 |
Once created, blood literally supplies the very materials that maintain life. Flowing through the arteries and veins, blood carries oxygen and nutrients to the body and returns waste materials to be expelled from the body.
|
|
Yet for millennia, the circulation of blood was unknown, and misguided theories abounded until relatively recently. For example, it was not until the 16th century that a Westerner dared to suggest that blood passes through the lungs. Though correct -- and 300 years behind the Egyptian physician Ibn al-Nafis' identical claim -- Michael Servetus was burned at the stake for heresy.
Forced through the body by the powerful pump known more affectionately as the heart, we explore the circulatory system and what makes it work. This stage in our journey features "Follow the Flow," an animation that demonstrates the heart, hard at work, and how it distributes blood throughout the human body.
|
|
|
 |
 |
 Ancient Greeks believed that arteries contained air.
 We know that arteries transport blood from the heart.
|
|
|
