The ______is the primary pacemaker of the heart.

a. atrioventricular node

b. sinoatrial node

c. Purkinje fiber system

d. atrioventricular bundle

Video transcript

Hi everyone. Let's take a look at this practice problem together. The part of the heart conduction system that leads the normal rhythm and rate of the heart is the answer. Options are a bundle of hiss b sinoatrial node, C atrial ventricular node and D Perini fibers. So recall that specifically it's the pacemaker cells that establish the normal heart rate. Where are these pacemaker cells located on the screen? I am now putting up a drawing that shows the heart with the conduction system components. Let's talk through it together. So recall that the pacemaker cells are located in the essay node. They begin the electrical signals and the essay node is located in the right atrium. The signal from the S A node or sinoatrial node travels along conducting cells to the A V node or atrial ventricular node. The A V node is located between the atria and ventricles. The signal then travels through the bundle of hiss through the left and right bundle branches and finally to the Perini fibers from here, the signal is then distributed to ventricles to the rest of the ventricles. So the part of the heart conduction system that leads the normal rhythm and heart rate is the structure at the very beginning of the conduction system that contains the pacemaker cells. That means the correct answer is option B sinoatrial node. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.