Term
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Definition
| short outgrowths that increase the surface area available for synapses |
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Definition
| The point from which the axon releases chemicals that cross through the junction between one neuron and the next |
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Definition
| Brings information into a structure |
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Definition
| Carries information away from a structure |
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Term
| Interneuron/intrinsic neuron |
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Definition
| A cell whose dendrites and axon are entirely contained within a single structure. |
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Term
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Definition
Glia that
-wrap around presynaptic terminal of a group of functionally related axons
-Synchronize activity in axons allowing them to send messages in waves
-Remove waste material when neurons die/control blood flow to each brain area
-Release chemicals that modify the activity of neighboring neurons |
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Term
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Definition
| Small cells that remove waste, viruses, fungi and other microorganisms. Function like part of immune system. |
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Definition
| Specalized CNS glia that build myelin sheaths that surround/insulate certain vertebrate axons |
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Definition
| PNS equivalent of oligodendrocytes |
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Definition
| a protein complex repeatedly transports three sodium ions out of the cell while drawing two potassium ions into it. Active transport system requiring energy. |
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Term
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Definition
| Difference in voltage in a resting neuron. -- proteins in cell. Prepares neuron to respond rapidly. Allows excitation to open sodium channels explosively. |
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Definition
| Rapid depolarization and slight reversal of usual polarization. Peak +30 mV. |
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Definition
| Membrane channels whose permeability depends on the voltage difference across the membrane |
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Term
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Definition
| The amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it. Toilet analogy. |
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Term
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Definition
| the period in which a cell resists further action potentials |
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Term
| absolute refractory period |
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Definition
| the first part of the refractory period, during which the cell -cannot- produce an action potential regardless of stimulation. (1 ms) |
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Term
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Definition
| a swelling where the axon exits the soma |
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Term
| All things being equal, the greater the diameter of the axon the _______ the ions flow |
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Definition
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Term
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Definition
| insulating material composes of fats & proteins. Speeds up impulse to 100 m/s |
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Term
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Definition
| Un-myelenated areas of axon about 1 micrometer wide. |
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Term
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Definition
| The jumping of action potentials from node to node. Conserves energy. |
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Term
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Definition
| Neurons without an axon that exchanges information only with closest neighbours. Produces graded potentials. |
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Term
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Definition
| Membrane potentials that vary in magnitude w/o following all-or-none law. When stimulated it de- or hyper-polarizes in proportion to the intensity of the stimulus. |
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