The Respiratory System

Contributor: Hannah Brooks. Lesson ID: 12380

When a doctor tells you to take a deep breath and listens to your chest, what is going on in there? Why does your chest get bigger? Where does your voice come from? Breathe easy and learn the answers!


Life Science

learning style
personality style
Grade Level
Intermediate (3-5), Middle School (6-8)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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What happens when you hold your breath? What happens inside when you breathe? Why do you breathe?

Take a deep breath in and then release.

  • What happened in your body when you drew in air? Did your chest get larger?

That is because your respiratory system is working to pull the oxygen from the air you inhaled for the rest of your body to use.

Your respiratory system takes in air and removes the oxygen for use by the body.

Before you continue, if you need a refresher on previous The Human Body lessons, find them in the right-hand sidebar under Related Lessons.

The image below shows the major components of the respiratory system:

The respiratory system uses the lungs, a major organ, located in the center of the chest. Your two lungs are located inside your rib cage for protection.

  • Did you know that your left lung is smaller than your right lung?

It allows extra space for your heart!

Under your lungs is your diaphragm, a muscle that contracts and releases to allow you to breathe. Check out a 3D view of diaphragm during breathing (

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Your respiratory system relies on your nose and mouth to take in air. The air is passed through the larynx and trachea and on to the lungs.

The larynx is the body part that allows you to speak. It is made up of small ridges, or vocal cords, that vibrate to create sound. This is how you sing, yell, talk, and whisper.

The trachea is also called the windpipe. Feel your neck — can you feel the ridges? That's the trachea! It allows air to flow freely between the mouth and the lungs.

Your lungs hold very special structures that help the body process air. Below the trachea, there are two tubes called bronchi. These lead into the left and right lung, and branch off into smaller, tiny tubes, called bronchioles. You have around 30,000 bronchioles in each lung!

These bronchioles lead to alveoli, small air sacs in the lungs. These air sacs help the lungs pull oxygen out of the air.

In review, your respiratory system is made up of organs, tissues, and cells that are responsible for taking air into the body and pulling out useful oxygen. It starts with the nose and mouth, which take in air that moves through the larynx and trachea. The trachea meets the large bronchi tubes that branch into many small tubes in each lung. These bronchioles end with alveoli, small air sacs located in the lungs.

Discuss this question with a parent or teacher:

  • How could the respiratory system be organized into a map?

In the Got It? section, you will practice identifying the important structures within the respiratory system.

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