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21 Cards in this Set
- Front
- Back
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Myelin-producing cells in the central
nervous system |
Oligodendrocytes
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Cells with nutritive and cleanup functions
within the CNS |
astrocytes
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Cells which clean the neural environment
and contribute to destruction of injured or aging axons |
microglia
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Myelin-producing cells in the peripheral
nervous system |
Schwann Cells
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Cells which receive and transmit
information via propagation of an electrical signal |
neurons
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neuron is specialized for receiving synaptic
input from other neurons? |
dendrites
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The structural part of a neuron that releases neurotransmitter is the:
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presynaptic terminal
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Pseudounipolar cells
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have two axon extensions
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Afferent neurons convey information
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from peripheral receptors to the CNS
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Mechanical force, temperature change, or
chemical stimulus |
modality gated channel
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Neurotransmitter binding to surface of a
channel receptor on a postsynaptic membrane |
ligand gated channel
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channel without any stimulus required
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leak or non-gated channel
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Change in electrical potential across the
cell membrane |
voltage gated channel
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The resting membrane potential is:
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Maintained by negatively charged ions inside the membrane, active transport of Na+
and K+, and passive diffusion of Na+, K+, and Cl through the cell membrane |
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Depolarization occurs when:
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a. The membrane potential becomes less negative than the resting membrane
potential. |
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Local potentials:
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May be either receptor or synaptic potentials
Spread passively only a short distance along the cell membrane Result from stimulation of sensory receptors or from the binding of neurotransmitter with chemical receptor sites on a postsynaptic membrane |
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nodes of ranivier utilized what type of channels
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Contain a high density of voltage-gated Na+ channels for rapid depolarization of
the membrane d. Have low membrane |
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demylenation of an axon
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a. Results in decreased membrane resistance, allowing leakage of electrical current
b. Results in slowed propagation of action potentials c. May prevent propagation of action potentials |
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peripheral demylenation
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Typically affects the Schwann cells of large diameter axons
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Guillain-Barré syndrome
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a. Involves demyelination of peripheral axons
b. Results from an autoimmune attack on Schwann cells |
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multiple sclerosis
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a. Results from an autoimmune attack on oligodendrocytes
Copyright © 2007 by Saunders, an imprint of Elsevier Inc. Student Workbook 2 2- b. Involves demyelination of axons within the CNS c. Has signs and symptoms associated with both motor and sensory impairment |
