UCLA EKG test (2025)
comprehensive questions and
verified answers ( detailed &
elaborated) ACTUAL EXAM 2025
TEST!!
Save
Terms in this set (45)
At rest;
K+ inside > outside; Na+ outside >
inside
Polarized
The difference b/w charges in/out of
cell wall is the electron potential.
Electrical potential = -90mV (Negative
inside)
, Contracting;
Depolarization Na+ moves into cell rapidly → Inside
loses negative potential =
Depolarization
Return to rest;
Repolarization
Ions return to resting state and heart
cells restore resting polarity
Pacemaker rate: 60-100 bpm
Sinoatrial (SA)
node
Pacemaker rate: 40-60 bpm
Atrioventricular
(AV) node
Pacemaker rate: 20-40 bpm
Purkinje fibers
("ventricle
pacemaker")
SA node → (internodal pathways) →
Conduction
AV node → (Bundle of His) → (Bundle
pathway
branches) → Purkinje fibers
, Primary pacemaker*
Rate: 60-100 bpm
Sinoatrial (SA)
node
Depolarize the atria via internodal
tracts = atrial contraction
Subsidiary pacemaker
Rate: 40-60 bpm
Atrioventricular
Responsible for slowing down
(AV) node
conduction from atria to ventricles
just long enough for atrial contraction
to occur
Subsidiary pacemaker
Purkinje cells
Rate: 20-40 bpm
EKG: Major leads V1 + Lead II
, V1 = Right sternal border, 4th
intercostal space
V1 + Lead II V2 = Left sternal border, 4th
placement intercostal space
locations V4 = Midclavicular line, 5th intercostal
space (PMI)
V2-6? V6 = Midaxillary line, 5th intercostal
space
V3 = Between V2-V4
V5 = Between V4-V6
1. P wave = Atrial depolarization (SA
node)
2. Completed atrial depolarization,
delayed impulse at AV node
Components of 3. QRS = Ventricular depolarization,
EKG atrial repolarization
4. Completed ventricular
depolarization
5. T wave = Ventricular repolarization
6. Repolarization complete
comprehensive questions and
verified answers ( detailed &
elaborated) ACTUAL EXAM 2025
TEST!!
Save
Terms in this set (45)
At rest;
K+ inside > outside; Na+ outside >
inside
Polarized
The difference b/w charges in/out of
cell wall is the electron potential.
Electrical potential = -90mV (Negative
inside)
, Contracting;
Depolarization Na+ moves into cell rapidly → Inside
loses negative potential =
Depolarization
Return to rest;
Repolarization
Ions return to resting state and heart
cells restore resting polarity
Pacemaker rate: 60-100 bpm
Sinoatrial (SA)
node
Pacemaker rate: 40-60 bpm
Atrioventricular
(AV) node
Pacemaker rate: 20-40 bpm
Purkinje fibers
("ventricle
pacemaker")
SA node → (internodal pathways) →
Conduction
AV node → (Bundle of His) → (Bundle
pathway
branches) → Purkinje fibers
, Primary pacemaker*
Rate: 60-100 bpm
Sinoatrial (SA)
node
Depolarize the atria via internodal
tracts = atrial contraction
Subsidiary pacemaker
Rate: 40-60 bpm
Atrioventricular
Responsible for slowing down
(AV) node
conduction from atria to ventricles
just long enough for atrial contraction
to occur
Subsidiary pacemaker
Purkinje cells
Rate: 20-40 bpm
EKG: Major leads V1 + Lead II
, V1 = Right sternal border, 4th
intercostal space
V1 + Lead II V2 = Left sternal border, 4th
placement intercostal space
locations V4 = Midclavicular line, 5th intercostal
space (PMI)
V2-6? V6 = Midaxillary line, 5th intercostal
space
V3 = Between V2-V4
V5 = Between V4-V6
1. P wave = Atrial depolarization (SA
node)
2. Completed atrial depolarization,
delayed impulse at AV node
Components of 3. QRS = Ventricular depolarization,
EKG atrial repolarization
4. Completed ventricular
depolarization
5. T wave = Ventricular repolarization
6. Repolarization complete
