test 3

Question 1

3 cerebellar nuclei

Answer 1

1. Fastigial Nucleus
2. Interposed nucleus
3. Dentate Nucleus

Question 2

mossy fibers

Answer 2

synapse on granule cells to excite. project to purkinje cells which have inhibitory function to deep cerebellar nuclei.

Question 3

Afferent info to cerebellum

Answer 3

stimulated by mossy in deep cerebellar nucleus. then other branch of mossy goes to cortex, granule cells then purkinje inhibit deep nucleus to form an excitatory then inhibitory loop

Question 4

climbing fibers

Answer 4

come from inferior olivary nucleus in medulla. still stimulate deep nucleus, but other branch goes directly to purkinje cells.
thought to be motor learning mechanism.

Question 5

Vestibulocerebellum

Answer 5

aka floculonodular.
no deep cerebellar associated
minimizes synapses for quick balance and righting against gravity.

Question 6

Afferents to vestibulocerebellum

Answer 6

directly from vestibular system to cerebellar cortex
or from visual system
to floculonodular lobe
excitation comes from afferents and purkinje project to vestibular nuclei through inferior cerebellar peduncle

Question 7

Clinical observations of vestibulocerebellum

Answer 7

difficulty with equilibrium
wide based gait and ataxia- series of motions not what they should be
nystagmus during movement
symptoms improve if patient lies down

Question 8

Nuclei of spinocerebellum

Answer 8

Fastigeal and interposed

Question 9

Afferent to spino cerebellum from lower extremities

Answer 9

info from lower extremities and trunk. travel up fasciculus gracilis, synapse on Clark’s nucleus in thoracic region. ascend in dorsal spinocerebellar tract. enter the cerebellum using the inferior cerebellar peduncle.

Question 10

Afferent to spino cerebellum from upper extremities

Answer 10

ascend fasiculus cuneatus without synapse. until medulla, where they synapse on external cuneate nucleus. then form the cuneocerebellar tract which enter the cerebellum using the inferior cerebellar peduncle.

Question 11

Afferent to spinocerebellum

Answer 11

indirectly from somatosensory, motor, visual and auditory cortex, through pontine nuclei and middle cerebellar peduncle to cerebellar cortex on mossy fibers to interposed and fastigial

Question 12

Fastigial nucleus targets- 2

Answer 12

1. bilaterally innervate the reticular formation and vestibular nuclei. influences reticulospinal and vestibulospinal tracts - axial musculature.
2. sends projections to the contralateral ventral lateral nucleus of thalamus. project to motor cortex- anterior corticospinal tract- so fastigial influences axial motor nuclei.

Question 13

Interposed nucleus targets - 2

Answer 13

1. contralateral red nucleus. which gives rise to a crossed rubrospinal tract that influences distal musculature.
2. contralateral ventral lateral nucleus in thalamus. then project to the motor cortex and give rise to the lateral corticospinal tract- distal muscles.

Question 14

fastigial clinical observations

Answer 14

usually damaged bilaterally b/c nuclei are so close- in vermis. damaged to axial systems and trunk. difficulty sitting and standing up. trunk titubations
drunken sailors gait. dysarthria from tongue control problems

Question 15

Interposed clinical observations

Answer 15

symptoms same side as damage
ataxia limb movements
intention tremor

Question 16

cerebrocerebellum

Answer 16

lateral portion of cerebellum- dentate nucleus

Question 17

afferent to cerebrocerebellum

Answer 17

from primary motor, premotor, primary sensory, and sensory association cortex via pontine nuclei and middle cerebellar peduncle on mossy fibers to dentate nucleus

Question 18

dentate nucleus targets -2

Answer 18

1. contralateral ventral lateral nucleus- info is returned to contralateral motor and premotor cortex
2. contralateral red nucleus- influence neurons that project to inferior olives- source of climbing fibers innervation to cerebellum- go back to dentate andd cortex- feedback loop

Question 19

clinical observations of cerebrocerebellum

Answer 19

dysmetria/ hypermetria
dysdiadochokinesia
initiation of movement
linguistic and spatial memories

Question 20

Nuclei of basal ganglia- 9

Answer 20

Receptive
1. caudate 
2. putamen
3. nucleus accumbens
Projection
4. globus pallidus internus
5. substantia nigra reticulata
6. ventral pallidum
Modulatory
7. globus pallidus externus
8. substantia nigra compacta
9. subthalamic nucleus