That means that the vans are very busy indeed, all the time. So it's a good job we've got the circulatory system to transport nutrients, water and oxygen to the entire body. If we could join all ...

The circulatory system consists of one heart, five liters of blood, and approximately 96,000 kilometers of blood vessels, responsible for transporting nutrients and waste throughout the body.

How Does the Heart Work? As the heart beats, it pumps blood through a system of blood vessels called the circulatory system. The vessels are elastic tubes that carry blood to every part of the body.