AEMCA Practice Exam

What vessel brings blood into the right atrium from systemic circulation?

1. Pulmonary vein

2. Aorta

3. Vena cava

4. Coronary sinus

The correct answer is: Vena cava

The vessel that brings blood into the right atrium from systemic circulation is indeed the vena cava. There are actually two main venae cavae: the superior vena cava and the inferior vena cava. The superior vena cava carries deoxygenated blood from the upper body, including the head, neck, and arms, while the inferior vena cava transports deoxygenated blood from the lower body, including the legs and abdominal organs. Once this deoxygenated blood enters the right atrium, it is then directed through the tricuspid valve into the right ventricle, where it will be pumped to the lungs for oxygenation. The pulmonary vein, on the other hand, is responsible for bringing oxygenated blood from the lungs to the left atrium, and therefore does not contribute to the systemic circulation to the right atrium. The aorta is the main artery that carries oxygenated blood away from the heart to the rest of the body, making it also unrelated to the flow of deoxygenated blood entering the right atrium. The coronary sinus collects deoxygenated blood from the heart muscle itself and drains into the right atrium, but it is not involved in the systemic blood return. Therefore, the vena cava is the primary vessel responsible for returning