1. The abdomen contains the organs of the digestive and urinary systems. It is bounded by muscles and vertebrae and contains loops of intestine, the liver, kidneys and more.
2. The abdominal cavity is divided into regions and quadrants by planes to aid localization of structures.
3. Major organs include the stomach, small and large intestines, liver, pancreas, spleen and kidneys. The peritoneum lines the walls and covers some organs.