Term
what cells have electricale potentials?
which are able to change the elctrochemical graident to send signals? |
|
Definition
all
only some like muscles |
|
|
Term
| what is the period when you cant re-excite an already excited area of cardiac muscle? |
|
Definition
|
|
Term
| what is excitation contraction coupling? |
|
Definition
| action potential causes contraction |
|
|
Term
| normally which part of the cell is postitive? why? |
|
Definition
outside
more Na on outside |
|
|
Term
| the Na/K pump requires what? |
|
Definition
|
|
Term
| what happpens when membranes depolarize |
|
Definition
| the outside of cell becomes neg and inside becomes positive- travels downward |
|
|
Term
which has fastest and shortest action potential:
nerve, skeletal, cardiac cells |
|
Definition
cardaic has longest
nerve has shortes |
|
|
Term
non pace maker has resting negatvitiy of what?
how does this differ form the SA node/pacemaker? |
|
Definition
|
|
Term
| action potentials involve what channels? |
|
Definition
fast Na
slow Ca
membrane permeability to K |
|
|
Term
what is phase 0 in action potentials?
what channels are invovled? |
|
Definition
rapid depolarization
fast Na |
|
|
Term
| what channels are invovled in phase 2-2 |
|
Definition
slow Ca
decreased membrane permeable to K |
|
|
Term
what is phase 3 called?
what causes this? |
|
Definition
repolarization
slow Ca channels close + K membrane permability increases |
|
|
Term
| which is the resting state? |
|
Definition
|
|
Term
| fast Na channels are _ dependent |
|
Definition
voltage- membrane potential negativity
has to be -90 |
|
|
Term
| spontaneous generation of action potentials happens where in the heart |
|
Definition
|
|
Term
| what is the order of how the action potential travels-4 |
|
Definition
| SA->atria->AV bundle->ventricles |
|
|
Term
| which part of the cardaic cycle is the ventricles contracting (depolarization) |
|
Definition
|
|
Term
| which part of the cardaic cycle is the generation of the action potential |
|
Definition
|
|
Term
| which part of the cardaic cycle is the repolarization |
|
Definition
|
|
Term
| where is the SA node located |
|
Definition
|
|
Term
| what does the PR segment show |
|
Definition
| time between atria contraciton and ventricle contraction |
|
|
Term
what channels are involved in SA node potentials? -2
what is new that leaks into cells in this? |
|
Definition
Ca channels
membrane permeability to K
Na |
|
|
Term
| when do the slow Ca channels open in SA node |
|
Definition
| phase 1- at the threshold ( -40) |
|
|
Term
Bpm for:
SA
AV
perkinje fibers |
|
Definition
|
|
Term
| what does the parasympathetic systme do to the cardaic cycle |
|
Definition
| slows depolariazation (slows down cycle) |
|
|
Term
acetocholyine causes what in the cardiac cycle?
how does it do this? |
|
Definition
hyperpolarization
increses permability to K- rapid leakage |
|
|
Term
| how does the sympathetic system increase SA conduction/contraciton |
|
Definition
| NE increases Ca and Na permability into the cell |
|
|
Term
| the most common type of arrythmia is |
|
Definition
|
|
Term
| what are the mechanisms of arrhythmias-2 |
|
Definition
| -abnormailty in generation/ conudciton or both of impulses |
|
|
Term
| bradyarrhythmias are caused mostly by? |
|
Definition
| blockage in heart that alters impulse from SA to AV node |
|
|
Term
| tachyarrhythmias is are caused by what mechanisms-3 |
|
Definition
increased automaticity
triggered afterdepolarizations during phase 3 or 4
reeentry |
|
|
Term
| major cause of arrhythmias is- |
|
Definition
|
|
Term
ischemia and hypokalemia cause a decrease in-
this then causes 3 things? |
|
Definition
Na/K ATPase
reduced repolarization
less neg potential/ closer to threshold
-easierr depolarization |
|
|
Term
| what causes increase automaticity that leads to tachycardias? -3 |
|
Definition
ischemia
hypokalemia
hyperkalemia |
|
|
Term
| what does mild hyperkalemia do to cause tachyacardia- 2 |
|
Definition
reduced repolarization
less neg potential |
|
|
Term
| what is more life threatening- hypo or hyperkalemia |
|
Definition
|
|
Term
| large hyperkalemia has what effects-2 |
|
Definition
heart is unexicteable
depolarization of membrane |
|
|
Term
| ischemia can cause _ rythms that cause cause abrnomal automticity |
|
Definition
|
|
Term
| what are voltages that occur during an action potential |
|
Definition
|
|
Term
| triggered automaticity is caused by- |
|
Definition
|
|
Term
what afterdeploarization occurs due to reactivation of L- Ca channels?
at what stage is this? |
|
Definition
|
|
Term
what afterdepolarization occurs due to extra intracell Ca in cytosol?
what stage is this? |
|
Definition
|
|
Term
| what can cause too much Ca leftover in the cytosol? -3 |
|
Definition
cardiac glycosides
catecholamines
ischemia |
|
|
Term
| Early ADs are made when there is a prolongation of- |
|
Definition
|
|
Term
| what is the most common mechanism of arrhythmias |
|
Definition
|
|
Term
| supraventricular arrhythmias are caused by what mechanism |
|
Definition
|
|
Term
| an asymptomatic ECG change to an arrhythmia can lead to- |
|
Definition
|
|
Term
| loss of conciousness due to arrhythmia most often results in- |
|
Definition
|
|
Term
| causes of ventricular tachyarrhythmias-4 |
|
Definition
sarcaodosis
hypertrophic cardiomypathy
chamber dilation
ventrciular systolic dysfunction |
|
|
Term
signs of atrial fibrilation-2
causes?-2 |
|
Definition
irregular atrial activation
ventricular rythm >120
alcohol intox, hyperthyroidism |
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