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Cards In This Set
| Front | Back |
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List the three structures of the neuron
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Axon
Dendrite
Cell Body
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What property of neurons allows them to communicate?
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They are excitable.
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What 3 things can neurons communicate with?
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Other
neurons, muscles, and glands
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What are the junctions between neurons called?
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Synapses
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What is the relationship between axon length and cell
body size?
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Longest axons are
associated with the longest cell bodies
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In long neurons, what makes up most of the cell’s
volume?
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Axons
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What actually insulates the axon?
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Tightly wound cell membrane after the cytoplasm has been squeezed out
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Why does it take many Schwann cells to insulate a single
axon?
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Due to axon length
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What are
the gaps between regions of myelination called? Why are they important?
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Nodes of Ranvier; they aid in salutatory conduction;
essential for conduction of action potential
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What does
an action potential consist of?
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A large change in membrane potential from a resting value
of –70mV to a peak of about +30mV and a return to –70mV
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In what
part of the neuron is the action potential generated?
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Axon hillock
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What is
special about this part of the neuron?
Why are action potentials generated here?
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Signals from the dendrites and cell body reach axon
hillock and cause depolarization
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When does
the action potential begin?
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Signals from the dendrites and cell body reach
the axon hillock and cause the membrane potential there to become more positive
(depolarization).
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What happens at threshold?
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If
the stimulus at the axon hillock causes the neuron to depolarize by about 15mV
and reaches a trigger point called threshold
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What
happens if the stimulus is too weak to achieve threshold?
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It does not reach threshold and does not produce an action potential
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