Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Test 2 > Cerebellum > Flashcards

Cerebellum Flashcards

1
Q

which cerebellar aa. supply the cerebellum?

A

SCA: covers superior, some of vermis, lateral hemispheres

AICA: cerebellar peduncles

PICA: lower portions of nodulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what do inferior cerebellar peduncles receive?

A

inferior cerebellar peduncles mostly receive cerebellar input from:

  • spinocerebellar tracts
  • vesbtibular input from olive
  • small portion of output to vestibular system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does middle cerebellar input receive?

A

all input: mostly from pontocerebellar fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does superior cerebellar conduct?

A

cerebellar output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

arbor vitae

A

white matter tracts head to center, and gray is on the surface of the cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the layers of the cerebellar cortex?

A

outer layer of cortex:

  1. molecular layer (parallel fibers)
  2. purkinge cell layer
  3. granule cell layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the basic circuitry pattern of cerebellum?

A
  • affarent information is taken in mostly via mossy fibers. Cell bodies are located in SC, vestibular nuclei and pontine nuclei.
  • Mossy Fibers are cholinergic and synapse (ACh) and stimulate granule cells.
  • Granule cells move towards cortex and make many synapses on purkinge cells of cerebellar cortex. Granule cells release glutamate.
  • Purkinge cells of cerebellar cx. project into deep cerebellar nucleus, and are inhibitory Gabanergic.
  • Deep Cerebellar nucleus influences UMN tracts.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are three important facts of the cerebellum?

A
  • Cerebellar cortex does NOT contribute to conscious awareness.
  • Cerebellar hemispheres control ipsilateral body
    BA 4= primary motor cx
    BA 6 = supplementary cx
    BA 8 = premotor cx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are three FUNCTIONAL divisions of cerebellum?

A
  1. Vestibulocerebellum
  2. Cerebrocerebellum
  3. Spinocerebellum
    * they are named according to source of affarents *
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where is vestibulocerebellum located?

A

flocculonodular lobe

  • made up of: floculi and nodules
  • named from primary affarents coming from vestibular nuclei and primary affarent from vestibular apparatus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is fn. of vestibulocerebellum?

A

coordinates proximal mm, maintains body posture/balance, coordinates eye movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

memorize vestibulocerebellar pathway

A

Input: Vestibular nuclei (1° afferents & from nuclei)

Cerebellar Nucleus: Fastigial nucleus

Targets: Lateral Vestibular & Reticular Nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

fn of cerebrocerebellum

A
  • located in lateral hemispheres

- fn: assists in planning, timing and initiation of complex mvmts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

memorize cerbrocerebellum pathway

A

Input: Area’s 4 and 6 (via pontine nuclei) (+ many other cortical regions)

Cerebellar Nucleus: Dentate

Targets: Area’s 4 and 6 via thalamus (also red nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where is spinocerebellum located?

A

vermis and paravermal regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

function of spinocerebellum?

A

Smoothness, accuracy, & coordination of voluntary movements
Modulation of Ongoing Motor Activity:Rate, Range, & Force of Voluntary Movements
COMPARATOR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

primary affarents of spinocerebellum? what are the tracts?

A
  • bring proprioception to the spinocerebellum via primary affarents that are the same as the DCML. (unconscious proprio)
  • 4 tracts, but we will only focus on two:
    1. cuneocerebellar tract
    2. posterior spinocerebellar tract
18
Q

unconscious proprio from lower limb? below L2

A

below L2- primary affarent will cell body in dorsal root ganglion, enters into dorsal horn and ascends ipsilaterally in the dorsal column.

  • In T1-L2, it synapses on the ipsilateral dorsal nucleus of clarke.
  • The second order neuron then travels in the Dorsal Spinocerebellar Tract (DSCT) ipsilaterally, and projects through the inferior cerebellar peduncle to the ipsilateral cerebellum
19
Q

unconscious proprioception from trunk? T1-L2

A
  • primary affarent with cell body in dorsal root ganglia enters in through the dorsal horn and synapses on second order neurons in the ipsilateral nucleus of clark
  • It then ascends in the DSCT to the inferior cerebellar peduncle and to ipsilateral cerebellum
20
Q

unconscious proprioception from arms? cervical branches

A
  • primary affarent with cell body in dorsal root ganglia enters into dorsal horn and travels in the ipsilateral cuneiocerebellar tract (most lateral portion of dorsal column).
  • It will synapse on second order neuron in the medulla in the accessory nucleus cuneatus.
  • The second order neuron will then travel ipsilaterally to the cerebellum via the inferior cerebellar peduncle.
21
Q

what upper motor systems do the spinocerebellar tracts influence?

A
  • Lateral: LCST and Rubrospinal tract

- Medial: Vestibulospinal and reticulospinal tracts

22
Q

what would damage to paravermal region look like?

