Sino-atrial node is called the pacemaker of our heart. Why? | NCERT solution | Class 11 Biology | Unit-18 Body Fluids and Circulation



Q.10:- Sino-atrial node is called the pacemaker of our heart. Why?

 

Answer:- 



Sino-atrial node (SAN) is a mass of neuromuscular tissue which lies in the wall of right atrium. It is responsible for initiating and maintaining the rhythmic contractile activity of the heart. Therefore, it is called the pacemaker.