Reference Terms
from Wikipedia, the free encyclopedia


In biology, a vein is a blood vessel which carries blood toward the heart.

Veins form part of the circulatory system.

The vessels that carry blood away from the heart are known as arteries.

Veins have one-way valves to prevent backflow caused by gravity.

Note:   The above text is excerpted from the Wikipedia article "Vein", which has been released under the GNU Free Documentation License.
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