Nose picking is one of the main reasons kids get nosebleeds. So if a kid in class suddenly gets a nosebleed - there's a pretty good chance he's been doing some serious nasal excavation.
Oxygen hitches a ride with our blood to get everywhere it needs to go. Find out how oxygen gets into our blood and how it travels inside our body.
Did you know that heart disease is the number one cause of death in the US? Learn more about it here.