Which serous membrane lines the abdominopelvic cavity?

• A. Parietal peritoneum
• B. Visceral pleura
• C. Dura mater
• D. Peritoneum

Answer: (D)

Serous membranes form closed sacs with a visceral layer covering organs and a parietal layer lining the cavity. In the abdomen and pelvis, the serous membrane is the peritoneum. The peritoneum lines the abdominopelvic cavity and also covers many of the abdominal organs with its visceral layer. The parietal portion specifically lines the cavity walls, while the visceral portion drapes over organs, but the membrane as a whole is called the peritoneum. The other options belong to different regions or structures (visceral pleura lines the lungs in the thorax; dura mater is a meningeal layer around the brain and spinal cord). So, the serous membrane that lines the abdominopelvic cavity is the peritoneum.