What happens to the bronchioles in an asthma attack? how do regular rescue inhalers treat asthma? (i. e. bronchodilators). how do steroids treat asthma symptoms in the long term (hint: they are not rescue inhalers)

Asthma refers to a disease in which swelling of the airways results in the restriction of airflow into and out of the lungs. During the occurrence of an asthma attack, the production of the mucus gets increased, the bronchial tree muscles become constricted, and the inflammation of the air passages lining occurs. This further minimizes the flow of air and generates a kind of wheezing sound.  

The bronchodilators quickly help in relieving the symptoms of acute asthma by opening the airways. The activity of inhaled bronchodilator begins some minutes post inhalation and endures for two to four hours.  

All the kinds of steroids minimize swelling in the airways, which transports air towards the lungs and minimize the generation of mucus produced by the bronchial tubes. This makes one breathe easily.  

The inhaled steroids cure swelling of the airways, and only a very minute concentration of it gets captivated by the body. Thus, these medicines do not seem to result in any kind of serious side effects in a long run.