The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node). There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles.
What is the pathway of the intrinsic conduction system?
More specifically, this intrinsic conduction system is thought to be comprised of the following subpopulations of cells: 1) pacemaker cells, those that spontaneously generate electrical activities; and 2) conduction fibers (in the ventricles, Purkinje fibers) those which preferentially conduct this activity throughout …
What happens to the electrical impulse when it reaches the AV node?
After an electrical impulse is generated by the sinus node (located at the top of the right atrium), it spreads across both atria, causing these chambers to beat. The AV node then “gathers” that electrical impulse and, after a brief delay, allows it to pass through to the ventricles.
What is the pathway of the cardiac conduction system?
The SA node starts the sequence by causing the atrial muscles to contract. That’s why doctors sometimes call it the anatomical pacemaker. Next, the signal travels to the AV node, through the bundle of HIS, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract.
What is the order of the conduction pathway?
The cardiac conduction system comprises the following structures, in order, the SA node, the AV node, the bundle of His, the bundle branches, and the Purkinje fibers.
What are the two phases of ventricular systole?
The cardiac cycle is essentially split into two phases, systole (the contraction phase) and diastole (the relaxation phase).
What happens when there is damage to the AV node?
Partial AV block occurs when AV node damage prevents some atrial impulses from being transmitted to the ventricles. In the particular case illustrated, every second P wave is not followed by QRS and T waves, producing 2:1 AV block. It is said that there are “dropped beats” of the ventricles.
What would happen if the AV node delay was too long?
If your AV node is not working well, you may develop a condition known as heart block. First-degree heart block is when it takes too long for your heartbeat to travel from the top to the bottom of your heart.
What are the 8 elements of the cardiac conduction system?
Cardiac Conduction System
- The sino-atrial (SA) node.
- The atrio-ventricular (AV) node.
- The bundle of His.
- The left and right bundle branches.
- The Purkinje fibres.
What is the sequence of events in the transmission of an impulse through the heart?
When the SA node sends an electrical impulse, it triggers the following process: The electrical signal travels from your SA node through muscle cells in your right and left atria. The signal triggers the muscle cells that make your atria contract. The atria contract, pumping blood into your left and right ventricles.
What is the function of Purkinje fibers?
Purkinje fibers are part of the specialized conduction network of the heart that ensures that the wave of excitation spreads rapidly and almost synchronously to the ventricular muscle mass.