ABDOMINAL CAVITY 295 



The lower portion of the posterior part of the cavity of the 

 great sac lies upon the floor of the pelvis, and, in the male, 

 it forms three definite pouches : a median, and a right and 

 left lateral pouch. The median or recto -vesical pouch is 

 bounded in front by the bladder, behind by the rectum, 

 and laterally, on each side, by a sacro-genital fold of 

 peritoneum, which passes from the region of the fundus of 

 the bladder, past the side of the rectum, to the sacrum. 

 Each of the two lateral pouches is bounded medially by the 

 side of the bladder and the sacro-genital fold, and laterally by 

 the side wall of the pelvis. In the female, by the interposi- 

 tion of the uterus and the upper part of the vagina, between 

 the bladder and the rectum, two median pouches are formed 

 a larger posterior pouch, the recto-uterine pouch (pouch of 

 Douglas), and a smaller anterior pouch, the utero- vesical 

 pouch; and the broad ligament, which connects the lateral 

 border of the uterus with the side wall of the pelvis, divides 

 each of the single lateral pouches present in the male into an 

 anterior or paravesical pouch, and a posterior part, the lateral 

 pouch of Douglas, in which the ovary and the termination of 

 the oviduct are situated. 



Peritoneum. The peritoneum is the great serous mem- 

 brane which forms the wall of the peritoneal cavity. Exter- 

 nally it is blended with the subserous or extra-peritoneal 

 tissue of the abdomen, in which the vessels and visceral 

 nerves of the abdomen lie. Internally it is covered with a 

 flat, glistening epithelium. Jn the male, the cavity of the 

 peritoneal sac is closed ; that is, it does not communicate 

 with the exterior of the body. In the female, on the 

 other hand, it does communicate with the exterior through 

 the female genital passages, viz. the uterine tubes, the uterus, 

 and the vagina. 



When the abdomen was opened the cavity of the 

 peritoneum also was opened, and the dissector's attention 

 was drawn to the smooth and glistening appearance of the 

 inner surface of the serous membrane which is due to the 

 lining epithelium. As the examination of the cavity pro- 

 ceeded the dissector must have noted that the peritoneum 

 gave more or less complete coverings to the various abdominal 

 viscera, and that its posterior wall was raised into numerous 

 complicated folds. The folds are the result of the invagina- 

 tion of the wall of the sac by the adjacent viscera, and the 

 ii 19 a 



