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

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

• A. Aortic semilunar
• B. Tricuspid
• C. Pulmonary semilunar
• D. Mitral valve

Answer: (A)

Valves ensure one-way blood flow and prevent backflow as the heart relaxes between beats. The aortic semilunar valve sits at the exit of the left ventricle into the aorta. When the heart finishes contracting, the pressure in the aorta stays higher than in the ventricle, so the aortic valve cusps meet and close, stopping blood from flowing back into the left ventricle. The other valves are in different locations and regulate flow between other chambers: the mitral and tricuspid valves prevent backflow from ventricles into the atria, and the pulmonary semilunar valve prevents backflow from the pulmonary artery into the right ventricle.

Valves ensure one-way blood flow and prevent backflow as the heart relaxes between beats. The aortic semilunar valve sits at the exit of the left ventricle into the aorta. When the heart finishes contracting, the pressure in the aorta stays higher than in the ventricle, so the aortic valve cusps meet and close, stopping blood from flowing back into the left ventricle. The other valves are in different locations and regulate flow between other chambers: the mitral and tricuspid valves prevent backflow from ventricles into the atria, and the pulmonary semilunar valve prevents backflow from the pulmonary artery into the right ventricle.