476 A MANUAL OF ANA TO MY. 



the transverse colon. This is the great, or gastrocolic 

 omentum. 



Raise the great omentum and with it the transverse 

 colon. The peritoneum passing from this part of the colon 

 to the posterior abdominal wall is the lower layer of the 

 transverse mesocolon. 



From the posterior attachment the peritoneum extends 

 down upon the small intestines ; enclosing them, it returns 

 to the abdominal wall, these two surfaces forming the right 

 upper and left lower layers of the mesentery. It will be 

 seen that the mesentery has a short base which is attached 

 to the abdomen in an oblique line extending from the left 

 of the second lumbar vertebra downward to end in the 

 right iliac fossa, that its intestinal end equals the length of 

 the small intestine, that its width is about eight inches. 



From the lower end of the mesentery the peritoneum is 

 seen to cover the beginning of the large intestine the 

 csecum and the little process the vermiform appendix 

 that extends off from it. The appendix has a narrow 

 mesentery, the caecum has none ; both are free in the peri- 

 toneal cavity. Upward from the caecum passes the as- 

 cending colon, which is found covered with peritoneum in 

 front and at the sides, that at the right being continued as 

 the lining or parietal layer of the abdomen, that to the left 

 being continued into the right surface of the mesentery. 

 Sometimes the colon has a distinct mesentery. 



The bend formed by the junction of the ascending and 

 transverse colon is the hepatic flexure ; from its outer bor- 

 der an extension of the transverse mesocolon is found 

 which is attached to the adjacent abdominal wall. This is 

 the sustentaculum hepatis, because the right extremity 

 of the liver rests upon it. 



At the left the transverse colon takes a sudden bend 



