660 



ORGANS OF DIGESTION. 



THE PERITONEUM. 



The Peritoneum (rtspitttveiv, to extend around) is a serous membrane, and, like 

 all membranes of this class, a shut sac. In the female, ho%ever, it is not 

 completely closed, the Fallopian tubes communicating with it by their free 

 extremities; and thus the serous membrane is continuous with their mucous 

 lining. 



The peritoneum partially invests all the viscera contained in the abdominal and 

 pelvic cavities, forming the visceral layer of the membrane ; it is then reflected 

 upon the internal surface of the parietes of these cavities, forming the parietal 

 layer. (Fig. 332.) The free surface of the peritoneum is smooth, moist, and 

 covered by a thin, squamous epithelium; its attached surface is rough, being 

 connected to the viscera and inner surface of the parietes by means of areolar 

 tissue, called the sub-peritoneal areolar tissue. The parietal portion is loosely 

 connected with the fascia lining the abdomen and pelvis ; but more closely to 

 the under surface of the Diaphragm, and in the middle line of the abdomen. 



In order to trace the reflections of this membrane (the abdomen having been 



Fig. 332. The Reflections of the Peritoneum, as seen in a vertical 

 Section of the Abdomen. 



opened), the liver should be raised and supported in that position, and the stomach 

 should be depressed, when a thin membranous layer is seen passing from the 

 transverse fissure of the liver, to the upper border of the stomach ; this is the 

 lesser or gastro-hepatic omentum. It consists of two thin, delicate layers of peri- 

 toneum, an anterior and a posterior, between which are contained the hepatic 



