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7 Cards in this Set
- Front
- Back
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spontaneous depolarization/rise to threshold occurs due to
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channels that open and allow Na+ in
aka pacemaker potentials |
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at threshold...
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Na+ channels close and fast voltage regulated Ca+ channels open and rapid depolarization occurs
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Repolaridation is due to
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voltage rgulated K+ Channels opening and K+ flowing out
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platau phase is due to
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voltage regulated Ca+ channels opening (inofming) during repolarization
incomoing Ca_ ions offset exiting K+ ions, leveling of positive ions... good becuase it does not permit muscle to have tetany |
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repolarization is caused by
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slow ca+ channels closing and K+ channels opening
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norepinephrine is released from sympathetic nerves and bind to betea andrenergenic receptors
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results in increased heart rate due to opening Ca+ channels which make reaching threshold easeier. Increased Ca+ also cause stronger contractions
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aceytolcholine
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hyperolarizes SA node by opening chemically regulated K+ channels and closign fast Ca+ channels making insisde of cell more negative... harder to reach threshold... heart rate slows
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