Neuro 24: Cerebellum

false (indirect)

T/F: the cerebellum acts directly on LMNs

superior cerebellar peduncle

what connects the cerebellum to the midbrain?

middle cerebellar peduncle

what connects the cerebellum to the pons?

inferior cerebellar peduncle

what connects the cerebellum with the medulla

folia

tight folds in the cerebellar cortex that allows the cells to be tightly packed

purkinje

what are the only cells that send info out of the cerebellum?

1. purkinje cell layer

2. molecular cell layer

3. granule cell layer

what are the three layers of the cerebellar cortex?

purkinje

middle layer of the cerebellar cortex that contains a single row of purkinje cell bodies

molecular

layer of the cerebellar cortex that contains dendrites of purkinje cells and interneurons (basket cells)

granule

layer of the cerebellar cortex that contains interneurons with axons that branch up to synapse on the dendrites of purkinje cells

granule

which layer of the cerebellar cortex is the most cellular dense?

1. spinal cord

2. pontine nuclei

3. vestibular ganglia

4. vestibular nuclei

5. trigeminal nuclei (mesencephalic)

where do mossy cerebellar afferent fibers come from (5)?

granule cells in the granular layer of the cerebellar cortex

where do mossy afferent cerebellar fibers primarily synapse?

parallel fibers

granule cells have ______ that synapse on the purkinje dendrites in the molecular layer

excitatory

are mossy fibers excitatory or inhibitory?

excitatory

are climbing fibers excitatory or inhibitory?

inferior olivary nucleus

where do cerebellar afferent climbing fibers come from ?

purkinje cell dendrites in the molecular layer of the cerebellar cortex

where do climbing fibers from the inferior olivary nucleus primarily synapse?

proprioceptive sensory info (also motor via the pontine nuclei)

mossy fibers primarily carry what type of info to the cerebellum?

purkinje fibers

what are the only axons that leave the cerebellar cortex?

deep cerebellar nuclei (DCN) located in the white matter

where do purkine fibers terminate and where is it located?

1. fastigial

2. globose

3. emboliform

4. dentate

what are the cerebellar nuclei (DCN) from most medial to most lateral?

nucleus interpositus

the globose and emboliform cerebellar nuclei are together called the?

flocculonodular lobe, terminate on the vestibular nuclei

purkinje fibers from where in the cerebellum bypass the DCN and where do they terminate instead?

1. vestibulocerebellum (flocculonodular lobe)

2. spinocerebellum (vermal and paravermal intermediate regions)

3. cerebrocerebellum (lateral hemispheres)

what are the three functional regions of the cerebellum?

1. vestibular ganglion via vestibular nerve

2. vestibular nuclei

3. primary and secondary visual cortex

4. cuenospinal tract

**note: must have at least 2 functioning or else will fall over

from where does the vestibulocerebellum (flocculonodular lobe) receive mossy fibers (afferents)?

vestibular nuclei

where do efferents from the vestibulocerebellum (flocculonodular lobe) go?

• medial and lateral vestibulospinal tracts (innervate axial and proximal limb)

• balance during stance and gait

• controls eye movements (smooth pursuit)

what does the vestibulocerebellum or flocculonodular lobe influence?

fastigial nucleus

where do efferents from the cortex of the vermis project?

1. axial skeleton proprioception

   1. dorsal spinocerebellar tracts

   2. ventral spinocerebellar tracts

   3. cuneocerebellar tracts

2. also some vestibular and visual

what is the afferent input to the vermis - mossy fibers?

1. medullary reticular formation

2. lateral vestibular nucleus

where do axons from the fastigial nucleus (from the vermis) project to (2)?

lateral reticulospinal tract

where do UMNs in the medullary reticular formation project to (originally from the vermis)?

lateral vestibulospinal tract

where do UMNs in the lateral vestibular nucleus project to (originally from the vermis)

vermis

the ______ region of the cerebellum mainly controls the brainstem components of the medial descending motor system

vermis

what region of the cerebellum governs posture, locomotion, and saccadic eye movements

• distal limb proprioception

  • dorsal spinocerebellar tract

  • ventral spinocerebellar tract

  • cuenocerebellar tract

where is the afferent input (mossy fibers) to the spinocerebellum (intermediate region) from?

interpositus nucleus

purkinje cells from the cortex of the intermediate region of the spinocerebellum project to?

1. red nucleus (rubrospinal tract)

2. indirectly to the lateral corticospinal tract

where do axons from the interposed nucleus project to - originally from the intermediate region of the spinocerebellum (2)?

interposed nucleus

what mainly controls the lateral descending motor system?

motor control of the distal limb and digit muslces

what is the output of the intermediate region of the spinocerebellum?

somatotopic

the spinocerebellar and trigeminocerebellar tracts have a _________ input to the spinocerebellum

frontal and parietal motor cortices (vai the corticopontine fibers)

where does the pontine nucleus receive input from?

middle cerebellar peduncle

where do pontocerebellar (mossy) fibers from the pontine nucleus project through to the cortex of the lateral cerebellar hemisphere?

cortex of the lateral cerebellar hemispheres

where do pontocerebellar fibers from the pontine nuclei project to?

cortex of the lateral cerebellar hemispheres (on purkinje cell dendrites located in the molecular layer)

where do climbing fibers from the inferior olivary nucleus project to?

dentate nucleus

purkinje cells of the cortex of the lateral cerebellar hemispheres project to what nucleus?

superior cerebellar peduncle

where do axons from the dentate nucleus (from the lateral hemispheres) exit the cerebellum?

1. contralateral ventrolateral nucleus of the thalamus → motor, premotor, prefrontal, parietal cortices

2. contralateral red nucleus → inferior olivary nucleus

dentate nucleus axons exit the superior cerebellar peduncle and terminate on (2)?

cerebrocerebellum

feedback circuit that regulates motor programs in a voluntary skilled movement

cerebrocerebellum

brings about (1) smooth and orderly sequence of muscle contraction and (2) accurate and precise movements in direction and force

cerebellum

uses the error from predictive to real sensory feedback to help guide corrective movements (in-flight correction)

muscle force

cerebellar damage can lead to lack of controlling _____ across several joints (e.g. tell patient to flex elbow, but they flex their elbow and shoulder)

interneurons, inhibitory

golgi, stellate, and basket cells are all local ____ that provide ______ input to the purkinje cells

inhibitory

the output of the cerebellar cortex to the DCN via the purkinje fibers is mainly _______