Ricky Raschick, Age 10, Of St. Paul, Minn., For His Question:

How long are the blood vessel in the human body?

Your pulsing heart sends a streaming river of rich red blood around to all the living ce118 in your body. It leaves the heart through a mighty artery called the aorta that branches into smaller and smaller blood vessels, right down to the tiny capillaries that bend and twist among the separate cells. From the capillaries, the used blood is channeled through larger and larger veins, back to the heart and lungs.

The blood vessels form an immense network of branching veins and arteries throughout the body. It has been estimated that this tubing in the body of man covers a distance of some 60,000 miles. If all the veins and arteries, large and small, including the microscopic capillaries, could be removed and arranged in a single line, they would span the earth's equator about two and one half times.