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(brŏng′kē-ōl) plural.bronchioles [L. bronchiolus, air passage]
One of the smaller subdivisions of the bronchial tubes. Bronchioles have no cartilage in their walls; they also have few glands in their mucosa.

respiratory bronchiole

The last division of the bronchial tree. Respiratory bronchioles are branches of terminal bronchioles and continue to the alveolar ducts, which lead to the alveoli.

terminal bronchiole

The next-to-last subdivision of a bronchiole, leading to the respiratory bronchioles.


Small airways extending from the bronchi into the lobes of the lungs.
References in periodicals archive ?
Lungs of nitrofen-exposed pups had 30% fewer terminal bronchioles than did controls, and they were developmentally immature (Leinwand et al.
The term cellular bronchiolitis describes disease in which the primary pattern is an inflammatory infiltrate within the bronchioles.
As with other infections, the granulomas may be peribronchiolar or may communicate with or destroy bronchioles.
During an asthma attack these bronchioles become narrowed, partly by inflammation and mucus but also by contraction of muscles, in the wall of these tiny tubes.
Their greatest disadvantage is a high rate of unwanted effects, like depression of the respiratory center, decreased secretion in the bronchioles, and inhibition of ciliary activity.
However, lung biopsy did not demonstrate organizing pneumonia in the terminal bronchioles or alveolar spaces characteristic of BOOP.
10]), because such particles can reach the terminal bronchioles and alveoli (6).
During normal breathing, the bronchi and bronchioles are opened and air passes through them.
His findings indicate that high-resolution CAT scans or examination of materials rinsed out of the lung's bronchioles can provide an earlier indication of lung scarring, or asbestosis, than can X-rays or breathing tests.
Many necrotic bronchial epithelial cells were adhered to the luminal surface, and many pleomorphic mycoplasma-like organisms were diffusely attached to the mucosal surface of bronchi and bronchioles (Figure 5, panel B).
The biopsy specimens also showed mixed airway-wall inflammation and membranous bronchioles containing hypertrophic mural smooth muscle or fibrous thickening that narrowed the lumen in the small airways.
Tubes called bronchi represent the "branches" of the bronchial tree (see diagram 1); much smaller tubes called bronchioles form the "twigs.