After pumping, your heart relaxes and fills with blood. "Contractility" describes how well the heart muscle squeezes. The myocardium does the main pumping work: It relaxes to fill with blood and then squeezes (contracts) to pump the blood. The four chambers of your heart are made of a special type of muscle called myocardium. Problems with this electrical system can cause an arrhythmia, which means that your heart chambers are beating in an uncoordinated or random way or that your heart is beating too fast (tachycardia) or too slow (bradycardia). When the electrical system is working properly, it maintains a normal heart rate and rhythm. The electrical system keeps your heart beating in a regular rhythm and adjusts the rate at which it beats. Your heart's electrical system controls the timing of the pump. Regulate the timing of your heartbeat.The task of your heart is to pump enough blood to deliver a continuous supply of oxygen and other nutrients to the brain and the other vital organs. How does my heart maintain its normal function? Your heart has its own electrical system that coordinates the work of the heart chambers (heart rhythm) and also controls the frequency of beats (heart rate). When your heart functions normally, all four chambers work together in a continuous and coordinated effort to keep oxygen-rich blood circulating throughout your body. The left ventricle is the strongest because it has to pump blood out to the entire body. The left and right ventricles are stronger pumps. The left and right atria are smaller chambers that pump blood into the ventricles. The left ventricle pumps the oxygen-rich blood through the aortic valve out to the rest of the body.The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve.The right ventricle pumps the oxygen-poor blood to the lungs through the pulmonary valve.The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle through the tricuspid valve.Your heart has four separate chambers that pump blood, two on the right side and two on the left. The left side of your heart receives oxygen-rich blood from your lungs and pumps it through your arteries to the rest of your body.The right side of your heart receives oxygen-poor blood from your veins and pumps it to your lungs, where it picks up oxygen and gets rid of carbon dioxide.Your heart is divided into two separate pumping systems, the right side and the left side. Your heart is a muscle, and its job is to pump blood throughout your circulatory system. Blood carries oxygen and other important nutrients that all body organs need to stay healthy and to work properly.
The heart is at the center of your circulatory system, which is a network of blood vessels that delivers blood to every part of your body.