AEMCA Practice Exam

Which component is affected by chronic exposure to irritants leading to chronic bronchitis?

1. Airway smooth muscle tone

2. Respiratory centers in the brain

3. Cilia and airway lining

4. Gas exchange in the alveoli

The correct answer is: Cilia and airway lining

Chronic exposure to irritants primarily affects the cilia and airway lining, making this choice the most accurate. In chronic bronchitis, the continual irritation and inflammation of the airways lead to changes such as hypersecretion of mucus and damage to the epithelial cells that line the respiratory tract. This results in impaired function of the cilia, which are essential for clearing mucus and debris from the airways. Over time, the damage can lead to mucus buildup, obstruction of airflow, and increased susceptibility to lung infections. When considering the other components mentioned, while airway smooth muscle tone can be affected in the context of bronchoconstriction, it is not the primary component impacted by chronic exposure to irritants. Similarly, the respiratory centers in the brain primarily regulate the overall function of breathing and are not directly altered by irritants in a way that leads to chronic bronchitis. Finally, gas exchange in the alveoli is a crucial aspect of lung function, but chronic bronchitis primarily impacts the larger airways rather than the alveolar spaces directly.