Term
| What are the two major spinal cord pathways that descending motor control travels down? |
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Definition
1. Lateral column
2. Medial column |
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Term
| What type of muscles are controlled by the lateral column and is this typically unilateral or bilateral? |
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Definition
Distal limb muscles (skilled movements, hand and fingers, for example)
Typically unilateral |
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Term
| What type of muscles are controlled by the medial column and is this typically unilateral or bilateral? |
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Definition
Axial and proximal limb and trunk muscles (for posture and balance)
Typically bilateral |
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Term
| What are the three descending upper motor control tracts in the brain and what does each typically control? |
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Definition
1. Lateral and Medial (vestibular) tracts - from the lateral vestibular nuclei, controls voluntary movements of proximal and distal muscles (driven by sensory inputs)
2. Reticulospinal tract - from the pontine and medullary reticular formation, driven by cerebral cortex, controls voluntary movements of proximal and distal muscles
3. Tectospinal tract - from the superior colliculus, controls the orientation response of the head and neck |
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Term
| What two pathways balance each other for coordinated flexor and extensor reflexes? |
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Definition
| Vestibular pathway and reticulospinal |
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Term
| Brain injuries such as stroke cause a decreased response in what pathway? |
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Definition
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Term
| What are the two subdivisions of the lateral descending pathway? |
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Definition
1. Corticospinal pathway
2. Cortico-rubro-spinal pathway |
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Term
| What is the size of the cortex devoted to a body part directly related to? |
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Definition
Precision of control required of the body part (NOT size of the body part)
i.e. hand and face have the 2 largest |
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Term
| What is the Babinski sign? |
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Definition
Rolling an object down the sole of the foot makes toes curl down (positive test result occurs when toes roll up)
- Sign of spasticity |
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Term
| Spasticity is an indicator of what? |
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Definition
| Imbalance in flexor/extensor reflexes |
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Term
| All lower motor neuron syndromes are indicative of what? |
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Definition
| Dead or dying lower motor neurons (who would have thought?) |
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Term
| Muscle weakness as an upper motor neuron disease is caused by what? |
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Definition
| Loss of input to lateral or medial descending pathways |
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Term
| A positive Babinski test is indicative of what? |
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Definition
| Loss of input to the lateral descending pathway |
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Term
| Loss of fine voluntary movement is indicative of what type of problem? |
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Definition
| Decreased input to the lateral descending pathway |
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