The Respiratory System

What is the term for the process of breathing out?

What is the gas produced by the body's cells when they use oxygen to create energy?

What happens to the carbon dioxide in the blood when it's time to exhale?

Why can't you hold your breath for more than a minute or two?

What is true about breathing in oxygen and breathing out carbon dioxide?

What is the primary function of the respiratory system?

What happens to the air when you inhale?

What is the purpose of the alveoli in the lungs?

What determines how loud a sound is when you're speaking or singing?

Why is the left lung smaller than the right lung?

The respiratory system is responsible for bringing oxygen into the body and removing carbon dioxide, and also enables making sounds through vocal cords.

Air can enter the respiratory system through the nostrils or mouth.
Air passes through the throat, voice box, and trachea (windpipe) into the lungs.
The voice box contains vocal cords that vibrate to produce sound when air passes over them.
The lungs have tubes that branch off and get smaller, like twigs on a tree, leading to tiny air sacs called alveoli.
Alveoli are covered by tiny blood vessels called capillaries, where oxygen from the air is absorbed into the blood.

Breathing out removes carbon dioxide, a gas produced by cells when they use oxygen to create energy.
Carbon dioxide moves from the blood into the alveoli, then out of the lungs, through the windpipe, and out of the nose or mouth.

The body breathes in oxygen and out carbon dioxide automatically, without conscious thought.
The body can force breathing if it's necessary, making it impossible to hold one's breath for more than a minute or two.