ELECTROCARDIOGRAM (EKG) EXAM |
COMPLETE STUDY GUIDE, PRACTICE
QUESTIONS AND ANSWERS
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Updated 2026 Questions and Answers
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,The ability of myocardial cells to respond to electrical D) Excitability
impulses generated by other myocardial cells is called:
Explanation: Excitability is the ability of myocardial cells to respond to an incoming
A) Contractility electrical impulse, allowing the heart to propagate signals and coordinate contraction.
B) Automaticity
C) Conductivity
D) Excitability
What does the conductivity property of myocardial cells C) Receive and transmit electrical impulses to neighboring cells
enable them to do?
Explanation: Conductivity is the ability of myocardial cells to transmit electrical impulses
A) Shorten and contract from one cell to another, ensuring coordinated heart muscle contraction.
B) Generate electrical impulses independently
C) Receive and transmit electrical impulses to neighboring
cells
D) Respond to electrical stimulation
The term 'contractility' in myocardial cells refers to: B) Their ability to shorten and cause myocardial contraction
A) Their ability to generate electrical impulses spontaneously Explanation: Contractility is the mechanical property where myocardial cells shorten in
B) Their ability to shorten and cause myocardial contraction response to electrical stimulation, producing the force needed for the heart to pump
C) Their ability to transmit electrical impulses blood.
D) Their ability to respond to external electrical stimuli
Where do the electrical impulses that initiate the heartbeat C) SA node
originate?
Explanation: The sinoatrial (SA) node is the heart's natural pacemaker, where electrical
A) AV node impulses first originate, initiating the heartbeat.
B) Bundle of His
C) SA node
D) Purkinje fibers
,After impulses leave the SA node, they travel across the atrial C) AV node
wall to which structure?
Explanation: The impulses spread through the atria and reach the atrioventricular (AV)
A) Bundle branches node, which acts as a gatekeeper to delay the signal before it passes to the ventricles.
B) Purkinje fibers
C) AV node
D) Interventricular septum
What is the primary function of the AV node in the heart's D) Delay the electrical impulse before ventricular contraction
conduction system?
Explanation: The AV node slows the conduction of impulses, allowing time for the atria to
A) Initiate the heartbeat contract and complete ventricular filling before the ventricles contract.
B) Conduct impulses directly to Purkinje fibers
C) Divide the impulse into left and right bundles
D) Delay the electrical impulse before ventricular contraction
Through which structure do impulses pass from the AV node A) Bundle of His
to reach the interventricular septum?
Explanation: The bundle of His carries impulses from the AV node, passing through the
A) Bundle of His fibrous skeleton and into the interventricular septum.
B) Purkinje fibers
C) SA node
D) Left and right bundle branches
The bundle of His divides into which of the following B) Left and right bundle branches
structures?
Explanation: The bundle of His splits into left and right bundle branches, which conduct
A) SA node and AV node impulses down the interventricular septum to each ventricle.
B) Left and right bundle branches
C) Purkinje fibers and AV node
D) Atrial fibers and ventricular fibers
, Which fibers carry the electrical impulse to the ventricular C) Purkinje fibers
walls causing contraction?
Explanation: Purkinje fibers rapidly transmit electrical impulses from the bundle branches
A) AV node fibers to the ventricular myocardium, leading to coordinated ventricular contraction.
B) Bundle branches
C) Purkinje fibers
D) SA node fibers
What is the absolute refractory period in cardiac muscle cells? B) The minimum time after an action potential when no new action potential can be
initiated
A) The time when a stronger than usual stimulus is needed to
start an action potential Explanation: The absolute refractory period is the phase during which myocardial cells
B) The minimum time after an action potential when no new cannot respond to any stimulus, preventing premature contractions and ensuring proper
action potential can be initiated heart rhythm.
C) The time when electrical impulses are conducted to the
ventricles
D) The time when electrodes transmit electrical signals to the
EKG machine
During which period can myocardial cells respond to a B) Relative refractory period
stronger than usual stimulus to initiate another action
potential? Explanation: In the relative refractory period, cells can only be excited if the stimulus is
stronger than normal, allowing for some flexibility in timing of heartbeats but maintaining
A) Absolute refractory period control.
B) Relative refractory period
C) Resting phase
D) Plateau phase
What are electrodes used for in an EKG setup? D) To conduct electricity from the body to the EKG machine
A) To record electrical impulses on paper Explanation: Electrodes are metal strips placed on the skin that detect electrical activity
B) To generate electrical impulses in the heart of the heart and conduct it to the EKG machine via leads.
