How would you describe surfactant and explain its function?
1 Answer
The granular cells of the pulmonary alveoli secrete a film of fatty substance, known as surfactant.
Explanation:
Re inflation of the alveoli following exhalation is made easier by pulmonary surfactant, which is a phospholipid and protein mixture that reduces surface tension in the thin fluid coating within all alveoli. The reduction in surface tension allows the membrane to separate, therefore increasing it's capacity to exchange gas.
The surfactant is produced by great alveolar cells (granular pneumocytes, a cuboidal epithelia), which are the most numerous cells in the alveoli, yet do not cover as much surface area as the squamous alveolar cells.
The surfactant is continuously released by exocytosis. It forms an underlying acquous protein - containing hypophase and an overlying phospholipid film composed primarily of dipalmitol phosphotidyl choline.
