Question
First heart sound is produced during closure of
auriculo-ventricular valves
eustachian valve
sinus valve
seminular valves
Solution
A.
auriculo-ventricular valves
First heart sound is produced during closure of auriculo- ventricular or AV node. The first sound is lubb. It is low pitched and is of long duration. It is produced by tight closure of bicupsid and tricupsid valve at the start of ventricular contraction.
