Term
| Neurons interact with one another at specialized sites called what |
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Definition
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Term
| most synapses in the CNS are what type of synapses |
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Definition
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Term
| what happens at excitatory synapses upon binding of the transmitter substance |
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Definition
| local depolarization of the postsynaptic membrane |
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Term
| what occurs at inhibitory synpases upon binding of the transmitter substance |
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Definition
| hyperpoarlization of the post synaptic membrane |
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Term
| the overall excitatory or inhibitory effect of the postsynaptic neuron depends on what |
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Definition
| summation of postsynaptic responses at its many synapses |
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Term
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Definition
| according to their locations |
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Term
| synapses made by one axon made by one neuron onto the synapse of another neuron |
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Definition
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Term
| synapses that are made onto the soma or cell body of a neuron |
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Definition
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Term
| synapses that one neuron makes onto the dendrites of another axon |
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Definition
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Term
| the potential across the membrane of an excitatory cell at rest |
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Definition
| resting membrane potential (RMP) |
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Term
| RMP is typically what range, depending on the cell |
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Definition
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Term
| If the post synaptic cell is excited what happesn |
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Definition
| an action potential is generated |
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Term
| If the postsynaptic cell is inhibited, what occurs to the action potential? |
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Definition
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Term
| inhibition is what type of process |
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Definition
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Term
| some neurons fire regularly, the rate of spontaneous firing can be altered by what |
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Definition
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Term
| Inhibition does not simply result in an ______ of activity |
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Definition
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Term
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Definition
| excitatory postsynaptic potential |
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Term
| EPSP is what type of event |
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Definition
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Term
| EPSP & IPSP have a graded potential meaning what |
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Definition
| they are capable of having an additive effect |
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Term
| action potential may result from _______/________ summation of many ESPSs |
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Definition
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Term
| cumulative effect from the firing of synapses |
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Definition
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Term
| The net effect of many ESPSs may result in what |
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Definition
| production of an action potential |
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Term
| cumulative effect from the firing of many synapses at approximately the same time |
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Definition
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Term
| cumulative effect from the rapid repeated firing of a single synapse |
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Definition
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Term
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Definition
| inhibitory postsynaptic potential |
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Term
| IPSPs are what type of event |
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Definition
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Term
| bringing the membrane closer to threshold but not necessarily producing an action potential |
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Definition
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Term
| Facilitation results from what |
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Definition
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Term
| results from volleys of ISPSs, sometimes called depression, may be pre-/postsynaptic |
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Definition
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Term
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Definition
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Term
| disfacilitation causes what |
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Definition
| relative hyperpolarization |
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Term
| disfacilitation causes relative hyperpolarization resulting in what |
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Definition
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Term
| removal of inhibitory pulses |
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Definition
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Term
| removal of inhibitory impulses moves closer to firing threshold, resulting in net ______ |
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Definition
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Term
| Describe recurrent inhibition in terms of axons |
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Definition
| a collateral axon excites an inhibitory interneuron, that in turn inhibits the same and/or neighboring neurons |
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Term
| found throughout the CNS as a means of feedback inhibition to control transmission or inhibit competing impulses |
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Definition
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Term
| inhibitory interneuron is excited inhibiting homonymous/synergistic neurons. What type of inhibition? |
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Definition
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Term
| what is the feedback system for (golgi) tendon organs |
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Definition
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Term
| impulses activating agonist muscles send collaterals to inhibitory interneurons to inhibit antagonists. what type of inhibition |
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Definition
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Term
| reciprocal inhibition is limited to action of what types of neurons |
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Definition
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Term
| in reciprocal inhibition, antagonists go flaccid. True or false |
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Definition
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Term
| Type of inhibition: Inactivation of calcium channels by another synapse, resulting in less calcium entering, meaning less neurotransmitter is released, meaning a reduced effect on the postsynaptic membrane |
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Definition
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Term
| volitional and reflexive behavior is due to what |
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Definition
| activity of neurons communicating with each other via synapses |
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Term
| within discrete populations of neurons, certain ones will fire as a result of incoming excitatory impulses, and are described as what |
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Definition
| being in the discharge zone |
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Term
| firing of a neuron is related to: 1 of 5 |
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Definition
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Term
| firing of a neuron is related to: 2 of 5 |
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Definition
| size of neuron, the larger it is the more difficult to excite/inhibit |
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Term
| firing of a neuron is related to: 3 of 5 |
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Definition
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Term
| how is the location of the synpase related the firing of a neuron |
