Differentiate between SA node and AV node

Sinuauricular (SA node) Auriculoventricular (AV node)

(i) It is located in the wall of right auricle (i) It is located in the wall between the near the opening of superior vene cava right auricle and the right ventricle.

(ii) It has a capacity of self excitation. (ii) It lacks this ability.

(iii) It spontaneously initiates auricular (iii) It initiates ventricular contraction contraction. when stimulated by auricular contraction.

(iv) It acts as a pacemaker. (iv) It has no such role.