Dub sound of heart is caused by
A. Closure of atrio-ventricular valves
B. Opening of semi-lunar valves
C. Closure of semi-lunar valves
D. Opening of atrio-ventricular valves
Answer:C
Dub sound of heart is caused by
A. Closure of atrio-ventricular valves B. Opening of semi-lunar valves C. Closure of semi-lunar valves D. Opening of atrio-ventricular valves