ABDOMINAL CAVITY 287 



to the oesophagus and the pylorus respectively. He will find, 

 at a later stage of the dissection, that the two folds are connected 

 with the peritoneum on the anterior surface of the pancreas ; 

 they are therefore called the left and right gastro- pancreatic 

 folds. The left is produced by the left gastric artery as it passes 

 round the left border of the sac to gain entrance into the lesser 

 omentum, and the right is produced by the hepatic artery as 

 it turns round the right margin of the sac at the lower border 

 of the epiploic foramen (Winslowi). 



Next, remove the remainder of the lesser omentum and so 

 open into the upper part of the omental bursa ; but take care 

 not to injure the contents of the lesser omentum. First cut 

 through the posterior layer along the left border of the hepatic 

 artery ; then carry the incision upwards along the margin of the 

 fossa for the ductus venosus. Finally cut through the posterior 

 layer for a short distance along the lesser curvature of the 

 stomach, along the left gastric artery, and turn the separated 

 portion of the lesser omentum to the left over the stomach. 

 Again introduce the hand from the lower part into the upper 

 part of the omental bursa and examine again the constriction 

 of the cavity between the ossophageal and pyloric ends of the 

 stomach, and the gastro-pancreatic folds, which cause it. 



It is not possible to make a thorough examination of the 

 cavity of the omental bursa till the stomach, which lies in its 

 anterior wall, has been turned aside. Divide the right gastric 

 artery and the right gastro-epiploic artery immediately to the 

 left of the pylorus, then cut through the stomach in the same 

 situation and turn it over to the left side. The greater part 

 of the anterior wall of the omental bursa is now removed, and 

 the cavity and the remaining boundaries can be examined. 



The Cavity of the Omental Bursa extends from the lower 

 margin of the greater omentum below to the liver above, and 

 a narrow, pouch-like recess is prolonged upwards, behind the 

 liver, to the inferior surface of the diaphragm. The posterior 

 wall of the sac is formed, from below upwards, by (i) the 

 posterior two layers of the greater omentum; (2) the transverse 

 colon, covered with peritoneum; (3) the transverse meso-colon; 

 and, above the line of attachment of the transverse meso-colon 

 to the posterior abdominal wall, by (4) the upper of the two 

 layers of the transverse meso-colon, the so-called "ascending 

 layer" which passes upwards, in front of the pancreas, the 

 upper and medial part of the left kidney, the left suprarenal 

 gland and the crura of the diaphragm, to the under surface of 

 the diaphragm, from which it is reflected forwards to the upper 

 part of the posterior surface of the caudate lobe of the liver. 

 The outline of the pancreas can be seen through the thin 

 peritoneum ; and the kidney and the suprarenal glands, if 

 not visible, are easily felt. 



The narrow, pouch-like upper portion of the cavity of the 



