MEDICAL PHYSIOLOGY

Detailed explanation-1: -"Lubb” is produced when the bicuspid and the tricuspid valves close shut, while the “dupp” sound is caused due to the closure of semilunar valves .

Detailed explanation-2: -Listen to the Lub-Dub This sound comes from the valves shutting on the blood inside the heart. The first sound (the lub) happens when the mitral and tricuspid valves close. The next sound (the dub) happens when the aortic and pulmonary valves close after the blood has been squeezed out of the heart.

Detailed explanation-3: -Heart Sounds The first heart sound (S1) represents closure of the atrioventricular (mitral and tricuspid) valves as the ventricular pressures exceed atrial pressures at the beginning of systole (point a). S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously.

Detailed explanation-4: -Lubb refers to the first sound generated when the tricuspid and bicuspid, that is, the atrioventricular valves get closed sharply at the beginning of the ventricular systole. Dup refers to the second sound, which is generated at the initiation of ventricular diastole.