Questions: The flow of blood into the heart Blood from the systemic circuit enters the heart and flows into the before being pumped into the lungs Multiple Choice left atrium, and then right ventricle right atrium, and then right ventricle left atrium, and then right atrium right atrium, and then left atrium

The answer is the second one: right atrium, and then right ventricle.

Explanation for each option:

1. Left atrium, and then right ventricle: This is incorrect because blood from the systemic circuit first enters the right side of the heart, not the left. The left atrium receives oxygenated blood from the lungs, not deoxygenated blood from the systemic circuit.

2. Right atrium, and then right ventricle: This is correct. Blood from the systemic circuit, which is deoxygenated, enters the heart through the right atrium. It then flows into the right ventricle, from where it is pumped to the lungs for oxygenation.

3. Left atrium, and then right atrium: This is incorrect because the left atrium receives blood from the pulmonary circuit (lungs), not the systemic circuit. The systemic circuit blood enters the right atrium first.

4. Right atrium, and then left atrium: This is incorrect because blood flows from the right atrium to the right ventricle, not to the left atrium. The left atrium receives blood from the lungs, not directly from the systemic circuit.

In summary, the correct flow of blood from the systemic circuit into the heart is through the right atrium and then into the right ventricle.