The abdominal cavity is a large cavity in the body which contains the major viscera. This body cavity is the largest cavity in the body, but it is far from an empty space. In fact, the abdominal cavity is quite full of various important organs which are ingeniously packed into place.

Above the abdominal cavity is the thoracic cavity, which contains the lungs and heart. It is separated from the abdominal cavity by a layer of tough tissue known as the diaphragm. The thoracic cavity is also distinguished from the abdomen because it is surrounded by the rib cage, which provides extra support and protection to the organs inside. The abdomen, by contrast, has no cage of bone to protect its contents. The body cavity located below the abdominal cavity is known as the pelvic cavity. It is not actually physically separated from the cavity above, but contains different organs for different functions and is thus treated as separate.

The entirety of the abdominal cavity is lined with the peritoneum. The peritoneum serves a number of important functions including protecting the organs it surrounds, supplying blood flow to the organs, anchoring organs in place, and absorbing impacts which may be sustained. There are several layers of peritoneum separated with a layer of serous fluid which provides lubrication so that the layers can slide past each other.

This body cavity contains the alimentary organs including the large and small intestines along with the liver, kidneys, spleen, and adrenal glands. Quarters in the abdominal cavity are actually quite cramped in most animals because the intestines are extremely long to allow the body to digest food. One problem which can emerge in this body cavity is peritonitis, in which inflammation sets in and spreads across the abdominal organs. Inflammation can be the result of puncture wounds, surgeries, or systemic issues inside the abdomen, such as a cancer which is left untreated.

Surgical procedures in the abdominal cavity are often performed by a general surgeon, although surgeons in other areas of specialty may have cause to enter the abdomen during procedures. Surgery on the abdomen is usually considered major surgery because it comes with a number of risks for the patient. The development of endoscopic surgery has radically reduced the risks of abdominal surgery by eliminating the need for open incisions with many surgical procedures. In addition to being less risky, such procedures have a dramatically decreased healing time and usually cause less pain for the patient.