SA Node
This acts as the heart's natural pacemaker.
What is the SA node?
The AV node typically fires at this rate if pacing.
What is 40–60 bpm?
The Bundle of His splits into these two pathways.
What are the right and left bundle branches?
These fibers cause this part of the heart to contract.
What are the ventricles?
This wave represents atrial depolarization.
What is the P wave?
The SA node is located in this chamber.
What is the right atrium?
The AV node’s main job is to delay conduction so this can occur.
What is ventricular filling?
These conduct impulses to the Purkinje fibers.
What are the bundle branches?
Purkinje fibers fire at this rate if acting as a pacemaker.
What is 20–40 bpm?
This wave represents ventricular repolarization.
What is the T wave?
What is 60-100 bpm.
This interval on the EKG represents AV node delay.
What is the PR interval?
A block in one of these branches can widen the QRS complex.
What is a bundle branch block?
Purkinje fibers conduct impulses rapidly because of this feature.
What is their large fiber diameter?
This ion plays the biggest role in rapid depolarization.
What is sodium (Na+)?
This term describes the SA node's ability to generate its own electrical impulses.
What is automaticity?
When the SA node fails, this node becomes the backup pacemaker.
What is the AV node?
This part of the conduction system is further divided into anterior and posterior fascicles.
What is the left bundle branch?
Ventricular depolarization on the EKG is represented by this.
What is the QRS complex?
The ability of cardiac cells to respond to an electrical stimulus.
What is excitability?
The SA node sends impulses to these heart structures next.
What are the atria?
The AV node passes the electrical impulse to this structure.
What is the Bundle of His?
This structure is the only normal electrical pathway between atria and ventricles.
What is the Bundle of His?
Damage to the Purkinje system can lead to this life-threatening arrhythmia.
What is ventricular fibrillation?
The entire sequence of electrical conduction through the heart in correct order.
What is SA node → AV node → Bundle of His → Right/Left bundle branches → Purkinje fibers?