Terminal & respiratory bronchioles (magnified)
Bronchiolus terminalis
RespiratoryOrgansWhole bodyRight side
- What it is
- Magnified view (~×10) of one pulmonary acinus: a terminal bronchiole, the last purely conducting airway, splits into respiratory bronchioles and alveolar ducts.
- Function
- Carries air into the gas-exchanging acinus; beyond this point the walls are lined by alveoli.
- Size
- Real terminal bronchioles are about 0.5 mm wide; an acinus is 6–10 mm across and there are ~30,000 of them.
- Clinical note
- Club (Clara) cells in the bronchiolar lining secrete protective proteins; centrilobular emphysema from smoking begins at the respiratory bronchioles.