Your PayingAttention: The circulatory system must supply all cells in the body, analogous highways & local street. By definition, arteries carry blood away from heat, veins back. Heart only pumps during contraction, relaxes to allow blood return from veins. Thus arteries expand & contract, pulsate, veins thin wall & minimal change in size heart beat to beat. Consciously, most people filter out the vast majority of data.
Answered 3/28/2017
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A doctor has provided 1 answer
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3 doctors weighed in across 2 answers
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