1. 4 Chambers The Human heart is a 4 Chambered heart
It consists of two atriums and two ventricles
Atriums receive blood while Ventricles pump it out to some part of the body
Arteries carry blood away from the heart while veins carry blood too the heart

3. Artery and Veins
Both of these carry Blood however the difference between them is the direction in which they carry blood.
Arteries carry blood away from the heart. Generally they carry oxygenated blood (this blood is red)
Veins Carry blood to the heart. Generally they carry blood that has no oxygen (this blood is blue or purple.)

4. Right Atrium
The right Atrium receives blood from the whole body except the lungs.
The Superior and Inferior Vena Cava carry the deoxygenated blood to this chamber.
The blood is then moved to the Right Ventricle.

5. Right Ventricle Receives deoxygenated blood from the Right Atrium.
Then it pumps this blood away from the heart and to the lungs. At the lung the blood will take up oxygen.
Blood is carried away from the Right Ventricle by the Pulmonary Artery.

6. Lungs
When blood is carried to the lungs by the Pulmonary Artery it goes through narrowing passage.
By the time the Blood gets to where it is oxygenated in the lungs the passage is so small only one blood cell at a time can fit through it.
It is then oxygenated and carried back to the heart via the pulmonary veins.

7. Left Atrium The left Atrium receives blood from only the lungs.
The Pulmonary Veins carry the blood to the Left Atrium
This blood is oxygenated.
The blood is then moved to the Left Ventricle.

8. Left Ventricle Receives oxygenated blood from the Left Atrium.
Then it pumps this blood away from the heart and to the whole Body except the lungs.
Blood is carried away from the Left Ventricle by the Aorta.

9. Why? The heart moves blood to the muscles.
Muscles need oxygen to work and to have waste removed from them.
This is what the blood does and why it is important for it to move through your body.