698 A MANUAL OF ANATOMY 



the termination of t-he ascending colon and the commencement of 

 the transverse colon. The bend takes place in a direction forwards 

 and to the left, and so brings the bowel in front of the second or 

 vertical part of the duodenum. The hepatic flexure has the 

 impressio colica on the inferior surface of the right lobe of the liver 

 above it, the sharp anterior margin of the liver on its outer side, and 

 the second part of the duodenum on its inner side. Posteriorly it 

 is in contact with the right kidney in the same locality as the upper 

 part of the ascending colon, and it is here uncovered by peritoneum. 



Transverse or Middle Colon. — ^This, which is comparatively long 

 and very arched, commences in the right hypochondrium in front 

 of the second part of the duodenum, and terminates in the left 

 hypochondrium in the splenic flexure. Its extremities are deeply 

 placed, the right being a little lower and more superficial than the 

 left, and both being comparatively fixed on account of the shortness 

 of the transverse meso-colon at these points. The greater part of it 

 descends into the umbilical region, where it usually lies just above 

 the umbilicus. The transverse colon is completely invested by 

 peritoneum, except occasionally for i inch or more posteriorly at 

 its right extremity. The serous membrane forms an extensive fold 

 behind it, called the transverse meso-colon, which passes backwards 

 to the anterior border of the pancreas, and is of very limited extent 

 at its right and left extremities. The transverse colon is covered 

 in front by the great omentum. Above it, from right to left, are the 

 liver, gall-bladder, great curvature of the stomach, inferior surface of 

 the pancreas, and basal surface of the spleen; behind it are the 

 second part of the duodenum, head of the pancreas, and transverse 

 meso-colon ; and below it are the coils of the jejunum. 



Splenic Flexure. — ^This is situated in the left hypochondrium 

 in contact with the basal surface of the spleen, and behind the 

 cardiac end of the stomach. It occupies a higher and deeper 

 position than the hepatic flexure, and its posterior surface is un- 

 covered by peritoneum. Connected with its left aspect there is a 

 triangular fold of the serous membrane, which attaches it to the 

 diaphragm opposite the tenth or eleventh left rib. This fold is 

 called the phreno-colic or costo-colic ligament, and it forms a 

 platform upon which the basal surface of the spleen rests : hence 

 the name sustentaculum lienis (' support of the spleen '). It will be 

 found described on p. 720. 



Descending or Left Colon. — ^This, which is of comparatively 

 small calibre, commences in the left hypochondrium at the splenic 

 flexure, and terminates in the lower part of the left lumbar region 

 on a level with the back part of the iliac crest, where it passes into 

 the iliac colon. It lies deeply in the left hypochondriac and left 

 lumbar regions, being directed at first downwards and slightly 

 inwards, and subsequently vertically downwards. Posteriorly it 

 is in contact, from above downwards, with the front of the left 

 kidney at its lower and outer part, and the left quadratus lumborum 

 muscle invested by its sheath. Anteriorly it is covered by coils 



