Question

In auscultation, the lubb represents the closing of semilunar valves and the dupp represents the closing of the atrioventricular valves.

Answer 1

The 'lub' represents the closing of the atrioventricular valves during ventricular contraction, while the 'dub' represents the closing of the semilunar valves during ventricular diastole.

Step-by-step explanation:

In a normal, healthy heart, the closing of the atrioventricular valves during ventricular contraction produces the first heart sound, known as the "lub." This sound can be heard as a result of auscultation. On the other hand, the closing of the semilunar valves during ventricular diastole creates the second heart sound, which is described as a "dub." These heart sounds can be heard with a stethoscope and are important indicators of heart health.