The heart is simply a pump.
The heart pumps blood round the body about 70 times a minute in adults.
It pumps about 300 liters of blood per hour.
The work of the heart is very important.
It continuously circulates blood through the blood vessels.
Oxygen gets into the blood when we breathe.
Vessels carrying blood away from the heart are called arteries.
Vessels returning blood to the heart are called veins.
Heart consists of four chambers, two atriums and two ventricles.