Arrange the following events in the pathway from airway irritation to reduced airflow.

### The order 1. Smoke irritates the airway lining. The material identifies smoke as an airway irritant. 2. The airway lining becomes inflamed and swollen. Irritation can lead to an inflammatory response. 3. The air passages become narrower. Swelling reduces the space available for air movement. 4. Airflow becomes more difficult. Narrowed passages make breathing air through the airways harder. ### The concept Airway inflammation is one mechanism by which smoke impairs lung function. Increased mucus can also block airways, but this sequence focuses on swelling and narrowing. Alveolar damage is a separate process that affects gas exchange rather than being the direct step in this airway pathway. ### Terms - **Airway lining**: The inner surface of the passages that carry air. - **Inflammation**: A response that can cause swelling and irritation. - **Airflow**: Movement of air through the respiratory passages. ### Remember Irritation can lead to swelling, narrowing, and then more difficult airflow.