Cerebellum

Question 1

location of cerebellum

Answer 1

sits in the dorsal aspect of the brainstem and forms the roof of the fourth ventricle

Question 2

rostral to caudal organization & functions of cerebellum

Answer 2

1) anterior lobe (motor coordination)
2) posterior lobe (motor coordination = medial; motor planning = lateral)
3) flocculonodular lobe (vestibular, balance, and eye movements)

Question 3

medial to lateral organization and function of cerebellum

Answer 3

1) vermis (midline) - motor coordination (rostral) and limbic function (caudal)
2) paravermis - motor coordination
3) lateral hemispheres - motor planning

Question 4

functional terms for cerebellar organization

Answer 4

1) vestibulocerebellum
2) spinocerebellum
3) neocerebellum

Question 5

vestibulocerebellum

Answer 5

*flocculonodular lobe
*coordinates balance, posture, and eye movements

Question 6

spinocerebellum

Answer 6

*anterior lobe, vermis, & paravermis
*responsible for muscular coordination

Question 7

neocerebellum

Answer 7

*lateral hemispheres
*responsible for movement planning and cognitive functions

Question 8

lateral hemispheres of cerebellum - function and motor pathway influenced

Answer 8

*functions: motor planning for extremities
*motor pathway influenced: lateral corticospinal tract

Question 9

intermediate hemispheres - function and motor pathway influenced

Answer 9

*function: distal limb coordination
*motor pathway influenced: lateral corticospinal tract and rubrospinal tract

Question 10

vermis - function and motor pathway influenced

Answer 10

*function: proximal limb and trunk coordination
*motor pathways influenced: anterior corticospinal tract, vestibulospinal tract, and tectospinal tract

Question 11

flocculonodular lobe - function and motor pathway influenced

Answer 11

*function: balance and vestibulo-ocular reflexes
*motor pathways influenced: medial longitudinal fasciculus

Question 12

the cerebellum coordinates movements of which side of the body

Answer 12

IPSILATERAL SIDE (cerebellum decussates to contralateral cortex, which then decussates again to the contralateral body, thus affecting ipsilateral body)

Question 13

classic cerebellar symptoms

Answer 13

1) delay in the initiation of movement
2) ataxia (intention tremor, dysmetria, dysdiadochokinesia)
3) hypotonia
4) unsteady gait

Question 14

classic sign of ANY cerebellar lesion

Answer 14

cerebellar ataxia (loss of balance & wide-based gait)

Question 15

dysmetria

Answer 15

*classic sign of cerebellar disorder
*loss of coordinated movement (example: inability to perform finger-to-nose test)

Question 16

intention tremor

Answer 16

*classic sign of cerebellar disorder
*can’t get hand to target/tremor starts as you approach the target

Question 17

dysdiadochokinesia

Answer 17

*classic sign of cerebellar disorder
*can’t make movements exhibiting a rapid change of motion (example, flipping hand in palm)
*indicates an issue with the spinocerebellum (coordination of movements)

Question 18

3 layers of cerebellar cortex

Answer 18

1) granule cell layer (innermost)
2) purkinje cell layer (middle)
3) molecular layer (outermost)

Question 19

inputs to the cerebellum are derived from what types of fibers

Answer 19

1) mossy fibers
2) climbing fibers

Question 20

climbing fibers

Answer 20

arise from contralateral inferior olivary nucleus, wrapping the purkinje cell body and proximal dendrite

Question 21

mossy fibers

Answer 21

all cerebellar inputs (other than those from the inferior olive); synapse on granule cells

Question 22

important cell types found within the cerebellum

Answer 22

1) purkinje fibers
2) deep nuclei

Question 23

purkinje fibers

Answer 23

*cerebellar neurons that receive numerous inputs
*project to deep nuclei
*INHIBITORY: release GABA onto the deep nuclei

Question 24

deep cerebellar nuclei

Answer 24

*cells that send projections OUT OF the cerebellum to thalamus, red nucleus, vestibular nuclei, etc

Question 25

4 important spinal cord fiber tracts that relay info about the limbs to the cerebellum

Answer 25

1. cuneocerebellar 2. posterior (dorsal) spinocerebellar 3. rostral spinocerebellar 4. anterior (ventral) spinocerebellar

Question 26

cuneocerebellar tract

Answer 26

relays real time information about UPPER LIMB movements

Question 27

posterior (dorsal) spinocerebellar tract

Answer 27

relays real time information about LOWER LIMB movements

Question 28

rostral spinocerebellar tract

Answer 28

reflects activity about spinal cord interneurons of UPPER limb

Question 29

anterior (ventral) spinocerebellar tract

Answer 29

reflects activity about spinal cord interneurons of LOWER limb

Question 30

4 deep cerebellar nuclei

Answer 30

1) dentate nucleus (lateral-most) 2/3) interposed nuclei: globus and emboliform 4) fastigial nucleus (medial)

Question 31

inferior cerebellar peduncles

Answer 31

*input to cerebellum, from: -spinal cord -brainstem -vestibular nuclei -inferior olive *carries ipsilateral spinal cord information about proprioception

Question 32

middle cerebellar peduncle

Answer 32

*input to cerebellum from PONS

Question 33

superior cerebellar peduncle

Answer 33

*output from cerebellum *carries efferents to the brainstem and the ventrolateral thalamus (VL is the relay to primary motor cortex)

Question 34

tremors

Answer 34

repetitive, oscillating movements

Question 35

resting tremors - structural association?

Answer 35

basal nuclei dysfunction

Question 36

intention tremors - structural association?

Answer 36

cerebellum dysfunction

Question 37

essential tremor - structural association?

Answer 37

possibly inferior olive dysfunction

Question 38

symptoms of upper motor neuron damage

Answer 38

-paralysis or paresis -loss of fine movement -evolves to spasticity *increased muscle tone *hyperreflexia *babinski sign

Question 39

symptoms of lower motor neuron damage

Answer 39

-paralysis or paresis -hyporeflexia -loss of muscle tone -fasciculation and fibrillation -muscle atrophy

Question 40

symptoms of cerebellar damage

Answer 40

*ataxia -hypotonia -intention tremor -balance and gait -brainstem signs -nystagmus

Question 41

symptoms of basal nuclei damage

Answer 41

-dyskinesia -rigidity -resting tremor -gait and dyskinesia -no brainstem signs -symptoms get worse