Scanning electron micrograph (SEM) of two Type II pneumocytes. Typically found at the alveolar-septal junction, these granular, cuboidal cells cover a smaller surface than Type I cells, but are far more numerous. They are responsible for the production of surfactant (dipalmitoylphosphatidylcholine), a phospholipid that reduces alveolar surface tension. Surfactant phospholipids are stored in Type II pneumocytes in lamellar bodies, and are released within these specialized bodies from birth onward.