274 ABDOMEN 



the small intestine are distributed uniformly round the tube, 

 but in the large intestine they are collected into three longi- 

 tudinal bands, called tania colt, which are separated from each 

 other by intervals and are distinctly visible to the naked eye. 

 The bands are shorter than the tube itself; consequently the 

 walls of the tube are puckered. (3) Attached to the great 

 intestine are the appendices epiploica. They are small 

 peritoneal pouches, containing fat, which hang from the free 

 border of the gut. 



The dissector should attempt to pull the small intestine 

 forwards, and he will find that it is attached to the posterior 

 wall of the abdomen by a fold of peritoneum, called the 

 mesentery, which runs obliquely downwards and to the right, 

 from the level of the left side of the second lumbar vertebra 

 to the right iliac fossa. 



The parts of the large intestine lying to the right of the 

 mass of coils of small intestine are the caecum below and 

 the ascending colon above. The part crossing from side to 

 side is the transverse colon ; it is above the small intestine, 

 now that the greater omentum is reversed, but it is normally 

 in front of the small intestine ; it is attached to the posterior 

 wall of the abdomen by a fold of peritoneum called the 

 transverse meso-colon. The parts to the left of the coils of 

 the small intestine are, from above downwards, the descending 

 colon in the lumbar region, and the iliac colon in the left 

 iliac region. 



The portion of the small intestine which is attached to 

 the posterior wall of the abdomen by the mesentery is 

 arbitrarily divided into two parts, an upper two-fifths, called 

 jejunum (intestinum jejunum), and a lower three-fifths, called 

 ileum (intestinum ileum). Pull the jejunum and ileum down- 

 wards and to the left and follow the mesentery to its highest 

 point, there the jejunum will be found to become continuous 

 with the terminal part of the duodenum at a distinct flexure, 

 the duodeno-jejunal flexure, which is not enclosed in the 

 mesentery but lies behind the peritoneum below the arch 

 of the transverse meso-colon. If the dissector will now 

 hold the omentum forwards he will be able to trace the 

 first or superior part of the duodenum from the pyloric 

 end of the stomach, backwards to the neck of the gall- 

 bladder, the second or descending part downwards behind 

 the transverse colon, on the right of the median plane, 



