how does the heart work ?
Heart is a pumping organ that beats continuously and pumps oxygen-rich blood to all parts of the body and carbon dioxide-rich blood to the lungs. It is located in the chest cavity and is approximately the size of your fist.
It is divided into four chambers – right auricle (atrium), right ventricle, left auricle (atrium), and left ventricle.
Since the blood goes twice through the heart, it is known as double circulation.