Question

When are the sounds LUBB and DUPP produced respectively during heart beat ?

Answer 1

The first sound “LUBB” is produced when the atrio-ventricular (tricuspid and bicuspid)valves get closed sharply at the start of ventricular systole. The second sound “DUPP” is produced when at the beginning of ventricular diastole, the semilunar valves at the roots of aorta and pulmonary artery get closed.