110 



DIGESTION 



stone in a sling. (See Fig. 34.) The entire mem- 

 brane is lubricated by a watery liquid or serum, and 



Fig. 34 — Intestine supported by a fold of the peritoneum (mesentery), showing 

 method of entrance of blood vessels. 



for this reason it is called a serous membrane. It is 

 also richly supplied with blood vessels. The organs sup- 



FiG. 35 — External view of the stomach, showing covering of peritoneum and 

 muscles ; 1, esophagus ; 2, cardiac end ; 3, pyloric end ; 4, small intestine ; 5, a 

 portion of peritoneum turned back ; 6, longitudinal muscle fibers ; 7, circular 

 muscle fibers ; 8, oblique muscle fibers. 



