Explain the role of S.A. node.. this question is for 3 marks .what all points i must include .....

The heart consists of special cardiac musculature called nodal tissue.
The SA node is a type of nodal tissue present at the upper right corner of the right atrium.
It is also known as the pacemaker of the heart because the action potential required to start a heart beat is generated by the SA node.
The S A node initiates the electrical impulse which triggers the contraction of cardiac muscles.