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25 Cards in this Set
- Front
- Back
the brain consists of aproximately 100 billion nerve cells called?
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neurons
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specialized to carry and process info
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neurons
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neutrons are made up of what?
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dendrites, soma, axons
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info in neurons flow in what order?
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dendrites, soma, axon
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part of the neuron that specializes in receiving messages from other neurons
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dendrites
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part of the nerve cell that collects and combines incoming info
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soma
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the part of the nerve cell that carries info away from the cell body to other neurons
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axon
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bulb shaped parts that send info to other neurons and branch out into smaller fibers
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axon terminals
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electrically charged molecules that are involved in a nerve impulse
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ions
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can be found both inside and outside the nerve cell
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ions
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positive ions exist OUTSIDE the neuron and more negative ions exist INSIDE the neuron when the neuron is?
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inactive
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the electrical charge of an inactive neuron
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resting potential
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a neurons trigger point for firing
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threshold
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threshold occurs when what electrical charge occurs within a nerve cell
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-50 millivolts
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fastest neurons can send impulses at how many miles per hour?
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200
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conduction of a nerve impulse down the axon; when a neuron reaches its threshold
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action potential
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channels that transport sodium and potassium within the axon
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ion channels
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during an action potential, which ions do the molecular gates open to allow?
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sodium
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the ion channels first open near?
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the soma
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the fact that action potentials occur completely or not at all
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"all or nothing event"
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a nerve cell briefly dropping below its resting level
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negative after-potential
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negative after-potentials are caused by the outward flow of what ions from the axon?
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potassium ions
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whitish fatty substance that surrounds the axon and aids conduction of a nerve impulse down the axon
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myelin
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small gaps in the myelin help nerve impulses move _____ as they jump from gap to gap
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faster
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when the action potential leaps from gap to gap in the myelin layer
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saltatory conduction
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