Heart conduction system

Heart Conduction System

The heart conduction system is a complex physiological mechanism responsible for the coordination of the cardiac cycle. It is a network of specialized cardiac cells that provide a path for the electrical signals controlling the heart's rhythm.

Structure

The heart conduction system consists of several key components:

• The Sinoatrial node (SA node), often referred to as the heart's natural pacemaker, initiates the electrical impulses.
• The Atrioventricular node (AV node) receives impulses from the SA node and delays them before sending them to the ventricles.
• The Bundle of His, a pathway that transmits impulses from the AV node to the bundle branches.
• The Purkinje fibers, which spread the impulse to the ventricular muscles.

Function

The heart conduction system ensures the heart beats in a coordinated and effective manner. The SA node generates an electrical impulse that spreads through the atria, causing them to contract and pump blood into the ventricles. This impulse then reaches the AV node, where it is delayed to allow the ventricles to fill with blood. The impulse then travels down the Bundle of His and through the Purkinje fibers, causing the ventricles to contract and pump blood to the lungs and the rest of the body.

Clinical significance

Disruptions to the heart conduction system can lead to various cardiac arrhythmias, such as atrial fibrillation, ventricular tachycardia, and heart block. These conditions can often be diagnosed using an electrocardiogram (ECG), which records the electrical activity of the heart.

See also

• Cardiac cycle
• Electrocardiography
• Cardiac electrophysiology