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17 Cards in this Set
- Front
- Back
Which spinal tracts do all vertebrates have?
Which do only higher monkeys and humans have? |
All vertebrates have:
Tectospinal Tr (from Sup/Inf Coll) Vestibulospinal Tr (from Vestibular Nucleus) Reticulospinal Tr (from reticular formation) Only higher animals have: Rubrospinal Tr (from Red Nucleus) Corticospinal Tr (from Cortex) |
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What tracts form the ventromedial brainstem pathway?
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Midbrain Tectum
Vestibular Nuclei Reticular Formation |
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What tracts form the lateral brainstem pathway?
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Rubospinal Tract
(has overlap with corticospinal tract!!) |
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Role of corticospinal tract?
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Fine dexterity
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Role of ventromedial brainstem pathway?
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Keep us standing, up right, awake
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Which descending tracts decussate and which tracts don't?
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Do decussate at medulla (ones above the pons):
-Corticospinal tract -Tectospinal tract -Rubrospinal tract Don't Decussate (at/below pons): Reticulospinal tract Vestibulospinal tract |
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Beginning with the cortex, Describe the path taken by the corticospinal tract.
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Cortex-->Internal capsule-->Cerebral Peduncle (midbrain)-->Medulla-->Medullary Pyramid (DECUSSATE)-->Spinal cord
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Beginning with the red nucleus,describe the path taken by the rubrospinal tract.
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Red nucleus (midbrain)-->DECUSSATE-->Medulla-->Spinal Cord
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In what region of spincal cord gray matter are soma for proximal muscle? Distal muxcles?
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Most medial (and ventral): Proximal mm (shoulders, chest)
Most lateral (and ventral): Disal mm (arms, forearms, hands) |
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What would constitute damage to a lower motor neuron? What would be the effect on:
Muscle atrophy Number of muscles affected Fasciculations Paralysis, Tone, Reflex |
Lower motor neurons = spinal or brainstem MNs, ventral roots, motor nerves
-Gross atrophy of mm -Can affect single mm -Fasciculations -Flaccid paralysis, no reflexes |
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What would constitute damage to an upper motor neuron? What would be the effect on:
Muscle atrophy Number of muscles affected Fasciculations Paralysis, Tone, Reflex |
Upper MNs=corticospinal and brainstem pw's
-No atrophy -Affects groups of mm -No fasciulations -Initial hypotonia, hyporeflexia; after weeks: hypertonia, hyperreflexia, clonus (spasticity) |
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What is Babinski's sign? What is indicative of?
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Fanning of toes (extensor plantar response)
Sign of corticospinal tract lesion |
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What is spasticity indicative of? Signs?
Treatment? |
Spasticity caused by damage to descending motor pw's
Signs: Hypertonia (increased tone/stiffness) Hyperreflexia Clonus (alternating contractions/relaxations) Can be treated by cutting dorsal roots |
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What is decorticate rigidity? Sign of?
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Arms flexed, legs extended
Intact midbrain, damaged corticospinal tract |
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What is decerebrate rigidty?
Sign of? |
Arms and legs extended
Injury to midbrain and brainstem/brainstem; knocks out ventromedial (keeps legs off ground) and lateral corticospinal tract (flexes arms) |
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What cranial nerves are effected in locked-in syndrome?
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VII, IX, X, XII
Paralysis of all limbs, no facial movements, speech abolished Capable of vertical but not horizontal (CN VI) eye movmt |
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