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blood vessels that carry waste containing blood from the tissues back to the heart


blood vessels that carry blood away from the heart


tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body


iron-containing protein in red blood cells that carries oxygen for delivery to cells

pulmonary circulation

pathway of circulation between the heart and the lungs

systemic circulation

pathway of circulation between the heart and the rest of the body except the lungs


flap of connective tissue between an atrium and a ventricle, or in a vein, that prevents backflow of blood

red blood cells

blood cells containing hemoglobin that carry oxygen through the bloodstream

white blood cells

cells that police the body by destroying foreign materials


tiny, disk-shaped bodies in the blood, important in blood clot formation

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