<prompt> Which of the following not true about alveolar lining?Type II cells make up 95 of the liningType II cells contain lamellar inclusion bodiesType II cells secrete surfactantNone of the above  <response>: The alveoli contain two types of epithelial cells. Type I cells are flat cells with large cytoplasmic extensions and are the primary lining cells of the alveoli, covering approximately 95 of the alveolar epithelial surface area. Type II cells granular pneumocytes are thicker and contain numerous lamellar inclusion bodies. A primary function of these cells is to secrete surfactant; however, they are also impoant in alveolar repair as well as other cellular physiology. Although these cells make up approximately 5 of the surface area, they represent approximately 60 of the epithelial cells in the alveoli. Ref: Ganongs Review of Medical Physiology 23rd edition, Chapter 35. 