Topic 105 - Intentional movements and the cerebellum   Flashcards

1
Q

Words to include in intentional movement

A

Stages of voluntary movement

  • Intension to move
    • Limbic
  • Movement planning
    • Brodman 6 area
  • Coordination of movement
    • Cerebellum
    • Basal ganglion
  • Execution of movement
    • Brodman 4 area precentral gyrus
  • Movement
    • Spinal cord
    • Muscle
  • Proprioceptions
    • Afferentation
  • Other afferentations
    • Visual
    • Hearing
  • Thalamic mediation
  • Movement initiating areas
    • Limbic system
      • Emotion
    • Orbital cortex
    • Hypothalamus
      • Vegetative integration
      • Endocrine integration
    • System of basal ganglia
      • Movement patterns
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2
Q

Words to include in cerebellum

A

Motor cortex

  • Cerebral cortex
    • Brodmann area
  • Brodman 4
    • Primary motor area
    • Precentral gyrus
    • Pyramidal tracts
    • Final execution of movements
  • Brodman 6 area
    • Premotor cortex
    • Somatotopy
    • Determination of movement order
  • A part of Brodman 6 area
    • Supplementary area
    • Center of intention of complex movement
  • Motor pathways
    • Pyramidal tracts
      • Percentral gyrus, brodman 4
      • Decussation of pyramids
      • Contralateral interneurons
      • Alpha and gamma motorneurons
    • Extrapyramidal tracts
      • Rubospinal tract
      • Vestibulospinal tract
      • Tectospinal tract
      • Reticulospinal tract

Basal ganglia and cerebellum

  • Movement execution
  • Planned movements
  • Afferent
  • Cortex
  • Basal ganglia
    • Sensory information
    • Thalamus
    • Voluntary movement
    • Generate intention for movement
    • Emotional afferentation
    • Striatum
    • Pallidum
    • Substantia nigra
      • Reticular substance
    • GABAergic activity
    • Inner regulatory circuit
    • Basic inhibitory tone
  • Cerebellum
    • Correction and refinement of movement plane
    • Learning and storing complex movement plans
  • Cortical movement patterns

Vestibulocerebellum

  • Arachiocerebellum
  • Vestibular apparatus
  • Eye movement
  • Balance
  • Afferents
    • Vestibular apparatus
      • Deiters nucleus
    • Collaterals of the visual pathway
  • Efferentation
    • Alpha and gamma motorneurons of spinal cord
    • Nucleus Fastigii
    • Deiters nucleus
    • Reticular formation
    • Nucleus ruber

Spinocerebellum

  • Spinocerebellar tracts
  • Paleocerebellum
  • Afferentations
    • Lateral (Flechsig) spinocerebellar tracts
    • Ventral (Gowers) spinocerebellar tracts
  • Efferentation
    • Alpha and gamma motor neurons
  • Somatotropic localization
  • Finely adjust the strength of the muscle

Cerebrocerebellum

  • Afferentations
    • Brodman 4
      • Primary motor area
    • Brodman 6
      • Premotor cortex
    • Gyrus postcentralis
      • Sensory cortex
  • Efferentations
    • Dentate nucleus (beginning)
    • Thalamus
    • Premotor area of the motor cortex
    • Nucleus ruber
    • Spinal cord nucleus ruber axis
    • Dentate nucleus - nucleus ruber- motor cortex loop
      • Cortical movement plan
  • Cerebellar movement pattern
  • Movement planning
    • Timing of movement

Cerebellar module

  • Functioal unit of cerebellum
  • GABAer inhibitory cells
    • Purkinje cells
      • Firing of deep nuclei (Ø)
      • Cerebellar efferent system
      • Inhibitory neuron
      • Main integrator cell type of the cerebellar cortex
    • Stellate cells
    • Basket cells
  • Glutamaterg facilitating cells / axons
    • Granular cells
    • Climbing fibers
    • Mossy fibers
  • Efferentation center of cerebellum
    • Cerebellar deep nuclei area
      • Nucl. fastigii
      • Interpositus nuclei
      • Dentate nuclei
    • Fibers reaches
      • Motor cortex
      • Nuclei of the brain stem
      • Nucleus Deiters
  • Somatotopic localization

