The heart is the body's hardest-working muscle. Whether you're awake or asleep, or exercising or resting, your heart is always at work. It pumps blood through arteries to deliver oxygen to organs and ...

The heart's primary function is to pump blood to all parts of the body, bringing nutrients and oxygen to tissues and removing waste products from them. Even when our body is at rest, our tissues ...

Your Blood Vessels Could Circle Earth Four Times Laid end to end, an adult's blood vessels could circle Earth's equator four ...

The human body is a wonderous thing, especially when you consider how intricate and efficient each bodily system is. For instance, an adult’s blood vessels could encircle the earth 2.5 times if ...