The region in the abdomen extending from the thoracic DIAPHRAGM to the plane of the superior pelvic aperture (pelvic inlet). The abdominal cavity contains the PERITONEUM and abdominal VISCERA, as well as the extraperitoneal space which includes the RETROPERITONEAL SPACE.

Synonyms: Cavities, Abdominal, Cavity, Abdominal, Abdominal Cavities, Abdominal Cavity, Cavitas abdominis