Ch. 11: Basil Ganglia, Cerebellum, and Movement Flashcards Preview

Neuroscience > Ch. 11: Basil Ganglia, Cerebellum, and Movement > Flashcards

Flashcards in Ch. 11: Basil Ganglia, Cerebellum, and Movement Deck (34):
1

What does the Basil Ganglia control?

  • Subcortical
  • Motor Control
  • Motor Planning
  • Motor Adjustment

"Predict the effects of various actions, then make and execute action plans"

A image thumb
2

In the Basil Ganglia, what is the Caudate and what does it do?

  • Connects to frontal lobe - connective link to prefrontal cortex
  • Helps decide what movement you want to make

3

In the Basil Ganglia, what is the Substantia Nigra and what does it do?

  • Compacta: Creates Dopamine = critical neurotransmitter for Basil Ganglia to work
  • Reticularis: output - helps control head and eye movement

4

What do the Basil Ganglia's projections to the motor planning areas of the cerebral cortex do?

  • Instructions to voluntary muscles on how you want to move
    • Ex: Grab cup
  • Output to motor planning areas of frontal lobe

5

What do the Basil Ganglia's projections to Pedunculopontine do?

  • Postural muscles so you dont' fall over
  • Mucleus of the midbrain - output to subcortical UMN's (esp cor & prox muscles

6

What do the Basil Ganglia's projections to the midbrain locomotor region do?

  • Stepping pattern generator

7

 In the Basil Ganglia what are the functions of the: 

Motor Loop

*Output of Basil Ganglia is inhibatory*

  • Sequencing of movements
  • Regulating muscle tone
  • Regulating muscle force
  • Facilitating or inhibiting specific motor synergies

VERY important in motor learning - may be the spot where old skills are stored

A image thumb
8

 In the Basil Ganglia what are the functions of the: 

Oculomotor Loop

Helps with moving eyes to know where you are going

9

In the Basil Ganglia what are the functions of the: 

Executive Loop

Connection to the prefrontal cortex - to executive areas

A image thumb
10

What are Hypokinetic Disorders and what is an example?

  • Excessing inhibition from output nuclei
  • Ex: Parkinson's Disease

A image thumb
11

What is the pathophysiology of Parkinson's Disease?

  • Death of dopamine producing cells
  • Lack of dopamine = inc inhibatory output from basil ganglia
    • Further inhibits Motor Thalamus = DEC voluntary muscle control
    • Further inhibits Pedunculopontine (inhibitor) = double negatives make a positive = OVERACITVE postural & girdle muscles
    • Further inhibits Midbrain locomotr regioan = DEC walking control

A image thumb
12

What are the signs of Parkinson's Disease?

  • Akinesia/hypokinesia. Less voluntary movement (less lateralcorticospinal)
  • Rigidity (typically “cog wheel”) - more core and prox muscles = stiff on both sides of the joint
    • NOT velocity dependent
  • Freezing during movement - Trouble with the motor plan
    • Cant send sequence signals to lateralcorticospinal
  • Visuoperceptive impairments - dec occulomotor loop
  • Postural instability - stiff and slow activation
  • Resting tremor - goes away with movement

 

A image thumb
13

What are Hyperkinetic Disorders and what is an example?

  • Inadequate inhibition from output nuceli
  • Ex: Huntington's Disease

14

What is the pathophysiology of Huntington's Disease?

  • Degeneration of basal gangli "input modules" and cerebral cortex (not as much info = not as much inhibition out)
    • Decreased inhibition to Motor Thalamus = OVERACITVE voluntary muscle control
    • Decreased inhibition of Pedunculopontine (inhibitor) =  = DECREASED postural & girdle muscles
    • Decreased inhibition of Midbrain locomotor region = OVERACITVE walking 

A image thumb
15

What are the signs of Huntington's Disease?

  • Chorea: involuntary extra movements that are typically twisting or writhing in nature
  • Dementia: Atrophy of cerebral cortex

16

What is the Cereballum the organ of?

  • Organ of coordination
    • compeares what you meant to do to what's actually happening and makes a change if needed.

17

What are the 2 inputs to the cereballar cortex?

