PATHOLOGY

Detailed explanation-1: -The first sound, a low-pitched, slightly prolonged “lub, ‘’ occurs when the atrioventricular valves close as the ventricles of the heart begin to contract. After a brief pause, this sound is followed by a sharper, higher-pitched “dup, ‘’ produced by closure of the aortic and pulmonary valves .

Detailed explanation-2: -During a joint diastole, the rapid closure of semilunar valves at the beginning of the ventricular diastole produces the second heart sound called ‘dup’.

Detailed explanation-3: -Overview. Heart murmurs are sounds-such as whooshing or swishing-made by rapid, choppy (turbulent) blood flow through the heart. The sounds can be heard with a device called a stethoscope. A typical heartbeat makes two sounds like “lubb-dupp” (sometimes described as “lub-DUP") when the heart valves are closing.