Serosa; Serous coat

Structure of Pleura.—Like other serous membranes, the pleura is covered by a single layer of flattened, nucleated cells, united at their edges by cement substance. These cells are modified connective-tissue corpuscles, and rest on a basement membrane. Beneath the basement membrane there are net-works of yellow elastic and white fibers, imbedded in ground substance (the subserous layer) which also contains connective-tissue cells. Bloodvessels, lymphatics, and nerves are distributed in the substance of the pleura.