THE PELVIS AND BLADDER. 529 



of the base of the bladder, and opens upon its mucous surface. 

 Lying along the posterior wall of the abdomen, it is situated behind 

 the peritoneum and is crossed by the spermatic vessels ; in its course 

 downwards it rests upon the anterior surface of the psoas, and 

 crosses the common iliac artery and vein, and then the external 

 iliac vessels. Within the pelvis it crosses the umbilical artery and 

 the vas deferens in the male, and the upper part of the vagina in the 

 female. There are sometimes two ureters to one kidney. 



The ureter, the pelvis, the infundibula, and the calices are com- 

 posed of two coats, an external or fibrous coat, the tunica propria ; 

 and an internal mucous coat which is continuous with the mucous 

 membrane of the bladder inferiorly, and with the lining of the tubuli 

 uriniferi above. 



Vessels and Nerves. The renal artery is derived from the aorta ; 

 it divides into several large branches before entering the hilus. 

 There are frequently two renal arteries and sometimes three. 



The Veins terminate in the vena cava by a single large trunk on 

 each side ; the left renal vein receiving the left spermatic vein. In- 

 jections thrown into the renal artery and returning by the vein, 

 generally make their way into those vessels by rupture ; and when 

 the injection returns by the tubuli uriniferi, it always occurs from 

 the bursting of the capillary vessels of the ducts into their cavities. 

 The lymphatic vessels terminate in the lumbar glands. 



The Nerves are derived from the renal plexus, which is formed 

 partly by the solar plexus, and partly by the lesser splanchnic nerve. 

 The renal plexus gives branches to the spermatic plexus, and 

 branches which accompany the ureters : hence the morbid sympa- 

 thies which exist between the kidney, the ureter, and the testicle ; 

 and by the communications with the solar plexus, with the stomach 

 and diaphragm, and indeed with the whole system. 



THE PELVIS. 



The cavity of the pelvis is that portion of the great abdominal 

 cavity which is included within the bones of the pelvis, below the 

 level of the linea-ilio-pectinea and the promontory of the sacrum. 

 It is bounded by the cavity of the abdomen above, and by the peri- 

 neum below ; its internal parietes are formed in front, below, and at 

 the sides, by the peritoneum, pelvic fascia, levatores ani muscles, 

 obturator fasciae and muscles; and behind, by the sacrum, and 

 sacral plexus of nerves. 



The Viscera of the pelvis in the male are the urinary bladder, the 

 prostate gland, vesiculee seminales, and the rectum. 



BLADDER. 



The Bladder is an oblong membranous viscus of an ovoid shape, 

 situated behind the os pubis and in front of the rectum. It is larger 

 in its vertical diameter than from side to side ; and its long axis is 



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