NHI Western Segment Practice Test

The right atrium is the correct answer because it plays a crucial role in the circulatory system by receiving deoxygenated blood from the body. Blood that is low in oxygen returns to the heart via two major veins: the superior vena cava and the inferior vena cava. Once this deoxygenated blood enters the right atrium, it is then pumped into the right ventricle, which will subsequently send it to the lungs for oxygenation.

The left atrium, on the other hand, receives oxygenated blood from the lungs, making it essential for delivering fresh oxygen to the body, but it does not handle deoxygenated blood. The right ventricle is responsible for pumping deoxygenated blood to the lungs but does not receive it, while the left ventricle handles oxygen-rich blood being sent out to the rest of the body. Thus, the right atrium serves as the initial collection chamber for deoxygenated blood returning from systemic circulation.