The correct term for the two-layered membrane that surrounds organs within the body cavities is the "serous membrane."
1. Serous membranes are thin, double-layered membranes that line the walls of certain body cavities (parietal layer) and cover the organs within those cavities (visceral layer).
2. These membranes secrete a fluid known as serous fluid, which helps reduce friction between the organs as they move within the cavities.
3. The serous membranes are found in various body cavities such as the pleural cavity (surrounding the lungs), pericardial cavity (surrounding the heart), and peritoneal cavity (surrounding abdominal organs).
4. The presence of serous membranes allows organs to move and function smoothly within the body without causing damage due to friction.
