K-5 friendly lesson
One small step at a time.Read the idea, try the activity, and celebrate each win as you go.

Lungs and Breathing

Inhale oxygen, exhale carbon dioxide.

Do this: Read the concept below, then try the quiz or activity.

Lesson 8 of 18

Concept

Air travels from your nose/mouth down the windpipe into the lungs. Tiny air sacs swap gases: oxygen in, carbon dioxide out.

Short Answer

Why do you breathe faster after running?

Air Path

Nose/Mouth
Windpipe (Trachea)
Lungs
Oxygen in / CO₂ out