What is alveoli?

Alveoli are tiny air sacs in your lungs that help you breathe easily and get energy from the air you inhale.

Imagine your lungs are like a big balloon. When you take a deep breath, this balloon fills up with air. But to really get oxygen into your blood, the balloon needs tiny pockets inside it, these are alveoli. They're so small that millions of them fit in just one lung!

Think of alveoli like little bubbles in a soda bottle. When you shake up the bottle, the bubbles pop open and let out carbon dioxide. In your lungs, when you inhale, these alveoli stretch open, letting oxygen from the air pass into your blood, just like how the bubbles let out gas.

When you exhale, the alveoli shrink back down, pushing out the used-up air. This happens millions of times every day, helping your body get the energy it needs to run, play, and laugh!