Neuro - Cerebellum

Front 1

Primary functions of cerebellum?

Back 1

Posture and balance, muscle tone, coordination of voluntary motor activity, learning of repeated motor functions

Front 2

Major cerebellar pathway?

Back 2

PURKINJE cells of cerebellar CORTEX -> cerebellar nuclei (e.g. DENTATE nuc) -> thru sup cerebell peduncle to contralateral VL (via dentothalamic tract) -> to primary MOTOR CORTEX of precentral gyrus -> to PONTINE nuclei (as corticopontine tract) -> to contralat cerebellar CORTEX (as pontocerebellar tract), and terminate as MOSSY FIBERS

Front 3

Three cell layers of cerebellar cortex?

Back 3

1. Molecular layer (outer)
2. Purkinje cell layer (middle)
3. Granule layer (inner)

Front 4

Input cerebellar peduncles?

Back 4

ICP, MCP

Front 5

2 types of cerebellar input fibers?

Back 5

Mossy, climbing

Front 6

Mossy fibers bring input from where? Excitatory or inhibitory? What do they terminate on?

Back 6

From pons (pontocerebellar), spinal cord (spinocerebellar), and vestibular nuc (vestibulocerebellar tracts); EXCITATORY; synapse on granule cell dendrites (which excite via parallel fibers)

Front 7

Climbing fibers bring input from where? Excitatory or inhibitory? What do they terminate on?

Back 7

From contralat inferior olivary nuc (olivocerebellar tract); EXCITATORY; terminate on cerebell nuc and purkinje dendrites

Front 8

Output cerebellar peduncle?

Back 8

SCP (from deep cerebellar nuclei: fastigial, interpositus, dentate)

Front 9

Output cerebellar fibers? Type of NT?

Back 9

Purkinje cell axons; GABA

Front 10

Where do Purkinje fibers project to?

Back 10

Cerebellar nuclei, vestibular nuclei

Front 11

What is anterior vermis syndrome? Common cause? Symptoms?

Back 11

-atrophy of ant lobe (leg region)
-caused by etoh abuse
-sx: gait, trunk, leg DYSTAXIA

Front 12

What is posterior vermis syndrome? Cause? Symptoms?

Back 12

-usu. caused by tumor in flocculonodular lobe, often in children
-sx: truncal DYSTAXIA

Front 13

Triad of cerebellar dysfunction

Back 13

HYPOTONIA (floppy, rag-doll, pendular reflexes)
DYSEQUILIBRIUM (gait and trunk dystaxia)
DYSSYNERGIA (loss of coordinated muscle activity)

Front 14

Types of DYSSYNERGIC symptoms

Back 14

dysmetria (inability to accurately control range of motion), INTENTION tremor, failure to check mvts, coarse nystagmus, dysdiadochokinesia (can't 'screw in lightbulb'), scanning dysarthria (difficulty articulating)

Front 15

Types of cerebellar tumors? (mostly in kids)

Back 15

1. astrocytomas (cerebellar hemisphere, good prognosis)
2. medulloblastomas (malignant, from granule layer, cause hydrocephalus)
3. ependymomas (often in 4th ventricle, cause hydrocephalus)

Front 16

What type of fibers excite Purkinje cells directly?

Back 16

Climbing fibers

Front 17

What type of fibers excite Purkinje cells indirectly?

Back 17

Mossy fibers (via granule cell/parallel fibers)

Front 18

What are the 3 types of local circuit neurons in the cerebellum? Are they excitatory or inhibitory?

Back 18

basket cells, stellates, cells, and Golgi type II cells

all are inhibitory, use GABA

Front 19

What two places do fibers leaving the superior cerebellar peduncle synapse?

Back 19

Red nucleus (and then descends as rubrospinal tract) and VL thalamus (to cortex, which then descends as corticopontine fibers or corticospinal fibers)

Front 20

Does a lesion of the cerebellum cause ipsilateral or contralateral cerebellar deficits?

Back 20

ipsilateral

Front 21

Does a lesion of the red nucleus cause ipsilateral or contralateral cerebellar deficits?

Back 21

contralateral

Front 22

Does a lesion of the VL cause ipsilateral or contralateral deficits?

Back 22

contralateral