Respiratory bronchiole

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Respiratory bronchiole
Diagram of the alveoli with both cross-section and external view.
Schematic longitudinal section of a primary lobule of the lung (anatomical unit); r. b respiratory bronchiole; al. d alveolar duct; at atria; a. s alveolar sac; 'a' alveolus or air cell; p. a.: pulmonary artery; p. v pulmonary vein; l lymphatic; l. n lymph node.
Latin	bronchioli respiratorii
Gray's	subject #240 1098
Code	TH H3.05.02.0.00018

The respiratory bronchioles are the narrowest airways of the lungs, one fiftieth of an inch across.^[1] The bronchi divide many times before evolving into the bronchioles. They are interrupted by alveoli which are thin walled evaginations. Alveolar ducts are distal continuations of the respiratory bronchioles.

According to Human Anatomy by Frederic Martini they are "the thinnest and most delicate branches of the bronchial tree, and they deliver air to the exchange surfaces of the lungs." "The epithelial cells of the respiratory bronchioles and the smaller terminal bronchioles are cuboidal. Cilia are rare, and there are no mucous or underlying mucous glands." (p. 643 "Human Anatomy" sixth edition".)

Additional images

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  Part of a secondary lobule from the depth of a human lung, showing parts of several primary lobules.

References

External links

• Diagram at davidson.edu
• Respiratory+bronchioles at eMedicine Dictionary
• Histology at BU 13606loa

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