282 THE ABDOMEN AND PELVIS 



of the omental bursa and completely shut it off from the great 

 sac on this side. Below the level of the spleen, the gastro- 

 splenic ligament is directly continuous with the two anterior 

 layers of the greater omentum, i.e. there is no break in the 

 continuity of the wall of the bursa. 



Transverse sections made through the omental bursa below 

 the epiploic foramen show it as a completely closed sac. In 

 Fig. 87 the section passes through the pylorus and the first 

 part of the duodenum. The peritoneum on the posterior aspect 

 of the stomach passes to the right and covers rather less than 

 the first inch of the duodenum before it passes backwards on to 

 the head of the pancreas. 



This reflection forms the right border of the omental bursa, 

 and the hepatic artery passes forwards round it in order to 

 reach the lesser omentum. 



Drainage of the Peritoneal Cavity. Collections of fluid 



in the peritoneal cavity differ in situation according to the position 

 of the patient, and, unless they are limited by adhesions, they 

 spread in a downward direction when the patient is in the erect 

 or semi-sitting posture. In the supine position, they will tend 

 to pass upwards towards the diaphragm. In the post-operative 

 treatment of inflammatory effusions, the patient is usually placed 

 in the Fowler (semi-sitting) position in order to diminish the 

 risk of upward spread into the sub-diaphragmatic region (p. 283). 



The peritoneal cavity is naturally subdivided into the pelvis 

 and the abdomen proper, and the latter is further subdivided 

 by the large sheets of peritoneum which form the greater 

 omentum and the mesentery. 



The uppermost or Supra - colic Compartment lies above 

 and in front of the greater omentum. It is partially subdivided 

 into a right and a left half by the falciform ligament of the liver, 

 and its contents include the liver, the gall-bladder, the stomach, 

 the first part of the duodenum, the spleen, and the upper poles 

 of both kidneys. The omental bursa (lesser sac) may be regarded 

 as a large diverticulum of the supra-colic compartment. In 

 addition other, smaller, recesses occur : (i) between the upper 

 surface of the liver and the under surface of the diaphragm 

 (Fig. 85) ; (2) the hepato-renal recess of Morrison, between 

 the under surface of the liver above and the right kidney and the 

 right (hepatic) flexure of the colon below ; and (3) between the 

 spleen and the left kidney. 



Anteriorly, the supra-colic compartment is bounded by the 



