Chronic bronchitis involves which mechanism?

Chronic bronchitis involves which mechanism?

• A. No airway obstruction.
• B. Destruction of alveolar walls only.
• C. Airway obstruction from chronic and excessive mucus secretion, inflammation and bronchospasm with infections.
• D. Alveolar cartilage growth.

Answer: (C)

Chronic bronchitis causes airway obstruction mainly from mucus-producing changes and inflammation in the airways. Long-term exposure leads to enlargement of mucus glands and increased goblet cells, so mucus production is excessive and can plug the airways. The bronchial walls become thickened and edematous, with inflammatory cells infil trating, further narrowing the lumen. Recurrent infections can intensify irritation and trigger bronchospasm, worsening the obstruction. This combination of mucus hypersecretion, inflammation, and bronchospasm explains the chronic productive cough and airflow limitation seen in chronic bronchitis. By contrast, destruction of alveolar walls is the hallmark of emphysema, not chronic bronchitis, and growth of alveolar cartilage is not a mechanism involved in this condition.

Chronic bronchitis causes airway obstruction mainly from mucus-producing changes and inflammation in the airways. Long-term exposure leads to enlargement of mucus glands and increased goblet cells, so mucus production is excessive and can plug the airways. The bronchial walls become thickened and edematous, with inflammatory cells infil trating, further narrowing the lumen. Recurrent infections can intensify irritation and trigger bronchospasm, worsening the obstruction. This combination of mucus hypersecretion, inflammation, and bronchospasm explains the chronic productive cough and airflow limitation seen in chronic bronchitis. By contrast, destruction of alveolar walls is the hallmark of emphysema, not chronic bronchitis, and growth of alveolar cartilage is not a mechanism involved in this condition.