bronchiolus


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bronchiole

 [brong´ke-ōl]
one of the successively smaller channels into which the segmental bronchi divide within the bronchopulmonary segments. adj., adj bronchi´olar.
respiratory b's the final branches of the bronchioles, communicating directly with the alveolar ducts; they are subdivisions of terminal bronchioles, have alveolar outcroppings, and themselves divide into several alveolar ducts.
Respiratory bronchiole. From Dorland's 2000.
( and see color plates.)
terminal bronchiole the last portion of a bronchiole that does not contain alveoli, i.e., one whose sole function is gas conduction; it subdivides into respiratory bronchioles.

bron·chi·ole

(brong'kē-ōl), [TA]
One of approximately six generations of increasingly finer subdivisions of the bronchi, all smaller than 1 mm in diameter, and having no cartilage in its wall, but relatively abundant smooth muscle and elastic fibers.
Synonym(s): bronchiolus [TA]

bronchiolus

/bron·chi·o·lus/ (brong-ki´o-lus) pl. bronchi´oli   [L.] bronchiole.

bronchiole

A conducting airway which begins at the last cartilaginous plate and ends at the last ciliated epithelial cell; bronchioli are any of 7–9 increasingly finer subdivisions of the bronchiolar tree (BT), measuring < 1 mm in diameter. In the distal BT, the respiratory epithelium becomes flatter, the ciliated cells fewer in number, the mucous glands less prominent and eventually disappear and, in the purely respiratory bronchioles, cuboidal nonciliated non-mucus-producing Clara cells appear.

Bronchiole types 
Respiratory bronchiole bronchiolus respiratorius MNA6
Any of 1–3 generations of ≤ 0.5-mm airways that connect terminal bronchioli to the alveolar ducts. Alveoli arise directly from the wall of RBs; the most distal RB is histologically characterised by an air space lined on one side by respiraotory epithelium and on the other by alveoli.
 
Terminal bronchiole bronchiolus terminalis NA6
Any of ±6 generations of purely conducting—i.e., nonrespiratory bronchioles—which connect; rare direct connections between TBs and alveoli may be seen, known as Lamberth’s canals.

bron·chi·ole

(brong'kē-ōl)
One of approximately six generations of increasingly finer subdivisions of the bronchi, each smaller than 1 mm in diameter, and having no cartilage in its wall, but relatively abundant smooth muscle and elastic fibers.
Synonym(s): bronchiolus [TA] .

bronchiolus

pl. bronchioli [L.] bronchiole.