498 



PERITONEUM. 



The simplest idea that can be given 

 of a serous membrane, which 'may 

 apply equally to all, is, that it invests 

 the viscus or viscera, and is then re- 

 flected upon the parietes of the con- 

 taining cavity. If the cavity contain 

 only a single viscus, the consideration 

 of the serous membrane is extremely 

 simple. But in the abdomen, where 

 there are a number of viscera, the se- 

 rous membrane passes from one to the 

 other until it has invested the whole, 

 before it is reflected on the parietes. 

 Hence its reflexions are a little more 

 complicated. 



In tracing the reflexions of the pe- 

 ritoneum in the middle line, we com- 

 mence with the diaphragm, which is 

 lined by two layers, one from the 

 parietes in front, anterior , and one 

 from the parietes behind, posterior. 

 These two layers of the sa*me mem- 

 brane, at the posterior part of the 

 diaphragm, descend to the upper sur- 

 face of the liver, forming the coronary 

 and lateral ligaments of the liver. 



1 They then surround the liver, one 



going in front, the other behind that 



viscus, and, meeting at its under surface, pass to the stomach, forming the 

 lesser omentum. They then, in the same manner, surround the stomach, 

 and, meeting at its lower border, descend for some distance in front of 

 the intestines, and return to the transverse colon, forming the great omen- 

 ium ; they then surround the transverse colon, and pass directly back- 

 wards to the vertebral column, forming the transverse meso-colon. Here 

 the two layers separate ; the posterior ascends in front of the pancreas and 

 aorta, and returns to the posterior part of the diaphragm, where it becomes 

 the posterior layer w r ith which we commenced. The anterior descends, 

 invests all the small intestines, and returning to the vertebral column, 

 forms the mesentery. It then descends into the pelvis in front of the 



* The reflexions of the peritoneum. D. The diaphragm. S. The stomach. C. The 

 transverse colon. D. The transverse duodenum. P. The pancreas. I. The small in- 

 testines. R. The rectum. B. The urinary bladder. 1. The anterior layer of the peri- 

 toneum, lining the under surface of the diaphragm. 2. The posterior layer. 3. The 

 coronary ligament, formed by the passage of these two layers to the posterior border of 

 the liver. 4. The lesser omentum ; the two layers passing from the under surface of 

 the liver to the lesser curve of the stomach. 5. The two layers meeting at the greater 

 ourve, then passing downwards and returning upon themselves, forming (0) the greater 

 omentum. 7. The transverse meso-colon. 8. The posterior layer traced upwards in 

 front of D, the transverse duodenum, and P, the pancreas, to become continuous with 

 the posterior layer (2). 9. The foramen of Winslow; the dotted line bounding this 

 foramen inferiorly marks the course of the hepatic artery forwards, to enter between 

 4hc layers of the lesser omentum. 10. The mesentery encircling the small intestine. 

 ..1. The recto-vesical fold, formed by the descending anterior layer. 12. The anterior 

 layer traced upwards upon the internal surface of the abdominal parietes to the layei 

 ( 1) with which the examination commenced. 



