1) What is an artery? 2) What is a vein? 3) What are the capillaries ? 4) What other waste product does the circulatory system pick up from the cells and take to the lungs to be exhaled? (hint: this waste product is produced when your cells use oxygen for energy) 5) What adds pressure to the circulatory system? 6) Why heart considered as the primary organ of the cardiovascular system

Circulatory system

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