Which valve prevents backflow from the left ventricle into the left atrium?

Which valve prevents backflow from the left ventricle into the left atrium?

• A. Bicuspid valve
• B. Tricuspid valve
• C. Pulmonary semilunar valve
• D. Chordae tendinae

Answer: (A)

This question tests understanding of which valve prevents backflow from the left ventricle into the left atrium. That valve is the mitral valve, also known as the bicuspid valve, which sits between the left atrium and left ventricle. When the left ventricle contracts, its pressure rises and the mitral valve closes to stop blood from moving back into the atrium. The valve’s leaflets are held shut by the chordae tendineae and papillary muscles, which prevent valve prolapse during strong contractions. The alternative on the right side, the tricuspid valve, handles the right atrium–ventricle connection. The pulmonary semilunar valve sits between the right ventricle and the pulmonary artery and prevents backflow into the ventricle, not into the atrium. Chordae tendineae are connective strands that anchor the leaflets; they’re not valves themselves. So the bicuspid (mitral) valve is the correct one.

This question tests understanding of which valve prevents backflow from the left ventricle into the left atrium. That valve is the mitral valve, also known as the bicuspid valve, which sits between the left atrium and left ventricle. When the left ventricle contracts, its pressure rises and the mitral valve closes to stop blood from moving back into the atrium. The valve’s leaflets are held shut by the chordae tendineae and papillary muscles, which prevent valve prolapse during strong contractions. The alternative on the right side, the tricuspid valve, handles the right atrium–ventricle connection. The pulmonary semilunar valve sits between the right ventricle and the pulmonary artery and prevents backflow into the ventricle, not into the atrium. Chordae tendineae are connective strands that anchor the leaflets; they’re not valves themselves. So the bicuspid (mitral) valve is the correct one.