554 PERITONEUM. 



ribs, the other with the highest points of the crests of the ilia, the 

 abdomen will be divided into three zones. Again, if a perpendicular 

 line be drawn at each side, from the cartilage of the eighth rib to 

 the middle of Poupart's ligament, the three primary zones will each 

 be subdivided into three compartments or regions, a middle and two 

 lateral. 



The middle region of the upper zone being immediately over the 

 small end of the stomach, is called epigastric (l-ri yeurrvpi over the 

 stomach). The two lateral regions being under the cartilages of the 

 ribs are called hypochondriac (l<xo xv^, under the cartilages). The 

 middle region of the middle zone is the umbilical; the two lateral, the 

 lumbar. The middle region of the inferior zone is the hypogastric 

 (yfo ya.ff<rri, below the stomach) ; and the two lateral, the iliac. 

 In addition to these divisions, we employ the term inguinal region, in 

 reference to the vicinity of Poupart's ligament. 



Position of the Viscera. In the zipper zone will be seen the liver, 

 extending across from the right to the left side ; the stomach and 

 spleen on the left, and the pancreas and duodenum behind. In the 

 middle zone is the transverse portion of the colon, with the upper part 

 of the ascending and descending colon, omentum, small intestines, 

 mesentery, and, behind, the kidneys and supra-renal capsules. In 

 the inferior zone is the lower part of the omentum and small intes- 

 tines, the caecum, ascending and descending colon with the sigmoid 

 flexure, and ureters. 



The smooth and polished surface, which the viscera and parietes 

 of the abdomen present, is due to the peritoneum, which should in the 

 next place be studied. 



PERITONEUM. 



The Peritoneum (<ri/>irtivuv, to extend around) is a serous membrane, 

 and therefore a shut sac : a single exception exists in the human 

 subject to this character, viz. in the female, where the peritoneum is 

 perforated by the open extremities of the Fallopian tubes, and is con- 

 tinuous with their mucous lining. 



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 reflected upon the parietes of the containing 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 serous 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 peritoneum in the middle line, we 

 commence 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 same membrane, at the posterior 

 part of the diaphragm, descend to the upper surface of the liver, 



