THE OMENTA. 311 



fissure and the posterior half of the longitudinal fissure (fig. 131, so, 



p. 346) ; below to the small curvature of the stomach and the first 



part of the duodenum. At its left or posterior end it is fixed to the 



diaphragm fora short distance, between the liver and the termination 



of the oesophagus. The part between the longitudinal fissure of the 



liver and the small curvature of the stomach is very thin, and can 



be separated into two layers only in the immediate neighbourhood 



of the viscera ; but that extending from the transverse fissure to contents. 



the duodenum is much thicker, and encloses the hepatic artery, 



portal vein, common bile-duct, and nerves and lymphatics of the 



liver. 



The great amentum (fig. 114, g orti) is the largest fold of the peri- Gastro-colic 

 toneum, and results from the meeting of the two layers which leave omentum: 

 the great curvature of the stomach and the first part of the duodenum, formation ; 

 The sheet thus formed descends in front of the intestine, extending 

 farther on the left side than the right, and at the lower part of the 

 abdomen is doubled backwards to join the transverse colon. The 

 fold therefore encloses the lower part of a space (cavity of the small cavity; 

 sac), which originally extended to its lower border ; but in the adult 

 the anterior and posterior portions of the omen turn are usually 

 closely adherent, and the small sac seldom exists below the transverse 

 colon. 



Between the layers of the great omentum, especially near the 

 stomach, are some branches of vessels, minute nerves, and a variable 

 quantity of fat ; but over the greater part of their extent the layers fusion of 

 are inseparably united, and the resulting membrane is very thin, la >' ers - 

 and in places cribriform. 



Dissection. Divide the part of the great omentum below the cavity of 

 stomach, and the cavity of the small sac of the omentum will be sma11 bag : 

 opened, and the hand may be introduced to ascertain its extent. In 

 front it is bounded by the anterior part of the great omentum, the boundaries 

 stomach, the small omentum, and the Spigelian lobe (fig. 131, SI} of 

 the liver. Behind it are the posterior part of the great omentum, the 

 transverse colon and meso-colon, the pancreas, the left kidney and 

 suprarenal capsule, and the diaphragm. To the right it extends as and extent. 

 far as the inner border of the duodenum (second pait), and to the 

 left as far as the spleen. Between the duodenum and the liver 

 it opens into the general cavity or large sac by the foramen of 

 Win slow. 



The foramen of Window is bounded in front by the right portion Boundaries 

 of the small omentum, containing the hepatic vessels ; below are the 



same vessels and the first part of the duodenum ; above is the caudate 

 lobe of the liver ; and behind, the inferior vena cava. 



The gastro-splenic omentum (fig. 115, gs om) reaches from the Ga.stro- 

 stomach on the left side to the spleen, and is continued below into omentum. 

 the great omentum. Between its layers are the gastric branches of 

 the splenic vessels. 



FOLDS ON THE LARGE INTESTINE. The disposition of the peritoneum Peritoneal 

 round the several portions of the colon has been explained in giving 



