Most organs in the abdominal cavity belong to the gastrointestinal system, however, a few belong to the urinary system. Both of these organ systems will eventually extend into the pelvic cavity (sigmoid colon, rectum, ureters, urinary bladder, etc.). In this exercise we will look at all of the portions of both systems because they descend into the pelvic cavity. The organs of reproduction found entirely in the pelvic cavity, will be studied in Exercise Four.
For now we can focus on the contents of the abdomen proper consisting primarily of the organs of the gastrointestinal and urinary systems. It is important to remember that while these organs are found in the abdominal cavity, many associated structures pass through the diaphragm to communicate with these organs. The following organs are included in this communicating structures group: