Identifying Heart Structures in Anterior Vertical Section

Steps:

• Examine top structure: Pulmonary vein enters left atrium superiorly.
• Identify second feature: Semilunar valve (aortic/pulmonary) guards outflow from ventricles.
• Locate third: Atrioventricular valve (mitral/tricuspid) separates atria from ventricles.
• Check bottom: Vena cava (superior/inferior) returns deoxygenated blood to right atrium.

Why C is correct:

• Matches standard anatomy: Pulmonary veins carry oxygenated blood to left atrium; semilunar valves prevent backflow to ventricles; AV valves regulate atrial-ventricular flow; vena cava delivers deoxygenated blood.

Why the others are wrong:

• A: Incomplete labels; "ventricular" is vague, not specific structure.
• B: Starts with aorta (arterial outflow, not venous inflow); misorders valves and pulmonary artery.
• D: Pulmonary artery is outflow tract, not inflow like pulmonary vein; valve order reversed.

Final answer: C