Neuroanatomy 4 - Cerebellum

Question 1

what are folia?

Answer 1

highly convoluted folds of the cerebellum

Question 2

in which cranial fossa is the cerebellum present in?

Answer 2

posterior cranial fossa

Question 3

functions of the cerebellum?

Answer 3

maintains balance and posture by influencing smooth contraction of voluntary muscles

co-ordinates complex movements - agonist & antagonist movements of muscles (contraction and relaxation) (e.g. for walking)

contributes to higher cognitive functions - thinking and language aspects

Question 4

what is the median structure between the two cerebellar hemispheres called?

Answer 4

vermis

Question 5

what are the three lobes of the cerbellum?

Answer 5

anterior lobe
posterior lobe
flocculonodular lobe

Question 6

the primary fissure separates which two cerebellar lobes?

Answer 6

anterior and posterior lobes

Question 7

what fissure separates the posterior and flocculonodular lobes?

Answer 7

posterolateral fissure

Question 8

what does the horizontal fissure separate?

Answer 8

separates the superior and inferior cerebellar surfaces - has no morphologic or functional significance

Question 9

list the three fissures of the cerebellum

Answer 9

primary
posterolateral
horizontal

Question 10

what is the arbor vitae?

Answer 10

innermost deep nuclei white matter of the cerebellum - has a branched tree-like appearance

Question 11

what does arbor vitae mean?

Answer 11

tree of life

Question 12

what does cerebellum mean?

Answer 12

little brain

Question 13

what is the significance of the arbor vitae?

Answer 13

the white matter transmits sensory and motor information from the cerebellar cortex to the deep cerebellar nuclei

allows for integration and co-ordination of voluntary movements, balance and posture; fine-tunes motor activity

Question 14

function of the cerebellar peduncles?

Answer 14

symmetrical bundles of nerves that connect the posterior aspect of the brainstem to the cerebellum - carry afferent/ incoming and efferent/ outgoing signals

Question 15

what are the three cerebellar peduncles and their general functions?

Answer 15

superior cerebellar peduncle - mainly efferent fibres to the thalamus and red nucleus

middle cerebellar peduncle - largest afferent fibres from the cerebral cortex (of the corticopontocerebellar pathway)

inferior cerebellar peduncles - mixed afferent and efferent fibres for sensory integration and motor control

Question 16

what type of fibres are predominantly found in the superior cerebellar peduncle?

Answer 16

mainly efferent fibres from the cerebellum to the thalamic and red nuclei

some afferent fibres from the ventral spinothalamic tract

Question 17

primary role of the middle cerebellar peduncle?

Answer 17

carries afferent fibres of the corticopontocerebellar pathway

transmits motor information from the cerebral cortex–> pons –> cerebellum

Question 18

which cerebellar peduncle carries fibres for the corticopontocerebellar pathway?

Answer 18

middle

Question 19

what afferent inputs travel via the inferior cerebellar peduncle?

Answer 19

mossy fibres from the dorsal spinocerebellar tract - for proprioception & postural information

climbing fibres from the inferior olivary nucleus of the medulla

Question 20

main efferent output of the inferior cerebellar peduncle?

Answer 20

efferent fibres travel from the cerebellum to the vestibular nuclei - for balance and coordination.

Question 21

what tract provides afferent sensory input to the superior cerebellar peduncle?

Answer 21

ventral spinothalamic tract - carries proprioceptive and sensory information

Question 22

which cerebellar peduncle is the largest?

Answer 22

middle cerebellar peduncle

Question 23

key roles of the inferior cerebellar peduncle?

Answer 23

integration of sensory and proprioceptive information

motor control for balance and postural stability

Question 24

which peduncle connects the cerebellum to the thalamic and red nuclei?

Answer 24

superior cerebellar peduncle

Question 25

what fibres process sensory inputs carried by the dorsal spinocerebellar tract?

Answer 25

mossy fibres of the inferior cerebellar peduncle

Question 26

what are the three structural zones of the cerebellum?

Answer 26

vermis - midline structure
intermediate zones - lateral to vermis
lateral hemispheres - most lateral regions

Question 27

what are the three functional divisions of the cerebellum?

Answer 27

cerebrocerebellum
spinocerebellum
vestibulocerebellum

Question 28

what are the functions of the cerebrocerebellum (neocerebellum)? (3)

Answer 28

motor planning and learning

co-ordinating muscle action

integrating inputs from the cerebral cortex and pontine nuclei

Question 29

to what structures does the cerebrocerebellum send outputs to?

Answer 29

thalamus & red nuclei

Question 30

functions of the spinocerebellum (paleocerebellum)? (2)

Answer 30

regulates body movements - provides error correction

maintains posture using proprioceptive information from the spinal cord

Question 31

where is the spinocerebellum located?

Answer 31

in the vermis & intermediate zones

Question 32

function of the vestibulocerebellum (archicerebellum)?

Answer 32

controls balance and ocular reflexes at an unconscious level

Question 33

what are the inputs and outputs of the vestibulocerebellum?

Answer 33

inputs from vestibular system
outputs to vestibular nuclei

ensures controlled balance and ocular reflexes at an unconscious level

Question 34

where is the vestibulocerebellum located?

Answer 34

flocculonodular lobe of the cerebellum

Question 35

inputs and outputs associated with the cerebrocerebellum?

Answer 35

inputs - from cerebral cortex and pontine nuclei
outputs - to thalamus and red nucleus

Question 36

which functional division of the cerebellum is involved in unconscious control of balance and eye reflexes?

Answer 36

vestibulocerebellum

Question 37

which functional division of the cerebellum maintains posture and coordinates movements during activity?

Answer 37

spinocerebellum

Question 38

how does the vestibulocerebellum interact with the vestibular system?

Answer 38

receives inputs from the vestibular system
sends outputs to the vestibular nuclei

controls balance and stabilises vision during movement

Question 39

is hypotonia or hypertonia a sign of cerebellar disease?

Answer 39

hypotonia

Question 40

list at least 4 symptoms of cerebellar disease (6)

Answer 40

• hypotonia
• altered gait
• ataxia/ disturbance of voluntary movements
• dysarthria/ difficulty speaking
• dysdiadochokinesia/ inability to perform rapid alternating movements
• nystagmus/ involuntary eye movements

Question 41

how is gait and stance affected in cerebellar disease?

Answer 41

lurching and staggering towards the affected side whilst walking

stiff legged & wide base when standing

Question 42

what is an intentional tremor? what test is used to assess for this?

Answer 42

intentional tremor = patient has tremor doing something, but no tremor at rest

finger-nose test = past-pointing/ not being able to touch nose properly is a positive sign