Parts of the Respiratory System: Lesson for Kids

Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

You can try to hold your breath, but before too long your body will make you breathe. The system that causes breathing is the respiratory system. This lesson will teach you about the three main parts of that system: the trachea, lungs and diaphragm.


Did you ever notice that you have to breathe more often when you run? When you exercise you need to breathe faster to get new air in and used air out. Your respiratory system is the part of your body that handles breathing.


Your lungs are the two biggest parts of your respiratory system. Give yourself a big hug, and then take in a deep breath of air. Did you feel your chest get bigger? That's because your lungs fill with air when you breathe in.

Even though your lungs fill up with air, they aren't empty balloons. In fact, if you were to look at one, you'd say it looks more like a sponge, than a balloon. That's because of all of the little air tubes and blood vessels inside your lungs.


Your lungs take up much of the space inside your chest. Your left lung is a bit smaller than the one on the right. That's because of your heart, which takes up some of the room on the left side of your chest.

Having your lungs so close to your heart is really helpful. Oxygen from the air you breathe goes into tiny air sacs deep within your lungs. Those air sacs hand off the oxygen to very small blood vessels. The oxygen that's now in your blood stream gets pumped around your body by your heart.


Below your lungs is a large flat muscle that helps you breathe called the diaphragm. While the diaphragm is a muscle, it is unlike the muscles in your arms and legs. Your diaphragm works all day long, without you needing to think about it! That way you don't stop breathing while you're asleep.

When you breathe in, your diaphragm pulls down and flattens out. This allows more room in your chest for your lungs to fill with air. When you breathe out, your diaphragm relaxes and moves up, which helps push air out of your lungs.

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