THE LARGE INTESTINE 



1181 



lower than the main curve. It is almost completely invested by peritoneum, and 

 is connected to the inferior border of the pancreas by a large and wide duplicature 

 of that membrane, the transverse mesocolon. It is in relation, by its upper surface, 

 with the liver and gall-bladder, the greater curvature of the stomach, and the 

 lower end of the spleen; by its under surface, with the small intestine; by its ante- 

 rior surface, with the anterior layers of the greater omentum and the abdominal 

 parietes; its posterior surface is in relation from right to left with the descending 

 portion of the duodenum, the head of the pancreas, and some of the convolutions 

 of the jejunum and ileum. 



The left colic or splenic flexure (Fig. 1056) is situated at the junction of the trans- 

 verse and descending parts of the colon, and is in relation with the lower end of the 

 spleen and the tail of the pancreas ; the flexure is so acute that the end of the trans- 

 verse colon usually lies in contact with the front of the descending colon. It lies 

 at a higher level than, and on a plane posterior to, the right colic flexure, and is 

 attached to the diaphragm, opposite the tenth and eleventh ribs, by a peritoneal 

 fold, named the phrenicocolic ligament, which assists in supporting the lower end 

 of the spleen (see page 1158). 



Femoral nerve 

 Femoral vessels 

 Peritoneum 



Levator ani muscle 



5. Iliac colon, sigmoid or pelvic colon, and rectum seen from the front, after removal of pubic bones 



and bladder. 



The Descending Colon 1 (colon descendens) passes downward through the left 

 hypochondriac and lumbar regions along the lateral border of the left kidney. 

 At the lower end of the kidney it turns medialward toward the lateral border of 

 the Psoas, and then descends, in the angle between Psoas and Quadratuslumborum, 

 to the crest of the ilium, where it ends in the iliac colon. The peritoneum covers 

 its anterior surface and sides, while its posterior surface is connected by areolar 

 tissue with the lower and lateral part of the left kidney, the aponeurotic origin of 



1 In the Basle nomenclature the descending colon is the portion between the left colic flexure and the superior aper- 

 ture of the lesser pelvis; it is, however, convenient to describe its lowest part as the iliac colon. 





