L4 - motor systems

Question 1

What does the motor cortex do?

Answer 1

projects through pyramidal tracts to the spinal cord, synapsing with peripheral motor neurons

Question 2

What is the extrapyramidal system?

Answer 2

includes pathways from the cortex, basal ganglia + cerebellum running outside the pyramidal tract through the brainstem and spinal cord

Question 3

What is the function of the primary motor cortex?

Answer 3

controls fine movements

Question 4

What is the pathway og the primary motor cortex?

Answer 4

Pyramidal tract: fine motor movements

Reticulospinal tract: facilitates or inhibits movement

Vestibulospinal tract: influences postular muscles

Tectospinal tract: coordinates head and eye movements

Question 5

What does the primary motor cortex do?

Answer 5

source of pyramidal tract neurons

Question 6

What does the supplementary motor cortex do?

Answer 6

conception + initiation of movement

lesions cause deficits in voluntary movement or speech

Question 7

what does the premotor cortex do?

Answer 7

important in motor coordination

lesions cause impairments in stability of stance, gait and hand coordination

Question 8

What does the basal ganglia do?

Answer 8

Positioned outside the motor cortex

modulates motor activity patterns

Question 9

What does the cerebellum do?

Answer 9

Also positioned outside of the motor cortex

controls neural programs for skilled movements

Question 10

What do the visual and somatosensory cortex do?

Answer 10

provide sensory feedback

Question 11

What does the motor nuclei of the thalamus do?

Answer 11

relay motor signals

Question 12

What is the prefrontal cortex involved in?

Answer 12

planning + decision-making

Question 13

What causes dysfunctions within the motor system?

Answer 13

damage to motor neurons

injury to spinal cord

damage to the primary motor cortex - results in paralysis or partial paralysis

Question 14

What are the characteristics of apraxia?

Answer 14

inability to carry out movements in response to commands despote no paralysis or loss of comprehension/ motivation

may be caused by a disconnection of the primary motor cortex from supplementary motor cortex areas and premotor cortex

Question 15

What are the symptoms + cause for a decomposition of movement?

Answer 15

inability to perform smooth patterns, movements are broken into individual segments

caused by damage to the cerebellum

Question 16

What are the symptoms of Parkinson’s disease?

Answer 16

resting tremor, muscle rigidity, akinesia, stooped posture, shuffling gait, excessive sweating, micrographia, altered cognitive function

Question 17

What is the cause of Parkinson’s disease?

Answer 17

degeneration of the nigrostriatal pathway leading to depletion of striatal dopamine

Question 18

What is the treatment for parkinson’s?

Answer 18

use of L-DOPA to increase brain dopamine

Question 19

What are the symptoms of Huntington’s disease

Answer 19

involuntary muscle jerks, intellectual deterioration, depression, psychosis

Question 20

What is the genetic explanation for Huntington’s disease?

Answer 20

single dominant gene causing degeneration of output neurons from the striatum, reducing inhibitory modulation of motor function

Question 21

What is the treatment for huntington’s disease?

Answer 21

no effective treatment