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

Question 1

what signals does the primary motor cortex send

Answer 1

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

Question 2

what does the premotor cortex (area 6) do

Answer 2

plans movement based on sensory and visual cues

Question 3

what does the supplementary motor area (area 6) do

Answer 3

retrieves and coordinates memorized motor sequences

Question 4

T/F cerebellum is essential for locomotion

Answer 4

FALSE

Question 5

what separates the 2 hemispheres of the cerebellum

Answer 5

vermis

Question 6

what are each hemisphere of the cerebellum divided into

Answer 6

intermediate zone and lateral zone

Question 7

what are the 3 lobes of the cerebellum

Answer 7

anterior lobe, posterior lobe, flocculonodular lobe

Question 8

what is the “oldest” lobe of the brain

Answer 8

flocculonodular lobe

Question 9

what is the intermediate zone associated with

Answer 9

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

Question 10

what is the lateral zone associated with

Answer 10

cerebral cortex with planning of sequential motor movements

Question 11

name the intracerebellar nuclei

Answer 11

dentate, emboliform, globose, fastigial

Question 12

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

Answer 12

extremity ataxia

Question 13

what happens if there is a lesion in the fastigial nuclei

Answer 13

trunk ataxia

Question 14

where do fastigial nuclei fibers project

Answer 14

to reticular formation and vestibular nuclei

Question 15

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

Answer 15

granule cells, golgi type 2 cells, and glomeruli

Question 16

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

Answer 16

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

Question 17

what cell in the cerebellar cortex is excitatory

Answer 17

granular cells

Question 18

describe granular cells

Answer 18

axons form parallel fibers in cortex

Question 19

describe golgi cells

Answer 19

project from parallel fibers to granular cell bodies

Question 20

describe basket cells

Answer 20

project from parallel fibers to purkinje axon hillock

Question 21

describe stellate cells

Answer 21

project from parallel fibers to purkinje dendrites

Question 22

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

Answer 22

basket and stellate cells

Question 23

what is the only output from the cortex

Answer 23

purkinje cells

Question 24

what do climbing fibers originate from

Answer 24

medullary olives

Question 25

what "conditions" the purkinje cells

Answer 25

climbing fibers

Question 26

where do mossy fibers originate

Answer 26

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

Question 27

where do mossy fibers synapse

Answer 27

on granule cells in glomeruli

Question 28

what neurotransmitter do purkinje cell axons use

Answer 28

GABA

Question 29

where do purkinje cell axons project

Answer 29

deep cerebellar nuclei and vestibular nucleus

Question 30

what do purkinje cell axons do

Answer 30

modulate output of cerebellum and provides synergy

Question 31

where does the output from a functional unit come from

Answer 31

a deep nuclear cell

Question 32

where are afferent inputs to cerebellum mainly from

Answer 32

climbing and mossy fibers

Question 33

where do all climbing fibers originate from

Answer 33

inferior olives

Question 34

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

Answer 34

vestibulocerebellum, spinocerebellum and cerebrocerebellum

Question 35

what is the main function of vestibulocerebellum

Answer 35

functions in control of balance and eye movement

Question 36

where does the vestibulocerebellum receive fibers rom

Answer 36

vestibular system and oculomotor system

Question 37

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

Answer 37

extreme disturbance of equilibrium and postural movements

Question 38

what changes occur when the cerebellum is removed

Answer 38

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

Question 39

what does the spinocerebellum consists mostly of

Answer 39

vermis an intermediate zone

Question 40

what is the main function of spinocerebellum

Answer 40

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

Question 41

where does the spinocerebellum send corrections of info from 2 sources

Answer 41

motor cortex via thalamus and magnocellular portion of red nucleus

Question 42

what does the cerebrocerebellum consists of

Answer 42

lateral parts of hemispheres

Question 43

what is the cerebrocerebellum involved in

Answer 43

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

Question 44

what is the cerebrocerebellum mostly associated with

Answer 44

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

Question 45

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

Answer 45

corticopontocerebellar, vestibulocerebellar, reticulocerebellar and spinocerebellar

Question 46

where does the vestibulocerebellar afferent tract terminate

Answer 46

in flocculonodular lobes

Question 47

where does the reticulocerebellar afferent tracts terminate

Answer 47

primarily in vermis

Question 48

describe dorsa spinocerebellar afferent tract

Answer 48

muscle spindles--> ipsilaterally in vermis and intermediate zones

Question 49

how does the ventral spinocerebellar afferent tracts terminate

Answer 49

both ipsilaterally and contralaterally

Question 50

signals from where excite the ventral spinocerebellar afferent tracts

Answer 50

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

Question 51

what do the axons of the olivocerebellar afferent tracts form

Answer 51

climbing fibers

Question 52

describe the cerebellareticular efferent tracts

Answer 52

fastigial nuclei --> reticular nuclei in pons and medulla

Question 53

describe the cerebellothalamocortical efferent tracts

Answer 53

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

Question 54

describe the cerebellorubral efferent tracts

Answer 54

dentate, emboliform, globose nuclei --> red nucleus

Question 55

describe the cerebellovestibular efferent tracts

Answer 55

cerebellum --> vestibular nuclei

Question 56

where do basal nuclei receive most of their input from

Answer 56

cerebral cortex

Question 57

where do basal nuclei return most of their output to

Answer 57

cerebral cortex

Question 58

what is the principal role of basal nuclei

Answer 58

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

Question 59

what paired nuclei do the basal nuclei consist of

Answer 59

striatum, globus pallidus, substantia nigra, subthalamic nucleus

Question 60

is the putamen circuit overall excitatory or inhibitory

Answer 60

excitatory

Question 61

what is the overall purpose of the putamen circuit

Answer 61

subconscious execution of learned patterns of movement

Question 62

is the putamen circuit direct or indirect

Answer 62

direct

Question 63

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

Answer 63

acetylcholine

Question 64

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

Answer 64

GABA and dopamine

Question 65

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

Answer 65

GABA

Question 66

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

Answer 66

glutamate

Question 67

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

Answer 67

dopamine

Question 68

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

Answer 68

direct: D1 receptors indirect: D2

Question 69

what is the caudate circuit used for

Answer 69

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

Question 70

is the caudate circuit overall inhibitory or excitatory

Answer 70

inhibitory

Question 71

what neurons are destroyed in huntingtons disease

Answer 71

GABA

Question 72

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

Answer 72

dopamine (inhibitory)

Question 73

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

Answer 73

GABA (inhibitory)

Question 74

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

Answer 74

acetylcholine (excitatory)

Question 75

what lesion is responsible for Parkinsons

Answer 75

widespread destruction of pars compacta of substantia nigra

Question 76

what are some characteristics of parkinson's

Answer 76

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

Question 77

what is huntington's probably caused by

Answer 77

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

Question 78

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

Answer 78

inhibits