lect 12/13- contributions of cerebellum & basal nuclei to motor function Flashcards Preview

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Flashcards in lect 12/13- contributions of cerebellum & basal nuclei to motor function Deck (78):
1

what signals does the primary motor cortex send

signals motor neurons to control skeletal muscle fibers via the corticospinal tract

2

what does the premotor cortex (area 6) do

plans movement based on sensory and visual cues

3

what does the supplementary motor area (area 6) do

retrieves and coordinates memorized motor sequences

4

T/F cerebellum is essential for locomotion

FALSE

5

what separates the 2 hemispheres of the cerebellum

vermis

6

what are each hemisphere of the cerebellum divided into

intermediate zone and lateral zone

7

what are the 3 lobes of the cerebellum

anterior lobe, posterior lobe, flocculonodular lobe

8

what is the "oldest" lobe of the brain

flocculonodular lobe

9

what is the intermediate zone associated with

concerned with controlling muscle contractions in the distal portions of the upper and lower libs (esp. hands, feet, fingers and toes)

10

what is the lateral zone associated with

cerebral cortex with planning of sequential motor movements

11

name the intracerebellar nuclei

dentate, emboliform, globose, fastigial

12

what happens when there is a lesion in the dentate, emboli form, or globose nuclei

extremity ataxia

13

what happens if there is a lesion in the fastigial nuclei

trunk ataxia

14

where do fastigial nuclei fibers project

to reticular formation and vestibular nuclei

15

what types of cells are in the granular layer of the cerebellar cortex

granule cells, golgi type 2 cells, and glomeruli

16

what types of cells are in the molecular layer of the cerebellar cortex

stellate cells, basket cells, purkinje dendrites, golgi type 2 cells, and axons of granule cells

17

what cell in the cerebellar cortex is excitatory

granular cells

18

describe granular cells

axons form parallel fibers in cortex

19

describe golgi cells

project from parallel fibers to granular cell bodies

20

describe basket cells

project from parallel fibers to purkinje axon hillock

21

describe stellate cells

project from parallel fibers to purkinje dendrites

22

what cells provide lateral inhibition on adjacent purkinje cells to provide damping

basket and stellate cells

23

what is the only output from the cortex

purkinje cells

24

what do climbing fibers originate from

medullary olives

25

what "conditions" the purkinje cells

climbing fibers

26

where do mossy fibers originate

from multiple centers in brainstem and spinal cord, including vestibulocerebellar, spinocerebellar and pontocerebellar tyracts

27

where do mossy fibers synapse

on granule cells in glomeruli

28

what neurotransmitter do purkinje cell axons use

GABA

29

where do purkinje cell axons project

deep cerebellar nuclei and vestibular nucleus

30

what do purkinje cell axons do

modulate output of cerebellum and provides synergy

31

where does the output from a functional unit come from

a deep nuclear cell

32

where are afferent inputs to cerebellum mainly from

climbing and mossy fibers

33

where do all climbing fibers originate from

inferior olives

34

what are the 3 levels of the cerebellum that coordinate motor functions

vestibulocerebellum, spinocerebellum and cerebrocerebellum

35

what is the main function of vestibulocerebellum

functions in control of balance and eye movement

36

where does the vestibulocerebellum receive fibers rom

vestibular system and oculomotor system

37

what happens if there is a loss of flocculonodular lobes in vestibulocerebellum

extreme disturbance of equilibrium and postural movements

38

what changes occur when the cerebellum is removed

movements are slow to develop, force developed is weak, movements are slow to turn off

39

what does the spinocerebellum consists mostly of

vermis an intermediate zone

40

what is the main function of spinocerebellum

functions in synergy: control of rate, force, range and direction of movement

41

where does the spinocerebellum send corrections of info from 2 sources

motor cortex via thalamus and magnocellular portion of red nucleus

42

what does the cerebrocerebellum consists of

lateral parts of hemispheres

43

what is the cerebrocerebellum involved in

coordination of skilled movement and spleen (involved in motor imagery)

