The pleural membrane is a thin, double-layered structure that surrounds the lungs. It consists of two parts: the visceral pleura, which is attached to the lung surface, and the parietal pleura, which lines the chest cavity. This membrane plays a crucial role in facilitating lung movement during breathing by reducing friction between the lungs and the chest wall. Between these two layers is the pleural cavity, which contains a small amount of pleural fluid. This fluid acts as a lubricant, allowing the lungs to expand and contract smoothly. The pleural membrane is essential for proper respiratory function and helps maintain the pressure needed for effective breathing.