How Your Heart Works

The heart is a vital organ responsible for pumping blood throughout the body. It is located in the chest cavity and is roughly the size of a fist. The heart is divided into four chambers: the right atrium, left atrium, right ventricle, and left ventricle.

The heart receives deoxygenated blood from the body through the superior and inferior vena cava, which enters the right atrium. The right atrium then contracts, pushing blood through the tricuspid valve and into the right ventricle.

The right ventricle then contracts, pumping blood through the pulmonary valve and into the pulmonary artery, which carries blood to the lungs. In the lungs, carbon dioxide is removed from the blood, and oxygen is added to it. The oxygenated blood then returns to the heart through the pulmonary veins, entering the left atrium.

The left atrium then contracts, pushing blood through the mitral valve and into the left ventricle. The left ventricle is the most muscular chamber of the heart, and it contracts forcefully to pump oxygenated blood through the aortic valve and into the aorta, the largest artery in the body. The aorta branches into smaller arteries that carry blood to all parts of the body, delivering oxygen and nutrients to the cells.

The heart’s rhythm is controlled by a group of cells called the sinoatrial node, located in the right atrium. This node sends electrical signals to the atria, causing them to contract and pump blood into the ventricles. The signal then travels to another group of cells, the atrioventricular node, which delays the signal briefly before sending it to the ventricles, causing them to contract and pump blood out of the heart.

The heart works continuously throughout a person’s life, pumping approximately 2,000 gallons of blood per day.