Question

What do the sounds lubb-dup mean in a cardiac cycle?

Answer 1

Cardiac cycle:

1. It is the period between the termination of one heartbeat to the termination of the next heartbeat.
2. It is formed of three phases, that is, atrial systole, ventricular systole, and joint diastole.

Lubb and Dup sound:

1. 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.
2. Dup refers to the second sound, which is generated at the initiation of ventricular diastole.
3. It is produced when the semilunar valves at the roots of the pulmonary artery and aorta get closed.