Anatomy and physiology of the peritoneum.

The peritoneum is commonly encountered in abdominal surgery. The development and rotation of the primitive gut tube lead to the normal adult arrangement of the peritoneal cavity, which forms bloodless planes allowing the retroperitoneal portions of the bowel to be safely mobilised. The arrangement of the peritoneum also forms spaces in which infected fluid or pus can collect. The microcirculation of peritoneal fluid is now well understood, and the large absorptive surface of the peritoneum can be exploited in peritoneal dialysis. The absorption of gas by the peritoneum following abdominal surgery is faster in neonates than in older children, and understanding this process contributes to the interpretation of post-operative radiographs.