434 DISSECTION OF THE ABDOMEN. 



surface of the liver, on the right of the gall bladder. It lies against the 

 quadratus lumborum inferiorly, but higher up it is placed in front of the 

 kidney. To its inner side are the convolutions of the small intestine. 

 The peritoneum fixes the colon immovably to the wall of the abdomen, 

 and surrounds commonly about two-thirds of the circumference ; but it 

 may encircle the tube, and form a fold behind, as in the caecum. 



The transverse colon (fig. 142, A) passes obliquely upwards and to the 

 left, along the curvature of the stomach, as far as the spleen ; in this course 

 it is deeper at each end than in the middle, and forms the arch of the colon 

 by being thus bent. 



Above the arch are placed the liver and the gall bladder, the stomach 

 .and the spleen : and below, is the small intestine. In front lies the great 

 omentum ; and behind is a long process of peritoneum, the transverse 

 meso-colon, which attaches it to the back of the abdomen, and contains 

 the vessels and nerves. 



The transverse colon is more movable than any other part of the large 

 intestine, its peritoneal fold allowing it to be raised on the margin of the 

 ribs. Small pieces of peritoneum, containing fat, the appendices epiploir-ce, 

 are attached along it. 



The descending colon (fig. 142, i) commences below the spleen, and 

 reaches to the left iliac fossa. At first it is placed deeply in the left hypo- 

 chondriac region ; and its whole course is deeper than that of the right 

 colon. In front of it are the convolutions of the small intestine; and be- 

 hind it are the diaphragm, the outer part of the kidney, and the quadratus 

 lumborum. 



This part of the intestine is smaller than either the right or the trans- 

 verse portion, and is less surrounded, commonly, by the peritoneum ; but 

 its upper end is attached to the diaphragm by a firm process (pleuro-colic) 

 of that membrane. 



The si g moid flexure of the colon (fig, 142, &) is lodged in the left iliac 

 fossa, to which it is attached by a process of the peritoneum, the sigmoid 

 meso-colon, but it often hangs in the cavity of the pelvis. The intestine 

 makes two turns like the letter S, and has obtained its name from that 

 circumstance. Its extent is from the crest of the hip bone to the sacro- 

 iliac articulation, where it ends in the rectum. It is concealed by the 

 small intestine, which is directed more to the left than the right side. 



The rectum, or the termination of the large intestine, which is contained 

 in the pelvis, will be examined in the dissection of that cavity. 



The liver (fig. 142, c, d) is situate in the right hypochondriac, and epi- 

 gastric regions, and reaches slightly into the left hypochondriac. Pieces 

 of peritoneum (ligaments) retain it in place. 



The upper surface, convex, is turned to the vault of the diaphragm, 

 and is divided into two parts by the suspensory ligament (e) ; the right 

 portion, more prominent than the left, reaches to the level of the fifth in- 

 tercostal space. The under surface is in contact with the stomach and 

 the duodenum, with the ascending colon, and with the right kidney and 

 suprarenal body ; attached to this surface is a fold of the peritoneum (small 

 omentum), containing the hepatic vessels. 



The anterior border is thin, and lies in the adult male usually within 

 the margin of the ribs, but in women and children it reaches below that 

 line. The gall bladder projects beyond this edge. The posterior border 

 is thick, and is connected to the diaphragm by certain ligaments or pieces 



