The homeostatic rôle of bronchoconstriction.

This article argues in favour of the hypothesis that the homeostatic rôles of bronchoconstriction are to retract the airway tree during expiration, and to assist in the expulsion of mucus from peripheral airways by increasing the velocity of outgoing air. In asthma, this function may be dangerously exaggerated because of the presence of unusually viscous airway secretions and the remodelling of airway walls. Copyright 2001 S. Karger AG, Basel