The first passages of the respiratory zone, which have alveoli in their walls, are called: (a) Terminal bronchioles (b) Respiratory bronchioles (c) Alveolar ducts (d) Alveolar sacs. | Homework.Study.com
Emphysema | medical disorder | Britannica
Alveolar sac hi-res stock photography and images - Alamy
Bronchioles and alveoli in the lungs - Mayo Clinic