Question

Differentiate between lub and dup sound.

Answer 1

Lub and dup are heart sounds, heard during a heart beat by placing a stethoscope on the chest wall above the heart. However, lub is the first sound which is fairly loud and is due to the closure of the atrioventricular valves, whereas the dup is the second sound which is softer and is due to the closure of the aortic and pulmonary valves. The lub corresponds with ventricular systole whereas the dup with atrial systole.