  1. From brain to pons
    • intended movements - "What I meant to do"
  2. Sensory receptors via spinal cord
    • State of body system at the moment - "What I am really doing"

18

What are the 3 cortical layers of the cerebellum?

Computer of the cerebellum

  • Outer - processing
  • Middle - Purkinjie cells: output
    • Sends inhibition like Basil Ganglia
    • Modulates or fine tunes movements
  • Inner - processing

19

What does the output of the cerebellar cortex do?

  • Inhibitory
  • Project to deep cerebellar nuclei and vestibular nuclei

20

What are the vertical divisions of the cerebellum and what do they control?

  • Midline vermis - most prox muscles
  • Paravermal hemisphere - slightly more distal muscles
  • Lateral hemisphere - distal muscles (esp hands and feet)

A image thumb
21

What are the 3 function divisions of the cerebellum?

  1. Vestibulocerebellum
  2. Spinocerebellum
  3. Cerebrocerebellum

A image thumb
22

What does the Vestibulocerebellum do?

*Handlebar mustache connected with inner ear*

  • Balance and equilibruim - hold you upright against gravity
  • "..influences eye movemetn and postural muscles.."
    • esp vestibulospinal tract (ext legs to keep you balanced)

A image thumb
23

What does the Spinocerebellum do?

*Midline of cerebellum - functionally linked with the spinal cord (esp core & prox muscles)

  • Gross movements of the limbs
    • generate activity to medial corticospinal & brainstem
  • Control ongoing movement via the brainstem descending tracts
    • facilitates directors & helpers of core & prox muscles
  • Receives rich "what am I doing now" info
  • Automatic corrections
  • New movement plans (ex: like when falling)

A image thumb
24

What does the Cerebrocerebellum do?

*Strongest connection with cerebral cortex*

  • Fine, distal, voluntary movements - esp hands & feet
  • Soordination of voluntary movments
  • Planning of movemnts - works with basil ganglia
  • Ability to judge time intervals and produce accurate rhythms
  • Output to lateral tracts
    • Rednucleus helper
    • Motor cortes - esp lateral corticospinal tract

A image thumb
25

What does the superior cerebellar peduncle do?

  • Most of cerebellar efferent - output of cerebellum
    • Wires that take messages out of cerebellum
    • Messages of unconscious (to helpers) and conscious (to directors) correction

26

What does the Middle cerebellar peduncle do?

  • Afferent from corticopontocerebellar fibers
    • In line with pons
  • Afferent from porticopontocerebellar (xerox copy)

27

What does the Inferior cerebellar peduncle do?

  • Afferent from spinal cord and brainstem
    • Closest to spinal cord
    • Messages of what I am really doing

28

What are the functions of the cerebellum?

  • Comparing actual motor output to the intended movement.
  • Adjusting actual motor output if there is a discrepancy.

29

What are sings of Clinical DIsorders of the Cerebellum?

  • Hypotonia
  • Ataxia: movements are erky & inaccurate
    • lack of coordination
  • Signs are ipsilateral to side of damage

30

What signs are associated with lesions of the Vestibulocerebellum?

  • Abnormal eye movements
    • Eyes may not move properly during movement
  • Dysequilibrium
    • Out of balance
  • Truncal ataxia
    • Trunk does not stay stable - makes coordinated movement difficult

31

What signs are associated with lesions of the Paravermis & Cerebrocerebellum?

  • Dysarthria
    • Difficulty/disordered mechanical production of speech.
  • Ataxic Dysarthria: Changes rate, pitch, annunciation (specific to cerebellar damage)
    • Sound drunk

32

What signs are associated with lesions of the Spinocerebellum?

  • Ataxic, wide-based gait
    • Mechanically more protected against falls

33

What signs are associated with lesions of the Spinocerebellum & Cerebrocerebellum?

  • Dysdiadokokinesia: Disordered alternating movement
    • Cerebellum having trouble gaging timing and rhythm of movement
  • Dysmetria: Inability to accurately hit a target
  • Action or intension tremor: Only tremor with movement

34

How do distinguish between Cerebellar Ataxia and Sensory Ataxia?

A image thumb