Find out how the circulatory system takes oxygen around the body. What is in your blood? Discover how blood vessels and blood cells help keep your body working. What are blood vessels? Inside ...

Your body is made up of over ... At this point, nothing dramatic happens for a while. But by a decade in, given enough moisture, the wet, low-oxygen environment sets off a chemical reaction ...

Human bodies work best at sea level. Down here, oxygen levels are adequate for our brains and lungs. At much higher altitudes, our bodies cannot function properly. But if climbers want to summit ...

Your body is made up of over ... At this point, nothing dramatic happens for a while. But by a decade in, given enough moisture, the wet, low-oxygen environment sets off a chemical reaction ...

Inside you, there is an amazing network of blood vessels, the tubes that carry blood all around your body. Every part of the body needs oxygen, food and water. The blood vessels are a bit like ...

That high level of sugar in the bloodstream causes cells to produce too much oxygen inside of them ... it makes you think about what goes into your body," Zon said. "Now, knowing what it is ...