Passage Of The Blood Through The Heart
( Originally Published 1921 )
I WONDER how many people there are who have never listened to the heart beat probably few. And yet I venture to say that few have known the significance of what they heard. In deed, there has always been some discussion among physicians as to what the sounds mean and where they come from.
There are two distinct sounds, one of which is caused by the abrupt closing of the valves that hold back the blood while the heart is expanding in preparation for its next stroke. The first sound of the heart is different in character, and has to do with the muscular action of the ventricles. With the ear over the heart we listen to these two sounds and such others as may be there in the particular heart we are examining. We notice the rhythm of the heart and try to estimate the amount of its strength.
No two hearts sound exactly alike, so that a vast amount of experience is necessary in judging which are perfectly natural and which are otherwise.