age 1 of 41
UCLA EKG TEST STUDY GUIDE 2025/2026 ACCURATE
QUESTIONS AND VERIFIED CORRECT SOLUTIONS
WITH RATIONALES || 100% GUARANTEED PASS
<RECENT VERSION>
electrically polarized at rest ......ANSWER........- inside of heart
cell has a high potassium concentration, whereas the outside has
a higher concentration of NA
-higher positive charge outside the cell cause more negative
charge inside cell
electrical potential ......ANSWER........difference between the
charges outside and inside of the cell wall
Depolarization ......ANSWER........NA moves into the cell rapidly
in response to an electrical impulse
,age 2 of 41
- inside cell loses negative potential
Replolarization ......ANSWER........ions return to their original
resting state
- heart cells restore their resting polarity
4 Phases of Electrophysiology of the heart cell
......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
Pacemaker cells ......ANSWER........- Sinoatrial node ( SA) node
,age 3 of 41
-Atrioventricular node )AV node
- Purkinjie fibers
SA node ......ANSWER........-primary pacemaker
- Rate: 60-100
- SA node depolarizes the atria via intro nodal tracts and
Bachmann;s bundle = resulting in atrial contraction
AV node ......ANSWER........- responsible for slowing down
conduction from the atria to ventricles just long enough for atrial
contraction to occur
- rate: 40-60
Bundle of His ......ANSWER........- divides left and right branches
, age 4 of 41
-impulses are conducted down LBB faster than RBB, allowing
both ventricles to contract at same time
Purkunje fibers ......ANSWER........- send impulses into mycardial
tissues of the ventricles and causes them to contract
- rate: 20-40
Myocardial cells ......ANSWER........-contractile machinery of the
heart
- myocardial cell is deplolarized, CA is released within cell
causing cell to contract
Normal ranges for electrolytes ......ANSWER........NA: 135- 146
meq/L
K: 3.6-5.3 meq/L
UCLA EKG TEST STUDY GUIDE 2025/2026 ACCURATE
QUESTIONS AND VERIFIED CORRECT SOLUTIONS
WITH RATIONALES || 100% GUARANTEED PASS
<RECENT VERSION>
electrically polarized at rest ......ANSWER........- inside of heart
cell has a high potassium concentration, whereas the outside has
a higher concentration of NA
-higher positive charge outside the cell cause more negative
charge inside cell
electrical potential ......ANSWER........difference between the
charges outside and inside of the cell wall
Depolarization ......ANSWER........NA moves into the cell rapidly
in response to an electrical impulse
,age 2 of 41
- inside cell loses negative potential
Replolarization ......ANSWER........ions return to their original
resting state
- heart cells restore their resting polarity
4 Phases of Electrophysiology of the heart cell
......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
Pacemaker cells ......ANSWER........- Sinoatrial node ( SA) node
,age 3 of 41
-Atrioventricular node )AV node
- Purkinjie fibers
SA node ......ANSWER........-primary pacemaker
- Rate: 60-100
- SA node depolarizes the atria via intro nodal tracts and
Bachmann;s bundle = resulting in atrial contraction
AV node ......ANSWER........- responsible for slowing down
conduction from the atria to ventricles just long enough for atrial
contraction to occur
- rate: 40-60
Bundle of His ......ANSWER........- divides left and right branches
, age 4 of 41
-impulses are conducted down LBB faster than RBB, allowing
both ventricles to contract at same time
Purkunje fibers ......ANSWER........- send impulses into mycardial
tissues of the ventricles and causes them to contract
- rate: 20-40
Myocardial cells ......ANSWER........-contractile machinery of the
heart
- myocardial cell is deplolarized, CA is released within cell
causing cell to contract
Normal ranges for electrolytes ......ANSWER........NA: 135- 146
meq/L
K: 3.6-5.3 meq/L
