Most common heart disease is coronary heart disease
→ coronary arteries lie on the outside of the heart branching from the aorta.
they carry blood to the muscles in the walls of the heart.
Blood supply to heart muscles → is greatly reduced due to blockage of the coronary arteries.
→ can cause heart attack.
What Happens during Heart Attack → blood flow to particular part of the heart may be completely blocked due to blocked blood flow → that part of the heart does not receive sufficient oxygen and nutrients. region of heart muscle dies → extensive heart muscle damage is often fatal → as heart is no longer able to pump blood to various parts of the body.
Causes of Coronary Heart Disease Fatty substances → such as cholesterol and saturated fats > may be deposited on inner surface of coronary arteries. → called Atherosclerosis → narrows the lumen of these arteries and increases blood pressure such an affected artery→ develops rough inner surface. increases risk of blood clot being formed in the artery. → if this occurs in coronary artery → supply of Blood and O2 to heart muscles may be completely cut off. O2 is need in aerobic respiration → to release energy for activities of muscle cells./ Without oxygen → heart muscle cells may be damaged - heart attack occurs.
Risk Factors of Heart Disease
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Smoking cigarette smoke → contains carbon monoxide and nicotine → which can increase risk of coronary heart disease. Nicotine → increases blood pressure and risk of blood clotting in arteries. Risk of smokers developing coronary heart disease → much higher than non-smokers.
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Unhealthy diet Diet high in cholesterol, saturated fats, salt content, increases risk of high blood pressure and heart attack
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Age Risk of heart attack increases with age. Majority of people → suffering from coronary heart disease are 65 or older
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Sedentary lifestyle Lack of exercise and being inactive → leads to build up of fatty deposits that block the arteries. → increase risk of getting coronary heart disease.
What can we do to reduce risk of coronary heart disease
- Healthy diet → reduces the risk of atherosclerosis. Animal fats in the deity should be substituted with polyunsaturated plant fats, which do not stick to the inner surface of the arteries. Such a diet will lower cholesterol level in the blood
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Smoking is harmful to the body and should be avoided. Cigarette smoke → contains nicotine and carbon dioxide that increases risk of getting coronary heart disease
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Regular physical exercise has long term beneficial effects on the circulatory system. → strengthens the heart and maintains the elasticity of arterial walls. → risk of high blood pressure or hypertension can be reduced.**
Refer to Human Transport System for all the diseases in 1 page