210 SPECIAL ANATOMY. 



d. Gland, s. crypta LieberkiihniarHZ are very small eversions of the mucous 

 membrane externally, which give to the last a cribriform appearance, lie be- 

 tween the basis of the villi, and are said to contain the commencements of 

 the lymphatics. 



439. a. Duodenum, the bile intestine, equal in length to 

 about the breadth of twelve fingers (eight to eleven inches), com- 

 mences at the Valvula pylori and terminates without any definite 

 boundary line to the left of the lumbar vertebrae, behind the art. 

 and ven. mesenterica superior. Figure : in the form of a horse- 

 shoe, with the concavity directed to the left, in which we find 

 the head of the Pancreas. 



1. The superior portion, pars horizontalis superior, about two 

 inches long, passes to the right and backwards, from the pylorus 

 to the neck of the gall bladder, which lies over it and is attached 

 to it by a fold of peritonaeum. It is more moveable than the fol- 

 lowing parts. Before it lie the lig. gastro-colic. and the abdom. 

 walls. Behind it, Vasa hepatica and lig. gastro-hepatic. 



2. The descending portion, p. descendens (s. renalis), two to 

 two and a half inches long, describes above, with the last portion, 

 an acute angle, descends vertically rather to the left (of first to 

 fourth lumbar vert.), behind the right extremity of the Colon 

 transv., crossing with it, before the concave border of the right 

 kidney, close to Ven. cava and duct, choledochus. Below the 

 centre of the posterior internal surface the duct, choledoc. and 

 pancreat. open into it. On its right side, Colon ascendens; on 



the left, the head of the Pancreas. 



3. The inferior portion, p. horizontalis inferior, passes off at 

 a right angle with the last portion backwards and to the left, 

 separated, before, from the stomach by a layer of omentum ; be- 

 hind, from the vertebral column by the Aorta, V. cava, and the 

 crura of the Diaphragm ; along its superior border, Pancreas ; at 

 the inferior border, meso-colon transversum. 



Structure, a. The mucous membrane of the Duodenum is distinguished 

 from that of the rest of the small intestines by : 



1. In the pars horizontal, sup., the valv. conniventes are wanting. 



2. The villi are cup-shaped, or in the form of a chaplet. 



3. Gland. Erunner. predominate, especially in the superior half, and are 

 lost at the inferior extremity, where they pass as gland, solitaruz over the rest 

 of the small intestines. 



4. Gland. Peycriana are (almost) entirely wanting. 



5. On the posterior internal wall (at the inferior extremity) we find the 

 opening of duct, choledochus and pancreaticus united together or separate (diverti- 

 culum Vateri). 



b. The muscular coat is thicker in the Duodenum than in the remainder of 

 the small intestine. 



c. The serous (Peiritonaum) covers the p. horizontal, super., above and 

 below only, and passes, in front, into the large, behind, into the small omen- 



