What is the normal conduction pathway of the heart?
The conduction system of the heart. Left: Normal excitation originates in the sinoatrial (SA) node then propagates through both atria. The atrial depolarization spreads to the atrioventricular (AV) node, and passes through the bundle of His to the bundle branches/Purkinje fibers.
What is the intrinsic conduction system of the heart?
The intrinsic conduction system of the heart is comprised of several specialized subpopulations of cells that either spontaneously generate electrical activity (pacemaker cells), or preferentially conduct this excitation throughout the four chambers of the heart in a coordinated fashion.
What is the correct sequence of electrical conduction of the heart?
AV node → SA node → Bundle of His → Right and left branches of bundle of His → Purkinje fibre.
What is the internodal pathway?
internodal pathways: specialized conductile cells within the atria that transmit the impulse from the SA node throughout the myocardial cells of the atrium and to the AV node.
What are the 5 parts of the conduction system in order?
The conduction system consists of pacemaker cells that generate spontaneous action potentials, and then deliver those impulses throughout the heart. 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 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 are the 5 parts to the heart’s intrinsic conduction system?
The main parts of the system are the SA node, AV node, bundle of HIS, bundle branches, and Purkinje fibers.
What are the 4 phases of cardiac cycle?
The cardiac cycle involves four major stages of activity: 1) “Isovolumic relaxation”, 2) Inflow, 3) “Isovolumic contraction”, 4) “Ejection”.
What is the function of Purkinje fibers?
Purkinje fibers play a major role in electrical conduction and propagation of impulse to the ventricular muscle. Many ventricular arrhythmias are initiated in the Purkinje fiber conduction system (eg.
Where are Purkinje fibers located?
The Purkinje fibers (/pɜːrˈkɪndʒi/ pur-KIN-jee; Purkinje tissue or subendocardial branches) are located in the inner ventricular walls of the heart, just beneath the endocardium in a space called the subendocardium.
What do the Purkinje fibers do?
Purkinje fibers play a major role in electrical conduction and propagation of impulse to the ventricular muscle. Many ventricular arrhythmias are initiated in the Purkinje fiber conduction system (eg. Here we will review properties of Purkinje fibers and cells, and compare them to those of ventricles.
What is a conduction pathway?
A network of specialized muscle cells is found in the heart’s walls. These muscle cells send signals to the rest of the heart muscle causing a contraction. This group of muscle cells is called the cardiac conduction system.
Which is the shortest route in the conduction system?
It is believed by many that there are three preferential anatomic conduction pathways from the sinoatrial node to the atrioventricular node [1,18]. In general, these can be considered as the shortest electrical routes between the nodes.
Where does the bundle branch of the conduction system run?
This bundle branch runs proximally, just beneath the endocardium, and its course runs slightly inferior to the septal papillary muscle of the tricuspid valve before dividing into fibers that spread throughout the right ventricle.
Where do depolarizations go in the conduction system?
However, it is generally accepted that: 1) the spread of depolarizations from nodal cells can go directly to adjacent myocardial cells; and 2) preferentially ordered myofibril pathways allow this excitation to rapidly transverse the right atrium to both the left atrium and the atrioventricular node (Figure 1).
What are defects in the intraventricular conduction system?
In this chapter we will discuss intraventricular conduction delays (defects), which are caused by functional or anatomical defects in the components of the intraventricular conduction system.