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12 Cards in this Set
- Front
- Back
What could we still do if the motor system were missing?
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Experience sensation, think, reason, problem solve, read, write, and do mental math
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Hierarchical architecture of the motor system
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-Cortex
-Cerebellum -Brainstem -Spinal cord -Motoneurons -Muscles |
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Characteristics of skeletal muscles
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-striated (striped) appearance because they are comprised of muscle fibers
-move through a pull action (contraction) -work in pairs with a reciprocal muscle (bicep/tricep) -stimulated by a Motor Neuron |
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Striated muscles are made of muscle fibers that have two parts
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outer fiber = extrafusal fiber
inner fiber = intrafusal fiber |
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What is wrapped around an intrafusal fiber?
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A sensory nerve that picks up the sensation of stretch
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gamma motor neuron
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motor neuron that synapses on the intrafusal fiber
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alpha motor neuron
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motor neurone that synapses on the extrafusal fibers
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motor unit
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one alpha motor neuron, can stimulate numerous muscle fibers
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neuromuscular junction
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neural link between the alpha motor neuron and the muscle fiber
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Muscle-spindle feedback circuit (2-part)
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dorsal horn: sensory input
ventral horn: motor output |
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degree of dexterity required for movement indicated by...
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ration between alpha motor neuron and number of muscles it innervates
large muscles (1:150) small muscles (1:10) |
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Motor Homunculus is related to...
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the number of alpha motor neurons needed to innervate muscles of various body regions
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