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Title: At what part of the cardiac conduction system does the electrical impulse travel most rapidly? Post by: xoxololo on Feb 25, 2018 At what part of the cardiac conduction system does the electrical impulse travel most rapidly?
a. Bundle of His b. Bundle branches c. Intraatrial pathways d. Purkinje fibers Q. 2 Why is the electrical impulse temporarily delayed at the atrioventricular (AV) node? a. To allow complete emptying of the ventri-cles b. To allow more sodium buildup in the my-ocardial cells c. To allow better filling of the ventricles d. To allow complete filling of the atria Q. 3 What structure serves as the backup pacemaker for the heart? a. Atrioventricular (AV) node b. Sinoatrial (SA) node c. Bundle of His d. Purkinje fibers Q. 4 What structure normally paces the healthy heart? a. Atrioventricular (AV) node b. Sinoatrial (SA) node c. Bundle of His d. Purkinje fibers Title: At what part of the cardiac conduction system does the electrical impulse travel most rapidly? Post by: gilv99 on Feb 25, 2018 The impulse travels the most rapidly in the Purkinje fibers, which is essential if contraction of the ventricles is to occur in a coordinated fashion. The impulse is temporarily delayed at the AV node in order to allow the ventricles time to fill with blood. That brief delay also limits the rate of the ventricular stimulation during excessively fast atrial rhythms that, if passed to the ventricles, would lead to inadequate cardiac output. After leaving the atria, the impulse moves to the AV node, located in the intraventricular septum in the inferior aspect of the right atrium (Figure 18-2). The AV node is the backup pacemaker because it has the second greatest degree of automaticity in the healthy heart. Normally, the SA node, which is located in the upper portion of the right atrium, has the greatest degree of automaticity and therefore paces the heart. Title: At what part of the cardiac conduction system does the electrical impulse travel most rapidly? Post by: xoxololo on Feb 25, 2018 Thank you for being my superhero!
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