Location: 1 Mark
Chambers: 2 Marks
Blood circulation: 2 Marks
The heart is located in the chest cavity with its lower tip slightly tilted towards the left.
It has four chambers. The two upper chambers are called atria and the two lower chambers are called the ventricles. 
The two types of blood circulation are pulmonary and the systemic circulation. 
During the pulmonary circulation - The blood low in oxygen flows from the heart to the lungs and then oxygenated blood flows back to the heart. This blood rich in oxygen flows from heart to the rest of the body then back again to the heart. This is called systemic circulation.