322 SPLANCHNOLOGY. 



nerves, and lymphatics or lacteals, hence it permits vascular and 

 nervous communication with the organ attached to it. 



The mesenteries are the mesentery proper, a huge sheet of 

 membrane suspending the jejunum and ileum from the abdominal 

 roof, and commencing at the level of the great mesenteric artery ; 

 narrow at its origin, it becomes gradually broader posteriorly. 

 The meso-colon attaches the great colon to the abdominal parietes, 

 a part uniting the upper and lower portions of it ; a portion of 

 this structure, the meso-ccecum, covers the csecum in a like manner, 

 joining part of it to the colon. The colic mesentery, similar to 

 the mesentery proper, suspends the floating colon, and a continu- 

 ation of it which suspends the anterior part of the rectum is 

 termed the meso-rectum. 



An omentum is a double fold passing from one abdominal 

 organ to another, sometimes establishing vascular and nervous 

 communication between them. There are three omenta, so called, 

 which are continuous with each other. The great or gastro-colic 

 omentum, stretches from the great curvature of the stomach and 

 duodenum to the colon ; the gastro-hepatic or small omentum, 

 extends from the lesser curvature of the stomach and oesophagus 

 to the liver ; while the g astro-splenic omentum passes from the 

 greater curvature of the stomach to the hilus of the spleen. 

 The three omenta together include an anterior sac (bursa omen- 

 talis), which communicates with the rest of the serous cavity by 

 an aperture called the hiatus of Winslow, situated between the 

 anterior end of the right kidney, the pancreas, and the Spigelian 

 lobe of the liver. 



In tracing the course of the peritoneum, it may simplify the 

 matter to divide it into two portions, a superior one, leaving the 

 abdominal parietes above, and an inferior one, leaving the parietes 

 below, both passing along the posterior part of the diaphragm, at 

 the centre of which they surround the vena cava, and pass on to 

 the liver, helping to form its ligaments. They then surround 

 that organ, one portion going up, the other down the anterior 

 surface, round to the posterior surface, which they cover, meeting at 

 the posterior fissure to form the gastro-hepatic or lesser omentum, 

 which proceeds from the liver to the lesser curvature of the 

 stomach. The two layers now cover the stomach, form the 

 coronary ligament round the oesophagus, and again meet at the 

 greater curvature, forming on the left the gastro-splenic omentum, 

 and passing to the hilus of the spleen, which is covered by 



