Conduction Pathway of the Heart
Conduction Pathway of the Heart
It consists of 1. Sinatrial node (SA node) 2. Atrial Ventricular Node (AV Node) 3. Bundle of Hiss or AV bundle 4. Right and Left bundle branches 5. Purkinjie Fibers
SA Node
It enables the heart to beat anywhere between 60 to 100 times and is called the natural pace maker of the heart.
SA Node
It fires electrical impulses at the rate of 60 to 100 per minute.
SA Node
It is composed of special cardiac cells and nerve fibers and is located in the upper portion of the right atrium in the superior posterior wall of the right atrium.
Bundles of Hiss or A.V Bundle
It is located next to the AV Node.
AV Node or AV Ventricular Node
It is located on the floor of the right atrium at the beginning of the inter ventricular septum. It causes a delay in the transmission of electrical impulses from the atria to the ventricles for the following reasons. To give both the atria enough time to empty all the blood before they relax. To protect the ventricles from the fast heart rate of the atria. It fires electrical impulses at the rate of 40 to 60 per minute. The AV node transfers impulses from the atria to the ventricles.
Bundle Branches
The right and left bundle branches run along either side of the interventicular septum.
SA Node
These electrical impulses are transmitted to the myocardial walls of the right and left atrium which results in the contraction of the 2 chambers.
Purkinjie Fibers
They transmit electrical impulses to the myocardial walls of the ventricles. They fire at the rate of 20 to 30 beats per minute.
