Multiple choice

What is the functional unit of lungs?

  1. Bronchus

  2. Alveolus

  3. Larynx

  4. Nose

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alveolus is the tiny air sac (only 1 cell thick) in the lungs at the end of the smallest airways, where the exchange of oxygen and carbon dioxide takes place. This is the functional unit of lungs.