Peritoneal cavity


The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum. The parietal and visceral peritonea are layers of the peritoneum named depending on their function/location. 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.
It is the largest serosal sac, and the largest fluid-filled cavity, 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.
Body fluid sampling from the peritoneal cavity is called peritoneocentesis.
The peritoneal cavity is involved in peritoneal dialysis.