Term
| What is the most common way in which descending motor pathways act? |
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Definition
| They synapse on interneurons to influence reflex arcs |
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Term
| What are medial alpha motoneurons responsible for? |
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Definition
| Control of the neck, trunk and proximal limbs |
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Term
| What are lateral motoneurons responsible for? |
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Definition
| Control of the distal parts of the limbs |
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Term
| Where does the lateral pathway travel in the spinal cord? |
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Definition
|
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Term
| Where does the medial pathway travel in the spinal cord? |
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Definition
| In the contralateral lateral funiculus |
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Term
| What tracts are involved in the medial system? |
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Definition
1. Tectospinal
2. Lateral and medial vestibulospinal
3. Medullary and pontine reticulospinal
4. Ventral corticospinal |
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Term
| What tracts are involved in the lateral system? |
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Definition
| The lateral corticospinal tract |
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Term
| What is the function of the tectospinal tract |
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Definition
| It controls neck muscles to produce head movements required for the fixation of gaze |
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Term
| What is the function of the vestibulospinal tract? |
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Definition
| Reflex control of equilibrium from the labyrinth |
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Term
| What is the function of the reticulospinal and ventral corticospinal tracts? |
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Definition
| Control of posture and locomotion |
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Term
| What is the function of the lateral corticospinal tract? |
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Definition
| Finely controlled voluntary movement |
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Term
| What impact would a stroke have on the medial and lateral systems. |
|
Definition
Medial: little effect (bilateral)
Lateral: large effect (lateral). |
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Term
| Which tracts of the medial system are not bilateral? |
|
Definition
1) Tectospinal
2) Lateral vestibulospinal
3) Rubrospinal |
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Term
| Where does the tectospinal tract originate? |
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Definition
|
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Term
| Where do the lateral and medial vestiubulospinal tracts originate? |
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Definition
| Lateral and medial vestibular nuclei. |
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Term
| Where do the lateral and medial reticulospinal tracts originate? |
|
Definition
1) Lateral: medullary reticular formation
2) Medial: Pontine reticular formation. |
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Term
| Where does the rubrospinal tract originate? |
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Definition
|
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Term
| What level does the lateral corticospinal tract decussate? |
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Definition
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Term
| Which motor nuclei control striated eye muscles? |
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Definition
| III, IV & VI motor nuclei. |
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Term
| Which motor nuclei control striated head muscles apart from the eye? |
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Definition
| V, VII, XII and nucleus ambiguus. |
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Term
| What are the monoaminergic pathways and what do they do? |
|
Definition
1) Locus ceruleus (noradrenaline, pons)
2) Raphe nuclei (serotonin, medulla)
-They modify the excitability of motoneurones. |
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Term
| What are the key differences between an upperand lower motoneurone lesion? |
|
Definition
LMN:
1) Decreased muscle tone
2) Decreased tendon jerk
3) Normal Babinski sign. |
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Term
| What does a lesion of the LCST cause? |
|
Definition
| UMN symptoms below the lesion site. |
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Term
| Where is the nerve supply to the upper limb? |
|
Definition
| 1) Brachial plexus: C5-T1. |
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Term
| Where is the nerve supply to the lower limb? |
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Definition
| Lumbosacral pelexus: L2-S3. |
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