Heart is located in the center of the chest cavity slightly tilted towards the left. It is a hollow muscular organ made up of cardiac muscle fibres. It is the pumping organ of the circulatory system. It has four chambers, the right and left auricles (or atria) and the right and left ventricles. A wall separates the right and left halves of the heart. Auricles are thin-walled chambers that receive blood from the body. Each auricle passes on the incoming blood to the ventricle of its own side. The ventricles are thick-walled and pump blood out of the heart.
the heart beats rhythmically throughout one’s life. The periodic contraction and relaxation of the heart is called the heartbeat. The normal human heartbeat is 70-72 per minute. Doctors use a stethoscope to record the heartbeat. If you place your ear on your friend’s chest you would hear a thumping sound. These sounds are the heartbeats, which can be beard more clearly and loudly using stethoscope. The human heart pumps about 5 litres of blood per minute. This can increase to about 20 litres per minute during strenuous exercise.
Place your fingers over your wrist, just a little below your thumb. Your will notice a thumping just below the skin. This thumping sensation is the pulse. As the blood is pumped b the ventricles into the arteries with force, a wave of expansion passes along the arteries. This recorded in order to know the heartbeat. The pulse rate is the same as the rate of heartbeat, i.e., 70-72 per minute.