6: Figure 6.8 Animation Video
Transcript:
Conduction System of the Heart
The conduction system of the heart includes two areas of nodal tissue and a network of conduction fibers. Electrical impulses formed by the sinoatrial (SA) node travel on a specific pathway through these structures and tell the ventricles of the heart to contract.
The process begins when the SA node generates an electrical impulse. That impulse travels through Bachmann's bundle and into the left atrium. The impulse also travels to the atrioventricular (AV) node through 3 internodal pathways. At the AV node, the electrical impulse becomes "tied up" for a little longer than a tenth of a second.
Once the impulse is released, it travels through the bundle of His in the ventricular septum. Here, the impulse travels down both the left bundle branches and the right bundle branches, and is transmitted to millions of Purkinje fibers. The Purkinje fibers are located in both ventricles of the heart. When the impulse arrives here, the Purkinje fibers stimulate the ventricles to contract.