Which changes occur in the lungs of a person with chronic bronchitis? Select all that apply.

Chronic bronchitis is a condition defined clinically as a productive cough lasting at least three months per year for two consecutive years, caused by prolonged airway irritation — most commonly from cigarette smoke. The pathophysiological changes are centered on the bronchi rather than the alveoli. Increased mucus production occurs because chronic irritation stimulates hypertrophy and hyperplasia of the mucus-secreting goblet cells and submucosal glands, leading to excessive, thick secretions that clog the airways. Swelling of the mucosa results from chronic inflammation, which causes edema and inflammatory cell infiltration of the bronchial lining. Thickening of the bronchial walls occurs because of smooth muscle hypertrophy and fibrosis in response to ongoing irritation, further narrowing the airway lumen. Airway dilation is incorrect — chronic bronchitis causes airway narrowing and obstruction, not dilation; bronchiectasis involves dilation but is a distinct condition. Destruction of alveolar walls is incorrect because this is the hallmark of emphysema, the other major form of COPD, in which proteases break down alveolar septal walls, enlarging air spaces. Distinguishing between the bronchial changes of chronic bronchitis and the alveolar destruction of emphysema is a key concept for understanding COPD pathophysiology.