New York State Emergency Medical Technician (EMT) Practice Exam

How is deoxygenated blood from the abdomen, pelvis, and lower extremities returned to the heart?

1. Common iliac vein

2. Coronary sinus vein

3. Inferior vena cava

4. Superior vena cava

The correct answer is: Inferior vena cava

Deoxygenated blood from the abdomen, pelvis, and lower extremities is returned to the heart primarily through the inferior vena cava. This large vein collects blood from the lower half of the body and channels it back to the right atrium of the heart. It is a crucial part of the systemic circulation, ensuring that the blood that has delivered oxygen and nutrients to the body tissues returns to the heart for reoxygenation in the lungs. The common iliac vein does play a role in this process as it drains blood from the lower body, but it ultimately feeds into the inferior vena cava. The coronary sinus vein is responsible for draining deoxygenated blood from the heart muscle itself, and the superior vena cava collects blood from the upper half of the body, which does not pertain to the blood circulation from the abdomen or lower extremities. Thus, the inferior vena cava is the correct choice for returning deoxygenated blood from those specific regions back to the heart.