Originally appeared on the NOVA Web site Cut to the Heart. Sure, you know how to steal hearts, win hearts, and break hearts. But how much do you really know about your heart and how it works?

If you clench your hand into a fist, this is approximately the same size as your heart. It is located in the middle of the chest and slightly towards the left. The heart is a large muscular pump ...

Sure, you know how to steal hearts, win hearts, and break hearts. But how much do you really know about your heart and how it works? Read on to your heart's content! Put your hand on your heart.