extends from the diaphragm to the groin. It is encircled by the abdominal wall and bones and muscles of the pelvis. It is divided into 2 portions even though no wall separates them.

• A. Abdominal cavity
• B. Pelvic cavity
• C. Thoracic cavity
• D. Abdominopelvic cavity

Answer: (D)

The concept here is how the body’s main cavities are organized and named. From the diaphragm down to the pelvic floor is a single continuous space that is bounded by the abdominal wall on the outside and by the pelvic bones and muscles at the bottom. There isn’t a hard wall separating an upper abdominal part from a lower pelvic part; instead, clinicians describe two portions—the abdominal portion and the pelvic portion—within one continuous space. That combined region is the abdominopelvic cavity, which includes both the abdominal cavity (the area housing most of the digestive organs) and the pelvic cavity (housing pelvic organs). The other options only describe part of this region: the abdominal cavity alone doesn’t extend into the true pelvic area; the pelvic cavity alone is confined to the pelvis; and the thoracic cavity lies above the diaphragm.