Peritoneum

About the Peritoneum

The peritoneum is the largest serous membrane in the body. Its parietal layer lines the inner walls of the abdomen and pelvis, and its visceral layer covers many of the abdominal organs. The potential space between them, the peritoneal cavity, contains a small amount of lubricating fluid that allows the organs to slide against one another during digestion and movement. Folds of peritoneum such as the mesentery, which suspends the small intestine and carries its blood vessels, nerves, and lymphatics, and the greater omentum, an apron of fatty tissue hanging from the stomach, support and connect the organs. Organs such as the kidneys and most of the duodenum lie behind the peritoneum and are described as retroperitoneal. Inflammation of the peritoneum, peritonitis, often results from a perforated appendix, ulcer, or bowel and is a surgical emergency. Fluid accumulation in the cavity is called ascites. The peritoneum is also used as a natural filter in peritoneal dialysis.