Basic ECG Interpretation Challenge Test Questions And
Answers Latest Updates 2025/2026/ 100%Complete
Solutions
What are the 6 parts of the cardiac conduction cycle? - ANSWER - -SA node
-Internodal pathways
-AV node
-Bundle of His
-R and L bundle branches
-Purkinje fibers
What is the SA node? - ANSWER - -Small cluster of cells located in the upper R atrium
*-Pacemaker of the heart*
What are internodal pathways? - ANSWER - Impulses sent by the SA node that travel through the atrial
muscle fibers via the intra-atrial pathways
Allows for simultaneous depolarization and contraction of the atria
Where is the AV node located? - ANSWER - Lower portion of the R atria
What is the inherent rate of the SA node? - ANSWER - 60-100 bpm
What does the AV node do? - ANSWER - -Receives impulse from the SA node
-Delays conduction to allow for the atria to contract, then conducts to the ventricle
Where is the Bundle of His? - ANSWER - -Upper part of the intraventricular septum
, -Connects AV node with bundle branches
What is the Bundle of His? - ANSWER - AV node and Bundle of His are known as the Junctional area
What is the inherent rate of the Bundle of His? - ANSWER - 40-60 bpm
What is the back up for the SA node? - ANSWER - AV junction
Where are the R and L bundle branches? - ANSWER - Arise from the bundle of His and travel down the R
and L side of the septum
What are purkinje fibers? - ANSWER - Smaller branches of the bundle branches that spread throughout
the myocardium and terminate there
What is the inherent rate of purkinje fibers? - ANSWER - 20-40 bpm
What is the final back up pacemaker for the SA node and AV junction? - ANSWER - Purkinje fibers
What is automaticity? - ANSWER - Ability to act as an impulse, initiating electrical activity and
spontaneous depolarization
*Most important difference between cardiac and skeletal muscle cells*
What is excitability? - ANSWER - Ability to respond to a stimulation and initiate an impulse
What is conductivity? - ANSWER - Ability to transmit an impulse that has been initiated and passes along
cell membranes
What is contractility? - ANSWER - Ability of a muscle fiber to shorten in response to a stimulus
Answers Latest Updates 2025/2026/ 100%Complete
Solutions
What are the 6 parts of the cardiac conduction cycle? - ANSWER - -SA node
-Internodal pathways
-AV node
-Bundle of His
-R and L bundle branches
-Purkinje fibers
What is the SA node? - ANSWER - -Small cluster of cells located in the upper R atrium
*-Pacemaker of the heart*
What are internodal pathways? - ANSWER - Impulses sent by the SA node that travel through the atrial
muscle fibers via the intra-atrial pathways
Allows for simultaneous depolarization and contraction of the atria
Where is the AV node located? - ANSWER - Lower portion of the R atria
What is the inherent rate of the SA node? - ANSWER - 60-100 bpm
What does the AV node do? - ANSWER - -Receives impulse from the SA node
-Delays conduction to allow for the atria to contract, then conducts to the ventricle
Where is the Bundle of His? - ANSWER - -Upper part of the intraventricular septum
, -Connects AV node with bundle branches
What is the Bundle of His? - ANSWER - AV node and Bundle of His are known as the Junctional area
What is the inherent rate of the Bundle of His? - ANSWER - 40-60 bpm
What is the back up for the SA node? - ANSWER - AV junction
Where are the R and L bundle branches? - ANSWER - Arise from the bundle of His and travel down the R
and L side of the septum
What are purkinje fibers? - ANSWER - Smaller branches of the bundle branches that spread throughout
the myocardium and terminate there
What is the inherent rate of purkinje fibers? - ANSWER - 20-40 bpm
What is the final back up pacemaker for the SA node and AV junction? - ANSWER - Purkinje fibers
What is automaticity? - ANSWER - Ability to act as an impulse, initiating electrical activity and
spontaneous depolarization
*Most important difference between cardiac and skeletal muscle cells*
What is excitability? - ANSWER - Ability to respond to a stimulation and initiate an impulse
What is conductivity? - ANSWER - Ability to transmit an impulse that has been initiated and passes along
cell membranes
What is contractility? - ANSWER - Ability of a muscle fiber to shorten in response to a stimulus
