ORIGIN OF ECG WAVES- Conduction System of the Heart

ORIGIN OF ECG WAVES AND CONDUCTION SYSTEM OF THE HEART.
The (heart) cardiac muscle is able to :
1. Contract
2. Generate its own impulse/ electrical activity - automaticity
3. be excitable as the heart muscle responds to an appropriate amount of stimuli and generate an action potential---an electrical pulse that spreads across the entire heart.This knowledge is applied in (CPR) cardiopulmonary resuscitation.

4 Conduct or  transfer the action potential from muscle cell to muscle cell originating at the sino-atrial (SA) node---the pacemaker of the heart. 

An action potential from the SA node travels through the heart at a rate of 0.8 to 1 meter per second

The heart has primary and secondary sites for electrical generation.
1,The sino-atrial node.The primary source of the cardiac impulse or electrical power.
Located on the right atrium at the junction of the opening of the superior vena cava.
The others below are considered as secondary.
2.The atrioventricular node.
3. The Bundle  of HIS
4.RIGHT AND LEFT BUNDLE branches
5.PURKINJE FIBERS
N/b The BACHMAN'S BUNDLE is responsible for the spread of the impulse to the left atrium for uniform atria contraction during systole.

The electrical impulse moves from the sino- atrial node via the AV node, bundle of HIS, bundle branches  down to the purkinje system of fibers.
This is known as the conductivity system of the heart.
This important activity is responsible for the contraction of the heart and to initiate a heart beat.


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