How does the heart pump blood throughout the body?

The heart pumps blood throughout the body by contracting and relaxing to create a pressure difference.

The heart, a muscular organ, is responsible for circulating blood throughout the body. It does this by a process of contraction (systole) and relaxation (diastole) which creates a pressure difference, enabling blood to flow from areas of high pressure to areas of low pressure.

The heart is divided into four chambers: two atria at the top and two ventricles at the bottom. The process begins when the atria receive blood. The right atrium gets deoxygenated blood from the body through the vena cava, while the left atrium receives oxygenated blood from the lungs via the pulmonary veins.

When the atria contract, the blood is pushed into the ventricles. Following this, the ventricles contract, pumping the blood out of the heart. The right ventricle sends deoxygenated blood to the lungs through the pulmonary artery where it gets oxygenated. The left ventricle, on the other hand, pumps oxygenated blood to the rest of the body through the aorta, the largest artery in the body.

This entire process is regulated by electrical signals. The sinoatrial node (SA node), often referred to as the heart's natural pacemaker, sends out an electrical impulse causing the atria to contract. This impulse then reaches the atrioventricular node (AV node), which after a slight delay, sends the signal to the ventricles causing them to contract.

The heart's ability to pump blood is crucial for the delivery of oxygen and nutrients to cells and tissues, and for the removal of waste products. This continuous cycle of contraction and relaxation, regulated by the heart's electrical system, ensures that blood is efficiently circulated throughout the body.