Final answer:
Serous membranes line body cavities and consist of two layers, the parietal and visceral, functioning in lubrication
Step-by-step explanation:
Serous membranes line body cavities closed to the exterior of the body, such as the peritoneal, pleural, and pericardial cavities. These membranes consist of two layers, the parietal layer that lines the walls of the body cavity and the visceral layer that covers the organs. Between these layers is a thin, fluid-filled serous space, or cavity, which acts as a lubricant to minimize friction between the serosal surfaces of the peritoneum.