Conducting System of Heart
How the pumping of Heart/ electrical conduction system
Cardiac muscle cell have automaticity or autorhythmicity the conduction system of Heart is responsible for regulating rate and rhythm of Heart.
Heart is a muscle with special electrical conduction system.
Electrical impulse from heart muscle cause heart to contract.
This electrical signals begins in the sinoartrial node (SA) located at top of the right atrium.
SA node is called natural pacemaker of Heart.
The electrical impulse travel from SA node to Atrioventricular node (AV node) near atrioventricular valve (tricuspid valve and bicuspid valve) and cause the atrium to contract.
After the atrioventricular node (AV node), the impulse travel to the bundle of His.
The impulses travel from bundle of His to the right and left bundle branches.
Bundle branches from the purkinje fibers and a impulse travel to purkinje fibers and a causes contraction of ventricles.
1. Sinoatrial (SA) node
SA node is located in posterior wall top of right atrium near the entrance of superior venacava.
2. Atrioventricular (AV) node
AV node is located near atrioventricular valves and receives impulses from SA node and transmit them to bundle of His.
3. Bundle of His
This is a mass of specialized fibers that originate from AV node. Bundle of His divided into right and left bundle branches.
Bundle of His transmits electrical impulses from AV node (located between atria and ventricles) to the point of apex via bundle branches.
4. Right and left bundle branches
AV bundle splitting into two branches
A. Right bundle branches
B. Left bundle branches
The impulse travel from bundle of His to the right and left bundle branches.
5. Purkinje fibers
AV bundle branches from the purkinje fibers, penetrate into the Heart apex, and turn superiorly into the ventricular walls.
Left ventricular is much larger than right ventricles, the Purkinje network is more extensive in left side of the Heart.
AV bundle, bundle branches and purkinje fibers convey electrical impulse from AV node to apex of myocardium, where wave of ventricular contraction begins, pumping blood into pulmonary artery and Aorta.
Heart Beat is two part pumping action that takes about a second. A blood collects in the upper (right and left atrium)
Impulse travel from SA node to AV node which enforces contraction of atria.
Blood from atria fill into ventricles through tricuspid valves after the contraction.
Impulse travel from AV node through bundle of his Bundle of branches and purkinje fibers and enforce in ventricle contraction.
With ventricle contraction the blood is pushed into pulmonary artery and Aorta through pulmonary valve and Aortic valve.
When blood is filled from atria into ventricles, ventricles are relax at that time and that period is called " Diastole"
When the blood from the ventricles is pushed into the lungs and systemic circulation, ventricles are contracted , that period is called "Systole".
Systole is equal to " ventricle contraction,"
Diastole is equal to "ventricle relaxation"
Blood pressure = 120/80 mmHg Systole/ Diastole. VentRicle contraction/ Ventricle relaxation
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