🫁 How Does Breathing Work?
4th Grade 🫀 Human Body
When you breathe in, your lungs fill with air and take oxygen into your blood. When you breathe out, you get rid of carbon dioxide.
The path of air
Air comes in through your nose or mouth, goes down the windpipe (trachea) and splits into two tubes, one for each lung. These branch into smaller and smaller tubes that end in tiny air sacs called alveoli.
The swap
The alveoli are wrapped in tiny blood vessels. Oxygen moves from the air into your blood, and carbon dioxide — a waste gas — moves from your blood into the air you breathe out.
The diaphragm
A dome-shaped muscle under your lungs, the diaphragm, does the work. When it pulls down, air rushes in. When it relaxes, air goes out. You breathe about 20,000 times a day without thinking about it!
Quick quiz
Which gas does your body need from the air?
What muscle helps you breathe?
What are the tiny air sacs in the lungs called?