Question

All of the veins of the systemic circulation drain into the ______________ before returning to the heart.
a. Pulmonary trunk
b. Superior and inferior vena cavae
c. Inferior vena cava
d. Pulmonary veins
e. Superior vena cava

Answer 1

Answer: Option B

Explanation:

All the blood from the body gets pure inside the heart. The impure blood from the body is collected by the superior vena cavae and inferior vena cavae.

The waste blood from the body is collected and enters collectively into the heart. This blood is impure(deoxygenated)  and need to be pure (oxygenated) before being circulated into the body.

So, the correct answer is option B