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12 Cards in this Set
- Front
- Back
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location of contractile cells in cardiac muscle?
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myocardium
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location of conductile cells
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SA node... AV node... AV bundle... Purkinje fibers
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features of contractile cells (2 of them); what are intercalated discs?
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striated, lattice work that divides and recombines; overlap of cells with gap junctions, AP travels fast (low resistance)
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features of conductile cells (5 of them)
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rapid contraction, controlled rate of conduction, pacemaker activity, weak contractile force with only a few contractile fibers inside, provides excitatory and transmission system for the heart
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resting membrane potential of contractile cells
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-85 to -90 mV (larger)
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resting membrane potential of conductile cells
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-55 mV
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Na+ sodium gates of contractile cells
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fast Na+ channels
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Na+ sodium gates of conductile cells
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Na+ channels are inactivated. Depoarization is due to Na+ leakage to -40 mV. AP depends on slow Ca++ channels
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Overshoot of contractile cells
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due to fast Na+ channels; fast depolarization stage
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Overshoot of conductile cells
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no overshoot
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Plateau of contractile cells
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due to slow Ca++ channels
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Plateau of conductile cells
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no plateau
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