Regional Anatomy of the Abdominal Cavity and Its Clinical Application

The boundary of the abdominal cavity is inconsistent with the surface area of the abdomen. The abdominal cavity is bounded superiorly by the dome-shaped diaphragm that protrudes into the thoracic cavity, inferiorly by the pelvic inlet that connects to the pelvis, and laterally by the abdominal walls. The dome-shaped roof extends on the left and right sides up to the level of the fourth and fifth intercostal spaces, respectively. The small intestine and other organs in the abdomen usually reside within the lesser pelvis. Therefore, the exact range of the abdominal cavity is much larger than that appears on the abdominal surface.