Central control of movement

Question 1

What are the functions of motor control systems?

Answer 1

Posture and balance, goal derived movements, and communication, guided by sensory systems

Question 2

How do muscle lesions (Myositis, MD) present?

Answer 2

Normal reflexes, weakness/wasting

Question 3

How do lesions at the neuromusclular junction present?

Answer 3

Fatiguable weakness, normal reflexes and muscle bulk

Question 4

How does an upper motor neuron lesion present

Answer 4

Normal muscle bulk, increased reflexes, tone, reduced extensors in arm power, flexors in leg, extensor plantar response

Question 5

How does LMN lesion present

Answer 5

Decreased muscle bulk, tone, and power, absent reflexes

Question 6

What 5 areas in the brain give rise to descending tracts?

Answer 6

corticospinal tract (pyramidal) in cerebral cortex. In brain stem and medulla are the reticular formation, vestibular nuclei, red nucleus, and tectum

Question 7

What part of the brain serves as the movement planner

Answer 7

The cerebral motor cortex

Question 8

WHat is the basal ganglia?

Answer 8

Deep cerebral nuclei (neostriatum, paleostriatum, subthalamic nucleus, and substantia nigra)

Question 9

What is the function of the basal ganglia?

Answer 9

Generates basic patterns of movement

Question 10

Describe the motor loop

Answer 10

All parts ofcerebral cortex project to corpus striatum, basal ganglia project to thalamus, thalamus projects to cerebral cortex

Question 11

What is the direct pathway of the basal ganglia?

Answer 11

Cortical excitation of neostriatum leads to disinhibition of thalamic nuclei
Movement follows activation of putamen by cortical areas

Question 12

Describe the indirect pathway of the basal ganglia

Answer 12

Indirect pathway
Cortical excitation of neostriatum leads to inhibition of inhibitory input to Subthalamus
Activation of indirect pathway leads to inhibition of cortical areas

Question 13

WHich pathway does the does the dopamine pathway activate

Answer 13

The direct pathway of the basal ganglia, inhibiting the indirect pathway

Question 14

What does the direct pathway facilitate?

Answer 14

facilitates the initiation and execution of voluntary movement.

Question 15

What does the indirect pathway facilitate

Answer 15

helps to prevent unwanted muscle contractions from competing with voluntary movements in conjucntion with direct pathway

Question 16

WHat disease is due to degeneration of dopaminergic neurons of the substantia nigra?

Answer 16

Parkinsons

Question 17

What are the symptoms of parkinsons

Answer 17

Bradykinesia (slow movement) akinesia (impaired control) and rigidity

Question 18

What disease is caused by degeneration of caudate, putamen, and globus pallidus?

Answer 18

Huntingtons chorea

Question 19

What are the symptoms of Huntingtons chorea

Answer 19

hyperkinesia (muscle spasm) and dyskinesia (impairment of voluntary movement)

Question 20

What happens when cerebellum function is lost?

Answer 20

Severe abnormalities in motor funtion

Question 21

What are the 3 layers of the cerebellar cortex?

Answer 21

Molecular layer, purkinje cell layer and granular layer

Question 22

What fibres have input to cerebellum

Answer 22

Climbing and mossy fibres

Question 23

What is the primary role of the cerebellum?

Answer 23

Supplement and correlate activities of other motor areas (correction of rapid muscular movement such as typing/musical intruments)

Question 24

What are the secondary and tertiary roles of the cerebellum?

Answer 24

exert control on movement-by-movement basis, mainains tone of muscles, maintains tone of the muscles

Cerebellum informed of movement before it occurs, cerebellum processes sensory info to generate an error signal fed back to cortex, which is adjusted.