<prompt> Over-inflation of lung is prevented by?Chemo-receptorHering-Breuer reflexSurfactantClara cells  <response>: Ans. B Hering Breur ReflexRef: Gattong, 25th ed. pg. 662 Hering- Breuer reflex is reflex triggered to prevent over inflation of lung. Smooth muscles of lung have pulmonary stretch receptors which respond to excessive stretching of lung during large inspirations. The reflex limits the tidal volume while increasing the respiratory frequency Hering Breur inflation reflex is increase in duration of expiration produced by steady lung inflation. Hering breur deflation reflex is a decrease in duration of expiration produced by steady lung deflation. Surfactant prevents collapse of the lung. 