The abdominal cavity is the body cavity of the human body (and animal bodies) that holds the bulk of the viscera. It is located below (or inferior to) the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the thoracic diaphragm (a thin sheet of muscle under the lungs), and its oblique floor is the pelvic inlet (the superior opening of the pelvis). It is a part of the abdominopelvic cavity. It is well connected with the pleural (thoracic) cavity.
Organs of the abdominal cavity include the stomach, liver, gallbladder, spleen, pancreas, small intestine, kidneys, and large intestine.
The abdominal cavity is lined with a protective membrane termed the peritoneum. The kidneys are located in the abdominal cavity behind the peritoneum, in the retroperitoneum. The viscera are also covered, in the front, with a layer of peritoneum called the greater omentum (or omental apron).