C) To amplify the electrical signals
D) To conduct electricity from the body to the EKG machine
COMPLETE STUDY GUIDE, PRACTICE
QUESTIONS AND ANSWERS
| GRADED A+ | GUARANTEED SUCCESS
Updated 2026 Questions and Answers
100% Verified Exam Prep
,The ability of myocardial cells to respond to electrical D) Excitability
impulses generated by other myocardial cells is called:
Explanation: Excitability is the ability of myocardial cells to respond to an incoming
A) Contractility electrical impulse, allowing the heart to propagate signals and coordinate contraction.
B) Automaticity
C) Conductivity
D) Excitability
What does the conductivity property of myocardial cells C) Receive and transmit electrical impulses to neighboring cells
enable them to do?
Explanation: Conductivity is the ability of myocardial cells to transmit electrical impulses
A) Shorten and contract from one cell to another, ensuring coordinated heart muscle contraction.
B) Generate electrical impulses independently
C) Receive and transmit electrical impulses to neighboring
cells
D) Respond to electrical stimulation
The term 'contractility' in myocardial cells refers to: B) Their ability to shorten and cause myocardial contraction
A) Their ability to generate electrical impulses spontaneously Explanation: Contractility is the mechanical property where myocardial cells shorten in
B) Their ability to shorten and cause myocardial contraction response to electrical stimulation, producing the force needed for the heart to pump
C) Their ability to transmit electrical impulses blood.
D) Their ability to respond to external electrical stimuli
Where do the electrical impulses that initiate the heartbeat C) SA node
originate?
Explanation: The sinoatrial (SA) node is the heart's natural pacemaker, where electrical
A) AV node impulses first originate, initiating the heartbeat.
B) Bundle of His
C) SA node
D) Purkinje fibers
,After impulses leave the SA node, they travel across the atrial C) AV node
wall to which structure?
Explanation: The impulses spread through the atria and reach the atrioventricular (AV)
A) Bundle branches node, which acts as a gatekeeper to delay the signal before it passes to the ventricles.
B) Purkinje fibers
C) AV node
D) Interventricular septum
What is the primary function of the AV node in the heart's D) Delay the electrical impulse before ventricular contraction
conduction system?
Explanation: The AV node slows the conduction of impulses, allowing time for the atria to
A) Initiate the heartbeat contract and complete ventricular filling before the ventricles contract.
B) Conduct impulses directly to Purkinje fibers
C) Divide the impulse into left and right bundles
D) Delay the electrical impulse before ventricular contraction
Through which structure do impulses pass from the AV node A) Bundle of His
to reach the interventricular septum?
Explanation: The bundle of His carries impulses from the AV node, passing through the
A) Bundle of His fibrous skeleton and into the interventricular septum.
B) Purkinje fibers
C) SA node
D) Left and right bundle branches
The bundle of His divides into which of the following B) Left and right bundle branches
structures?
Explanation: The bundle of His splits into left and right bundle branches, which conduct
A) SA node and AV node impulses down the interventricular septum to each ventricle.
B) Left and right bundle branches
C) Purkinje fibers and AV node
D) Atrial fibers and ventricular fibers
, Which fibers carry the electrical impulse to the ventricular C) Purkinje fibers
walls causing contraction?
Explanation: Purkinje fibers rapidly transmit electrical impulses from the bundle branches
A) AV node fibers to the ventricular myocardium, leading to coordinated ventricular contraction.
B) Bundle branches
C) Purkinje fibers
D) SA node fibers
What is the absolute refractory period in cardiac muscle cells? B) The minimum time after an action potential when no new action potential can be
initiated
A) The time when a stronger than usual stimulus is needed to
start an action potential Explanation: The absolute refractory period is the phase during which myocardial cells
B) The minimum time after an action potential when no new cannot respond to any stimulus, preventing premature contractions and ensuring proper
action potential can be initiated heart rhythm.
C) The time when electrical impulses are conducted to the
ventricles
D) The time when electrodes transmit electrical signals to the
EKG machine
During which period can myocardial cells respond to a B) Relative refractory period
stronger than usual stimulus to initiate another action
potential? Explanation: In the relative refractory period, cells can only be excited if the stimulus is
stronger than normal, allowing for some flexibility in timing of heartbeats but maintaining
A) Absolute refractory period control.
B) Relative refractory period
C) Resting phase
D) Plateau phase
What are electrodes used for in an EKG setup? D) To conduct electricity from the body to the EKG machine
A) To record electrical impulses on paper Explanation: Electrodes are metal strips placed on the skin that detect electrical activity
B) To generate electrical impulses in the heart of the heart and conduct it to the EKG machine via leads.
C) To amplify the electrical signals
D) To conduct electricity from the body to the EKG machine
