find the attachment below on the conduction mechanism of the heart

1. Conduction of the heart
The conduction system of the heart comprises
of
I. Sinoatrial node
II. Atrioventricular node
III. Atrioventricular bundle
IV. Bundle branches
V. Purkinje fibres

2.  Sinoatrial node
The sinoatrial node is located at the right atria
near the entrance of superior venacava, this is
natural pace maker of the heart , it initiates
all heart beat and and determine heart rate
.the SA node initiates the heart beats by
firing electrical impulses which spread
through the right and left atria and stimulate
contraction

3. Atria
Atrioventricular node
Located on the other side of the right atrium
near the atrioventricular valve , the AV node
serves as the electrical gateway to the
ventricle it delays the passage of electrical
signals to the ventricle , this is to ensure that
the atria has discharged all blood to the
ventricle

4.  Before the ventricle contract .theAV node
receives signals from the SA node and passes
them to the AV bundles this bundle is divided
 Into right and left bundle braches which
conduct the impulse towards the apex of the
Heart .The signals are then passed to purkinje
fibers, turning upward through out the
ventricular myocardium