Lubb sound is produced when:
Correct answer: C. A.V valves close
- A. A.V valves open
- B. Semilunar valve close
- C. A.V valves close
- D. Semilunar valve open
Explanation
In healthy adults there are two normal heart sounds. often described as a lubb and dubb, that occur in sequence with each heartbeat. These are the first heart sound (S1) and second heart sound (S2), produced by the closing of the atrio-ventricular valves and semilunar valves, respectively.
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