A cell of the walls between the air sacs in the lung.
A type of cell that lines the walls separating the air sacs in the lungs. Type I pneumocytes are flat and inconspicuous. Type II pneumocytes are cuboidal and secrete surfactant.
Either of the two types of cells that form the alveoli of the lung. Type I cells are simple squamous epithelium that permit gas exchange. Type II cells are rounded and produce surfactant.