Concequences of removal of the cerebellum

  • Refined coordinated movement (Ø)
  • Vestibulocerebellum (Ø)
    • Incoordinated, ataxic movement
  • Spinocerebellum (Ø)
    • Accurate fine movement (Ø)
  • Cerebellocerebellum (Ø)
    • Movement planning (Ø)
  • Ataxia
  • Hypotonia
  • Dysmetria
  • Dyadochochinesis
    • Fast altering movement execution
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3
Q

Inential movements

Give the stages of volutary movement

A
  1. Intension to move (limbic)
  2. Movement planning (Brodman 6 area)
  3. Coordination of movement (cerebellum & basal ggl)
  4. Execution of movement (Brodman area precentral gyrus)
  5. Movement: spinal cord and muscle
  6. Proprioceptions (afferentation)
  7. Other afferentation (visual/hearing)
  8. Thalamic mediation
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4
Q

Itentional movement

Give the most important movement intiating areas

A
  • Limbic system (emotion)
  • Orbital cortex
  • Hypothalamus (vegetative and endocrine integration)
  • System of basal ganglia (movement patters)
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5
Q

Brodmann area

A
  • Brodmann area: regions of the cerebral cortex in primates, defined by its structure and organization of cells
  • Motor cortex: The cortical area, that is responsible for small stimulus evoke movements of the controlateral body side are called motor cortex
  1. Primary motor area
    • Brodmann 4 area
    • Precentral gyrus
    • Origin of pyramidal tracts
    • Role: final execution of movements
  2. Premotor cortex
    • _​_Brodmann 6 area
    • Role: determination of the complex sequence of movement
    • Shows somatotopy
  3. Supplementary area
    • A part of Brodmann 6 area
    • Center of intention of complex movement
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6
Q

Motor pathways

A
  • Motor pathways originate at two areas:
    1. Pyramidal tracts
      • _​​_Axons derive from the pyramidal cells of the 5th cytoarchitectonial layer
      • These fibers leave as corticospinal and bulbospinal tracts, giving collaterals to brain stem, cerebellum and basal ganglia
      • The fibers end on alpha and gamma motorneurons of the ventral horn of the spinal cord
    2. Extrapyramidal system
      • ​​Formed by:
        • Rubospinal tract
        • Vestibulospinal tract
        • Tectospinal tract
        • Reticulospinal tract
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7
Q

Basal ganglia and cerebellum

What are their function together

A
  • In movement execution the parallel function of basal ganglia and cerebellum is important
  • The two motor systems are informed about planned movments via afferentation from the cortex
  • They compare the existing movement patterns with the plan and send it back to the cortex in a modified, coordinated form
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8
Q

Basal ganglia and cerebellum

Efferentation

A
  • Their efferentation is dual
  1. They provide thalamus with tonic vegetiative impulses (GABAergic)
  2. They send efferents to the brain stem nuclei and influences the posture
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9
Q

Cerebellum

Role of cerebellum

A
  • Cerebellum is the organ of movement coordination and movement learning
  • Role of cerebellum
    1. Correction and refinement of the movement plan
    2. Learning and storing complex movement plans
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10
Q

Cerebellum

Afferentation

A
  • Afferent connecitions with:
    • Vestibular area
    • Spinal area
    • Cortical area
  • Afferentation is integrated by the purkinje cells
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11
Q

Cerebellum

Efferentation

A
  • No direct efferent connection to the spinal cord
  • Cerebellum directs muscle function by indirectly influencing cortical movement patterns
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12
Q

