Cerebellum

Question 1

Inability to maintain proper balance resulting from cerebellar lesion

Results mainly from disruption of input from the vestibular system

Answer 1

disequilibrium

Question 2

Decreased muscle tone and difficulty in maintaining posture resulting from cerebellar lesion

Results from disruption of spinocerebellar inputs

Answer 2

hypotonia

Question 3

Lack of coordination of muscles that usually work together resulting from cerebellar lesion

Results from damage to the pathways from higher levels (cortico-ponto-cerebellar) or from lower levels (spinocerebellar)

Answer 3

asynergia

Question 4

lack of coordination of voluntary movements resulting from cerebellar lesion

Answer 4

ataxia

Question 5

Tremor most apparent during a planned movement just before the patient reaches the target resulting from cerebellar lesion

Answer 5

intention tremor

Question 6

Patient tends to overshoot or undershoot reaching for a target resulting from cerebellar lesion

Answer 6

dysmetria

Question 7

Mainly contains fibers entering the cerebellum from spinal cord and brainstem

Contains outputs to the medulla oblongata, vestibular nuclei and reticular formation

Attaches cerebellum to the medulla oblongata

Answer 7

inferior cerebellar peduncle

Question 8

Only contains fibers entering the cerebellum from pons

Attaches the cerebellum to the pons

Answer 8

middle cerebellar peduncle

Question 9

Mainly contains cerebellar outputs going to the red nucleus and VA/VL thalamus

Exception – input from spinal cord (ventral spinocerebellar tract)

Attaches cerebellum to the midbrain

Answer 9

superior cerebellar peduncle

Question 10

cerebellar input
Originates from nucleus Dorsalis of Clark (C8-L2)
Runs on the ipsilateral side of the spinal cord and brainstem
Enters the cerebellum by via the inferior cerebellar peduncle
Axons synapse mainly in the anterior lobe of the cerebellum
Conveys information regarding muscle tone for the lower extremity

Answer 10

dorsal spinocerebellar tract

Question 11

cerebellar input
Originates from posterior horn neurons in the spinal cord at all cord levels
Axons cross in anterior commissure of the spinal cord
Enters cerebellum in the superior cerebellar peduncle
Axons synapse mainly in the anterior lobe of the cerebellum
Conveys information about whole muscle movement

Answer 11

ventral spinocerebellar tract

Question 12

cerebellar input
First order neuron (DRG cells) axons ascend in the dorsal funiculus to synapse in the lateral cuneate nucleus of the medulla oblongata (lateral to the nucleus cuneatus)
Axons of neurons in the lateral cuneate nucleus form the cuneocerebellar tract which enters the cerebellum in the inferior cerebellar peduncle and projects to the anterior lobe
Conveys information regarding muscle tone for the upper extremity

Answer 12

cuneocerebellar tract

Question 13

cerebellar input
Axons cross in the medulla oblongata and enter the cerebellum in the inferior cerebellar peduncle
Axons project to the entire cerebellar cortex

Answer 13

inferior olivary nucleus

Question 14

cerebellar input
Axons enter the cerebellum in the inferior cerebellar peduncle
Axons project mainly to the anterior lobe

Answer 14

reticular formation

Question 15

cerebellar input
Axons enter the cerebellum in the inferior cerebellar peduncle
Axons project mainly to the flocculonodular lobe

Answer 15

vestibular nuclei axons and vestibular ganglion cell axons

Question 16

cerebellar input
Axons from cerebral cortex synapse in the pontine grey nuclei
Axons of the pontine grey nuclei form pontocerebellar axons which cross in the pons to enter the cerebellum in the middle cerebellar peduncle
Motor areas of cerebral cortex project to cerebellum via pons

Answer 16

cerebral cortex does not connect directly to cerebellum but relays through pons

Question 17

superficial layer of cerebellar cortex
located under the pia mater, contains mainly large bundles of unmyelinated axons packed together (parallel fibers) and dendrites of Purkinje cells

Answer 17

molecular layer

Question 18

intermediate layer of cerebellar cortex
single layer of Purkinje cell bodies
Axons of Purkinje cells leave the cerebellar cortex and synapse with neurons in deep cerebellar nuclei
Purkinje cells are all inhibitory and are the only neurons of cerebellar cortex whose axons leave the cerebellar cortex
All others neurons in cerebellar cortex are interneurons

Answer 18

Purkinje cell layer

Question 19

deep layer of cerebellar cortex
granule cells whose axons form the parallel fibers running in the molecular layer and synapsing on Purkinje cell dendrites, parallel fibers are excitatory

Answer 19

granular layer

Question 20

originate from neurons in the spinal cord, reticular formation, vestibular nuclei, potine grey, and vestibular ganglion cells

Synapse mainly with granule cells
Enter the cerebellar cortex and send collateral axon branches to the deep cerebellar nuclei neurons where they synapse

excitatory fibers

Answer 20

mossy fibers

Question 21

originate from neurons in the inferior olive and synapse mainly on dendrites of the Purkinje cells in the molecular layer

Enter the cerebellar cortex and send collateral axon branches to synapse on neurons in the deep cerebellar nuclei

excitatory fibers

Answer 21

climbing fibers

Question 22

deep cerebellar nucleus
lies close to midline
receives input from Purkinje cells in the vermis, vestibular nuclei, and vestibular ganglion cells
outputs mainly go to vestibular nuclei and reticular formation
concerned with regulating extensor muscle tone and adjusting posture

Answer 22

fastigial nucleus

Question 23

deep cerebellar nucleus
Several small groups of neurons found lateral to the fastigial nucleus
Receives input from Purkinje cells in the intermediate zone
Output goes to the red nucleus and VA/VL thalamus
Concerned with regulating flexor muscle tone and limb movements

Answer 23

globose nucleus and emboliform nucleus (interposed nucleus)

Question 24

Largest and most laterally places deep cerebellar nuclei
Receives input from Purkinje cells in the lateral cerebellar hemispheres
Output foes to red nucleus and VA/VL thalamus
Concerned with coordinating somatic motor activity by influencing motor regions of cerebral cortex
Coordinates finger movements and skilled movements

Answer 24

dentate nucleus