Function Of The Heart And The Structure Of Arteries, Veins And Capillaries

2283 WordsJul 1, 201610 Pages
Explain the function of the heart and the structure of arteries, veins and capillaries. Referring to Louise Tucker 5th edition, the heart is an organ that pumps blood through the body via the circulatory system, supplying nutrients and oxygen to the tissues and removing carbon dioxide and other waste products. According to Louise Tucker arteries are thick walled, hollow tubes with a fibrous outer covering, a middle layer of muscle and elastic tissue. The functions of arteries are: • Carry oxygenated blood away from the heart to the rest of the body • Transport nutrients e.g. iron, zinc • Main artery is the aorta Structure: • Lumen, small passage • Thick, muscular and elastic walls Veins have three layered walls, their walls are much thinner, not muscular or elastic and the lumen is much larger compared to arteries. Veins have valves which prevents the back flow of blood. Vein function: • Carry deoxygenated blood from the body • Transport blood to the heart • Deoxygenated blood contains a high concentration of waste products Capillaries are the smallest blood vessels. • They have a thin wall • They are porous allowing oxygen to pass through • They allow the flow of gases and nutrients e.g. sodium, potassium • They have a large amount of water • Blood is brick red, it carries oxygen and carbon dioxide Explain and label the cardiac cycle and include the flow of the blood through the main blood vessels by using the diagram overleaf. Refer to diagram attached. The cardiac
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