The right side of the heart deals with
Deoxygenated Blood
The given diagram shows the movement of oxygenated and deoxygenated blood in the heart. Deoxygenated blood enters the right atrium as it expands and when the right atrium contracts, the blood moves into the right ventricle. The right ventricle transfers the blood to the lungs for oxygenation. The oxygenated blood from the lungs come to the left side of the heart. Therefore, the right side of the heart only deals with deoxygenated blood and the left side only deals with oxygenated blood. There is no mixing of the two.