Final answer:
The fast-healing, thin membrane lining the abdominal cavity is called the peritoneum. It is a broad serous membrane that covers the walls and organs in the abdominopelvic cavity.
Step-by-step explanation:
The fast-healing, thin membrane lining the abdominal cavity is called the peritoneum. It is a broad serous membrane that covers the walls and organs in the abdominopelvic cavity. The peritoneum is composed of two regions - the parietal peritoneum that lines the abdominal wall, and the visceral peritoneum that covers the abdominal organs.