A double apron like fold peritoneum which hangs from: Greater curvature of the stomach Lower part of the first part of the duodenum. Contains: Extraperitoneal fat Gastroepiploic vessels and their nerve plexuses Lymph vessels and nodes Parts Gastrosplenic ligament containing: Short gastric vessels and their nerve plexus Lymph vessels and nodes Fat. Gastrophrenic ligament Gastrocolic ligament containing mainly fat, lymphatics and lymph nodes

Functions:

• Fat depot
• Mechanical cushion
• Protective “policeman” of the abdominal cavity – tends to adhere to any areas of inflamed peritoneum, with which it may come into contact, and thus often prevents the escape of the contents of a hollow viscus which may have perforated.
• It contains defence cells such as macrophages and lymphocytes

Divisions of the peritoneal cavity

• Two peritoneal sacs:
  
  
• Greater sac
  
  
• Lesser sac.
  
  
• The peritoneal sac entered through the anterior body wall is the greater sac.
  
  
• The lesser sac lies behind the stomach,lesser omentum and liver

Subdivisions

The greater omentum, transverse colon and transverse mesocolon form a shelf dividing the greater sac into supracolic and infracolic compartments.

Supra colic compartment

Sub divided into smaller spaces:

•  The right and left subphrenic recesses separated by the falciform ligament.They lie between the lower     surface of the diaphragm and the upper surfaces of the right and left lobes of the liver.
  
  
• The hepatorenal recess lies between the inferior surface of the right lobe and the right  kidney.

Infra colic compartment

• Is subdivided by the obliquely lying mesentry into right and left infra colic spaces.
  
  
• Because of the obliquity of the partition, the right infra colic space is above to the right and the left infra colic space is below and to the left.
  
  

Smaller peritoneal recesses

• They are of practical importance because a viscus may intrude into such a recess, producing an internal hernia which may become impacted.
  
  
• The surgeon must recognize the danger of cutting such a vascular fold in his attempt to free the impacted viscus.

Smaller recesses occur in three regions: