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In Biology / College | 2025-07-05

What causes the 'lub' sound in heart sounds?
A) Atrial contraction
B) Ventricular contraction
C) Closing of the semilunar valves
D) Closing of the AV valves

Asked by jnorton1024

Answer (1)

The 'lub' sound in heart sounds is caused by the closing of the AV valves during ventricular contraction. This sound is crucial for preventing backflow of blood into the atria. It's essential to understand that 'lub' signifies the start of ventricular systole. ;

Answered by GinnyAnswer | 2025-07-05

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