Question

After the long diastolic pause and preceding the short systolic pause, what heart sound do you hear?

1) S1
2) S2
3) S3
4) S4

Answer 1

The first heart sound, S1, is heard after the long diastolic pause and before the short systolic pause, signifying the start of ventricular systole with the closing of the atrioventricular valves.

Step-by-step explanation:

After the long diastolic pause and preceding the short systolic pause, you would hear the first heart sound, S1. This sound represents the closing of the atrioventricular valves during ventricular contraction, commonly described as 'lub'. It signifies the start of ventricular systole, where the heart is pumping blood out to the body.

The S1 sound occurs after the completion of the diastolic phase, which is a period of relaxation and filling of the heart's chambers, and right before the systolic phase begins.