Term
Conduction Pathway and EKG
-Atrial Excitation |
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Definition
WAVE STUFF
-SA node initiates P wave (pacemaker), AV node = P WAVE DUE TO CONTRACTION OF ATRIA CONTRACTILE CELLS |
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Term
Conduction Pathway and EKG
-Ventricular Excitation |
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Definition
- begins during atrial relaxation (first part of R wave)
- complete with contraction of ventricles LARGE R SPIKE
-bundle of his deliver excit to apex of heart so bentricular contraction occurs in upward sweep |
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Term
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Definition
| T WAVE is relaxation of the ventricles |
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Term
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Definition
| CAPABLE OF SPONTANEOUS RHYTHMICAL SELF EXCITATION |
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Term
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Definition
| NORMAL CARDIAC EXCITATION CONTRACTION SEQUENCE BEGINNING AT SA NODE (DRIVES IT ALL) |
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Term
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Definition
LYING QUIET OR HIDDEN, not active potential pacemakers
-AV NODE AND CONDUCTING CELLS |
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Term
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Definition
ABNORMAL, ANY SITE DRIVING BENTRICULAR EXCITE-CONTRACT
WHEN LATENT BECOMES PRIMARY
-I.E/ SA NODE CELLS DIE OFF WITH AGE |
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Term
| PACEMAKER CELLS INTRINSIC DEPOLARIZATION RATES |
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Definition
SA NODE 100-120 APS/MIN
AV NODE 60-80 APS/MIN
PURKINJIE FIBERS 30-50 APS/MIN |
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Term
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Definition
HR GREATER THAN 100BPM
SINUS DURING EXERCISE |
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Term
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Definition
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Term
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Definition
SUPER BAD
IRREGULAR AND CHAOTIC AP PROPAGATION
CAN BE FATAL |
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Term
| 3 types of action potentials for different cell types based on... |
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Definition
changes in ion permeability via opening/closing of ion channels (#)and type of ion channel
-nodal cell
-conducting cell
-contractile cell |
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Term
| PHASE ORDER OF AP CONTRACTILE CELL |
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Definition
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Term
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Definition
| resting membrane potential |
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Term
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Definition
RAPID OPENING OF VOLTAGE GATED SODIUM CHANNELS LEADS TO RAPID DEPOLARIZATION PHASE
UPSTROKE IS DUE TO NA++
NOTE: NO EPSP=> NOT GRADED! |
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Term
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Definition
SLIGHT DIP DUE TO NA++ INACTIVATION
AND I_TO |
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Term
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Definition
L TYPE CA++ RECEPTORS ALLOW INTO CELL (DHPR)
THIS IS THE PLATEAU OF DEPOLARIZATION
BECAUSE OF PROLONGED OPENING OF THE VOLTAGE GATED CA++ CHANNELS
LITTLE HILL ON GRAPH |
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Term
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Definition
INCREASED PERMEABILITY TO K
K LEAVES THROUGH OPENING OF CHANNELS
REPOLARIZATION PHASE |
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Term
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Definition
| I_f (CURRENT DUE TO F-TYPE--FUNNY NA CHANNELS)CAUSES DRIFT |
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Term
NODE AP PHASE 0
(2 INWARD CURRENTS) |
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Definition
NA FLUX THROUGH F-TYPE CHANNEL AND CA++ MOVING IN THROUGH T CA++ CHANNELS CAUSE DEPOLARIZATION TO THRESHOLD
AFTER THRESHOLD, DEPOL DUE TO LARGE INCREASE IN MEMBRANE POTENTIAL OF L TYPE CA++ CHANNELS |
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Term
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Definition
ROUND AT TOP
DOESN'T REALLY HAVE DISTINCT |
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Term
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Definition
| ROUND DOESN'T QUITE HAVE ONE |
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Term
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Definition
DUE TO REOPENING OF POTASSIUM CHANNELS AND
CLOSING OF L TYPE CALCIUM CHANNELS
CAUSES REPOLARIZATION
ALSO MAXIMUM DIASTOLIC HYPERPOLARIZATION OCCURS DUE TO THIS. |
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Term
| CONDUCTING CELL ACTION POTENTIAL |
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Definition
MASHUP OF OTHER (NODE AND CONTRACTILE) CELLS
DRIFT LIKE NODAL CELL DUE TO I_F
I_CA GETS TO THRESHOLD
ONCE THERE (0 PHASE) SUPERFAST DUE TO NA CHANNEL ACTIVATION
SLIGHT DIP IN PHASE ONE DUE TO NA INACTIVATION
MORE GRADUAL HILL DUE TO SLOW CLOSING L TYPE CA CHANNELS
AND THEN IMMEDIATE DROP PHASE 3 DUE TO INCREASED K CONDUCTANCE
DRIFT |
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