The coronary artery which supplies the heart muscles with oxygen and nutrients in the blood
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How does the heart function?
4 chambers-2 atria above- 2 ventricles below. Natural pacemaker top chamber. Electronic impulse spreads into the ventricles causing the muscle to contract and pump blood around the body and to the lungs. Chemicals released by nerves regulate it
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Compare the thickness of the aorta wall and the ventricle walls
Ventricles are thicker because they need to be stronger as they pump blood to the whole body at a high pressure. The atria only pump blood to the lower chamber and therefore don't need to be as strong
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Advantages of double circulation
Blood flow is delivered at a greater rate to tissues around the body because the heart pumps the oxygenated blood returned to it from the lungs. It's useful because as blood flows through the lungs, its pressure is reduced
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Describe the transport of materials between capillaries and tissue fluid
Capillary walls have small pores that allow certain substances to pass in and out of the blood vessel. Walls allow water and small solutes not proteins.
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What are the roles of blood clotting?
Prevents extensive blood loss and the entry of pathogens
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