Elements of the conduction system of heart and heartbeat
The conduction system of the heart is a group of specialized cells that generates and coordinates the electrical signals that regulate the heartbeat. These cells are located in several areas of the heart, including the sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, and Purkinje fibers.
- Sinoatrial (SA) node: The SA node is a group of cells located in the right atrium that acts as the heart’s natural pacemaker. It initiates the electrical impulses that cause the heart to contract and generates an electrical signal that spreads through the atria, causing them to contract.
- Atrioventricular (AV) node: The AV node is located between the atria and ventricles, and it acts as a gatekeeper, slowing down the electrical signal before it reaches the ventricles. This delay allows the atria to fully contract before the ventricles receive the signal to contract.
- Bundle of His: The bundle of His is a group of specialized muscle fibers that conduct the electrical signal from the AV node to the ventricles.
- Purkinje fibers: The Purkinje fibers are specialized muscle fibers that distribute the electrical signal throughout the ventricles, causing them to contract in a synchronized and coordinated manner.
The heartbeat is the result of the electrical signals generated by the conduction system of the heart, which causes the heart to contract and pump blood throughout the body. The heartbeat is controlled by the SA node, which initiates an electrical signal that spreads through the atria, causing them to contract. The electrical signal then passes through the AV node, where it is delayed, allowing the ventricles to fill with blood. The signal then travels down the bundle of His and the Purkinje fibers, causing the ventricles to contract and pump blood out of the heart.
In summary, the conduction system of the heart and the coordinated electrical signals it generates are critical to the normal function of the heart and the circulation of blood throughout the body.
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