Anti-Asthmatic Drugs: Mechanisms and Applications"

Anti-arrhythmic drugs
Cardiac Conduction
System

,Cardiac Conduction System
The cardiac conduction system
consists of the following components:
1. Sinoatrial node:
• located in the right atrium near the
entrance of the superior vena cava
• natural pacemaker of the heart
• It initiates all heartbeat & determines
heart rate.
• Electrical impulses from SA node spread
throughout both atria and stimulate them
to contract.

,Cardiac Conduction System
2. The atrioventricular node, or
AV node,
• located on the other side of the right atrium,
near the AV valve.
• The AV node serves as electrical gateway
to the ventricles.
• It delays the passage of electrical impulses
to the ventricles.
• This delay is to ensure that the atria have
ejected all the blood into the ventricles
before the ventricles contract.

, Cardiac Conduction System
3. Bundles of His
• The AV node receives signals from the SA node and passes
them onto the atrioventricular bundle - AV bundle or bundle of
His

4.Right & left bundle branches:
• bundle is then divided into right and left bundle branches which
conduct the impulses toward the apex of the heart.

5. Purkinje fibers:
• The signals are then passed onto Purkinje fibers, turning upward
and spreading throughout the ventricular myocardium.