Part of the AV junctionConducts the impulse through the fibrous plate that separates the atria and the ventricles; consists of the AV node and the bundle of His; functions also to slow the conduction speed to allow for atrial conduction prior to ventricular conduction..., the bundle of His conducts the impulse through the fibrous plate that separates the atriaRight and left atria (1/3 volume and muscle mass of the ventricles) pump blood to the ventricles. Chambers and Layers of the Heart 1. Six Second ECG Guidebook (2012), T Barill, p. 190 and the ventricle; the bundle of His is also a pacemakerAn electronic pulse generator that stimulates depolarization of the atria and/or the ventricles. 1. Six Second ECG Guidebook (2012), T Barill, p. 201, firing at 40-60/minute.
The bundle of His serves as an electrical connection between the atria and the ventriclesThe larger chambers of the heart (3 times the volume and muscle thickness than the atria), responsible for the pumping of blood to the lungs and the rest of the body., traversing the fibrous plate that separates the atrial and ventricular electrical systems. The AV nodeIs located in the inferior aspect of the right atria; functions to slow the conduction speed to allow for atrial conduction prior to ventricular conduction (atrial kick); also serves as a pacemaker if the SA node fails to fire. The... and bundle of His form the AV junctionConnects the atria to the ventricle and slows the impulse conduction speed sufficiently to allow for atrial kick; the junction consists of the AV node and the bundle of His; the junction is a supraventricular structure. 1. Six Second ECG... (sometimes just called the junction).
Note that the AV junction, atria and SA nodeThe SA node, usually the dominant pacemaker, is located in the right atrium at the opening of the superior vena cava. The SA (sinoatrial) node is a clump of hundreds of specialized cardiac cells that have the ability to self-initiate... are the three main supraventricularLocated above the ventricle – includes the bundle of His, AV node, atria and the SA node. 1. Six Second ECG Guidebook (2012), T Barill, p. 206 (located above the ventricles) electrical sites. This is an exceptionally simple and important distinction. As you will soon discover, in order for an impulse to be transmitted down the bundle branchesThe bundle of His terminates in the right and left bundle branches, insulated rapidly conducting electrical pathways that connect with the Purkinje network and thus begin depolarizing waves across the ventricles; the left bundle branch splits into three smaller branches..., the impulse must be supraventricular in origin.
The bundle of His carries the impulse from the AV node in the atria to the bundle branches in the ventricle. The bundle of His and the AV node, called the AV junction, can serve as a pacemaker at 40-60 beats/minute.
A wave of depolarizationThe rapid influx of positive ions (sodium and/or calcium) into a cell – depolarization is necessary for contraction to occur. A depolarizing wave moves through the myocardium on average along a trajectory or vector. A vector is a force moving... normally begins with the SA node. This electrical wave from the SA node passes quickly across the atria, through the AV junction (the AV node and the bundle of His) then across the ventricles via the bundle branches and the Purkinje networkA matrix of fibres located throughout the myocardium that connects the impulse from the bundle branches to the myocardial tissue. The bundle branches and the Purkinje network facilitate rapid depolarization throughout the ventricles. The Purkinje network also creates a typical....
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 46, 50, 56, 192