In patients with chronic asthma, which physiological change is typically observed?

• A. Reduction of smooth muscle
• B. Hypertrophy and hyperplasia of smooth muscle
• C. Decreased mucus production
• D. Improvement in airway elasticity

Answer: (B)

In patients with chronic asthma, hypertrophy and hyperplasia of smooth muscle is a characteristic physiological change. Over time, the chronic inflammatory processes associated with asthma lead to thickening of the airway walls. This is due to an increase in both the size of the smooth muscle cells (hypertrophy) and an increase in the number of these cells (hyperplasia).

This change occurs as a response to ongoing airway inflammation and obstruction, which leads the smooth muscle to remodel to deal with chronic airflow limitation. The resultant thickening of the airway walls can contribute to the increased airway reactivity and reduced airflow, symptoms typically seen during an asthma exacerbation.

Reduction of smooth muscle would not be expected, as asthma involves a reaction where the airway smooth muscle becomes more prominent due to remodeling. Decreased mucus production contradicts the common finding in asthma of increased mucus production, especially during exacerbations. Improvement in airway elasticity also does not align with asthma pathology, as chronic airway inflammation generally leads to reduced elasticity, making the airways more prone to collapse during expiration. Thus, hypertrophy and hyperplasia of smooth muscle is a key feature in the pathophysiology of chronic asthma.