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

The valve that prevents backflow of blood from the aorta into the left ventricle is the aortic valve. This valve is located at the junction where the aorta exits the heart. During ventricular contraction, the left ventricle pumps oxygenated blood into the aorta through the aortic valve. Once the ventricle relaxes, the aortic valve closes to prevent blood from flowing backward into the left ventricle, ensuring a unidirectional flow of blood and maintaining proper circulation throughout the body.

The aortic valve's role is crucial for effective cardiovascular function, as it helps maintain the pressure necessary for blood flow and prevents any regurgitation that could compromise the heart's efficiency. The other valves listed have different functions and locations within the cardiovascular system, which does not relate to preventing backflow from the aorta to the left ventricle.