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Definition
| the closer it is to the initial segment, the more effective |
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Term
| firing of a neuron is related to: 4 of 5 |
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Definition
| number of competing EPSPs and IPSPs |
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Term
| firing of a neuron is related to: 5 of 5 |
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Definition
| relative excitability of the membrane |
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Term
| neurons that are subjected to teh same EPSPs as the neurons in the discharge zone, but do not fire are considered to be in what |
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Definition
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Term
| inhibition is often referred to as an increase in what |
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Definition
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Term
| describe post-tetanic potentiation |
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Definition
| prolonged period of facilitation of synaptic transmission, following repetitive tetanic stimulation of the presynaptic neuron |
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Term
| this effect is related to an increased release of transmitter rather than a change in the postsynaptic excitability |
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Definition
| post-tetanic potentiation |
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Term
| a reduction in response to maintained stimulation |
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Definition
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Term
| what is it called when the membrane acts as if it is beocming accustomed to the stimulus |
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Definition
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Term
| accommodation allows the neuron to be more responsive to what |
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Definition
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Term
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Definition
| inputs from several interneurons may converge onto one neuron to increase its chances of firing or to provide it with information from different neural systems |
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Term
| input from one area may spread to a larger area (neuron integration) |
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Definition
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Term
| when an impulse excites a neuron, thereby initiating a discharge, setting up a positive feed back loop which continues the discharge long after the original stimulus has occured |
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Definition
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Term
| what is the difference between an infant's CNS and an adult's CNS. |
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Definition
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Term
| Postnatal Maturation of the Spinal Cord-proliferation of ______ root collaterals |
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Definition
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Term
| proliferation of dorsal root collaterals increases the strength of what |
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Definition
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Term
| proliferation of dorsal root collaterals results in ties between what |
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Definition
| afferents, efferents overlying a particular muscle and its synergists |
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Term
| Postnatal Maturation of the Spinal Cord - what undergoes remodeling |
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Definition
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Term
| what happens during synaptic and dendritic remodeling, simply? |
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Definition
| morphology and numbers of synapses change |
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Term
| if neurons add dendrites during synaptic and dendritic remodeling, what happens |
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Definition
| increased number of synapses |
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Term
| if neurons lose dendrites during synaptic and dendritic remodeling, what happens |
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Definition
| decreased number of synapses |
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Term
| Postnatal Maturation of the Spinal Cord - continued ________ of the CNS |
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Definition
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Term
| during continued myelination within the CNS, what neuroglia will synthesize several times their own weight of myelin |
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Definition
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Term
| during continued myelination within the CNS, what role do Oligodendrocytes play |
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Definition
| synthesize several times their own weight of myelin each day during infancy |
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Term
| During continued myelination within the CNS< any one oligodendrocyte may send out processes to invest segments of how many axons |
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Definition
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Term
| using a part of a body more frequently causes what in terms of cortical representation |
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Definition
| that part is given greater cortical representation |
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Term
| neuroplasticity may include: activation of ______ ____ |
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Definition
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Term
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Definition
| neurons previously not active |
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Term
| neuroplasticity may include: increased ______ efficacy |
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Definition
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Term
| given the same input, a greater number of postsynaptic cells become active after injury, which indicates what |
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Definition
| increased synaptic efficiency |
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Term
| neuroplasticity may include: ______ reorganization |
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Definition
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Term
| what happens during anatomical reorganization due to neuroplasticity |
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Definition
| collateral sprouts to undamaged synaptic sites, rengeneration or growth of injured axons |
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Term
| Response of Peripheral Nerves to Axotomy: What happens proximal to the lesion in terms of the cut end? |
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Definition
| the cut end is sealed off |
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Term
| Response of Peripheral Nerves to Axotomy: what happens to the distal most part of the axon stump |
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Definition
| rapid degeneration of the distal most part of the axon stump |
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Term
| Response of Peripheral Nerves to Axotomy: What happens if the lesion close to the cell body |
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Definition
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Term
| Response of Peripheral Nerves to Axotomy: dispersion of rough ER in readiness for protein production |
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Definition
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Term
| Response of Peripheral Nerves to Axotomy: displacement of what to the edge of the soma |
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Definition
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Term
| Response of Peripheral Nerves to Axotomy: number and diameter of dendrites decreases |
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Definition
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Term
| Response of Peripheral Nerves to Axotomy: what happens at the cut end of the axon |
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Definition
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Term
| Response of Peripheral Nerves to Axotomy: what is formed? |
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Definition
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Term
| terminal degeneration resulting in teh axon distal to the lesion degenerates and is removed |
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Definition
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Term
| Schwann cells phagocytose the presynaptic element of the neuromuscular junction is an example of what |
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Definition
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Term
| fine connective tissue sleeves that surround each axon |
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Definition
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Term
