THE MESENTERY 



147 



panics the digestion of the food, a serous layer is added outside of all to prevent 

 friction. 



The digestive fluid of the stomach is acid; in all other parts it is alkaline, 



Peristalsis is the name given to the peculiar motion of the 

 stomach and intestine during the passage of their contents. The 

 circular fibers compress the food and at the same time the longi- 

 tudinal fibers shorten the tube. This action goes on from above 

 downward, causing a sort of worm-like movement which is de- 

 scribed as peristalsis, or peristaltic movement. 



Epiploic foramen 

 Pancreas . 



Duodenum 



Transverse meso-colon 

 Aorta 



Rectum 



Li 



Gestrohepatic omentum 



Stomach 



Transverse colon 



Mesentery 



Small intestine 



Uterus 



Bladder 



FIG. in DIAGRAM OF A SAGITTAL SECTION OP THE TRUNK, SHOWING THE RELA- 

 TIONS OP THE PERITONEUM. (Allen Thompson.) 



The mesentery is the fold of peritoneum which holds the 

 jejunum and ileum in place. This fold leaves the posterior ab- 

 dominal wall at a line inclining downward to the right, about five 

 or six inches long; but it includes twenty feet of intestine, and 

 therefore it is like a very full ruffle twenty feet in length with a 

 band of six inches. The vessels and nerves of the intestine lie 

 between the layers of the mesenteric fold. 



Any fold of peritoneum which connects a portion of intestine to the wall of 

 the trunk is a mesentery. The meso-colon connects the colon with the abdom- 



