Picture of Bronchioles

Bronchiole: A tiny tube in the air conduit system within the lungs that is a continuation of the bronchi and connects to the alveoli (the air sacs) where oxygen exchange occurs. Bronchiole is the diminutive of bronchus, from the word bronchos by which the Greeks referred to the conduits to the lungs.

Bronchiolitis is inflammation of the bronchioles and is most commonly due to viral infections.