Question

The first sound______is produced when the auriculo-ventricular valves get closed at the start of ventricular systole.

Answer 1

Ventricular systole:

1. Ventricular systole occurs when ventricles are contracting and vigorously ejecting two separated blood supplies from the heart.
2. One to the lungs and another to all other body organs and systems, at the same time the two atria remain relaxed known as atrial diastole.

Lubb:

1. The sounds are produced due to the valves shutting inside the heart.
2. The first sound (the lubb) is produced when the mitral and tricuspid valves close.

Final answer: The first sound lubb is produced when the auriculo-ventricular valves get closed at the start of ventricular systole.