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26 Cards in this Set
- Front
- Back
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integration
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determines animals ability to cope with different environmental conditions
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neuron
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high speed; Electrical signal -> release neurotransmitter -> receptors on adjacent target cell
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endocrine
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slower chemical message -> hormone secreted -> bloodstream delivery to all cells -> only target cells with receptor proteins respond
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neurons
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cell specialized to transmit electrical signals
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dendrites
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“signal in” from other neurons or sensors
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cell body
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signal integration – processes multiple signals
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axon
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conduction component
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synapse
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cell-cell contact point; connection via neurotransmitters
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afferent neurons
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sensory signal to integrative center of CNS
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interneuron
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within CNS
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efferent neuron
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sensory signal from integrative center of CNS to effector
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glial cells
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surround and protect neurons; Schwann cells, oligodendrites, microglial cells, astrocytes
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oligodendrites
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in CNS (brain and spinal cord)
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Schwann cells
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peripheral nerves; form myelin sheath; increase velocity of impulse transmission
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astrocytes
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intermediary between capillary and neuron
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microglial cells
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mediate immune response - phagocytosis
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resting membrane potential
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50 to -80 mV difference; (-) inside relative to (+) outside
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action potential
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transient change in electrical potential (~1 msec) in response to change in membrane permeability; rapid depolarization followed by rapid repolarization of membrane; -65 mV inside to +40 mV inside -> change of ~100 mV lasts ~1mSec
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Voltage threshold
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critical voltage; if it is not reached, no change in resting potential
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resting
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K+ leak channel open, voltage gated Na+ and K+ channel closed
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rising
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voltage gated Na+ opens; Na+ in
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falling
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voltage gated Na+ inactivated; voltage gated K+ channel opens; K+ out
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recovery
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voltage gated Na+ closed; voltage gated K+ channel gradually closes
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signal propagation
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depolarization occurs at one place and then self-propagates along entire membrane
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what prevents bidirectional propagation?
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refractory periods
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what does impulse velocity depend on?
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axon diameter, mylenation and T⁰
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