Which serosa lines the walls of a body cavity?

Which serosa lines the walls of a body cavity?

• A. Parietal serosa
• B. Visceral serosa
• C. Both
• D. Neither

Answer: (A)

The lining that covers the walls of a body cavity is the parietal serosa. In serous membranes, two layers form a continuous sheet: the parietal layer lines the cavity itself, while the visceral layer covers the organs inside the cavity. Between them is a small space filled with serous fluid that reduces friction during organ movement. Since it’s the cavity walls that are lined, the parietal serosa is the correct choice. The visceral serosa, by contrast, stays on the surfaces of the organs, not the cavity walls.

The lining that covers the walls of a body cavity is the parietal serosa. In serous membranes, two layers form a continuous sheet: the parietal layer lines the cavity itself, while the visceral layer covers the organs inside the cavity. Between them is a small space filled with serous fluid that reduces friction during organ movement. Since it’s the cavity walls that are lined, the parietal serosa is the correct choice. The visceral serosa, by contrast, stays on the surfaces of the organs, not the cavity walls.