THE SMALL INTESTINE. 



511 



of the abdomen. For purposes of description, it is said to be com- 

 posed of three portions : first, of a short portion named the duodenum, 

 d, d (duodeni, twelve), because it corresponds in length to the width 



Fig. 89. 



Fig. 89. Diagram, showing the abdominal portion of the a' : mentary canal, its subdivisions, and the 

 general position of these in the abdomen, s, the stomach, o, the oesophageal, or cardiac end. j>, the py- 

 lorus, d, d, the duodenum, or first oortion of the email intestine, curving from right to left, j, coils of the 

 jejunum, or second part of UIM small intestine, i, t, coils of the ileum, or third and last part of the small 

 intestine, c, the csecum, or first part of the large intestine, with its vermiform appendix, co. co, co, 

 ascending, transverse, and descending portions of the colon. /. si^moid flexure of the colon, r, straight 

 intestine or rectum. The small intestine is seen to occupy the middle of the abdomen, and to be sur- 

 rounded on three sides by the large intestine. 



of twelve fingers placed side by side ; secondly, of a longer portion 

 named the jejunum, j (jejunus, fasting), from its being usually found 

 empty after death ; and, lastly, of a still longer portion, named, from 

 its numerous coils or convolutions, the ileum, i (e?Aeiv, to coil). 



The duodenum, d, d, is about 8 or 10 inches long ; it is the widest 

 part of the small intestine, measuring from 1 J to If inches in diameter; 

 it is also the most fixed part, having no mesentery, the peritoneum 

 merely covering it in front, except near the stomach. The duodenum 

 describes a horseshoe-like curve, the convexity of which is turned to 

 the right ; first it ascends, for about 2 inches, towards the under sur- 

 face of the liver and gall-bladder ; then it descends in front of the 

 right kidney ; next it passes from right to left, across the second 

 lumbar vertebra, the attachment of the diaphragm, the ascending vena 



