Basal Ganglia, Cerebellum, & CN Motor Pathways

Question 1

what are the parts of the basal ganglia?

Answer 1

striatum, lenticular nucleus, substantia nigra, subthalamic nucleus

Question 2

what makes up the striatum?

Answer 2

putamen, nucleus accumbens, caudate nucleus
this is a functional nucleus

Question 3

what makes up the lenticular nucleus?

Answer 3

putamen and globus pallidus

Question 4

what is the net affect of the direct pathway?

Answer 4

turn on the motor cortex
disinhibition of thalamic control of motor planning

Question 5

what is the net affect of the indirect pathway?

Answer 5

turning off the motor cortex
activation of inhibition

Question 6

draw the direct pathway

Question 7

draw the indirect pathway

Question 8

draw the indirect dopamine pathway

Question 9

what is Parkinson’s? what are some characteristics of Parkinson’s?

Answer 9

a hypo kinetic disorder caused by depletion of dopamine particularly in the substantial nigra
resting tremors, shuffling gait, cogwheel rigidity

Question 10

what is hemiballismus?

Answer 10

a hyperkinetic disorder in which the subthalamic nucleus is affected
violent, involuntary movement of proximal limbs

Question 11

what is Huntington’s disease?

Answer 11

hyperkinetic disorder in which the striatum is primarily affected
dancing movement of distal limbs

Question 12

what are the three functional divisions of the cerebellum?

Answer 12

spinocerebellum, cerebrocerebellum, vestibulocerebellum

Question 13

spinocerebellum

Answer 13

made up of the vermis and paravermis
postural and movement control of trunk and limbs

Question 14

cerebrocerebellum

Answer 14

lateral hemispheres
fine motor and non-motor planning

Question 15

vestibulocerebellum

Answer 15

flocculonodular lobe
coordinating head and eye movements

Question 16

what are the deep nuclei of the cerebellum?

Answer 16

dentate, emboliform, globose, fastigial

Question 17

what is the dentate nucleus?

Answer 17

relay nucleus of the cerebrocerebellum to motor centers

Question 18

what are the emboliform and globose nucleus?

Answer 18

aka interposed nuclei
relay nuclei of the spino-cerebellum to motor centers

Question 19

what does the fastigial nucleus do?

Answer 19

project to reticular formation and vestibular nuclei

Question 20

what are the afferent tracts of the inferior cerebellar peduncle?

Answer 20

olivocerebellar, dorsal spinocerebellar, cuneocerebellar, vestibulocerebellar

Question 21

what are the efferent tracts of the inferior cerebellar peduncle?

Answer 21

vestibulospinal tract
fibers from the fastigial nucleus travel to join with CN VIII

Question 22

what are the afferent tracts of the middle cerebellar peduncle?

Answer 22

pontocerebellar

Question 23

what are the afferent tracts of the superior cerebellar peduncle?

Answer 23

ventral and rostral spinocerebellar

Question 24

what are the efferent tracts of the superior cerebellar peduncle?

Answer 24

dentatothalamic tract
fibers from the interposed nuclei

Question 25

why are ventral and rostral spinocerebellar tracts special?

Answer 25

they provide anatomical insurance since they are functionally very similar to the dorsocerebellar and cuneocerebellar tracts

Question 26

what are the input tracts of the spinocerebellum?

Answer 26

Dorsal and ventral spinocerebellar (LE&T) cuneocerebellar and rostral spinocerebellar (UE)

Question 27

what is special about the rostral and ventral spinocerebellar tracts?

Answer 27

they double cross, go to the contralateral side and then back to the ipsilateral side

Question 28

what is the pathway of the dorsal spinocerebellar tract?

Answer 28

starts by following the gracile fascicle in the dorsal columns, which then ascends and synapses on Clark's nucleus in the thoracic sc area the tract will move more dorsolateral in the sc and ascend through the inferior cerebellar peduncle

Question 29

what is the pathway of the cuneocerebellar tract?

Answer 29

follows the cuneate fascicle and synapses on the cuneate nucleus in the medulla ascends through the inferior cerebellar peduncle

Question 30

where does the fastigial nucleus project to?

Answer 30

the reticular formation in the reticulospinal tract and vestibular nuclei in the vestibulospinal tract spinocerebellum output

Question 31

where does the interposed nuclei project to?

Answer 31

the red nucleus and ventrolateral nucleus of the thalamus

Question 32

where does the vestibulocerebellum get input from?

Answer 32

directly from vestibular afferents, vestibular nuclei

Question 33

what are the outputs of the vestibulocerebellum?

Answer 33

medial longitudinal fasciculus medial vestibulospinal - coordinates neck/eye movements lateral vestibulospinal - maintains balance

Question 34

what are the inputs of the cerebrocerebellum?

Answer 34

corticopontine fibers - pontine nuclei - pontocerebellar tract projects to the contralateral cerebellum cortico-rubro-olivary pathway leads to the olivocerebellar tract

Question 35

what are the outputs of the cerebrocerebellum?

Answer 35

dentatothalamic fibers send signals to the ventrolateral nucleus of the thalamus fibers to red nucleus form loop through inferior olivary nucleus

Question 36

what are the layers of the cerebellum from outside to inside?

Answer 36

molecular layer, purkinje cell, granular cell layer

Question 37

what do granular cells receive input from?

Answer 37

all pathways but the inferior olive

Question 38

what do purkinje cells receive input from?

Answer 38

contralateral inferior olive (climbing fibers) and granule cells

Question 39

where do purkinje cells project to?

Answer 39

deep nuclei

Question 40

symptoms of vestibulocerebellum lesion

Answer 40

wide gait, nystagmus

Question 41

symptoms of spinocerebellum lesion

Answer 41

ataxia, stomping gait

Question 42

symptoms of cerebrocerebellum lesion

Answer 42

intention tremor, dysdiadochokinesia fine motor loss

Question 43

where are the oculomotor and Edinger-Westphal nuclei located? what is the blood supply?

Answer 43

rostral midbrain at the level of the red nucleus paramedian branches from basilar or PCA

Question 44

where is the trochlear nucleus located? what is the blood supply?

Answer 44

dorsal, caudal midbrain nerve fibers decussate immediately in the tectum paramedian branches or PCA

Question 45

where is the trigeminal motor nucleus located? what is the blood supply?

Answer 45

medial to principle sensory nucleus mid -pons AICA or circumferential branches

Question 46

where is the abducens nucleus located? what is the blood supply?

Answer 46

the dorsal aspect of the caudal pons paramedian branches

Question 47

where is the facial nucleus located? what is the blood supply?

Answer 47

ventral area of the tegmentum in the caudal pons AICA or circumferential branches

Question 48

where is the superior salivatory nucleus located?

Answer 48

dorsomedial to the facial nucleus in mid to caudal pons

Question 49

where is the nucleus ambiguus located? what is the blood supply?

Answer 49

mid to central portion of the rostral medulla PICA

Question 50

where is the dorsal motor nucleus of vagus located? what is the blood supply?

Answer 50

in rostral medulla, deep to vagal trigone provides parasymp innervation for most visceral organs in thorax/abdomen PICA

Question 51

where is the spinal accessory nucleus located? what is the blood supply?

Answer 51

in the same area as the ventral horn in the upper cervical sc PICA or VA

Question 52

where is the hypoglossal nucleus located? what is the blood supply?

Answer 52

in rostral medulla deep to hypoglossal trigone ASA or VA