<physiology> A surface active agent, the best known example of which is the lung surfactant that renders the alveolar surfaces hydrophobic and prevents the lung filling with water by capillary action.

The lung surfactant is produced just at parturition and it has often been speculated that deficiencies in surfactant metabolism might cause cot death.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)