The greater omentum:  


A double apron like fold peritoneum which hangs from:

  • Greater curvature of the stomach
  • Lower part of the first part of the duodenum.


  • Extraperitoneal fat
  • Gastroepiploic vessels and their nerve plexuses
  • Lymph vessels and nodes


  • 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


  • 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


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:


Near the duodenal flexure
Near the ileocecal junction
At the sigmoid mesocolon

  •  Inferior duodenal recess
  • Superior duodenal recess (sometimes under a vascular fold)
  • Paraduodenal recess (behind a vascular paraduodenal fold)
  • Retroduodenal recess
  • Mesocolic recess
  • Superior ileocecal recess
  • Inferior ileocecal recess
  • Retrocecal recess
  • The intersigmoid recess

Lesser sac    

  • The lesser sac is also called the omental bursa.

  • It lies behind the stomach and facilitates its movement

Epiploic / Omental foramen

Forms the entrance into omental bursa


Vestibule – lies behind stomach and lesser omentum

Superior recess- behind the liver

Inferior recess- behind the stomach

Splenic recess- anterior to spleen.

Caudate lobe of liver

Free edge of lesser omentum containing:

  • Common bile duct
  • Hepatic artery proper
  • Portal vein
Inferior vena cava First part of duodenum


The Peritoneum