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Bronchioles of the Lungs

From the tertiary bronchi, air is conducted to and from the alveoli (or air sacs) by a series of small, branching tubules called image descriptionbronchioles

Zoom in image of lobular bronchiole
Branching bronchioles of the lungs
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  • The bronchioles branch many times on their way to the alveoli, and each division produces tubules that are progressively smaller in diameter (magnified here for display).
  • A image descriptionlobular bronchiole (or preterminal bronchiole), conducts air in and out of a pulmonary lobule (or secondary pulmonary lobule).
Zoom in image of lobular bronchiole
Lobular bronchioles of the lungs
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  • After entering a pulmonary lobule, a lobular bronchiole divides into three or more image descriptionterminal bronchioles.
Zoom-in of the pulmonary lobule
The terminal bronchioles are labeled and highlighted
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  • Terminal bronchioles measure 0.5 – 1 mm (or less) in diameter and have walls made of simple ciliated cuboidal cells, a few smooth muscle cells, and connective tissue. They are too thick for air exchange, so these tubes are considered to be the last of the conducting zone structures.
  • Two or three image descriptionrespiratory bronchioles typically branch from each terminal┬ábronchiole. These thin-walled tubules are the first respiratory zone structures, and they, in turn, give rise to alveolar ducts, alveoli, and alveolar sacs.
Zoom-in of the pulmonary lobule
The respiratory bronchioles are labeled and highlighted
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An Overview of the Bronchioles of the Lungs:

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Zoom in of pulmonary lobule with answers shown
Zoom in of pulmonary lobule with answers hidden
Zoom in of pulmonary lobule with answers shown
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