Figure 1.

Airway wall remodeling in chronic lung disease. In contrast to the healthy airway wall, the airway wall in asthma, left, and chronic bronchitis, right, displays airway constriction, associated with smooth muscle thickening at the outer airway wall, and airway inflammation, associated with mucosal growth at the inner airway wall. These changes manifest themselves in an increase in pressure at the outer wall and an increase in volume at the inner wall, resulting in a narrowing of the lumen and progressive airflow obstruction; adapted from [1,4].