artery

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Blood vessel that carries blood from the heart to any part of the body. It is built to withstand considerable pressure, having thick walls that contain muscle and elastic fibres. As blood pulses out of the heart, arteries expand to allow for the increase in pressure – this elasticity helps the blood to flow evenly. The pulse or pressure wave generated can be felt at the wrist. Not all arteries carry oxygenated (oxygen-rich) blood – the pulmonary arteries convey deoxygenated (oxygen-poor) blood from the heart to the lungs.

Arteries are flexible, elastic tubes, consisting of three layers. The middle layer is muscular and its rhythmic contraction aids the pumping of blood around the body. In middle and old age, artery walls become damaged. Some of this damage is caused by the build-up of fatty deposits (see fats). This reduces elasticity and narrows the space (or bore) through which the blood can flow. This condition is known as hardening of the arteries or atherosclerosis and can lead to high blood pressure, loss of circulation, and death. When it affects the arteries supplying blood to the muscle of the heart wall it is called heart disease. People with heart disease run an increased risk of having a heart attack. In a heart attack blood vessels supplying the heart muscles are blocked by a blood clot and this can result in sudden death. Research indicates that for some people a typical Western diet, high in fat from animals, increases the chances of heart disease developing.

Red stands for hardiness and valour. White signifies purity and innocence. Blue represents vigilance, perseverance, and justice. The latest star, representing Hawaii, was added in 1960. Effective date: 4 July 1960. >>