Cerebellum Flashcards
(104 cards)
1
Q
What sits in the posterior fossa, dorsal to the brainstem and the 4th ventricle
A
Cerebellum
2
Q
True or False:
Embryologically the cerebellum is part of the pons, but the functions are so different that they are considered their own entity
A
True
3
Q
What separates the cerebellum from the cortex
A
Tentorium cerebelli
4
Q
True or False:
There are 2 halves to the cerebellum that are partially separated by the falx cerebelli
A
True
5
Q
What percent of the brain volume does the cerebellum make up
A
10%
6
Q
What percent of the brain function does the cerebellum make up
A
50%
7
Q
What are the folds of the cerebellum called
A
Terminal folia
8
Q
True or False:
The cortex of the cerebellum is organized into folia
A
True
9
Q
Does the cerebellum initiate movement
A
No, it coordinates it
10
Q
The cerebellum may also be involved in what (2)
A
- Cognitive functions (attention and language)
2. Regulating fear and pleasure responses
11
Q
What is the most solidly established function of the cerebellum
A
Movement related functions
12
Q
How many anatomical divisions are there in the cerebellum
A
3
13
Q
What is the gross anatomy of the cerebellum (4)
A
- Cerebellar peduncles
- Folia
- Major divisions
- Deep cerebellar nuclei
14
Q
What is functional anatomy of the cerebellum (4)
A
- Spinocerebellum
- Cerebrocerebellum
- Cerebellar vermis
- Vestibulocerebellum
15
Q
What is the function of the spinocerebellum
A
Proprioceptive input and output
16
Q
What is the function of the cerebrocerebellum
A
Info from the motor cortex down and back up
17
Q
What is the function of the vestibulocerebellum
A
Vestibular nuclei to cerebellum and back out
18
Q
What do the cerebellar peduncles do
A
Connect the cerebellum to the brainstem
19
Q
True or False:
The cerebellar peduncles is composed of 3 bilateral pairs of axon tracts
A
True
20
Q
What type of pathway is the superior cerebellar peduncles
A
Efferent motor pathways
21
Q
What does the superior cerebellar peduncle connect with
A
Midbrain
22
Q
What type of pathway is the middle cerebellar peduncles
A
Afferent pathway arising from the pontine nuclei
23
Q
What is the main type of pathway of the inferior cerebellar peduncle
A
Afferent but does have some efferent
24
Q
What does the inferior cerebellar peduncle connect to
A
The medulla
25
Which of the cerebellar peduncles is the smallest but most complex
Inferior cerebellar peduncle
26
What provides the main blood supply to the superior cerebellar peduncle
Superior cerebellar artery
27
Where does the middle cerebellar peduncle receive afferents from
Contralateral cerebral cortex inputs
28
What provides the main blood supply to the middle cerebellar peduncle
Anterior inferior cerebellar artery and superior cerebellar artery
29
Where does the inferior cerebellar peduncle receive afferents from
Ipsilateral proprioceptive input from the spinal cord
30
What provides the main blood supply to the inferior cerebellar peduncle
Posterior inferior cerebellar artery
31
What are the 3 lobes of the cerebellum
1. Spinocerebellum
2. Neocerebellum
3. Vestibulocerebellum
32
What is the newest part of the cerebellum
Posterior lobe
33
What is the oldest part of the cerebellum
Flocculonodular lobe
34
What are the major longitudinal divisions of the cerebellum (3)
1. Vermis
2. Intermediate hemisphere
3. Lateral hemisphere
35
What info does the vermis receive
Kinesthetic and somatosensory inputs from the spinal cord
36
What does the vermis project to
Fastigial nucleus
37
What does damage to the vermis interrupt
Posture and walking
38
In monkeys what does unilateral lesions of the fastigial nucleus cause
The monkey to fall to the ipsilateral side
39
With damage to the cerebellum what side do they lean to
Side of the damage
40
Where is the intermediate zone located
Between the vermis and lateral part of the cerebellum
41
What does the intermediate zone receive input from
Red nucleus and somatosensory info from the spinal cord
42
Where does the intermediate zone of the cerebellum project
Interpositus nucleus to the red nucleus
43
What does damage to the intermediate zone cause (3)
1. Rigidity
2. Difficulty in moving limbs
3. Action tremor or intention tremmor
44
What is an intention tremor
A tremor causing movement to occur in a staggered manner during motor act
45
What does the lateral zone receive input from
Motor and association cortices
46
Where does the lateral zone send projections
Dentate nucleus to primary motor and premotor cortex
47
What is the function of the lateral part of the cerebellum (5)
1. Ballistic movements
2. Multi-joint movements
3. Learning of new movements
4. Timing of motor movements
5. Cognitive functions
48
What is an example of a ballistic movement
Swinging of a bat in baseball trying to hit a fastball
49
What is a ballistic movement
A movement that occurs so quickly that it can not be modified by feedback
50
Dart experiment
People with cerebellar damage weren't able to adjust after putting on the prism glasses while people without cerebellar damage can adjust
51
What is the somatotopy of the cerebellum
The head always faces the middle of the cerebellum
52
True or False:
| Folia are made by big long sheets of cells that are folded like an accordion
True
53
What are within the thin layer of cells that make the folia
