Figure 5.

(A) Simple model of a single constricting airway. We consider narrowing of this airway by two distinct mechanisms: (1) shortening of the airway smooth muscle by a factor α < 1 and (2) thickening of the bronchial mucosa such that the airway lumen is reduced by the same factor. (B) Airway resistance (relative to baseline) as a function of smooth muscle shortening and wall thickening when either occurs separately or both occur together (both effects are quantified by the fraction α).