Bronchiole Health Dictionary

One of many small airways of the lungs.

Bronchioles branch from larger airways (bronchi) and subdivide into progressively smaller tubes before reaching the alveoli (see alveolus, pulmonary), where gases are exchanged.

n. a subdivision of the bronchial tree that does not contain cartilage or mucous glands in its wall. Bronchioles open from the fifth or sixth generation of bronchi and extend for up to 20 more generations before reaching the terminal bronchioles. Each terminal bronchiole divides into a number of respiratory bronchioles, from which the *alveoli open. Each terminal bronchiole conducts air to an acinus in the *lung. —bronchiolar adj.