THE PERITONEUM 



1259 



Starting from here, the lesser sac maybe traced across the aorta and over the inner 

 part of the front of the left kidney to the hilus of the spleen as the anterior layer 

 of the lienorenal ligament. From the spleen it is reflected to the stomach as the 

 posterior layer of the gastrosplenic omentum. It covers the postero-inferior 

 surfaces of the stomach and commencement of the duodenum, and from the 

 lesser curvature of the stomach extends upward to the liver as the posterior layer 

 of the gastrohepatic omentum; the right margin of this layer is continuous around 

 the hepatic artery, bile duct, and portal vein with the wall of the greater sac. 



The foramen of Winslow (foramen epiploicum) is the passage of communication 

 between the greater and lesser sacs. It is bounded in front by the free border 

 of the gastrohepatic omentum, with the hepatic artery, common bile duct, and 

 portal vein between its two layers; behind by the peritoneum covering the inferior 

 vena cava; above by the peritoneum on the caudate lobe of the liver, and below 

 by the peritoneum covering the commencement of the duodenum and the hepatic 

 artery, the latter passing forward below the foramen before ascending between the 

 two layers of the gastrohepatic omehtum (Fig. 982). 



Lig. teres 



Common 'bile duct 



Portal vein 



Foramen of 

 Winslow 



Inferior-Vena Cava 



FIG. 982. Transverse section of peritoneum above the transverse colon. The arrow points to the lesser 

 sac and passes through the foramen of Winslow. 



The boundaries of the lesser sac will now be evident. It is bounded in front, 

 from above downward, by the Spigelian lobe of the liver, the gastrohepatic omen- 

 tum, the stomach, and the anterior two layers of the greater omentum; behind, it 

 is limited, from below upward, by the two posterior layers of the greater omentum, 

 the transverse colon, and the ascending layer of the transverse mesocolon, the 

 upper surface of the pancreas, the left suprarenal gland, and the upper end of 

 the left kidney. Laterally, the lesser sac extends from the foramen of Winslow 

 to the spleen (recessus lienalis) (Fig. 985), where it is limited by the lienorenal 

 ligament and the gastrosplenic omentum. 



In the fetus the lesser sac reaches as far as the free margin of the great omentum, 

 but in the adult its vertical extent is usually more limited, owing to adhesions 

 between the layers of the omentum. It should be stated that during a considerable 

 part of fetal life the transverse colon is suspended from the posterior abdominal wall 



