Question

which of the following membranes line cavities that communicate with the exterior of the body?
○ pleural
○ cutaneous
○ serous
○ synovial
○ mucous

Explanation:

To solve this, we analyze each membrane:

• Pleural membranes line the pleural cavities (around lungs), not communicating with exterior.
• Cutaneous membrane is the skin, a surface membrane, not lining internal cavities communicating with exterior.
• Serous membranes line closed body cavities (e.g., peritoneal, pleural) with no exterior communication.
• Synovial membranes line joint cavities, which are closed and don't communicate with exterior.
• Mucous membranes line cavities like digestive, respiratory, etc., that open to the exterior (e.g., mouth, nose, anus), secreting mucus.

Answer:

E. mucous