L6 - motor systems 1

Question 1

2 neurons in the descending tracts

Answer 1

upper motor neuron (UMN) and lower motor neuron(LMN)

Question 2

effects due to damage done to UMN

Answer 2

muscel weakness

- decrease muscle tone

Question 3

function of cerebellum

Answer 3

• involved in brainstem mechanisms
  -control of muscle tone
  -sensorimotor coordination
  motor learning

Question 4

function of basal ganglia q

Answer 4

integ of sensory and motor info

Question 5

3 components of cerebellum

Answer 5

spino cereb-
vestibulo cereb
cerebro cerrebellum

Question 6

function of spino cereb

Answer 6

function is receiving sensory input and output to the reticular tract via reticulospinal
and red nucleus via rubrospinal
-

Question 7

function fo vestibulo cerreb

Answer 7

input from and output to vesticular nucelaus via vestibulospinal tract
- control over posture and balance and eye movement

Question 8

function of cerebo cerebellum

Answer 8

instructs primary motor cortex about movement, direction

- compares intended movements with actual movements

Question 9

inputs to the purkjine cells in the outer layer of cerebullum

Answer 9

• climbing fibres from inferior olive

- mossy fibres from the brainstem nuclei

Question 10

what part of the cerbellum can compare input from the mossy, climbing fibres and purkinje jibres

Answer 10

deep cerebellar nuclei (DCN)

Question 11

what is basal ganglia

Answer 11

group of subcortical nuclei responsible primarily for motor control from the cortex

• relays back to cortex via thalamus
• initiation of vol movement

Question 12

what is motor loop

Answer 12

a loop linking basal
ganglia, thalamus and cortex
- the loop is activated (disinhibition) to coordinate movement

Question 13

structures in the basal ganglia

Answer 13

striatum (STR)
globus pallidus (GP)
substantia nigra
subthalamic nucleus (STN)

Question 14

two pathways in the basal ganglia

Answer 14

direct and indirect

Question 15

what is the direcft pathway in the basal ganglia

Answer 15

cortex > straitum > SNr and GPi > thalamus > cortex

• the striatum is activated by dopamine on the D1 receptors
• this promotes movement

Question 16

what is the indirect pathway in the basal ganglia

Answer 16

• cortex > straitum > GPe> STN> SNr and GP i > thalamus > cortex

the straitum is activated by the dopamine on inhibitory D2 receptors
- faciliates movement

Question 17

what happens when there is an imbalance between the direct and indirect pathways

Answer 17

• motor dysfunction

like hypo and hyperkinetic diseases

Question 18

eg of hypokinetic diease

Answer 18

parkinson disease PD

Question 19

symptoms of PD

Answer 19

tremor, bradykineasa( slowness of movement ), rigidity

Question 20

cause of the PD in the basal ganglua

Answer 20

DOPamine loss int he basal ganglia -

Question 21

treatments for PD

Answer 21

drugs like
L-DOPA - precursor for dopamine
- dompamine agonists,
-drugs that reduce dopamine breakdown

Question 22

eg of hyperkinetic disease

Answer 22

huntingdon’s disease (HD)

Question 23

symptoms of HD

Answer 23

excessive movment

uncontrollable rapid motor patterns

Question 24

effect of HD in the basal ganglia

Answer 24

loss of straital output neurons in the indrect pathway

- leads to involuntary movement

Question 25

results of damage done to spino cerebellum

Answer 25

hypotonia - reduced muscle tone

dysmetria - inaccurate termination of movement

Question 26

result of damage to vestibulocerebellum

Answer 26

slow saccades - ocular movement impaired

Ataxia - unsteady gait

Question 27

result of damage of cerebro cerebellum

Answer 27

ataxia
dystemetria
uncoordinated agonist and antagonist muscles
inarticulate speech

Question 28

what does DCN do iif there is a difference between the intended and actual movements

Answer 28

send a compensatory response to the brainstem and thalamus

Question 29

relationship between BG and thalamus when in a normal state

Answer 29

the BG inhibits thalamus so no movement is initaited

Question 30

cons of using L-DOPA as a drug for PD

Answer 30

effectiveness reduce over time

- need to increase dose freq over time

Question 31

alternatives of using LDOPA

Answer 31

DOPAMINE receptor agonist

Question 32

what happends during surgey for PD

Answer 32

STN in the BG inactivated

Question 33

treatment for HD

Answer 33

tetrabenazine - reduces DA storage and release

Chlorpromazine - DA antagonist

Question 34

other hyperkinetic idsorders

Answer 34

HEMIBallismus

tardive dyskinesia