Cerebellum

Question 1

Cerebellum constitutes ____ of brain volume, but contains ____ of CNS cells

Answer 1

1/10 volume
>1/2 CNS cells

Question 2

Most tracts bring information ____

Answer 2

Into cerebellum

Question 3

Functions of cerebellum

Answer 3

Contribute to fine tuning of movement; involved in motor learning
(i.e., unconscious/subconscious proprioception)

Question 4

Divisions of cerebellum

Answer 4

2 hemispheres & vermis

Question 5

____ divides cerebellum into anterior & posterior lobes

Answer 5

Primary fissure

Question 6

_____ separates the flocculonodular lobe

Answer 6

Dorsolateral fissure

Question 7

The vermis is divided by the _____

Answer 7

Posterior border of tonsil

Question 8

The ____ is in the superior vermis

Answer 8

Lingula

Question 9

The ____ is in the inferior vermis

Answer 9

Nodule (Flocculonodular lobe)

Question 10

Superior cerebellar peduncle connects to the ____

Answer 10

Midbrain

Question 11

Middle cerebellar peduncle connects to the ____

Answer 11

Pons

Question 12

Inferior cerebellar peduncle connects to the ____

Answer 12

Medulla

Question 13

Name the deep cerebellar nuclei

Answer 13

Dentate
Emboliform
Globose
Fastigial

Question 14

3 layers of cerebellar cortex

Answer 14

Molecular
Purkinjie
Granular

Question 15

Molecular layer contains…

Answer 15

• Cell bodies of basket & stellate cells
• axons of granule cells that form parallel fibers
• dendrites of Purkinjie cells

Question 16

Purkinjie layer contains…

Answer 16

Cell bodies of Purkinjie cells

Question 17

Granular layer contains…

Answer 17

Cell bodies of granule & golgi cells

Question 18

Mossy fibers originate from ____ and relay ____

Answer 18

Spinal cord & brainstem nuclei (eg. DSCT, VSCT)
Peripheral information

Question 19

Mossy fibers excite ____ and ____, which in turn excite ____

Answer 19

Deep cerebellar nuclei and granule cells excite Purkinjie cells

Question 20

Climbing fibers originate from ____ and relay ____

Answer 20

Inferior olivary nucleus
Sensory & visual information

Question 21

Climbing fibers excite ____ and ____

Answer 21

Deep cerebellar nuclei and Purkinjie cells

Question 22

What is the only output of the cerebellar cortex?

Answer 22

Purkinjie fibers

Question 23

Purkinjie fibers function

Answer 23

Inhibit deep cerebellar nuclei that project out of cerebellum & other nuclei outside of cerebellum

Question 24

Deep cerebellar nuclei receive ____ impulses from mossy & climbing fibers

Answer 24

Excitatory

Question 25

Deep cerebellar nuclei receive ____ impulses from Purkinjie fibers

Answer 25

Inhibitory

Question 26

Name the functional divisions of cerebellum

Answer 26

Flocculonodular lobe Medial cerebellar hemispheres Lateral cerebellar hemispheres

Question 27

Flocculonodular lobe projects to the ____ nuclei and functions in…

Answer 27

Vestibular nuclei Balance & eye movement

Question 28

The vermis is part of the ____, and effects….

Answer 28

Flocculonudular lobe Trunk & head & neck muscles

Question 29

Afferents of Flocculonudular lobe

Answer 29

- vestibular fibers (info on head motion & position re gravity) - superior colliculus & occipital lobe fibers (visual/visual reflex info) - vermis receives visual, auditory, vestibular info and sensory from spinal cord

Question 30

Efferents of Flocculonudular lobe

Answer 30

- projects to vestibular nuclei (control eye movements & head/eye coordination) - fastigal nucleus projects to medial descending system (controls proximal muscles of body & limbs)

Question 31

Lesion of Flocculonudular lobe

Answer 31

- truncal ataxia & in-coordination (impaired vestibular cues) - failure of tandem gait test and Romberg’s test (may be unsteady/fall with eyes open/closed)

Question 32

Function of Medial portions of cerebellar hemispheres (tonsils, globose nuclei, emboliform nuclei)

Answer 32

Posture & locomotion

Question 33

Afferents of Medial cerebellar hemispheres

Answer 33

Receive sensory info from limbs

Question 34

Efferents of medial cerebellar hemispheres

Answer 34

Globose & emboliform nuclei project to lateral descending system (control distal limb muscles)

Question 35

Lesion of medial cerebellar hemispheres

Answer 35

- hypotonia - pendular reflexes (keeps going) - scanning speech - appendicular ataxia (uncoordinated extremities) exhibited by dysmetria (fail finger to nose test) - ataxic joint motion - Intention tremor (disappears at rest)

Question 36

Function of Lateral cerebellar hemisphere (with dentate nuclei)

Answer 36

- Planning complex actions - conscious assessment of movement - perceptual cognitive functions

Question 37

Afferents of lateral cerebellar hemispheres

Answer 37

Receive info from cortex via pontine nuclei (Frontopontine & temporopontine fibers -> pontine nuclei -> MCP)

Question 38

Efferents of lateral cerebellar hemispheres

Answer 38

- Dentate nucleus fibers exit via superior cerebellar peduncle - synapse with red nucleus - projects to inferior olivary nucleus - to thalamus -> premotor cortex

Question 39

Fibers from the red nucleus to the thalamus form the ____

Answer 39

Dentatorubrothalamic tract

Question 40

fibers of the dentatorubrothalamic tract join the ____ and function to…

Answer 40

Basal ganglia Control & preparation of movement

Question 41

Lesion of dentate nucleus

Answer 41

- decomposition of movements - have to think about subconscious movements - truncal ataxia evidenced by **dysrhythmia** and **dysdiadochokinesia** (inability to do rapid, alternating movements)