Second heart sound comes at :Lubb – Start of Ventricular systoleLubb  – Start of Ventricular diastoleDubb  – Start of Atrial  diastoleDubb – Start of Joint  diastole

The "lub" sound of the "lub-dub" heartbeat is due to what?Multiple Choicethe closing of the AV valvesthe closing of the semilunar valvesthe right atrium contractingthe left atrium contractingthe relaxation of both atria

Which of the following indicates the first and second heart sound in the correct order a. Atrioventricular valve closure — semilunar valve closure b. Ventricular diastole — atrioventricular valve closure c. Atrial systole — ventricular systole d. Ventricular systole — semilunar valve closure

What causes the lubb-dubb sound of a heartbeat, as heard through a stethoscope?Multiple choice question.the rush of blood out of the ventricles and into the arteriesthe contraction of the atria and ventriclesthe vibrations in heart tissue as blood flow is slowed when valves close

A doctor listening to the heartbeat through a stethoscope hears two sounds, lub and dub.How are these two sounds produced?

Which heart sound occurs at the beginning of isovolumetric contraction?Multiple choice question.ThirdFirstSecond