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29 Cards in this Set
- Front
- Back
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functional classification is based on?
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direct inpulses conduction
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What do sensory affarent neurons do?
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transmit impulses from skin or internal organs toward CNS
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What do motor neurons so?
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carry impulses away from CNS
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Inerneurons
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Lie between motor and sensory neurons
make up majoriy of neurons shuttle signal through CNS pathways |
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Why are neuron highly irritable
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its a response to stimulus
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What happens when a neuron is adequatly stimulated
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*an electrical impulse is conducted along the length of the axon
*termed an AP or nerve impulse |
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During the resting membrane potential: the polarized state what is the voltage across the membrane
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70mV
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What happens during the depolarization
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*reduction in membrane potential
*inside of the membrane becomes less neg |
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What happens during hyperpolarization?
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Membrane probility of producing impulses reduces potential becomes more neg
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What is Action Potential (AP)?
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principal way neurons communicate
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only cells with what can generate AP
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excitable membranes
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what is the total amplitude charge of AP
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100mV
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How long is AP
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a few millisec
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Does it decrease in strength with distance
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no
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When is AP transmitted
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only when neuron is adequatly stimulated
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During the resting state of AP the voltage-gated channels are?
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cosed
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During the resting state small amounts of what are passed outward?
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K+
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Smaller amounts of what are diffusing in?
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Na+
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How many voltages do Na+ have and what kind of gates?
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2 and sensitive
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The activation gate is closed when?
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cell is in resting
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Responds to depolarization by?
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opening rapidly
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The inactivation gate is open when?
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@ rest
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It responds to depolarization by?
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Closing slowly
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Ea K+ gate has a
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single voltage sensitive gate
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During depolarization what is increased?
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Na+ permeability
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As axonal membrane is depolarized what happens?
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Na+ channel gates open quickly
Na+ rushes into cell Influx of +charges which opens more activation gates |
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WHen depolarization reaches threhold what are the critical lvls?
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-55 and -50Vm
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WHat is decreased in the repolarizing phase?
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Na+
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As membrane potentially passes what heppens
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*0Vm and it becomes increasingly +
*+ intracellular charge resists further Na+ entry *Slow activation gates had time to respond and begin to close |
