AP BIOLOGY

Detailed explanation-1: -Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

Detailed explanation-2: -When you breathe, air travels to your lungs through airways called bronchi. The bronchi divide into smaller airways, called bronchioles, which end in clusters of tiny air sacs, called alveoli.

Detailed explanation-3: -The alveoli form clusters, called alveolar sacs, that resemble bunches of grapes. By the same analogy, the alveolar ducts leading to the sacs are like the stems of individual grapes, but, unlike grapes, the alveolar sacs are pocketlike structures made up of several individual alveoli.

Detailed explanation-4: -In your lungs, the main airways (bronchi) branch off into smaller and smaller passageways-the smallest, called bronchioles, lead to tiny air sacs (alveoli).