The Kidneys. 243 



pelvis they are distant about two and a half inches from 

 each other. In the true pelvis they at first diverge but 

 soon approach one another as they near the bladder, and 

 at their terminations in the bladder, in the wall of which 

 they run for about half an inch, they are about one and a 

 half inches apart. Three constrictions are often found in 

 these tubes at which calculi are liable to be arrested one 

 above, about two inches from the hilum ; a second, where 

 it crosses the common iliac artery opposite the sacro-iliac 

 symphysis, and a third, just before it enters the bladder. 



Delations. Posteriorly, each ureter rests, in the 

 abdominal cavity, on the psoas muscle, the genito-crural 

 nerve and the common iliac artery. Anteriorly, are the 

 peritoneum, the intestine, i.e., the ileum on the right and 

 the sigmoid flexure on the left, and the spermatic vessels 

 Internal to the right ureter is the vena cava, while the 

 aorta is on the inner side of the left one, and is situated at 

 a distance from it varying from one inch, above, to half an 

 inch, below. In the pelvis the ureter rests on the obtu- 

 rator muscle and fascia, and on leaving these it passes in a 

 reflection of the peritoneum to the bladder, being crossed 

 in its course by the vas deferens in the male. In the 

 female it passes behind the uterine artery across the base of 

 the broad ligament, and, passing over the upper third of 

 the lateral wall of the vagina, enters the bladder opposite 

 the middle of the latter canal. Nerves. The ureter is 

 supplied by nerves derived from the renal, the spermatic, 

 the mesenteric and the hypogastric plexuses. 



Landmarks for the Kidneys (Fig. 7). To out- 

 line the kidneys in front, take a point on the seventh costal 

 cartilage about two inches transversely from the tip of the 

 ensiform cartilage, to represent the upper limit of the 

 right kidney. A second point should be marked on the 

 skin two and a half inches from, and one inch above the 



