ABDOMINAL CAVITY 493 



the two posterior layers of the great omentum. The right 

 extremity of its upper border is in relation to the under surface 

 of the liver and the posterior surface of the gall-bladder, and, 

 in the remainder of its extent, it is attached posteriorly by the 

 transverse meso-colbn to the pancreas, and anteriorly it en> 

 braces the lower part of the greater curvature of the stomach, 

 behind the line of attachment of the greater omentum to the 

 lower border of that viscus, 



The Transverse Meso-colon is a fold of peritoneum which 

 connects the posterior part of the upper border of the trans- 

 verse colon to the front of the head and to the anterior border 

 of the body of the pancreas. It is not so extensive as the 

 transverse colon and is absent to the right of the head of the 

 pancreas where the transverse colon is in direct contact with 

 the second part of the duodenum. The lower layer of this fold 

 has already been removed, but the upper layer and the arteries 

 which lie between the two layers are still in position and will 

 enable the dissector to verify the attachments of the fold, 

 which contains the middle colic artery and its branches, the 

 accompanying veins, lymph vessels, and nerves, and the 

 terminal portions of the upper branches of the right and left 

 colic vessels and their anastomoses with the middle colic 

 vessels. 



Before removing the ascending colon and the transverse 

 colon the dissector should again examine the longitudinal 

 muscle fibres of the walls of the large intestine. They are 

 arranged in the form of three longitudinal bands (tcenice. coli\ 

 The bands converge together on the medial and posterior 

 aspect of the caecum and fuse into a continuous layer on the 

 vermiform process. At the opposite end of the large gut 

 they converge again on the wall of the rectum, first into two 

 bands and then into a continuous layer, but in the remaining 

 parts of the large intestine the bands are widely separated, one 

 running along the anterior border (tcenta libera\ one along 

 the posterior border (tcenia mesocolica)^ whilst the third lies 

 along the medial borders of the ascending and descending 

 portions of the colon, and along the lower border of the 

 transverse colon (tcenia omentalis). 



Dissection. Place two ligatures round the upper part of the ascending 

 colon, immediately below the right colic flexure ; divide the intestine between 

 the ligatures and remove the caecum and ascending colon. Place two liga- 

 tures round the transverse colon to the left of the right colic flexure, and 



