Peritoneal cavity

The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall. It is one of the spaces derived from the coelomic cavity of the embryo, the others being the pleural cavities around the lungs and the pericardial cavity around the heart.

The peritoneal cavity is the largest serosal sac in the body and secretes approximately 50 ml of fluid per day. This fluid acts as a lubricant and has anti-inflammatory properties.

Clinical significance

The peritoneal cavity is a common injection site, used in intraperitoneal injection.

An increase in the capillary pressure in the abdominal viscera can cause fluid to leave the interstitial space and enter the peritoneal cavity, a condition called ascites.

In cases where cerebrospinal fluid builds up, such as in hydrocephalus, the fluid is commonly diverted to the peritoneal cavity by use of a shunt placed by surgery.