circulation

circulation system

• the circulatory system consists of your hearts, blood vessels and blood. the heart is the gas machine is the circulatory system.

the heart

• the heart is the main system in your circulatory system, it has 4 chambers, 2 of which pump the oxygenated blood, and 2 that pump deoxygenated blood. it's blood vessels carry nutrients and blood in and away from the heart.
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arteries

• arteries are the thickest of the blood vessels. they carry blood away from the heart. arteries are thick because their walls need to withstand the pressure of the walls.
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capillaries

• capillaries are the finest of the blood vessels. their jobs is to carry nutrients in the body and carry wastes away from the body. they are only 1 cell thick.
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veins

• veins are the last of the three blood vessels. They carry blood back to the heart. they are blue unlike other blood vessels. they have valves to stop the blood from escaping them.
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double circuit system

• the human circulatory system is known as a double system. this is because there are 2 circuits going around the body from the heart. one goes from the heart to the lungs then back to the heart, the other from the heart, to the body, then back to the heart.
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types of blood and other materials

• blood is the only organ in the body that is a liquid. there are red blood cells, which transports the oxygen to the body, white blood cells that fight with the immune system. platelets are parts of cells that help clot blood. and plasma is a yellowish liquid that is 90% water and 10% dissolved materials.
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