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93 Cards in this Set
- Front
- Back
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t/f
cardiac muscle is striated |
t
actin and myocin filaments |
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t/f
if you divide the individual cardiac cells then they will not depolarize |
f
they will depolarize due to AUTOMATICITY |
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is there partial contraction in cardiac cells
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no
all or none |
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where are the darkened areas in the cardiac tissue
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intercalated disc
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why do action potential go thru continuously
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due to intercalated disc
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the intercalated disc reduce ----
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resistance
thus, the continuous action potential |
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why is the is cardiac muscle known as functional syncytium
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cuz there are a lot of connections btw cardiac cells
the whole atrium is coordinated contraction w/ ventricles so, contract like one big muscle helps w/ pumping |
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conduction system is made up of ---- cardiac cells
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modified
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t/f
conduction system has neuronal cells |
f
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what allows the ventricles and atrium to work together. . .to allow pumping from bottom up
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conduction system
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SA node has an ---- rate
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inherant
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pacemaker of the heart
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SA node
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why does the heart follow the SA node
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cuz it's the fastest depolarizing cell in the heart
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inherant rate of the SA node
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80-90
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inhernat rate of the AV node
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40-60
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inherant rate of the purkinje fibers
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15-40
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the heart follow the --- impulse
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fastest
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site other than the sa node
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ectopic pacemaker
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t/f
AV has automaticity |
t
will beat by itself |
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if there's damage to sa, av, and conduction system what will be the pacemaker
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perkinje fibers
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if the sa node is beating at 80-90 bpm and the ectopic in the ventricles is 120. what will be the hr
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atrium: 80-90
ventricles: 120 bad pumping |
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t/f
cardiac muscle is a 2 way conduction system |
f
one way |
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what keeps the conduction from going backwards in the heart
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refractory period
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time when another action potential can't be started
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refractory period
prevents impulse from going in opposite direction |
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time to get from SA to AV node
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0.03 sec
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during the 0.03 sec from the SA to AV
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impulse going over the whole surface of the atrium
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what's good about the AV delay
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allows atrium to contract and relax before the ventricles
prevents bl from going back in to ventricles |
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atrial muscle depolarization
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p wave
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ventricular depolarization
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QRS
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ventricular repolarization
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t wave
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why isn't there a atrial repolarization
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buried in QRS
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pr intervals: conduction system from AV to -----
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bundle of his
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if you slow done conduction how will this be reflected in the ekg
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longer PR interval
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pr interval is the time from --- to ---- contraction
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atrial
ventricular |
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which two don't have sharp action potentials
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SA and AV node
no much plateau depends on the ions generated |
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what ion mainly plays a part in the SA and AV node
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Ca
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phase 0 there's inward -- current
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Na
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phase 1 has outward current of -- and inward current of ----
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outward K
inward Cl |
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phase 2 has inward current of ---
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Ca
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phase 3 has outward current of ---
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K
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what controls phase 4
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Na/K ATPase
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which phase has an inward current of Ca
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phase 2
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which phase has an outward curretn of K
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phase 3
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which phase has an outward current of K and inward of Cl
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phase 1
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which phase is controlled by Na/K ATPase
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phase 4
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which phase has an inward current of Na
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phase 0
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what reestablishes gradient
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NaK ATPase
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what potential does Ca open
close |
open: -55
close: -30 |
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can't cause another action potential due to closing/reseting Na and Ca channels
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absolute refractory period
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an another action potential can occur cuz already depolariazed
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relative refractory
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where can an arrhythmia occur
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relative refractory
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where does fast response occur
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cardiac muscle
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where does the slow response occur
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sa and av node
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in slow response there's no abrupt increase in --
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Na
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why is the slow response slow. . . why no abrupt increase in Na
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resting potential is less than fast response: - 65, compared to -90 of the fast
at - 65 the Na channels already deactivated |
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in slow response there's no abrupt increase in --
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Na
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t/f
phase 4 of the slow response is flat |
f
due to inequality of K and Na. . .more positive |
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why is the slow response slow. . . why no abrupt increase in Na
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resting potential is less than fast response: - 65, compared to -90 of the fast
at - 65 the Na channels already deactivated |
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t/f
phase 4 of the slow response is flat |
f
due to inequality of K and Na. . .more positive |
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phase 0 of slow response : inward --- current
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Ca
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phase 2 of slow is inward --- and outward ---
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inward Ca
outward K |
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phase 3 of slow is outward --- current
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K
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phase 0 of slow response : inward --- current
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Ca
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phase 4 is controlled by ---- and ---- --- --
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Na/K ATPase
Leaky Na current |
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phase 2 of slow is inward --- and outward ---
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inward Ca
outward K |
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phase 3 of slow is outward --- current
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K
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phase 4 is controlled by ---- and ---- --- --
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Na/K ATPase
Leaky Na current |
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phase:
inward Ca current |
phase 0
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phase: Na/K ATPase
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phase 4
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phase? Outward K current
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Phase 3
Phase 2 |
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phase? Inward Ca Current, outward K current
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Phase 2
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phase? leaky Na current
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phase 4
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which effects will decrease K conductance
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adrenergic
decrease K leaving, os more + on inside. . . reach threshold faster. . . increased HR |
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t/f
w/ cholinergic there be decreased K conductance |
f
increased |
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abnom impulse due to altered---- and -----
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automaticity
after-depolarization |
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abnorm impulse conduction due to ---- and ---- block
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reentry
unidirectional |
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if you slow down automaticity what occurs
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bradycardia
speed up: tachycardia |
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what can cause after depolarization
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ischemia
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afterdepolarization are --- or ------ contractions
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early or delayed
leads to arrhythmias |
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in this movement the impulse keeps on going
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circus/rentry
due to blockade of one branch of the perkinje fiber so there are not 2 impulses to cancel each other out |
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t/f
reentry/cirus dependent on SA node |
f
independent |
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when r and l contraction not equal
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unidirectional block
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fibrillation due to several ---- ------
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ectopic pacemakers. . . no coordinated contraction
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where do PSVTs orginate in
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atrium
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Atrium rate in A fib
ventricle rate in A fib |
300-600 bpm
150-180bpm so inappropriate filling |
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what do you use to slow down av node conduction
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dig
separates A and V |
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A flutter Atrium rate
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150-300
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in a flutter there's variable ---- thru the --- node
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conduction
AV so some get there during refractory and some don't |
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what happens if conduction meets the refractory period
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it disappears
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what happens of conduction doesn't meet a refractory period
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keeps going
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monomorphic vent tach due to ---- ----
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ectopic pacemaker
all beats match each other |
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t/f
torsades de pointes is monomorphic |
f
polymorphic delayed/slowed conduction |
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what can occur due to stagnant blood in a fib/flutter
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blood clots
so use anticoagulants |
