Today’s Wonder of the Day was inspired by Daniel from AL. Daniel Wonders, “why do we need oxgen to live” Thanks for WONDERing with us, Daniel!

What do you need to do to survive each and every day here on Earth? If you're like most kids, eating and drinking are the two things that probably come to mind first.

However, there's one other important thing you need to do constantly to survive. What are we talking about? Breathing, of course!

We do it so often — and without thinking — that it's easy to forget about. We can go days without water and possibly weeks without food. We can't go minutes without breathing, though!

But why is that? What purpose does breathing serve? The importance of breathing is linked directly to the importance of one particular element your body needs constantly: oxygen.

When you inhale, a large muscle called the diaphragm flexes downward to help draw air into your lungs. Your lungs are one of the largest organs in your body. They work together with the rest of your respiratory system to keep your body's cells supplied with necessary oxygen.

If you put your hand on your chest, you can feel it expand and contract as you inhale and exhale. That's the power of your lungs working together with your diaphragm to bring air into and out of your body.

As you breathe in air, it travels through large tubes in your lungs called bronchi. The bronchi branch off into many smaller tubes called bronchioles. You have about 30,000 bronchioles in each lung.

At the end of each bronchiole are clumps of extremely tiny air sacs called alveoli. How small are alveoli? Very small! So small, in fact, that there are about 600 million of them in your lungs!

The alveoli in your lungs are covered with tiny blood vessels called capillaries. It's there, in your alveoli, that the oxygen in the air you breathe passes into your blood via the capillaries. From your capillaries, the oxygenated blood travels to the heart, where it's pumped out to the rest of the cells in your body.

Your cells need oxygen to convert the nutrients you eat into energy for your body. In the process of making that energy, some waste products are produced. One of the main waste products is a gas called carbon dioxide.

Your body needs to get rid of carbon dioxide, so what does it do? It breathes it out! That's right! Not only does breathing provide your body with necessary oxygen, but it also rids the body of waste like carbon dioxide.

To get rid of carbon dioxide, your blood delivers it to the capillaries surrounding your alveoli. In the alveoli, the carbon dioxide moves into the lungs, where it leaves the body when you exhale. Exhaling occurs when your diaphragm flexes upward to push air out of your lungs and back into the air.

Wonder What's Next?

Tomorrow, Wonderopolis serves up a new Wonder of the Day that will make quite a racket!