Cerebellum

Give the major division of cerebellum

A
  • There are three functional areas of cerebellum:
    1. Vestibulocerebellum
    2. Spinocerebellum
    3. Cerebrocerebellum
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13
Q

Cerebellum

Vestibulocerebellum: O__rigin and main function

A
  • Origin:
    • Arachiocerebellum
    • Vestibular apparatus
  • Main function: To ensure appropriate eye movement and balance
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14
Q

Cerebellum

Vestibulocerebellum: Afferentation

A
  • Afferents are arriving into the cerebellum from two locations:
    • Vestibular apparatus
    • Collaterals of the visual pathway
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15
Q

Cerebellum

Vestibulocerebellum: Efferentation

A
  • Efferentation reaches alpha and gamma motorneurons of the spinal cord through:
    • Fastigii nucleus
    • Deiters nucleus
    • Reticular formation
    • Ruber nucleus
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16
Q

Cerebellum

Spinocerebellum: What is it composed of?

A
  • Composed of:
    • Complex of the spinocerebellar tracts
    • Paleocerebellum
17
Q

Cerebellum

Spinocerebellum: Afferentation

A
  • Lateral spinocerebellar tract
  • Ventral spinocerebellar tract
  • These tracts contain fine muscular sensory information about the actual tension of the innervated muscle fibers
  • Afferentation gives information to the cerebellar centers about the parameters of actually occuring movement
18
Q

Cerebellum

Spinocerebellum: Efferentation

A
  • Efferentation affects the deep nuclei of the cerebellum
  • The deep nuclei modulate the original movement plan partly throught two loops:
    1. Thalamus - motor cortex - spinal cord loop
    2. Nucleus ruber - spinal cord loop
19
Q

Cerebellum

Cerebrocerebellum: Role

A
  • The cerebrocerebellum is a major element in:
    • Movement planning
    • Timing
20
Q

Cerebellum

Cerebrocerebellum: Afferentation

A
  • Afferentations of the cerebrocerebellum:
    1. ​Brodman 4 area / Primary motor area
    2. Brodman 6 area / Premotor cortex
    3. Gyrus postcentralis /Sensory cortex
21
Q

Cerebellum

Cerebrocerebellum: Efferentation

A
  • Connection between dentate nucleus and nucleus ruber is important in the efferentation
    • The connection partly influences the spinal cord - nucleus ruber axis
  • Dentate nucleus - nucleus ruber - motor cortex loop refines the movements
22
Q

Cerebellum

The cerebellar module

A
  • The functional unit of cerebellum = the cerebellar module
  1. GABAerg inhibitory cells:
    • ​Purkinje cells
      • General inhibitory neuron
      • Inhibits the firing of the deep nuclei
      • Part of cerebellar efferent system
      • ↓ activity of purkinje cells → disinhibition - facilitation of the deep nuclei
    • Stellate cells
    • Basket cells
  2. Glutamaterg facilitating cells/axons:
    • Granular cells
    • Climbing fibers
    • Mossy fibers
      • Afferentation (information is duplicated, one to deep nuclei & one to cerebrocortex)
      • From spinal cord and brain stem
23
Q

Cerebellum

Give the main efferentation center of the cerebellum

A
  • The main efferentation center of the cerebellum is the area of cerebellar deep nuclei
    1. ​​Nuclei Fastigii
    2. Interpositus nuclei
    3. Dentate nuclei
  • These nuclei obtain direct afferentation
24
Q

Cerebellum

Consequences of removal of the cerebellum

A
  • Refined coordinated movements disappears
  • Ataxia: symptom of the impaired cerebellar function
    • Hypotonia: decreased muscle tone
    • Dysmetria: loss of correct space estimation
  • Loss of vetibulocerebellum
    • Incoordinated, ataxic movement
  • Lesion in the spinocerebellum
    • Fine movements Ø
  • Loss of cerebrocerebellum
    • Loss of capability to initiate movement at the proper time