Diagram of the alveoli with both cross-section and external view. The bronchioles (/ ˈbrɑːŋkioʊls / BRONG-kee-ohls) are the smaller branches of the bronchial airways in the lower respiratory tract.

Sep 5, 2025 · Bronchioles are the smallest air passages inside the lungs. They branch off like tree limbs from the bronchi —the two main air passages that receive air from the trachea …

Mar 27, 2024 · The bronchioles are small air passages that form part of the conducting zone in the respiratory system. Learn more at Kenhub!

Apr 27, 2017 · The bronchioles are tubes in the lungs which branch off from the larger bronchi that enter each lung, from the large and singular trachea which connects to the mouth.

Unlike the larger bronchi, bronchioles lack cartilage and instead have smooth muscle to regulate airflow. These small airways are crucial in controlling the flow of air within the lungs. …

Bronchioles are made up of smooth muscle layers to facilitate bronchodilatation and bronchoconstriction. The epithelial cells mainly lining the bronchial tree are ciliated columnar …

It is in the smaller bronchi that major obstruction commonly occurs in asthma: these bronchi contain smooth muscle in their walls, and the muscle may contract, causing airway …