Pulmonary Histology
_Airways Respiratory Zone
_Terminal bronchiole to Respiratory bronchiole - lined by ciliated cells  and CLARA CELLS; by transitional zone to RB, all Clara cells.
_Alveolar ducts/sacs
�Type I cells 90% of alveolar surface
�Type II cells
_Cell types
�CLARA CELLS - produce a component of surfactant and are the bronchiolar reserve cell
�TYPE I CELLS - Thin lining cell for gas exchange
�TYPE II CELLS - surfactant and alveolar reserve cell