Oxygenated blood from the lungs is carried to the left atrium of the heart through the

Step 1: Analyze the question The question asks which vessel carries oxygenated blood from the lungs to the left atrium of the heart.

Step 2: Concept Blood circulation in mammals is double circulation:

• Pulmonary circulation: heart → lungs → heart
• Systemic circulation: heart → body → heart

Key rule: arteries carry blood away from the heart, and veins carry blood toward the heart.

Normally, arteries carry oxygenated blood and veins carry deoxygenated blood. The pulmonary vessels are the exception.

Step 3: Trace the path

1. Deoxygenated blood leaves the right ventricle through the pulmonary artery to the lungs.
2. In the lungs, gas exchange occurs, so the blood picks up oxygen.
3. Oxygenated blood returns to the left atrium through the pulmonary vein.
4. It then passes to the left ventricle and is pumped out through the aorta to the body.

Step 4: Check each option

• A. Portal vein: carries digested food from the intestine to the liver. Wrong.
• B. Pulmonary artery: carries deoxygenated blood from the heart to the lungs. Wrong.
• C. Pulmonary vein: carries oxygenated blood from the lungs to the left atrium. Correct.
• D. Renal artery: carries blood to the kidneys. Wrong.
• E. Superior vena cava: brings deoxygenated blood from the upper body to the right atrium. Wrong.

Answer: C. Pulmonary vein

Exam tip: Remember "PV = Pure, to the Left": the Pulmonary Vein brings Pure (oxygenated) blood to the Left atrium. The pulmonary vessels are the only ones where the artery carries deoxygenated blood and the vein carries oxygenated blood.