and medially to the corresponding 

 posterior angle of the bladder. As it runs forwards and 

 medially it passes beneath the lower border of the broad 

 ligament and the uterine artery, and obliquely above and in 

 front of the upper end of the vagina. 



The student should verify the important relations of the 

 ureter to the vagina and to the uterus by passing a finger 

 into the vagina, and noting that when the tip of his finger lies 

 at the top of the vagina and at the side of the lower end of 

 the uterus, it is immediately below the medial part of the lower 

 border of the broad ligament, and that the ureter passes 

 obliquely, from behind forwards and medially, across it. 



Running forwards on the side wall of the pelvis, and 

 passing to the lateral side of the ureter, will be found the 

 obliterated umbilical artery and the obturator nerve and 

 vessels. In the female, the obliterated umbilical artery is 

 frequently below the level of the obturator nerve behind the 

 broad ligament, but it rises above the nerve as it passes 

 forwards. The uterine artery will be found descending in 

 front of the ureter, before it turns medially to cross above 

 the duct, beneath the lower border of the broad ligament. 