44

what is the cerebrocerebellum mostly associated with

premotor and the primary and association somatosensory areas of the cerebral cortex

45

what tracts form the mossy fibers that terminate on the granule cells in the cerebral cortex

corticopontocerebellar, vestibulocerebellar, reticulocerebellar and spinocerebellar

46

where does the vestibulocerebellar afferent tract terminate

in flocculonodular lobes

47

where does the reticulocerebellar afferent tracts terminate

primarily in vermis

48

describe dorsa spinocerebellar afferent tract

muscle spindles--> ipsilaterally in vermis and intermediate zones

49

how does the ventral spinocerebellar afferent tracts terminate

both ipsilaterally and contralaterally

50

signals from where excite the ventral spinocerebellar afferent tracts

cortex via corticospinal and rubrospinal tracts; internal motor pattern generators within spinal cord

51

what do the axons of the olivocerebellar afferent tracts form

climbing fibers

52

describe the cerebellareticular efferent tracts

fastigial nuclei --> reticular nuclei in pons and medulla

53

describe the cerebellothalamocortical efferent tracts

dentate, emboliform, globose nuclei --> thalamus --> motor cortex

54

describe the cerebellorubral efferent tracts

dentate, emboliform, globose nuclei --> red nucleus

55

describe the cerebellovestibular efferent tracts

cerebellum --> vestibular nuclei

56

where do basal nuclei receive most of their input from

cerebral cortex

57

where do basal nuclei return most of their output to

cerebral cortex

58

what is the principal role of basal nuclei

work with corticospinal system to modulate thalamic output to the motor cortex to plan and execute smooth movements

59

what paired nuclei do the basal nuclei consist of

striatum, globus pallidus, substantia nigra, subthalamic nucleus

60

is the putamen circuit overall excitatory or inhibitory

excitatory

61

what is the overall purpose of the putamen circuit

subconscious execution of learned patterns of movement

62

is the putamen circuit direct or indirect

direct

63

what is the neurotransmitter involved in the cerebral cortex to the putamen in the putamen circuit

acetylcholine

64

what is the neurotransmitter involved in putament to glubus pallid us and substantial nigra reticular is in the putamen circuit

GABA and dopamine

65

what is the neurotransmitter involved in the globus pallid us and substantial nigra reticular to the thalamic relay nuclei in the putamen circuit

GABA

66

what is the neurotransmitter involved in thalamic relay nuclei to primary motor cortex in the putamen circuit

glutamate

67

what neurotransmitter is used for connections between the striatum and the substantial nigra in the putamen circuit

dopamine

68

what type of receptors does dopamine use in the indirect and direct pathways

direct: D1 receptors
indirect: D2

69

what is the caudate circuit used for

cognitive planning of sequential and parallel motor patterns and major role is in cognitive control of motor activity

70

is the caudate circuit overall inhibitory or excitatory

inhibitory

71

what neurons are destroyed in huntingtons disease

GABA

72

what neurotransmitter is used to go from substantial nigra to caudate nucleus and putamen (indirect pathway)

dopamine (inhibitory)

73

what is the neurotransmitter involved in the caudate nucleus and putamen to globus pallid us and substantial nigra (indirect pathway)

GABA (inhibitory)

74

what is the neurotransmitter involved in the cortex to caudate nucleus and putamen (indirect pathway)

acetylcholine (excitatory)

75

what lesion is responsible for Parkinsons

widespread destruction of pars compacta of substantia nigra

76

what are some characteristics of parkinson's

rigidity, involuntary tremors, akinesia, postural instability, dysphagia, speech disorders, fatigue, gait disturbances

77

what is huntington's probably caused by

loss of most cell bodies of GABA-secreting neurons of caudate nucleus and putamen and of Ach neurons in other parts of the brain

78

what do GABA neurons usually do to parts of globes pallidus and substantial nigra

inhibits