Tags: Anatomical Structure.
Alveolar ducts are tiny ducts that connect the respiratory bronchioles to alveolar sacs each of which contains a bunch of alveoli (the balls). They are tiny end ducts of the branching airways that fill the lungs. Each lung holds approximately 1.5 to 2 million of them. The tubules divide into two or three alveolar sacs at the distal end. They are formed from the confluence openings of several alveoli.
