A&P II (2) |THE SMART WAY TO PASS | REAL TESTS, REAL
RESULTS!
ion channels contractile cells Answer: Ca: timed gate for closing
K
Na
Phases of contractile cell action potential Answer: 1. rapid depolarization
2. initial repolarization
3. plateau phase
4. repolarization phase
rapid depolarization phase Answer: 1st - contractile
Na channel opens/ Na goes into cell
membrane potential become more positive
initial depolarization phase Answer: 2nd- contractile
Na channel closes
K channel opens/ K goes out of the cell
short phase
action potential become more negative
plateau phase Answer: 3rd- contractile
Ca channel opes/ Ca goes into cell
K channel opens / K goes out of cell
K and Ca go in and out at the same rate (membrane potential stabilizes)
repolarization phase (contractile) Answer: 4th- contractile
Ca channel closes
K channel opens/ K goes out of cell
negative membrane potential
Pacemaker ion channels Answer: Ca
K
HCN : non specific cation
Phases of pacemaker cell action potential Answer: 1. slow initial depolarization phase
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1
,2. full depolarization
3. repolarization phase
4. minimum potential phase
slow initial depolarization phase Answer: 1st- pacemaker
HCN opens/ HCN go in and out of cell (bidirectional)
increases membrane potential
slower
full depolarization Answer: 2nd - pacemaker
Ca channel opens/ Ca goes into the cell
membrane potential increases
repolarization (pacemaker) Answer: 3rd - pacemaker
K channel opens/ K goes out of cell
negative membrane potential
minimum potential phase Answer: 4th - pacemaker
K channel opens/ K goes out of cell
trough tiggers the opening of HCN
end of action potential is used to trigger the next one
Pacemaker cells Answer: Sinoatrial node (SA) node
atrioventricular (AV) node
purkinje fiber
SA node Answer: right atrium
by the opening of the superior vena cava
fastest rate of depolarization
60-70 AP per min
sets the HR
AV node Answer: cluster of pacemaker cells
next to tricuspid valve
slower rate of depolarization
40-50 AP per minute
if SA node were to fail, the AV node could set the HR but it would be slower
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2
, Purkinje Fiber System Answer: AV bundle
R/L bundle branches
terminal branches
slowest rate of depolarization
20 AP per minute
P wave Answer: atrial depolarization
QRS complex Answer: ventricular depolarization and atrial repolarization
T wave Answer: ventricular repolarization
S-T segment Answer: ventricular plateau phase
R-R interval Answer: entire duration of a cardiac action potential
P-R interval Answer: duration of atrial depolarization and AV node delay
Q-T interval Answer: entire duration of a ventricular action potential
Bradycardia Answer: HR is slower than normal
tachycardia Answer: HR is faster than normal
Sinus tachycardia Answer: has sinus rhythm
HR is faster than normal
disruption in conduction pathway Answer: block at AV node
signals not traveling to the ventricles
signals travel through the atria
Atrial fibrillation Answer: cells are depolarizing at different rates
large peaks
not immediately life threatening
Ventricular Fibrillation Answer: cells are depolarizing at different rates
small inconsistent rates
immediately life threatening
defibrillation is used
asystole Answer: flatline
epinephrine and CPR is used
systole Answer: Contraction of the heart
disastole Answer: Relaxation of the heart
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3
RESULTS!
ion channels contractile cells Answer: Ca: timed gate for closing
K
Na
Phases of contractile cell action potential Answer: 1. rapid depolarization
2. initial repolarization
3. plateau phase
4. repolarization phase
rapid depolarization phase Answer: 1st - contractile
Na channel opens/ Na goes into cell
membrane potential become more positive
initial depolarization phase Answer: 2nd- contractile
Na channel closes
K channel opens/ K goes out of the cell
short phase
action potential become more negative
plateau phase Answer: 3rd- contractile
Ca channel opes/ Ca goes into cell
K channel opens / K goes out of cell
K and Ca go in and out at the same rate (membrane potential stabilizes)
repolarization phase (contractile) Answer: 4th- contractile
Ca channel closes
K channel opens/ K goes out of cell
negative membrane potential
Pacemaker ion channels Answer: Ca
K
HCN : non specific cation
Phases of pacemaker cell action potential Answer: 1. slow initial depolarization phase
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,2. full depolarization
3. repolarization phase
4. minimum potential phase
slow initial depolarization phase Answer: 1st- pacemaker
HCN opens/ HCN go in and out of cell (bidirectional)
increases membrane potential
slower
full depolarization Answer: 2nd - pacemaker
Ca channel opens/ Ca goes into the cell
membrane potential increases
repolarization (pacemaker) Answer: 3rd - pacemaker
K channel opens/ K goes out of cell
negative membrane potential
minimum potential phase Answer: 4th - pacemaker
K channel opens/ K goes out of cell
trough tiggers the opening of HCN
end of action potential is used to trigger the next one
Pacemaker cells Answer: Sinoatrial node (SA) node
atrioventricular (AV) node
purkinje fiber
SA node Answer: right atrium
by the opening of the superior vena cava
fastest rate of depolarization
60-70 AP per min
sets the HR
AV node Answer: cluster of pacemaker cells
next to tricuspid valve
slower rate of depolarization
40-50 AP per minute
if SA node were to fail, the AV node could set the HR but it would be slower
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
, Purkinje Fiber System Answer: AV bundle
R/L bundle branches
terminal branches
slowest rate of depolarization
20 AP per minute
P wave Answer: atrial depolarization
QRS complex Answer: ventricular depolarization and atrial repolarization
T wave Answer: ventricular repolarization
S-T segment Answer: ventricular plateau phase
R-R interval Answer: entire duration of a cardiac action potential
P-R interval Answer: duration of atrial depolarization and AV node delay
Q-T interval Answer: entire duration of a ventricular action potential
Bradycardia Answer: HR is slower than normal
tachycardia Answer: HR is faster than normal
Sinus tachycardia Answer: has sinus rhythm
HR is faster than normal
disruption in conduction pathway Answer: block at AV node
signals not traveling to the ventricles
signals travel through the atria
Atrial fibrillation Answer: cells are depolarizing at different rates
large peaks
not immediately life threatening
Ventricular Fibrillation Answer: cells are depolarizing at different rates
small inconsistent rates
immediately life threatening
defibrillation is used
asystole Answer: flatline
epinephrine and CPR is used
systole Answer: Contraction of the heart
disastole Answer: Relaxation of the heart
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
