MODEL RELEASED. General practice doctor demon- strates the use of a Ventolin inhaler to a female asthma sufferer. The patient is shown how to take deep breaths through her mouth while inhaling an asthma drug into her lungs. The Ventolin inhaler contains the drug salbutamol, which dilates the bronchial muscles, allowing air to pass more easily into the lungs. In bronchial asthma the narrowing of the airways is produced by spasm of the muscles in the bronchial tubes of the lungs. Asthmatic spasms are associated with a swelling of the surfaces lining the lungs and an increased production of lung secretions.