Which layer covers the outer surface of the lungs?

• A. Parietal pleura
• B. Visceral pleura
• C. Pleural fluid
• D. Mediastinal pleura

Answer: (B)

Directly covering the outer surface of each lung is the visceral pleura. These membranes form a smooth, tightly adherent layer on the lung itself, continuing at the lung hilum with the parietal pleura that lines the chest wall, diaphragmatic surface, and mediastinum. The space between the visceral and parietal pleura is the pleural cavity, filled with pleural fluid that lubricates breathing. So, the layer that actually coats the lung surface is the visceral pleura.