[Campbell Biology P.999] According to the diagram and text on mammalian double circulation, ... | Practice Question

According to the diagram and text on mammalian double circulation, which sequence correctly describes the flow of oxygenated blood from the lungs through the systemic circuit and back to the heart?

  • A: Lungs → Pulmonary veins → Left atrium → Left ventricle → Systemic arteries → Body tissues → Systemic veins → Right atrium
  • B: Lungs → Pulmonary arteries → Right atrium → Right ventricle → Systemic arteries → Body tissues → Systemic veins → Left atrium
  • C: Body tissues → Systemic veins → Right atrium → Right ventricle → Pulmonary arteries → Lungs → Pulmonary veins → Left atrium
  • D: Left ventricle → Systemic arteries → Body tissues → Systemic veins → Right atrium → Right ventricle → Pulmonary arteries → Lungs

Explanation

Oxygen-rich blood from the lungs enters the left atrium via the pulmonary veins. From the left atrium, it moves to the left ventricle, which then pumps it into the systemic arteries to reach the body tissues. After oxygen is delivered, deoxygenated blood returns via systemic veins to the right atrium, completing the cycle as described in option A.