What is External respiration?

External respiration is when your body takes in air and sends out used-up air, like a tiny breath machine working all day long.

Imagine you're playing with a balloon. When you blow it up, you’re putting air inside, that's like taking in oxygen through your nose or mouth. Then, when you let the air out, it’s like giving back the carbon dioxide you don’t need anymore. That’s what happens during external respiration!

Your lungs are like big balloons inside your chest. When you take a breath in, your muscles help stretch those balloons open, letting fresh air, full of oxygen, flow into tiny air pockets called alveoli.

Then, the oxygen moves from the air into your blood, which is like a special delivery truck carrying it to all your body parts. At the same time, your blood drops off carbon dioxide, the used-up air you need to let out.

Without external respiration, your body wouldn’t get the oxygen it needs to keep moving and growing, just like your balloon needs air to stay full!