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Neuroanatomy > Descending Motor Systems > Flashcards

Flashcards in Descending Motor Systems Deck (16):
1

Where are the lower motor neurons located?

In the lamina 8 of the spinal cord, ventral (anterior) gray matter

2

Where is the primary motor cortex located?

pre-central gyrus

3

What happens when the pre-motor cortex is damaged?

apraxias

4

What are the two effects that the UMN has on LMN?

-increases firing rate during voluntary movements
-inhibits afferent input to LMN through inhibitory interneurons

5

Where does the vestibulospinal tract receive input from?

NOT the cortex, the vestibular ganglia

6

what is the lateral vestibulospinal tract responsible for?

anti-gravity response

7

What is the medial vestibulospinal tract responsible for?

ipsilateral/contralateral and mediates other responses to vestibular input; cross at the medullary-pontine junction

8

Where is the "vestibule area"?

floor of the fourth ventricle

9

What symptoms does brainstem disease produce?

life-threatening coma and alterations to heart rate and breathing

10

What are the 7 things that can cause weakness?

1. muscular pathology (muscular dystrophy)
2. neuromuscular junction
3. nerve pathology (compression)
4. lower motor neuron pathology
5. corticospinal tract pathology (stroke of the internal capsule)
6. primary motor cortex pathology
7. premotor correct pathology

11

Weakness, hyper-flexia, hypertonia, spasticity, disuse atrophy, hyper-reflexia are all signs of a lesion where?

Upper motor

12

weakness, hyporeflexia, hypotonia, "marked" atrophy, fasciulations of muscles are signs of a lesion where?

lower motor lesion

13

What tract inhibits reflexes

corticospinal tract

14

Are reflexes exaggerated or diminished if the corticospinal tract is damaged?

exaggerated

15

skilled movements of the extremities

lateral corticospinal tract

16

postural adjustments

anterior corticospinal tract (axial)