Mammal, lung (LM, Medium)

Structure List Bronchiole Respiratory bronchiole Alveolar duct Alveolar sacs Alveoli High Magnification View

ALVEOLAR DUCTS arise from the respiratory bronchioles. They are like halls with rooms (alveoli) opening into them. There are some distinguishing features: lined by simple squamous or cuboidal epithelium, and smooth muscle cells are prominent around the openings into the alveoli.