Several types of neurons with a highly regular arrangement
54
What do the folia provide
Massive signal processing capability
55
True or False:
| Most of the cerebellar output passes through a small set of deep cerebellar nuclei
True
56
How many layers does the cortex (gray matter) of the folium have
3
57
What are the 3 layers of the cortex of the cerebellum from superficial to deep
1. Molecular layer
2. Purkinje layer
3. Granular layer
58
What does the molecular layer consist of (2)
1. Axons of granule cells
| 2. Dendrites of purkinje cells
59
What does the purkinje layer consist of (1)
Single layer of output cells
60
Is the purkinje layer excitatory or inhibitory
Inhibitory
61
What does the granular layer do
Excites purkinje cells
62
What does exciting the purkinje cells do
Increases their inhibitory effects
63
What are the only output neurons of the cerebellum
Purkinje cells
64
What do the purkinje cells do
Utilize GABA to inhibit neurons in deep cerebellar nuclei
65
What do the granule cells do (2)
1. Utilize glutamate as an excitatory transmitter
| 2. Excite purkinje cells via axonal branches called parallel fibers
66
What are intrinsic cells of the cerebellar cortex
Granule cells
67
What are the inhibitory interneurons of molecular layer (2)
1. Basket cells
| 2. Golgi cells
68
What do the basket cells do
Utilize GABA to inhibit purkinje cells so that motor movement occurs
69
What do the golgi cells do
Feedback inhibition on the mossy granule relay
70
What are mossy and climbing fibers
Afferents that are excitatory
71
What do the mossy and climbing fibers excite (2)
1. Granule (mossy)
| 2. Purkinje (climbing fibers)
72
True or False:
| The mossy and climbing fibers give off collaterals as they enter the cerebellum and excite the deep cerebellar nuclei
True
73
True or False:
| All of the input to the cerebellum is excitatory
True
74
True or False:
| All of the efferents from the cerebellum are inhibitory
True
75
True or False:
| Basket cells wrap around the purkinje cells
True
76
True or False:
| Purkinje cells in all 4 zones project to different deep cerebellar nuclei
True
77
What are the deep nuclei of the cerebellum (4)
1. Dentate
2. Interpositus
3. Fastigial
4. Vestibular nuclei
78
What does the denate nucleus receive input from (1)
1. Purkinje cells from the lateral zone of the cerebellum
79
What does the interpositus nucleus receive input from (1)
1. Intermediate zone
80
What does the fastigial nucleus receive input from (1)
1. Medial zone
81
What does the vestibular nuclei receive input from (1)
1. Flocculonodular lobe
82
True or False:
| Damage to the lobe causes damage to corresponding deep nuclei
True
83
True or False:
| Purkinje cells of the cerebellar cortex make tonically inhibitory connections onto the cerebellar nuclei
True
84
Where do all outputs from the cerebellum originate from
Deep cerebellar nuclei
85
True or False:
| A lesion to the deep cerebellar nuclei has the same effect as a complete lesion of the entire cerebellum
True
86
What are the 3 main functional roles of the cerebellum
1. Coordination of movement the cerebellum modulates the timing and pattern of muscle activation during movement
2. Maintenance of balance/equilibrium (in conjunction with the vestibular receptors and proprioceptors)
3. Regulation of muscle ton modulates spinal cord and brainstem mechanisms involved in postural control
87
Where is the cerebrocerebellum located
Lateral lobe
88
Where is the spinocerebellum located
Medial lobe
89
Where is the cerebellar vermis located
Medial lobe
90
Where is the vestibulocerebellum located
Flocculonodular lobe
91
What is the function of the lateral hemisphere of the cerebellum
Motor planning of the extremities
92
What motor pathway does the lateral hemisphere of the cerebellum influence
Lateral corticospinal tract
93
What is the function of the intermediate hemispheres of the cerebellum
Distal limb coordination
94
What motor pathways does the intermediate hemisphere of the cerebellum influence (2)
1. Lateral corticospinal tract
| 2. Rubrospinal tract
95
What is the function of the vermis and flocculonodular lobe (4)
1. Proximal limb and trunk coordination
2. Regulation of muscle tone for posture and locomotion
3. Balance
4. Vestibulo-ocular reflexes
96
What pathways do the vermis and flocculonodular lobe influence (5)
1. Anterior corticospinal tract
2. Reticulospinal tract
3. Vestibulospinal tract
4. Tectospinal tract
5. Medial longitudinal fasciculus
97
Cerebellar damge produces disorders in what (4)
1. Movement
2. Equilibrium
3. Posture
4. Motor learning
98
What is a disturbance that alters the rate, direction, and extent of voluntary movements, abnormal gait and uncoordinated movements
Ataxia
99
What is altered range of motion (misjudge distance)
Dysmetria
100
What is oscillating motion of limbs or (especially) of head, during movement, often increasing as target approaches
Intention tremor
101
What is nystagmus and head tilt
Vestibular signs
102
What is slow and uneven in attempting fast hand alternating movements
Dysdiadochokinesis
103
What is abnormalities in speech modulation, rate of speech, explosive scanning speech, slurred speech, irregular stress patterns, and vocalic and consonantal misarticulations
Dysarthia
104
What is vestibulo-ocular reflex indicative of
Motor learning deficits
