Heart Disease





World’s Most Efficient Pump – the Heart

1.1 The heart is a conical hollow muscular organ situated behind the breastbone sternum just a little off centre. The clinched fist-size heart weighs about 340 grams in adult males and about 270 grams in females. The heart, world’s most efficient pump, propels roughly 7,600 litres of blood through about 100,000 kilometers of blood vessels (arteries, veins and capillaries) every 24 hours. If these blood vessels of an adult person are joined together, these would circle 2½ times round the earth. The power of the heart is less than 100 watts bulb but has incredible efficiency of filling tanks of 300 cars per day and that too without rest and break and year after year. No other muscle in the body is as hardworking and as strong as the heart is. Heart is only 0.5% of body weight but needs 5% of total blood supply to take care of its nutritional needs.

1.2 The heart is the body’s circulatory system’s pump. Actually, the heart is two pumps placed side-by-side. The septum, a muscular wall divides the right and left sides of the heart. It prevents the blood from crossing over from one side to the other. The right side of the heart pumps blood to the lungs, and the left side pumps blood to the rest of the body. The atria receive blood and pump it into ventricles. The ventricles push the blood out of the heart. The ventricles’ job requires a greater force, so the ventricles are large and more muscular. Valves in the heart allow blood to move through it in one direction only.

1.3 Blood enters the right atrium of the heart and is pumped into the right ventricle. When the right ventricle contracts, blood is pumped through the pulmonary arteries to the lungs, where the blood gives off carbon dioxide and picks up oxygen. Oxygen-rich blood returns to the heart through the pulmonary veins and the left atrium. It is, then pumped to the left ventricle. The left ventricle contracts, pumping blood into the large artery, aorta, and out to various parts of the body. When the cells use up all the oxygen, the veins carry the blood back to the heart. The arteries coming out of the right side of the heart carry this blood to the lungs, where it gets more oxygen. Then the oxygen-rich blood is carried to the left side of the heart, and the cycle begins all over again. Blood that does not get oxygen is purplish-red in colour. Blood that is rich in oxygen is scarlet or bright red in colour.

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