430 SPLANCHNOLOGY, OR ANATOMY OF THE VISCERA 



and empty into the splenic nodes, situated around the hilum 

 of the spleen; (3) a set which drains the greater curvature and 

 ends in the right gastroepiploic nodes, the efferents of which 

 pass to the subpyloric nodes; (4) those draining the pylorus 

 empty into the hepatic and subpyloric nodes. 



SMALL INTESTINE 



The Duodenum 



The duodenum is about 10 inches long, and runs in a curved 

 direction from the pylorus to the jejunum, which it joins on 

 the left side of the second lumbar vertebra. The concavity 

 of the curve looks toward the left and embraces the head of 

 the pancreas. It is divided, for description, into four parts 

 or portions. 



The first portion of the duodenum is almost completely sur- 

 rounded by peritoneum, derived from the two layers of the 

 lesser omentum, except a small space, posteriorly, near the 

 neck of the gall-bladder and the vena cava. The second portion 

 is covered by peritoneum anteriorly, except where it is in rela- 

 tion with the transverse colon. The third portion is covered 

 by peritoneum anteriorly, except where the superior mesenteric 

 vessels cross, about its middle aspect. The fourth portion is 

 fixed by peritoneum to the abdominal wall, which covers it 

 anteriorly. 



The first portion extends from the pylorus to the neck of 

 the gall-bladder. Its length varies in different subjects, and 

 its direction changes with the degree of distention of the 

 stomach. 



The second portion extends from the neck of the gall-bladder 

 down along the right side of the vertebral column, usually 

 to the body of the fourth lumbar vertebra. It is 3 or 4 inches 

 long. 



The third portion begins where the second ends and passes 

 from right to left over the great vessels and crura of the dia- 

 phragm in front of the third or fourth lumbar vertebra. It 

 is 2 or 3 inches long. 



The fourth portion ascends along the left side of the vertebra' 

 and aorta upon the left crus of the diaphragm and ends at the 



