MICROANATOMY

Detailed explanation-1: -This sound comes from the valves shutting on the blood inside the heart. The first sound (the lub) happens when the mitral and tricuspid valves close. The next sound (the dub) happens when the aortic and pulmonary valves close after the blood has been squeezed out of the heart.

Detailed explanation-2: -The valves are located between the atria and ventricles, and between the ventricles and the major arteries from the heart. Normal heart sounds are called S1 and S2. They are the “lubb-dupp” sounds that are thought of as the heartbeat. These sounds are produced when the heart valves close.

Detailed explanation-3: -The first sound, a low-pitched, slightly prolonged “lub, ‘’ occurs when the atrioventricular valves close as the ventricles of the heart begin to contract.

Detailed explanation-4: -The “lub” sound occurs during the early phase of ventricular contraction and is produced by closing of the atrioventricular valves, which prevents blood backflow into the atria. When the ventricles relax, the blood pressure drops below what is in the arteries and the semilunar valves close, producing the “dub” sound.

Detailed explanation-5: -Lub sound is produced due to the closure of the (atrioventricular valve). The valves present between the atrium and ventricles are called atrioventricular valves.