What Is the Respiratory System? When we breathe, the respiratory system takes in oxygen and sends out carbon dioxide. The cells in our bodies need fresh oxygen to stay alive. As cells do their jobs, ...

Carbon dioxide – a waste gas that the body needs ... I think I could use some exercise myself. Stand back kids, let me show you how it’s done. All living things need oxygen to survive.

There is increasing evidence that the level of carbon dioxide in the Earth’s atmosphere is rising. There is also evidence that humans are responsible for this rise. There is more carbon dioxide ...

This is called obstructive sleep apnea (AP-nee-uh). Obstructive sleep apnea (OSA) interrupts sleep and can make the body's oxygen levels fall or carbon dioxide levels rise. This can make kids miss out ...