UTONEU1 



duodenum, they join together and ascend as a double fold to the porta of the liver; 

 to the left of the porta the fold is attached to the bottom of the fossa for the ductus 

 venosus, along which it is carried to the diaphragm, where the two layers separate 

 to embrace the end of the esophagus. At the right border of the omentum the 

 two layers are continuous, and form a free margin which constitutes the anterior 

 boundary of the epiploic foramen. The portion of the lesser omentum extending 

 between the liver and stomach is termed the hepatogastric ligament, while that 

 between the liver and duodenum is the hepatoduodenal ligament. Between the two 

 layers of the lesser omentum, close to the right free margin, are the hepatic 

 artery, the common bile duct, the portal vein, lymphatics, and the hepatic plexus of 

 nerves all these structures being enclosed in a fibrous capsule (Glisson's capsule}. 

 Between the layers of the lesser omentum, where they are attached to the 

 stomach, run the right and left gastric vessels. 



The greater omentum (omentum majus; great omentum; gastrocolic omentum} is the 

 largest peritoneal fold. It consists of a double sheet of peritoneum, folded on itself 

 so that it is made up of four layers. The two layers which descend from the stomach 

 and commencement of the duodenum pass in front of the small intestines, sometimes 

 as low down as the pelvis; they then turn upon themselves, and ascend again as 

 far as the transverse colon, where they separate and enclose that part of the intes- 

 tine. These individual layers may be easily demonstrated in the young subject, 

 but in the adult they are more or less inseparably blended. The left border of the 

 greater omentum is continuous with the gastrolienal ligament; its right border 

 extends as far as the commencement of the duodenum. The greater omentum is 

 usually thin, presents a cribriform appearance, and always contains some adipose 

 tissue, which in fat people accumulates in considerable quantity. Between its 

 two anterior layers, a short distance from the greater curvature of the stomach, 

 is the anastomosis between the right and left gastroepiploic vessels. 



The mesenteries are: the mesentery proper, the transverse mesocolon, and the 

 sigmoid mesocolon. In addition to these there are sometimes present an ascending 

 and a descending mesocolon. 



The mesentery proper (mesenteriwri) is the broad, fan-shaped fold of peritoneum 

 which connects the convolutions of the jejunum and ileum with the posterior wall 

 of the abdomen. Its root the part connected with the structures in front of the 

 vertebral column is narrow, about 15 cm. long, and is directed obliquely from the 

 duodenojejunal flexure at the left side of the second lumbar vertebra to the right 

 sacroiliac articulation (Fig. 1040). Its intestinal border is about 6 metres long; and 

 here the two layers separate to enclose the intestine, and form its peritoneal coat. 

 It is narrow above, but widens rapidly to about 20 cm., and is thrown into numerous 

 plaits or folds. It suspends the small intestine, and contains between its layers 

 the intestinal branches of the superior mesenteric artery, with their accompanying 

 veins and plexuses of nerves, the lacteal vessels, and mesenteric lymph glands. 



The transverse mesocolon (mesocolon transverswn) is a broad fold, which connects 

 the transverse colon to the posterior wall of the abdomen. It is continuous with 

 the two posterior layers of the greater omentum, which, after separating to surround 

 the transverse colon, join behind it, and are continued backward to the vertebral 

 column, where they diverge in front of the anterior border of the pancreas. This 

 fold contains between its layers the vessels which supply the transverse colon. 



The sigmoid mesocolon (mesocolon sigmoideum) is the fold of peritoneum which 

 retains the sigmoid colon in connection with 'the pelvic wall. Its line of attachment 

 forms a V-shaped curve, the apex of the curve being placed about the point of 

 division of the left common iliac artery. The curve begins on the medial side of 

 the left Psoas major, and runs upward and backward to the apex, from which it 

 bends sharply downward, and ends in the median plane at the level of the third 

 sacral vertebra. The sigmoid and superior hemorrhoidal vessels run between the 

 two layers of this fold. 



two lay 



