Transition of terminal to respiratory bronchiole
This passageway shows the transition of a terminal bronchiole (conducting portion) as it branches into two respiratory bronchioles (respiratory portion). Respiratory bronchioles, like terminal bronchioles, are lined by a simple cuboidal epithelium containing ciliated and club cells. However, respiratory bronchioles possess alveoli as components of their wall and thus the epithelium appears interrupted. Respiratory bronchioles are the initial passageways of the respiratory portion of the respiratory system. 100x
Terminal bronchiole >
A terminal bronchiole is the terminal part of the conducting portion of the respiratory system. It is lined by simple, ciliated columnar epithelium with club cells. No alveoli are present.
Respiratory bronchioles >
The respiratory bronchiole possesses alveoli as part of its wall. The lumens of the alveoli are directly continuous with that of the respiratory bronchiole and thus the respiratory bronchiole is capable of gas exchange. This bronchiole is lined by a cuboidal epithelium with cilia and club cells.
Associated alveoli >
These alveoli are components of the wall of the respiratory bronchiole. The lumen of the bronchiole is continuous with that of the alveoli.
Non-associated alveoli >
Numerous alveoli surround the respiratory bronchiole, however, they belong to other respiratory bronchioles, alveolar ducts or alveolar sacs.
Pulmonary arteries >
These vessels accompany the bronchiole and carries deoxygenated blood to the alveoli for gas exchange.
Next image >
The next image show the region within the rectangle at higher magnification.
Image source >
This image was taken of a slide from University of Iowa collection.
