THE GENITO-URINARY APPARATUS. 261 



tional" variety,, consisting of several layers of cells of varying 

 shapes, resting upon a basement membrane. 



The nerves are derived from the renal plexus of the sympa- 

 thetic, formed by branches in the semilunar ganglion, the solar 

 plexus, and the lesser and smallest splanchnic nerve. 



The lymphatics communicate with the lumbar glands. 



The ureter proper is a musculo-membranous tube, sixteen to 

 eighteen inches in length, about the diameter of a goose-quill, 

 extending from its origin in the pelvis of the kidney to the 

 basal or posterior angle of the vesical trigone, which it enters by 

 passing obliquely through the muscular and mucous walls of 

 the bladder. 



Course. It descends upon the psoas magnus muscle, be- 

 neath the peritoneum, being crossed by the spermatic vessels. 

 About the first division of the sacrum it crosses the external or 

 common iliac artery, passing behind the sigmoid flexure on the 

 left and the ileum on the right side, to enter the pelvis, where it 

 reaches the bladder within its posterior false ligament. 



In the male it passes behind the vas deferens. 



In the female it crosses the uterine artery 1 / 3 to 1 / 2 inch 

 from the cervix uteri and passes along the side and upper part of 

 the vagina to the bladder (vide Vagina). 



Muscles of the Ureters. Two oblique muscles. Origin, be- 

 hind the orifices of the ureters ; insertion, into the middle lobe of 

 the prostate gland ; action, they guard the orifices of the ureters, 

 and prevent the reflux of urine. 



SUPRARENAL CAPSULES (vide Ductless Glands). 



THE BLADDER. 



The bladder is a musculo-membranous sac, the reservoir for 

 the urine, situated in the anterior part of the pelvis, behind the 

 pubes, in front of the uterus and vagina in the female, and the 

 rectum in the male. 



It measures, moderately distended, five inches in length, 

 three in width, and holds about one pint. It consists of a body, 

 summit, base, and neck. 



The body is partially invested with peritoneum behind, but 

 in front it is wanting, the body being in relation with the sym- 

 physis pubis, triangular ligament, and internal obturator muscles. 



The summit, or apex, is rounded, and directed upward and 

 forward, being connected to the umbilicus by the urachus, the 

 ri'iiwins of the foetal allantois, and also by the obliterated hypo- 

 gastric arteries, one on either side. 



