THE DUODENUM. 565 



face forms the anterior boundary of that cul-de-sac of the peritoneum 

 which is situated behind the lesser omentum and extends into the 

 greater omentum. 



SMALL INTESTINES. 



The small intestine is about twenty-five feet in length, and is divi- 

 sible into three portions, duodenum, jejunum, and ileum. 



Fig. 169.* 



The Duodenum (called ^ixee^cixTuXov by Herophilus) is somewhat 

 larger than the rest of the small intestines, and has received its name 

 from being about equal in length to the breadth of twelve fingers. 

 Commencing at the pylorus, it ascends obliquely backwards to the un- 

 der surface of the liver ; it next descends perpendicularly in front of the 



* A vertical and longitudinal section of the stomach and duodenum, made in 

 such a direction as to include the two orifices of the stomach. 1. The oesopha- 

 gus ; upon its internal surface the plicated arrangement of the cuticular epithe- 

 lium is shewn. 2. The cardiac orifice of the stomach, around which the fringed 

 border of the cuticular epithelium is seen. 3. The great end of the stomach. 

 4. Its lesser or pyloric end. 5. The lesser curve. 6. The greater curve. 7. 

 The dilatation at the lesser end of the stomach, which has received from Willis 

 the name of antrum of the pylorus. This may be regarded as the rudiment of 

 a second stomach. 8. The rugae of the stomach formed by the mucous mem- 

 brane : their longitudinal direction is shewn. Q. The pylorus. 10. The oblique 

 portion of the duodenum. 11. The descending portion. 12. The pancreatic 

 duct and the ductus communis choledochus close to their termination. 13. 

 The papilla upon which the ducts open. 14. The transverse portion of the 

 duodenum. 15. The commencement of the jejunum. In the interior of the 

 duodenum and jejunum, the valvulse conniventes are seen. 



