Each 2.54 square centimetre (a square inch) of human skin has six metres (20ft) of blood vessels. Veins hold about 65 per cent of the body's blood and have one-way valves tohelp blood move.

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 blood vessels in a human body together end-to-end ...

The circulatory system includes the heart, blood vessels and blood, and is vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance). The system's main function ...

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.

A closed system of blood vessels: Blood vessels include: There are two blood circulatory systems in the body. The systemic circulatory system is the main blood circulatory system that transports ...

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.