A
  • deficits in distal limb musculature, lack of rate/range/force of distal limb mm.
23
Q

what would damage to vermis look like?

A
  • defitis in axial limb mm, huge deficit in coordination, balance and postural mm. widebased stance
24
Q

know spinocerebellar tract, influencing axial/proximal limb mm.

A
  • modulation of ongoing motor activity
  • neck,trunk and proximal limb proprioceptive fibers travel in Dorsalspinocerebellar tract to inferior cerebellar peduncle and into the cortex of the vermis.
  • Purkinje fibers from vermis project and synapse onto fastigial nucleus.
  • Fastigial nucleus synapses in vestibular nuclei and reticular nuclei and modulates MVST, LVST, MRST, LRST to influence axial proximal limb mm.
25
Q

know spinocerebellar tracts for distal limb mm.

A
  • modulates ongoing coordination/comparator of distal limb musculature (and flexors)
  • distal limb proprioceptive information is sent to ipsilateraly paravermal cerebellum via the DSCT and cuneiocerebellar tract
  • Paravermal projects via purkinje neurons to the ipsilateral interposed nuclei.
  • interposed nuclei decussate at superior cerebellar peduncle to thalamus and mangocellular red nucleus.
    1. Thalamus projects to BA 4 which decussates in pyramids and descends in LCST to influence distal limb mm.
    2. mangocellular red nucleus decussates immediately and runs in rubrospinal tract to influence distal limb mm.
26
Q

where will cerebellar lesions present?

A 
ipsilateral defecits in unilateral lesion. coordination will be ipsilateral to the lesion 
- see motor ataxia ipsilateral to lesion
- dysrythmia
dysmetria
- intention tremor
- dysdiadochokinsia
26
Q

where will cerebellar lesions present?

A 
ipsilateral defecits in unilateral lesion. coordination will be ipsilateral to the lesion 
- see motor ataxia ipsilateral to lesion
- dysrythmia
dysmetria
- intention tremor
- dysdiadochokinsia
27
Q

intention tremor

A
  • cerebellum called upon more when trying to get closer to the target.
  • intention tremor (seen when patient is trying to accomplish a task) is opposite of Parkinson’s tremor
  • seen ipsilateral to cerebellar lesion
27
Q

intention tremor

A
  • cerebellum called upon more when trying to get closer to the target.
  • intention tremor (seen when patient is trying to accomplish a task) is opposite of Parkinson’s tremor
  • seen ipsilateral to cerebellar lesion
28
Q

motor ataxia

A
  • uncoordinated movements ipsilaterally to the lesion.
28
Q

motor ataxia

A
  • uncoordinated movements ipsilaterally to the lesion.
29
Q

Dysrythmia

A

abnormal timing, seen ipsilateral to cerebellar lesion

29
Q

Dysrythmia

A

abnormal timing, seen ipsilateral to cerebellar lesion

30
Q

dysmetria

A

abnormal trajectory, (i.e. past pointing) - seen ipsilateral to cerebellar lesion

30
Q

dysmetria

A

abnormal trajectory, (i.e. past pointing) - seen ipsilateral to cerebellar lesion

31
Q

dysdiadochokinesia

A

inability to rapidly alter movement - seen ipsilateral to cerebellar lesion.

31
Q

dysdiadochokinesia

A

inability to rapidly alter movement - seen ipsilateral to cerebellar lesion.

32
Q

Midline lesion effects?

A

“Vermal Lesion” - results in unsteady gait and truncal sway

  • wide based stance
  • uncoordinated eye movments
33
Q

Lateral lesion effects?

A

“Paravermal lesion”

  • results in ataxia of limbs (appendicular ataxia)
  • past pointing
  • dysdiadochokinsia
34
Q

sensory ataxia?

A
  • loss of DCML
  • lose conscious proprioception
  • signs and symptoms are very similar of cerebellar ataxia, except for the presence of near-normal coordination when the movement is visually observed by the patient, but marked worsening of coordination when the eyes are shut.
  • Sensory ataxia also lacks the associated features of cerebellar ataxia such as pendular tendon reflexes, scanning dysarthria, nystagmus and broken pursuit eye movements.
  • Patients with sensory ataxia often demonstrate pseudoathetosis and Romberg’s sign. They usually complain of loss of balance in the dark
35
Q

Romberg’s Sign

A
  • In the Romberg test, the standing patient is asked to close his or her eyes. A loss of balance is interpreted as a positive Romberg’s test.
  • A positive Romberg test suggests that the ataxia is sensory in nature, that is, depending on loss of proprioception. If a patient is ataxic and Romberg’s test is not positive, it suggests that ataxia is cerebellar in nature, that is, depending on localized cerebellar dysfunction instead.

Neuro Test 2 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions