cerebellum

Question 1

The cerebellum is connected to the brainstem by three paired fiber bundles or peduncles:

Answer 1

the inferior, middle and superior cerebellar peduncles

Question 2

The inferior and middle peduncles carry the major ________ to the cerebellum, and the superior peduncle contains the _______ .

Answer 2

inputs,

output

Question 3

The flocculo-nodular lobe of the cerebellum is the phylogenetically oldest portion of the cerebellum, and is also referred to as the
_______.

Answer 3

archicerebellum

Question 4

the posterior lobe of the cerebellum is evolutionarily most recent and most of it comprises what is referred to as the ______.

Answer 4

neocerebellum

Question 5

The ______ refers to the midportion of the anterior lobe and the posterior lobe of the cerebellum

Answer 5

paleocerebellum

Question 6

Thus the flocculo-nodular lobe (archicerebellum) is also called ______the since it receives input from the vestibular organs, and outputs to the vestibular nucleus in the brainstem.

Answer 6

vestibulocerebellum

Question 7

the paleocerebellum is also called the ______ since it receives extensive input from spinal afferents, and outputs onto motor control nuclei (e.g., the red nucleus).

Answer 7

spinocerebellum

Question 8

the cerebellum consists of a three-layered cortex overlying a group of paired central nuclei. There are four nuclei on each side, the : __________

Answer 8

dentate, globose and emboliform (together referred to as the nucleus interpositus or interposed nucleus)
and fastigial nuclei

Question 9

The medial or vermal zone of the cerebellum has output connections through the _____ nucleus and is involved in control of axial musculature, posture and balance, and integration of head and eye movements

Answer 9

fastigial

Question 10

the intermediate (or paravermal) zone has outputs through the ______ and fine-tunes movements of the limbs

Answer 10

interposed nuclei

Question 11

while the lateral (or hemispheric) zone of the hemispheres has connections through the ______ nucleus and is involved in higher level coordination of movements, including planning and initiation of movements

Answer 11

dentate

Question 12

The cerebellar outputs from the deep nuclei of the medial regions (vermis, vestibulocerebellum) , ultimately modulate these 3 medial descending pathways.

Answer 12

vestibulospinal tracts,
reticulospinal tracts,
tectospinal tracts

Question 13

The cerebellar outputs from the lateral regions (paravermis and vestibulocerebellum) project to the dentate and interpositus nuclei, which ultimately modulate the rubrospinal and corticospinal outputs. These are responsible for the control of _______

Answer 13

fine, distal muscle movements

Question 14

Cerebellar cortex has cells that recieve two distinct inputs:
one is modality-specific input (i.e. balance, limb position, eye-hand coordinates) that represents a copy of the reflex input called ________-
another input from the inferior olivary nucleus, hypothesized to signal errors- unexpected responses- in reflex activity called _________-

Answer 14

MOSSY FIBERS,

CLIMBING FIBERS

Question 15

Axons from the cortex synapse on ipsilateral neurons in the ______ and the _____ neurons send axons contralaterally to the cerebellar hemispheres.

Answer 15

basal pons,

pontine

Question 16

the medial cerebellum must be involved in functions of

______ and ________

Answer 16

EQUILIBRIUM (reflecting the interconnections with vestibular nuclei and descending spinal tracts),
POSTURE (recognizing the distribution of proprioceptive and cutaneous afferents from the axial musculature to this region).

Question 17

Paravermal or intermediate cerebellum is concerned with the control of movement of the _____, and outflow goes to the _______ via the interposed nuclei

Answer 17

distal limbs,

red nucleus

Question 18

Lateral cerebellum is less directly associated with particular body regions, but has extensive interconnections with motor cortex. This reflects the role of the neocerebellum in cortical coordination and ________-.

Answer 18

planning and initiation of movement

Question 19

cerebellar lesions result in loss of ______ but no loss of sensation or muscle strength.

Answer 19

coordination (including equilibrium)

Question 20

cerebellar deficits are always _______.

Answer 20

ipsilateral

Question 21

what is past-pointing or dysmetria ?

Answer 21

inability to bring a limb to a required or desired point in space. ( due to lesions in cerebellum)

Question 22

If the flocculo-nodular lobe is impaired, due for example to a medulloblastoma that is common in childhood, _____ is impaired but not coordination or muscle tone.

Answer 22

equilibrium

Question 23

there is occasionally degeneration of the vermal cerebellum in alcoholism that results in ________

Answer 23

postural problems involving trunk muscles

Question 24

Cerebellar deficits can be remembered with the mnemonic “HANDS Tremor” it stands for:

Answer 24

Hypotonia- mainly with anterior lobe injury
Ataxia- this means “without order” and includes the 3 “D”s
-dysdiadochokinesia- or impaired rapid alternating
movements
-decomposition of movement
-dysmetria- or “past pointing”
Nystagmus
Dysarthria
Stance and gait problems
Tremor- specifically, intention tremor. This involves increasing oscillation as the limb approaches a target, i.e. touching one’s nose

Question 25

Climbing fibers come from the contralateral ______.

Answer 25

inferior olivary nucleus

Question 26

______ fibers carry input to the cerebellar cortex from a wide variety of sources, including primary vestibular afferents and pontine nuclear cells

Answer 26

Mossy

Question 27

The ascending axons of the ____ cells branch in a T-shaped manner to form the parallel fibres,

Answer 27

granule

Question 28

With the exception of _____ cells, all cerebellar cortical neurons, including the Purkinje cells, make inhibitory synaptic connections with their target neurons.

Answer 28

granule

Question 29

the only output from the cerebellar cortex is via the ______ cells

Answer 29

Purkinje

Question 30

When the inferior olive detects a discrepancy between planned and actual motor performance it generates _________ activity (an error signal) that modulates cerebellar function, including long-term depression of sensitivity to mossy fiber input

Answer 30

climbing fiber