UCLA EKG CERTIFICATION EVALUATION FULL
QUESTIONS AND CORRECT ANSWERS
◉ What does it mean when the heart is electrically polarized at rest?
Answer: The inside of the heart cell has a higher potassium
concentration, whereas the outside has a higher concentration of
sodium.
• The higher positive charge outside the cell causes a relatively more
negative charge inside the cell.
• The difference between the charges outside and inside of the cell
wall is known as its electrical potential.
◉ What occurs during depolarization within the heart cell? Answer:
Na+ moves into the cell rapidly in response to an electrical impulse:
Inside of cell loses negative
potential.
Depolarization is propagated from cell to cell, transmitted across the
entire heart.
• The wave of depolarization represents a flow of electricity.
◉ What happens in repolarization of the heart? Answer: The ions
return to their original resting state and the heart cells restore their
resting polarity.
,◉ List in phases the electrophysiology of the heart Answer: Phase 0:
Na+ flow in and rapid depolarization occurs
when stimulated
Phase 1: Rapid return to isoelectric level
Phase 2: Ca++ ions flow in and myocytes contract
Phase 3: K+ flow out and rapid depolarization occurs
Phase 4: Polarized resting phase
◉ Name the three different type of heart cells Answer: Allow the
heart to integrate electrical and mechanical
activity of the heart
1. Pacemaker cells
2. Electrical conduction cells
3. Myocardial cells
◉ What do pacemaker cells do? Answer: Pacemaker cells have the
ability to initiate an impulse
(automaticity)
o Sinoatrial (SA) node:
o Atrioventricular (AV) node
o Purkinje fibers
o Every cell in the heart has automaticity, but normally suppressed.
, ◉ What do the electrical conduction cells do? Answer: Wires of the
heart's electrical circuit
• Carry current rapidly and efficiently to distant regions of the heart
◉ What is electrical pathway of the heart starting from SA node
Answer: Sinoatrial (SA) node ->Internodal pathways -
>Atrioventricular (AV) node->Bundle of His->Bundle branches ->
Purkinje fibers
◉ What is the pathophysiology of the SA node Answer: SA
(Sinoatrial) Node • Located in the right atrium near
the superior vena cava
• Primary pacemaker • Inherent rate: 60-100 bpm • Innervated by
autonomic nervous
system
• Electrical impulses from SA node
"depolarizes" the atria via
internodal tracts and
Bachmannn's bundle, resulting in
atrial contraction.
◉ What is the pathophysiology of the AV node? Answer: AV
(Atrioventricular) Node • Located in the inferior right
atrium
• Responsible for slowing down
conduction from the atria to the
QUESTIONS AND CORRECT ANSWERS
◉ What does it mean when the heart is electrically polarized at rest?
Answer: The inside of the heart cell has a higher potassium
concentration, whereas the outside has a higher concentration of
sodium.
• The higher positive charge outside the cell causes a relatively more
negative charge inside the cell.
• The difference between the charges outside and inside of the cell
wall is known as its electrical potential.
◉ What occurs during depolarization within the heart cell? Answer:
Na+ moves into the cell rapidly in response to an electrical impulse:
Inside of cell loses negative
potential.
Depolarization is propagated from cell to cell, transmitted across the
entire heart.
• The wave of depolarization represents a flow of electricity.
◉ What happens in repolarization of the heart? Answer: The ions
return to their original resting state and the heart cells restore their
resting polarity.
,◉ List in phases the electrophysiology of the heart Answer: Phase 0:
Na+ flow in and rapid depolarization occurs
when stimulated
Phase 1: Rapid return to isoelectric level
Phase 2: Ca++ ions flow in and myocytes contract
Phase 3: K+ flow out and rapid depolarization occurs
Phase 4: Polarized resting phase
◉ Name the three different type of heart cells Answer: Allow the
heart to integrate electrical and mechanical
activity of the heart
1. Pacemaker cells
2. Electrical conduction cells
3. Myocardial cells
◉ What do pacemaker cells do? Answer: Pacemaker cells have the
ability to initiate an impulse
(automaticity)
o Sinoatrial (SA) node:
o Atrioventricular (AV) node
o Purkinje fibers
o Every cell in the heart has automaticity, but normally suppressed.
, ◉ What do the electrical conduction cells do? Answer: Wires of the
heart's electrical circuit
• Carry current rapidly and efficiently to distant regions of the heart
◉ What is electrical pathway of the heart starting from SA node
Answer: Sinoatrial (SA) node ->Internodal pathways -
>Atrioventricular (AV) node->Bundle of His->Bundle branches ->
Purkinje fibers
◉ What is the pathophysiology of the SA node Answer: SA
(Sinoatrial) Node • Located in the right atrium near
the superior vena cava
• Primary pacemaker • Inherent rate: 60-100 bpm • Innervated by
autonomic nervous
system
• Electrical impulses from SA node
"depolarizes" the atria via
internodal tracts and
Bachmannn's bundle, resulting in
atrial contraction.
◉ What is the pathophysiology of the AV node? Answer: AV
(Atrioventricular) Node • Located in the inferior right
atrium
• Responsible for slowing down
conduction from the atria to the
