496 A MANUAL OF ANATOMY. 



the ensiform and umbilicus the border is curved upward to 

 the lower part of the pylorus. 



If the lower border of the stomach reaches below the 

 umbilicus the case is one of pathological distention. 



The stomach is entered through the triangle above given. 

 The incision may be parallel with the costal margin or 

 through the semilunar line. 



The Intestine. 



The intestine is the alimentary canal below the stomach. 

 It is divided into the small and large intestine. The small 

 intestine consists of the duodenum, the jejunum, and the 

 ileum. The large intestine is divided into the caecum, as- 

 cending, transverse, and descending colon, the omega loop 

 (sigmoid flexure), and rectum. 



The Duodenum. Figs. 103, 104, 105. Though this 

 portion of the intestine is one of the last to be dissected, it 

 will be described now along with the rest of the intestine. 

 The duodenum comprises the first ten inches of gut below 

 the pylorus, and is about two inches in diameter. It is 

 divided into four portions, the proximal ascending part, 

 two inches long ; the descending portion, two and three- 

 fourths inches long ; the transverse portion four to five 

 inches long ; and the distal ascending portion, one inch in 

 length. The duodenum is the only fixed portion of the 

 small intestine. Its adult position is secured through the 

 rotation of the gut in the foetus (see page 462), by which 

 the duodenum is crowded to the back of the abdominal 

 cavity by the transverse colon which passes in front of it. 



(i) The proximal ascending- part. This is two inches 

 long, passes upward to the right and ends opposite the neck 

 of the gall bladder. It is enclosed by peritoneum pro- 

 longed from the stomach, and is freely movable. 



