Fig. 2.2.

Schematic of the respiratory bronchiole during an asthma attack. The airway is lined by the respiratory epithelium which is made of ciliated and mucous producing cells. These mucous producing cells increase mucous production. Mucous then plugs up the airway, making it harder for the asthmatic to breathe. Underneath the respiratory epithelium lies a layer of smooth muscle. When the smooth muscle contracts, the airway becomes smaller, decreasing airflow