Your lungs are two spongy organs in your chest that bring air into your body. When you breathe in, your lungs fill with air and take in oxygen. When you breathe out, they push out a waste gas called carbon dioxide.
Have children take deep breaths and feel their chest and belly expand and contract. Blow up a balloon to show how lungs inflate. Count breaths per minute at rest and after exercise. Place a hand on the chest and a hand on the belly to feel both move during breathing.
Children sometimes think they breathe in "good air" and breathe out "bad air," which is partially right but oversimplified — they breathe out mostly the same air, just with more carbon dioxide and less oxygen. Some children think they only have one lung. Others think holding their breath is dangerous, when holding it briefly is harmless.
Take a deep breath right now. Feel your chest rise? That is your lungs filling up with air. You have two lungs inside your chest, one on each side, protected by your rib cage. They are spongy and stretchy, kind of like balloons. When you breathe in, they expand and fill with air. When you breathe out, they shrink back down and push air out.
But your lungs do not just hold air — they work like a filter. The air you breathe in contains a gas called oxygen, which your body needs to survive. Inside your lungs, oxygen passes from the air into your blood. Your heart then pumps that oxygen-rich blood to every cell in your body. At the same time, your cells send back a waste gas called carbon dioxide, which they do not need anymore. The blood carries carbon dioxide back to your lungs, and you breathe it out. In with oxygen, out with carbon dioxide — this exchange happens with every single breath.
You breathe about 15 to 20 times per minute without even thinking about it. When you exercise, that number goes up because your muscles need more oxygen. When you sleep, it slows down because your body is resting. Breathing is one of those things your body does automatically — you do not have to remind yourself to do it. But you can control it too: you can take a slow, deep breath on purpose, hold it for a moment, and let it out slowly. This is why deep breathing is so good at calming you down — you are taking control of something your body usually handles on its own, and it tells your whole body to relax.