Rigidity of tracheae and bronchi during muscular constriction.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001980:Bronchi / Q000502:physiology*; D002415:Cats; D004548:Elasticity; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D014132:Trachea / Q000502:physiology*
D000109:Acetylcholine