ABSTRACT
The pleural space consists of a continuous serosal lining. The side of the surface toward the lung is the visceral pleura and the other side, which covers the chest wall, is the parietal pleura. In the parietal pleura, a single sheet of the mesothelial cells lies on a connective tissue layer. The endothoracic fascia consists of the part of the parietal pleura adjacent to the muscle layer of the chest wall. The single layer of mesothelial cells, the thin layer of connective tissue, the chief layer of connective tissue rich in collagen and elastic fibers, and the vascular layer adjacent to the limiting membrane of the lung parenchyma constitute the structure of the visceral pleura. Unique to the parietal pleura are openings or stomata situated between mesothelial cells and centered over dilated lacunar portions of lymphatic channels (1). These stoma function as one-way valves for the removal of particulate matter. There is no communication between lymphatics of the visceral pleura and the pleural space.
