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Arteries carry blood
pumped from the heart. Veins return
blood back to the heart. Unlike arteries,
vein walls contain little or no muscle
tissue. In our legs the contraction
of muscles surrounding the veins helps
return the blood back up to the heart
against gravity. Valves within the veins
direct the blood towards the heart and
normally close to prevent blood from
flowing backwards.
Most blood is returned to the heart
by deep veins that lie within the muscle
compartments of the leg. A small amount
of blood travels through a network of
superficial veins located near or just
under the skin. The superficial veins
drain into the deep veins through direct
connections or perforating veins that
travel through the muscle between the
superficial and deep systems.
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