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34 Cards in this Set
- Front
- Back
Apraxia |
A condition where people can perform only simple movements. Happens after lesion of PMA (premotor area) or SMA (supplementary motor area) |
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Basal ganglia |
collections of neurons in the base of forebrain. Includes caudate nucleus, putamen, globus pallidus, subthalamus, substantia nigra |
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Caudate |
Nucleus beside lateral ventricles |
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What makes up the striatum? |
Caudate nucleus and putamen |
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cerebellar lesion cause |
ataxia (uncoordinated movements) and intention tremors |
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nucleus ambiguous location |
In the medullary reticular formation Controls lower motor neurons that innervates larynx and pharynx |
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Parkinsons disease is associated with what structure? |
Substantia nigra |
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The motor loop through basal ganglia pathway is |
cortex (m1) to striatum to globus pallidus to thalamus to cortex |
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bradykinesia |
slow movements |
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Akinesia |
difficulty initiating movements |
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Symptoms of parkinsons disease |
bradykinesia, akinesia, rigidity, tremor at rest, dopamine depletion in substantia nigra, caudate and putamen |
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Huntingtons disease symptoms |
Degeneration of caudate, putamen, globus pallidus Hyperkinesia and dyskinesia Chorea: spontaneous and purposeless movements |
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Cerebellum function |
coordinate movements receives input from pons |
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hemiballism |
unilateral flinging hyperkinesia |
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Motor loop through cerebellum |
Cortex -> pons -> cerebellum-> thalamus -> cortex |
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Where are upper motor neurons located? |
From primary motor cortex down the spinal cord. |
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What do upper motor neurons control? |
Somatic (voluntary) movements |
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Where are lower motor neurons located? |
Spinal efferents in ventral horn, include alpha motor neurons |
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What is a motor unit? |
Alpha motor neuron and all the fibers it innervates |
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What is a motor neuron pool? |
All alpha motor neurons that innervate a single muscle |
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What is ALS? (Amyelotrophic Lateral Sclerosis) |
A degenerative disease of the alpha motor neurons |
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What neurons does stretching activate? |
1a afferents, alpha efferents shut off 1a efferents, gamma efferents reactivate 1a afferents |
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What is the reverse myotactic reflex? |
Too much strain inhibits lower motor neuron, preventing overload, allows fine movements |
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What gauges strain on a muscle? |
Golgi tendon organ and 1b afferent nerves |
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Alpha efferents activate what |
1b afferents |
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What is Lou Gehrig’s Disease? |
Loss of voluntary movement (walking, speaking, swallowing) due to loss of lower motor neurons. |
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What are some causes of Lou Gehrig’s Disease? |
Genetics: damage from oxygen (bad glia) Excitotoxicity from glutamate |
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What are the physical properties of a muscle determined by? |
Neurons |
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What are the 3 inputs to alpha motor neurons? |
Input from spinal interneurons, muscle spindles, upper motor neurons in the brain. |
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What are two types of stretch receptors? |
Muscle spindles and 1a afferents |
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What is the myotactic, monosynaptic reflex? |
When the muscle contracts when it is stretched |
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What are 1a afferents typically involved in? |
Reciprocal inhibition |
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Alpha motor neurons innervate what fibers? |
Extrafusal fibers of the motor unit |
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Gamma motor neurons innervate what fibers? |
Intrafusal fibers of the muscle spindle |