How We Breathe: Trachea, Lungs and Diaphragm

0:00How do we breathe in and out?

0:03Your body needs oxygen, one of the gases in the air.

0:07Air goes in through your nose or your mouth.

0:11Then it goes down a tube in your neck called the trachea, or windpipe.

0:16The trachea splits in two and leads into your two lungs.

0:21Under your lungs is a dome-shaped muscle called the diaphragm.

0:25When you breathe in, the diaphragm tightens and moves down.

0:30This makes more space in your chest, so air rushes into your lungs.

0:36Inside your lungs are tiny air sacs, with blood flowing all around them.

0:42Oxygen passes from the air in the sacs into your blood.

0:46At the same time, carbon dioxide, a waste gas, leaves your blood and goes into the air sacs.

0:53When you breathe out, the diaphragm relaxes and moves back up.

0:58This makes less space, so air is pushed out, carrying the carbon dioxide away.

1:05So remember: diaphragm down, air in. Diaphragm up, air out.