David Skelton, age l0,of South Portland, Maine, for his question:

Are veins the same as arteries?

Both Veins and arteries are blood vessels and the body needs both of them. The circulatory system has a closed network of branching blood vessels that weaves its way through every corner of the body. It must be a closed, unbroken network so that the blood can keep flowing around and around in a never ending circuit. The moving circuit steers the flowing blood out tb:the body then back to the heart and on to the lungs. There it is purified and refreshed, sent back to the heart and out once again on its way.

Fresh, red blood from the heart carries vital oxygen to the living cells through¬out the body. The blood vessels that carry this fresh blood are called arteries. Along the way, the branching blood vessels become thinner and thinner. As the hungry cells take oxygen, they return their waste carbon dioxide gas as the blood goes by. This used blood flows on its way back to the heart and lungs to be purified and refreshed for the next trip around the circuit. The blood vessels that carry the used blood back for purification are called veins.