PBS: Nova: Body + Brain Interactive: Map of the Human Heart

Take a virtual tour through the human heart, beginning with the oxygen-poor blood in the right atrium and ending with the oxygen-rich blood going out to different parts of the body. Along the way, you can learn the anatomy of the heart, as well as some quick facts about the heart's function. While you are learning from the website, the website is tracking how much blood your heart is processing in the same time period.

courtesy of netTrekker