Evening Republican, Volume 21, Number 184, Rensselaer, Jasper County, 14 August 1918 — Why We Hear Heart Throbs. [ARTICLE]

Why We Hear Heart Throbs.

The cause of the sound of nprmal heart < beats has not been definitely ascertained. There are normally two sounds —the’ first, -which is called systolic, is dull and somewhat prolonged; it is followed quickly by the second, called dmstolic, which Is shorter and sharper. A pause follows the second sound. It is supposed that the vibration and closure of the valves between the auricles and ventricles 4$ one of the causes of the first sound; the contraction of the ventricles, or the striking of the heart against the walls of the chest, may be the cause. The second sound Is known to be caused by the vibration' produced by the the semilunar valves.