Question

When listening to heart sounds (auscultation), the first sound heard is referred to as LUBB. This sound is produced by:

a. the blood flowing against the SL valves causing them to close
b. blood turbulence causing the closure of the two AV valves at ventricular diastole
c. blood turbulence causing the closure of the two AV valves at ventricular systole
d. blood flow against the two SL valves during ventricular relaxation

Answer 1

The first sound heard when listening to heart sounds is called S1 or the "lub" sound. It is produced by the closing of the atrioventricular valves during ventricular contraction.

Step-by-step explanation:

In a normal, healthy heart, the first sound heard when listening to heart sounds is called S1 or the "lub" sound. S1 is produced by the closing of the atrioventricular valves during ventricular contraction. The atrioventricular valves separate the atria from the ventricles and prevent blood from flowing back into the atria.