458 ABDOMEN 



less complete coverings to the various abdominal viscera, and 

 that its posterior wall was raised into numerous complicated 

 folds. The folds are due to the imagination of the wall of 

 the sac by the adjacent viscera, and the complication of the 

 folds has been produced by changes in form and position of 

 the viscera, and by the fusion and partial disappearance of 

 some of the primitive folds. 



The portion of the peritoneum which lines the inner 

 surface of the abdominal wall is called parietal peritoneum. 

 The portion which covers the viscera is termed " visceral 

 peritoneum" and the folds which connect the viscera with 

 each other or with the wall of the abdomen are defined as 

 omenta, mesenteries, and ligaments. 



The term mesentery is generally applied to folds of peri- 

 toneum which connect portions of the alimentary canal with 

 the posterior wall of the abdomen. 



The term " omentum " has usually been applied, in English 

 terminology, to folds of peritoneum which connect the 

 stomach with other viscera, and the term ligament was 

 applied to any fold which did not fall into either of the two 

 first divisions. Now, however, it is becoming customary to 

 speak of folds and portions of folds which connect the 

 stomach to adjacent viscera as ligaments ; thus the lesser 

 omentum is said to consist of the hepato- gastric and the 

 hepato- duodenal ligaments, the two terms being applied 

 respectively to the parts which connect the liver to the 

 stomach and the liver to the duodenum. The gastro-lienal 

 omentum becomes the gastro-lienal ligament, and the greater 

 omentum is sometimes spoken of as the gastro-colic ligament. 



The relations of the layers of the visceral and parietal 

 peritoneum to each other, and the relations of the layers 

 which bound the omental bursa to those which limit the 

 cavity of the great sac to each other, can be easily followed 

 in Figs. 171, 172, 173, and 174. The dissector should 

 study the figures and confirm their accuracy by following the 

 peritoneum at the levels, and in the planes indicated in them. 



Dissection. After examining the various parts of the peritoneal cavity, 

 and the different folds of the peritoneal membrane, the dissector should 

 remove the peritoneum of the posterior wall of the omental bursa, above 

 the level of the root of the transverse meso-colon. Commence immediately 

 above the line of attachment of the transverse meso-colon to the lower 

 border of the pancreas, which can be seen through the thin peritoneum, 

 and work upwards, taking care not to injure either the pancreas itself or 



