PERITONEUM. CGI 



vessels and nerves. Of these two layers, the anterior should first be traced, and 

 then the posterior. 



The anterior layer descends to the lesser curvature of the stomach, and covers 

 its anterior surface as far as the great curvature ; it descends for some distance in 

 front of the small intestines, and, returning upon itself to the transverse colon, 

 forms the external layer of the great omentum; it then covers the under surface 

 of the transverse colon, and, passing to the back part of the abdominal cavity, 

 forms the inferior layer of the transverse mesocolon. It then descends in front of 

 the duodenum, the aorta, and vena cava, as far as the superior mesenteric artery, 

 along which it passes to invest the small intestines, and, returning to the vertebral 

 column, forms the mesentery; whilst, on either side, it covers the ascending and 

 descending colon, and is thus continuous with the peritoneum lining the walls of 

 the abdomen. From the root of the mesentery, it descends along the front of the 

 spine into the pelvis, and surrounds the upper part of the rectum, which it holds 

 in its position by means of a distinct fold, the mesorectum. Its course in the male 

 and female now differs. 



In the male, it forms a fold between the rectum and bladder, the recto-vesical 

 fold, and ascends over the posterior surface of the latter organ as far as its summit. 



In the female, it descends into the pelvis in front of the rectum, covers a small 

 part of the posterior wall of the vagina, and is then reflected on to the uterus, the 

 fundus and body of which it covers. From the sides of the uterus, it is reflected 

 on each side to the wall of the pelvis, forming the broad ligaments ; and from its 

 anterior surface it ascends upon the posterior wall of the bladder, as far as its 

 summit. From this point it may be traced, as in the male, ascending upon the 

 anterior parietes of the abdomen, to the under surface of the Diaphragm ; from 

 which it is reflected upon the liver, forming the upper layer of the coronary, and 

 the lateral and longitudinal ligaments. It then covers the upper and under sur- 

 faces of the liver, and at the transverse fissure becomes continuous with the 

 anterior layer of the lesser omentum, the point from whence its reflection was ori- 

 ginally traced. 



The posterior layer of the lesser omentum descends to the lesser curvature of 

 the stomach, and covers its posterior surface as far as the great curvature; it 

 then descends for some distance in front of the small intestines, and, returning 

 upon itself to the transverse colon, forms the internal layer of the great omentum ; 

 it covers the upper surface of the transverse colon, and, passing backwards to the 

 spine, forms the upper layer of the transverse mesocolon. Ascending in front of 

 the pancreas and crura of the Diaphragm, it lines the back part of the under sur- 

 face of this muscle, from which it is reflected on to the posterior border of the liver, 

 forming the inferior layer of the coronary ligament. From the under surface of 

 the liver, it may be traced to the transverse fissure, where it is continuous with 

 the posterior layer of the lesser omentum, the point from whence its reflection was 

 originally traced. 



The space included in the reflections of this layer of the peritoneum is called 

 the lesser cavity of the peritone^tm or cavity of the great omentum. It is bounded, in 

 front, by the lesser omentum, the stomach, and the descending part of the great 

 omentum ; behind, by the ascending part of the great omentum, the transverse 

 colon, transverse mesocolon, and its ascending layer ; above, by the liver ; and 

 below, by the folding of the great omentum. This space communicates with the 

 general peritoneal cavity through the foramen of Winslow, which is situated be- 

 hind the right free border of the lesser omentum. 



The foramen of Winslow is bounded in front by the lesser omentum, inclosing 

 the vena portae and the hepatic artery and duct ; behinS, by the inferior vena cava ; 

 above, by the lobus Spigelii ; below, by the hepatic artery curving forwards from 

 the cceliac axis. 



This foramen is nothing more than a constriction of the general peritoneal 

 cavity at this point, caused by the hepatic and gastric arteries passing forwards from 

 the coaliac axis to reach their respective viscera. 



