recessus

Recessus, in anatomy, is a Latin term meaning recess. It denotes a recess, pocket, or extension of a body cavity or organ, formed by folds of membranes, ligaments, or surrounding structures. The term is used for small, often elongated spaces that may communicate with a larger cavity or organ.

Many recesses occur in the peritoneal cavity, created by reflections of the peritoneum around organs. Their size and shape vary with anatomy and body position. Recesses may serve as spaces where fluids, air, or masses accumulate, and they can influence clinical assessment and surgery.

Common examples in the peritoneal cavity include the recessus hepatorenalis (hepatorenal recess or Morison's pouch) between the liver and right kidney; recessus rectovesicalis between the rectum and bladder in males; and recessus rectouterinus between the uterus and rectum in females, also called the rectouterine pouch or pouch of Douglas.

Clinically, recesses are relevant in imaging and surgery because accumulated fluid or gas in these spaces can indicate pathology; in trauma, ultrasound assessment of the hepatorenal recess is part of many bedside evaluations, and other recesses may reveal abnormalities on CT or MRI.