The central organ of the circulatory system is the heart.
The heart contains four chambers - two atriums and two ventricles.
The right atrium receives carbon-dioxide laden blood from other body organs. The superior vena cava delivers blood from the upper body parts while the inferior vena cava delivers blood from lower body parts.
The right ventricle pumps this blood to the lungs via the pulmonary artery for oxygenation.
The left atrium receives oxygen-rich blood from the lungs and is sent to the left ventricle.
The left ventricles proceed to pump oxygen-rich blood to other body parts.
The heart walls are made up of muscles that undergo rhythmic contractions to pump blood.
The human heart is very strong and is capable of pumping blood up to 30 feet distance.
An average heart beats maximum of 70-80 beats per minute and is considered healthy.
The efficiency of the heart can be maintained and improved by performing physical activity.
