The 'lub' sound heard during a heartbeat is due to the closure of which valves?
Q1. The 'lub' sound heard during a heartbeat is due to the closure of which valves?
Answer: Atrioventricular valves
Explanation: The 'lub' sound is due to the closure of atrioventricular valves. 'Dub' sound is due to semilunar valves closure.