The lining of the thoracic cavity is called the pleura. The pleura is a double-layered membrane that surrounds the lungs and lines the chest wall. It consists of two parts: the visceral pleura, which adheres directly to the surface of the lungs, and the parietal pleura, which is attached to the inner surface of the chest wall.
The pleura serves several important functions. Firstly, it provides a protective barrier for the lungs and helps reduce friction between the lungs and the chest wall during breathing. The pleura also plays a role in the respiratory process by allowing the lungs to expand and contract smoothly. Furthermore, the pleural cavity, the space between the visceral and parietal layers, contains a small amount of pleural fluid that lubricates these layers and aids in efficient respiratory movement.