Figure 2 is a diagram showing how airways are affected by asthma. To the left is a drawing of a man with the lungs and airways visible. The centre part of the diagram shows a cross section of a normal airway and labels the muscle and airway wall. The final part of the diagram shows an airway during asthma symptoms. The airway is narrowed allowing limited airflow; the muscles are tight, constricting the airway, and there is mucus further restricting the flow of air.