Small Intestine. 



Duct. choledocJi. 

 et pancreal. 



354. The Inner Surface of the Duodenum, 



at its descending portion. 



The d node n u m presents a curve, embracing the head of the 

 pancreas; it is divided into a superior or superior transverse, a 

 descending, and an oblique or inferior transverse p o r t i o n. 

 The superior portion is nearly completely invested by peritoneum ; the 

 inferior transverse portion lies between the two layers of the transverse 

 mesocolon ; the descending portion is covered by peritoneum only on its 

 anterior surface. 



The jejunum and ilium form numerous convolutions in the 

 abdominal and pelvic regions ; they present no characteristic marks to 

 distinguish the termination of the one and the commencement of the 

 other; they are attached to the mesentery, jbkwnteri.um, and by its 

 root, Radix Me.wnte.rfi, to the lumbar portion of the vertebral column. 



The layers of the s m all intestine are the same as those 

 of the stomach : peritoneum (serous coat), muscular coat (consisting of 

 external longitudinal and internal circular fibres), and the mucous mem- 

 brane, which consists of a layer of muscular tissue, of folds called Valvulae 

 conniventes, of villi and of glands. 



