Arrange the events in the stimulation of heart muscle in order from earliest (1) to latest (5). Note that this question does not list every step in the pathway, but the steps presented should be arranged in order.

1) Pacemaker impulse generation.

2) AV node impulse conduction

3) AV bundle impulse conduction.

4) Bundle branches conduction.

5) Purkinjie fibres impulse conduction.

Explanation:

The cardiac conduction has following components.

1) SA node is the heart pacemaker in the right upper quadrant of heart. It generates electrical impulses and these impulses then move through atria and AV node to the Purkinjie fibres.

2) The impulses reach AV node. It controls heart rate. It serves as electrical relay station which slows the electrical current sent by SA node before the signals has passed to ventricles.

3) AV bundle is continuation is AV node and it transmits impulse from AV node to the Purkinjie fibres.

4) Electricle impulses from bundle of his passes through bundle branches (right and left) to Purkinjie fibres.

5) Purkinjie fibres take the impulses from the bundle branches to the myocardium of ventricles.