| what purpose do the endoneurial tubes serve |
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Definition
| can serve as guides for regenerating axons |
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Term
| what happens to the endoneurium and basement membrane of axolemma during wallerian degeneration |
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Definition
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Term
| regeneration of peripheral nerves begins with what |
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Definition
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Term
| regeneration of peripheral nerves: degenerative changes represent an early preparation for what |
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Definition
| regrowth of the peripheral elements of the nerve |
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Term
| what are the two factors that influence peripheral nerve recovery |
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Definition
| site of injury, extent of trauma |
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Term
| How does site of injury influence the regeneration of peripheral nerves? |
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Definition
| proximal injuries often result in neuronal death |
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Term
| What are the terms used to describe the severity of a peripheral nerve injury |
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Definition
| neurapraxia, axonotmesis, neurotmesis |
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Term
| a transient nerve block, usually caused by pressure. Loss of function is probably related to ischemia, full functional recovery is expected |
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Definition
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Term
| axons are severed, but the connective tissue ensheathing them remain intact. Type of lesion occurs in crush and traction injuries. |
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Definition
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Term
| Good recovery of function may be expected because the nerve fibers maintain their normal anatomical relationships as they regenerate |
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Definition
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Term
| Regenerating axons may grow how much per day |
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Definition
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Term
| a complete sectioning of the gross peripheral nerve. Functional recovery is dependent upon accurate surgical re-approximation of the cut ends of the nerve trunk |
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Definition
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Term
| What can happen to denervated muscle fibers, when some motor fibers are lost |
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Definition
| may be adopted by regenerating nerve fibers |
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Term
| when regenerating nerve fibers adopt denervated nerve fibers what happens |
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Definition
| some motor units may increase in size |
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Term
| What happens when a motor unit increases in size |
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Definition
| may contribute to the decrease in the fine coordination of affected muscles |
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Term
| a normal reduction in the input to a neuron alters its morphology, leading to what happening to the dendritic tree |
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Definition
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Term
| with minor loss of input leads to what kind of changes occur to the dendrites |
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Definition
| minor changes to the dendrites |
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Term
| dendrite shrinkage is specific to what |
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Definition
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Term
| With severe loss of a large part of the neuron's afferents, what happens to the denervated neurons |
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Definition
| total degeneration, no part of it survives |
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Term
| the morphology of a neuron is plastically matched to what |
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Definition
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Term
| the morphology of a neuron is plastically matched to its input, meaning what |
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Definition
| if there is little significant input, the neuron dies |
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Term
| process whereby an uninjured cell dies in consequence of injury to its afferent neurons |
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Definition
| transneuronal degeneration |
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Term
| a transneuronally degenerated cell will in turn deprive its target neuron(s) of what |
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Definition
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Term
| What happens to a cell with a damaged axon? |
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Definition
| depends on the damage, loss of a small part of the axonal tree has no great effect on the cell |
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Term
| if the damaged part of the axon is considerable, the cell lacks some vital signal from its target and it shuts down |
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Definition
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Term
| if the degenerated cell was part of a closed circuit so that its afferents have no other target neurons what will happen |
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Definition
| suffer from deprivation of vital signal from their target and die |
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Term
| retrograde degeneration in a closed circuit can result in what |
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Definition
| transneuronal degeneration of successively earlier cells in the pathway |
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Term
| transneuronal degeneration as a result of retrograde degeneration may present with what clinical symptoms |
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Definition
| result of loss of these secondarily damaged cells than of the original lesion |
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Term
| if part of the total input to a nucleus is lost what happens |
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Definition
| surviving fibers replace them |
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Term
| if part of teh total input to a nucleus is lost, surviving fibers replace them, if teh fibers are from the neighbors from the lost input, what is this called? |
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Definition
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Term
| if part of the total input to a total nucelus is lost, surviving fibers replace them, and fibers come from outside the immediate region of damage, what is this caleld |
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Definition
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Term
| In topographically precise circuits, where the position of a fiber in a tract is part of the information conveyed by that fiber, replaced synapses may what |
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Definition
| blur the acuity of the system, perhaps increasing the handicap |
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Term
| In circuits where topographical relations are uninformative, replacement of a lost fiber by its neighbors may what |
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Definition
| successfully restore function |
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|
Term
| key points of plasticity of the CNS: 1 of 3: developmental changes |
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Definition
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Term
| key points of plasticity of the CNS: 2 of 3. ______-induced plasticity of the brain |
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Definition
| function-induced plasticity of the brain |
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Term
| key points of plasticity of the CNS: 3 of 3. plasticity and the Physical therapist |
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Definition
| clinical implications of neural plasticity |
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Term
| key points of plasticity of the PNS: 1 of 4. response of peripheral nerves to ______ |
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Definition
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Term
| key points of plasticity of the PNS: 2&3 of 4. changes due to damage to a cells _________ or ________ |
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Definition
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Term
| key points of plasticity of the PNS: 4 of 4. on the topic of neighbors |
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Definition
| changes due to damage in neighboring cells |
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