The document provides information about the heart. It describes the heart's location on the left side of the chest, its size of 15 cm x 10 cm and weight of 350 grams. It has two upper chambers called auricles that pump blood to the lungs and two lower chambers called ventricles that pump blood to the body. The heart muscles are the strongest in the body and it pumps over 3 lakh tons of blood in a lifetime. Exercise prevents diseases like diabetes, heart attacks, strokes and controls blood pressure while smoking should be avoided for heart health. A healthy diet and active lifestyle leads to a strong heart.