what is a pace maker and what are its function?

Dear Student

A pacemaker is a small device placed inside the chest to control abnormal beats of the heart. It controls the contraction of auricles and ventricles by generating electrical impulse that get transferred to whole of the heart muscles.  SA node (Sinoatrial node) are the special nodal tissue of heart that act as the natural pacemaker. They are present in the upper right corner of the right atrium that autogenerates electrical stimulus to control heart beat. 

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