The Lub Sound Of The — Heart Is Caused By _top_

The heart has four chambers: two at the top (atria) and two at the bottom (ventricles). To keep blood flowing in one direction, the heart uses four valves. The "lub" involves the two valves that sit between the upper and lower chambers: Located on the left side of the heart.

The heart produces two primary sounds during each cardiac cycle, commonly called "lub" and "dub". The first heart sound. Dub (S2): The second heart sound. 2. Identifying the Cause of the "Lub" the lub sound of the heart is caused by