Let's get straight to the heart of the matter—the heart's job is to move blood. Day and night, the muscles of your heart contract and relax to pump blood throughout your body. When blood returns ...

For most of history, the human heart has been regarded as a forbidden organ too delicate to tamper with. It might have remained so, were it not for World War II. Military doctors, facing injury ...

Her writing has also appeared in The Philadelphia Inquirer, Popular Science, PBS NOVA, and more. View Full Profile. Learn about our Editorial Policies. The simple, constant rhythm of a beating heart ...