Key Points

• The pleura is made of two serosal membranes, one covering the lung (visceral pleura) and one covering the inner chest wall and mediastinum (parietal pleura).
• The visceral pleura is devoid of somatic innervation, whereas the parietal pleura is innervated through a rich network of somatic, sympathetic, and parasympathetic fibers.
• Pleural fluid is constantly secreted, mostly by filtration from the microvessels in the parietal pleura.
• The resorption of pleural fluid may be through lymphatic stomata in the parietal pleura rather than through the visceral pleura.
• The pleural pressure, which is subatmospheric, is proportional to the pressure developed within the lung.