The heart is a vital organ that pumps blood throughout the body, delivering oxygen and nutrients to the cells and removing waste products.
The heart is composed of four chambers: the right atrium, right ventricle, left atrium, and left ventricle. The right atrium and ventricle are responsible for receiving and pumping blood to the lungs, while the left atrium and ventricle receive and pump oxygen-rich blood to the rest of the body.
The heart works in a rhythmic cycle of contraction and relaxation, called the cardiac cycle. During the cardiac cycle, the heart’s electrical system sends signals that cause the heart muscles to contract and pump blood. The electrical impulses begin in the sinoatrial (SA) node, a group of specialized cells located in the right atrium. From the SA node, the electrical signal travels to the atrioventricular (AV) node, which is located between the atria and ventricles. The AV node delays the signal briefly to allow the atria to fully contract before sending the signal to the ventricles.
When the electrical signal reaches the ventricles, the ventricular muscles contract and pump blood out of the heart. The blood is pumped through the pulmonary artery to the lungs or through the aorta to the rest of the body.
After the heart pumps blood, the muscles relax and fill with blood again, preparing for the next cycle. This cycle repeats continuously, providing a steady supply of oxygen and nutrients to the body’s tissues.
In summary, the heart works by using its electrical and muscular systems to pump blood throughout the body, delivering oxygen and nutrients to the cells and removing waste products.