Final answer:
The statement is false. The serous membrane that directly covers the lungs is the visceral pleura, while the parietal pleura lines the thoracic wall, mediastinum, and diaphragm.
Step-by-step explanation:
The statement that the serous membrane that covers the external surface of both lungs is called the parietal pleura is false. The correct terminology for the membrane that directly covers the lungs is the visceral pleura, not the parietal pleura. The parietal pleura is actually the outer layer that lines the thoracic wall, the mediastinum, and the diaphragm. The pleural cavity is the space between the visceral and parietal layers, and it is filled with a small amount of fluid that helps reduce friction between the lungs and the thoracic wall.