A normal human being’s body contains 4-5 litres of blood. The blood is the means of transport by which oxygen and nutrients reach parts of the body and waste materials are carried away. This system consisting of the heart and blood vessels that makes the circulation of blood possible is called the circulatory system.
The heart is located in the chest, inside the rib cage tilting towards the left side. The heart is like a pump, or two pumps in one. The right side of your heart receives blood from the body and’ pumps it to the lungs. The left side of the heart receives blood from the lungs and pumps it to the body.
The heart consists of red and blue blood vessels that help to carry the blood from the heart to the body and then back to the heart. The red vessels are called arteries and the blue vessels are called veins. The arteries carry blood that is rich in oxygen from your heart to every part of your body. The veins carry blood full of carbon dioxide and wastes back to your heart where the whole process is repeated.