
Respiratory bronchiole
An edge of a terminal bronchiole is seen transitioning into a respiratory bronchiole. 100x

Terminal bronchiole
An edge of a terminal bronchiole is seen transitioning into a respiratory bronchiole. 100x

Respiratory bronchiolar wall
An edge of a terminal bronchiole is seen transitioning into a respiratory bronchiole. 100x

- Associated alveoli
An edge of a terminal bronchiole is seen transitioning into a respiratory bronchiole. 100x

Pulmonary artery
An edge of a terminal bronchiole is seen transitioning into a respiratory bronchiole. 100x

Macrophages >
Macrophages, filled with black carbon particles, are seen scattered in the connective tissue surrounding the bronchioles. Such macrophages are called “dust cells.”