What makes the first heart sound “Lubb” S1?

Here is the answer for the question – What makes the first heart sound “Lubb” S1?. You’ll find the correct answer below What makes the first heart sound “Lubb” S1? The Correct Answer is The snapping shut of the AV valves (tricuspid and mitral) Reason Explained The snapping shut of the AV valves (tricuspid and … Read more