646 URINARY BLADDER. 



have been designated by anatomists : 1. The superior, in 

 contact with the recti muscles, and with the small intes- 

 tines, when the bladder is distended, and attached to which 

 are the urachus and obliterated umbilical arteries ; 2 and 3. 

 The lateral regions, corresponding to the sides of the pelvis ; 

 4. The posterior region, in relation with the rectum in the 

 male, and the uterus in the female ; 5. The anterior re- 

 gion behind the pubis and recti muscles, deprived of the 

 peritoneum ; and 6. The inferior region, resting upon the 

 vesiculae seminales and prostate, and in relation with the 

 rectum in the male, and, in the female, contiguous to the 

 vagina. 



Structure. The bladder is composed of four coats, the 

 peritoneal, muscular, cellular, and mucous. The peritoneal 

 or serous coat is only partial, covering simply the posterior 

 part and sides of the bladder, extending from the summit 

 to within an inch of the base of the prostate, whence it is 

 reflected upon the rectum, forming the pouch which is seen 

 between these organs. The muscular coat is arranged into 

 fasciculi of pale fibres running in various directions, hav- 

 ing spaces between them through which the mucous mem- 

 brane sometimes protrudes so as to form pouches in which 

 calculi occasionally lodge, and are not detected. 



The muscular fibres are seen to run longitudinally and 

 circularly, and some again present a reticular arrangement. 

 The longitudinal are regarded as the most numerous and 

 strongest. They commence about the cervix and are traced 

 upward, expanding over the anterior surface of the bladder 

 to its summit, and thence descending upon the posterior 

 surface and sides, back to the neck, where, according to 

 Wilson, they are inserted into a ring of elastic tissue, as 

 pointed out by Sir A. Cooper surrounding the beginning 

 of the urethra, and into the isthmus of the prostate. The 

 anterior fibres are traced into the pubes and rami of the 

 ischia, to which they are attached by four tendons, two on 

 each side, a superior and inferior. This muscular coat re- 

 ceives the name of the detrusor urince. 



The longitudinal fibres in the female, according to Mr. 



