The Respiratory System

Lesson Plan - Get It!

Audio:

From Air to Awesome

Your body gets air from the world around you. Air enters through your nose or mouth.

Your nose does extra work. It helps warm, moisten, and filter the air before it travels deeper into your body. Tiny hairs and sticky mucus in your nose trap dust, germs, and other particles. Your mouth can also bring in air, especially when you need more air quickly, such as during exercise.

After air enters your body, it travels through these parts.

Nose and mouth: These openings let air enter and leave your body.

Pharynx: This is the space in the back of your throat where air passes through.

Larynx: This is your voice box. It sits in your throat above your windpipe. It holds your vocal cords, also called vocal folds.

Trachea: This is your windpipe. It is a strong tube that carries air toward your lungs.

Bronchi: These are two large tubes that split from the trachea. One bronchus goes into your right lung, and one goes into your left lung.

Bronchioles: These are smaller tubes that branch out inside each lung like tiny tree branches.

Alveoli: These are tiny air sacs at the ends of the bronchioles. This is where oxygen moves into your blood and carbon dioxide moves out.

Lungs: These are the main organs of breathing. Your lungs sit inside your rib cage, which helps protect them. Your right lung has three sections, called lobes. Your left lung has two lobes, which leaves room for your heart.

The Diaphragm: Your Breathing Boss

Under your lungs sits the diaphragm. The diaphragm is a thin, dome-shaped muscle. It separates your chest from your belly.

The diaphragm is the main muscle that helps you breathe.

When you breathe in, your diaphragm tightens and moves downward. This gives your lungs more space to expand. Your rib muscles also help your ribs move up and out. As your chest space gets bigger, air rushes into your lungs.

When you breathe out, your diaphragm relaxes and moves upward again. Your chest space gets smaller, and air leaves your lungs.

Try picturing your diaphragm like the bottom of a balloon pump. When it pulls down, air comes in. When it relaxes upward, air goes out.

The Alveoli: Tiny Air Trading Stations

Inside your lungs, the bronchioles end in clusters of alveoli. Alveoli look a little like bunches of tiny grapes. They may be small, but they do a huge job.

Each alveolus has tiny blood vessels around it. When fresh air reaches the alveoli, oxygen passes through the thin walls of the alveoli and moves into your blood. Your blood carries that oxygen around your body.

At the same time, carbon dioxide moves from your blood into the alveoli. Then you breathe it out.

This trade happens every time you breathe:

Oxygen goes in.

Carbon dioxide goes out.

Your body does this over and over all day and all night, even when you sleep. Your lungs are basically the most dependable delivery workers ever.

Your Voice Box: Where Air Becomes Sound

Now for the noisy part.

Your larynx, or voice box, sits near the middle of your neck. Inside it are two bands of tissue called vocal cords or vocal folds. They stretch across the top of your trachea.

When you breathe quietly, your vocal cords stay open. This lets air move in and out of your lungs.

When you speak or sing, your vocal cords move closer together. Air from your lungs pushes through the small space between them. That moving air makes the vocal cords vibrate. Those vibrations create sound.

The sound starts in your larynx, but it does not stay there. Your throat, mouth, tongue, lips, teeth, and nose help shape the sound into words, songs, laughs, and whispers.

Try this: Place your fingers gently on the front of your throat and hum. You may feel a buzz. That buzz comes from vibration. Your vocal cords are doing their tiny-but-mighty job.

Vocal Cords Are Not Strings

The name vocal cords can be a little tricky. They are not like guitar strings. They are folds of living tissue. They have layers, including muscle and a smooth outer covering. They open, close, and vibrate very quickly.

Your vocal cords also help protect your airway. When you swallow, a flap called the epiglottis helps cover the opening to your airway. This helps keep food and liquid from going down the wrong pipe.

If a tiny bit of liquid gets near your airway, your body may cough to clear it out. Annoying? Yes. Helpful? Also yes.

Your Voice Can Change

People do not all have the same voice. Vocal cords can be different lengths and thicknesses. Longer or thicker vocal cords often make lower sounds. Shorter or thinner vocal cords often make higher sounds.

As children grow, the larynx and vocal cords grow too. During puberty, the voice may change because the larynx gets larger and the vocal cords grow longer. This can make the voice sound lower.

Sometimes the voice cracks while the body adjusts. It may feel awkward, but it is a normal part of growing.

Taking Care of Your Voice

Your vocal cords work hard. Talking, singing, cheering, and laughing all use them. Usually, your voice handles everyday use just fine.

Sometimes your voice may sound rough, scratchy, weak, or breathy. This is called hoarseness. Hoarseness can happen when your vocal cords get irritated or strained. Loud yelling, lots of cheering, singing too hard, illness, allergies, dry air, smoke, and reflux can all bother the vocal cords.

A little hoarseness after a big game or a loud event often goes away with rest. Your voice is not a machine, though. It needs care.

You can help protect your voice by doing these things.

Drink water.

Rest your voice when it feels tired.

Avoid yelling when you can.

Use a normal speaking voice instead of forcing a strange voice for a long time.

Stay away from smoke and strong fumes.

Tell a trusted adult if your voice stays hoarse, hurts, or makes breathing or swallowing hard.

If vocal cords get strained again and again, small bumps called vocal cord nodules can form. These bumps can make the voice stay hoarse. A doctor or voice specialist can check the vocal cords and help decide what care is needed.

The Big Breath Recap

Your respiratory system brings oxygen into your body and removes carbon dioxide. Air enters through your nose or mouth, moves through your throat, passes the larynx, travels down the trachea, splits into the bronchi, moves through bronchioles, and reaches the alveoli.

In the alveoli, oxygen enters your blood and carbon dioxide leaves your blood.

Your diaphragm helps your lungs fill and empty. Your vocal cords use air from your lungs to create sound. That means every breath helps keep your body working, and some breaths even turn into your voice.

Now that you know how air moves, how breathing works, and how your voice uses the respiratory system, you are ready to check your understanding and practice using the key ideas.