Why Do We Breathe?

What You'll Learn

• We breathe to bring oxygen into our bodies
• Our lungs take oxygen from the air and pass it into our blood
• Our blood carries oxygen to every part of the body to give us energy
• We breathe out carbon dioxide, a gas our body doesn't need

Words to Know

Breathe

Pull air in and push it out

"I breathe in oxygen and out carbon dioxide."

Oxygen

A gas your body needs for energy

"My lungs take oxygen from the air."

Lungs

The organs inside your chest that move air

"My lungs fill up like balloons."

Carbon dioxide

A leftover gas your body breathes out

"We breathe out carbon dioxide."

Check What You Learned

Fun Facts

• Breathing brings oxygen into the body and removes carbon dioxide

  Source: American Lung Association

• Humans breathe approximately 20,000 times per day

  Source: Cleveland Clinic

• The lungs contain about 300 million alveoli where gas exchange occurs

  Source: American Lung Association

• Oxygen diffuses from the alveoli into the bloodstream and binds to hemoglobin in red blood cells

  Source: National Heart, Lung, and Blood Institute

• Cells use oxygen in cellular respiration to produce ATP (energy)

  Source: Britannica

• Carbon dioxide is a waste product of cellular respiration and is transported back to the lungs to be exhaled

  Source: NHLBI