cerebellum and basal ganglia

Question 1

cerebellum basic functions

Answer 1

coordinates voluntary movements

maintenance of posture and balance

motor learning and adaptation

integration of sensory input to fine-tune motor activity

Question 2

where is the cerebellum located?

Answer 2

posterior to the cranial fossa above the foramen magnum

inferior to the occipital and temporal lobes

Question 3

what is the cerebellum covered in?

Answer 3

tentorium cerebelli (dura mater)

Question 4

what separates the cerebellum from the medulla and pons?

Answer 4

fourth ventricle

Question 5

how is the cerebellum connected to the brainstem?

Answer 5

superior cerebellar peduncle
middle cerebellar peduncle
inferior cerebellar peduncle

Question 6

afferent and efferent cerebellar tracts travel through the ____, to and from the ipsilateral cerebellar cortex

Answer 6

peduncles

Question 7

three lobes of cerebellum

Answer 7

anterior
posterior
flocculonodular

Question 8

what are the basic functions of the three lobes of the cerebellum?

Answer 8

Anterior lobe: Primarily involved in
coordinating movements of the limbs and
trunk (proprioception).

Posterior lobe: Plays a significant role in fine
motor control, planning, and coordination of
voluntary movements.

Flocculonodular lobe: Associated with
balance and eye movements (vestibular
functions).

Question 9

what are the hemispheres and vermis of the cerebellum mostly in charge of?

Answer 9

hemisphere: fine motor coodination

vermis: postural adjustments

Question 10

functional zones of the cerebellum

Answer 10

cerebrocerebellum
spinocerebellum
vestibulocerebellum

Question 11

lesion in lateral cerebellum would affect the ___
lesion in the vermis would affect the ___

Answer 11

lesion in lateral cerebellum would affect the “LIMBS”

lesion in the vermis would affect the “TRUNK”

Question 12

symptoms will be ____ to the side of the lesion in the cerebellum

Answer 12

ipsilateral

Question 13

ataxia

Answer 13

Symptoms of damage to cerebellar pathways and the cerebellum

Question 14

lesions of the vestibulocerebellum result in (3)

Answer 14

Impaired balance and gait

Marked nystagmus – involuntary eye movements

These symptoms can also occur with damage to the vestibular system.

Question 15

lesions of the spinocerebellar result in

Answer 15

Impaired gait - often stomping. Lack of proprioceptive information makes patients unsure of where their legs and feet are without visual input.

Question 16

lesions of the cerebrocerebellum result in (3)

Answer 16

Intention Tremor – amplitude of tremor increases during voluntary movement as the individual gets close to target. Example: trying to touch your nose with your index finger.

Difficulty with skilled movements

“Subtle” nystagmus

Question 17

The cerebellum is composed of the outer ____ matter (cerebellar cortex) and inner ___ matter (cerebellar
medulla)

Answer 17

outer - gray
inner -white

Question 18

cerebellum matter
outer:
inner:

Answer 18

outer: gray - cerebellar cortex
inner: white - cerebellar medulla

Question 19

the cerebellar cortex is made of ___ matter

Answer 19

gray

Question 20

the cerebellar medulla is made of ___ matter

Answer 20

white

Question 21

three distinct layers of cerebellar cortex (grey)

Answer 21

molecular layer
purkinjie layer
granule layer

Question 22

what is the cerebellar medulla composed of (4)?`

Answer 22

mossy fibers
climbing fibers
Purkinje cell axons
deep cerebellar nuclei

Question 23

what are the only output of the cerebellum?

Answer 23

deep nuclei

Question 24

Don’t Eat Greasy Food

Answer 24

denate
emboliform
globose
fastigial nucleus

Question 25

what are the four nuclei of the deep cerebellar nuclei?

Answer 25

denate emboliform globose fastigial nucleus Don't Eat Greasy Food

Question 26

afferent: info to ____ to be ____

Answer 26

cerebellum to be processed

Question 27

efferent: info ____ cerebellum to ____

Answer 27

leaves cerebellum to help coordinate motor activity

Question 28

afferent tracts travel mainly thought the ___ and ___ cerebellar peduncles

Answer 28

inferior and middle

Question 29

Ventral/Anterior Spinocerebellar Pathway

Answer 29

Carries proprioceptive information from muscle spindles, Golgi tendon organs, and joint receptors of lower extremities to cerebellum

Question 30

Ventral/Anterior Spinocerebellar Pathway brainstem: cerebellum: terminates:

Answer 30

Brainstem: axons cross back over Cerebellum: Enters through superior cerebellar peduncle Terminates: Ipsilateral vermal / paravermal cortex

Question 31

Dorsal/Posterior Spinocerebellar Pathway brainstem: cerebellum: terminates:

Answer 31

Brainstem: remains ipsilateral Cerebellum: Enters through inferior cerebellar peduncle Terminates: Ipsilateral cerebellar cortex

Question 32

Dorsal/Posterior Spinocerebellar Pathway

Answer 32

Carries proprioceptive information from muscle spindles, Golgi tendon organs, and joint receptors of trunk and lower extremities to cerebellum

Question 33

Friedreich's ataxia

Answer 33

A hereditary ataxia affecting the spinocerebellar tracts

Question 34

Multiple sclerosis

Answer 34

Demyelination affecting cerebellar pathways

Question 35

Cerebellar stroke

Answer 35

Damage to spinocerebellar tracts or associated nuclei

Question 36

afferent pathways from the cerebral cortex

Answer 36

corticopontocerebellar cortico-olivocerebellar cortico-reticulocerebellar

Question 37

where do the afferent pathways from the cerebral cortex travel through and terminate?

Answer 37

signals through brainstem to cerebellum

Question 38

corticopontocerebellar pathway

Answer 38

cerebral cortex pontine nuclei mossy fibers cerebellar hemisphere via middle cerebellar peduncle *enters through middle peduncle *terminates in the contralateral cerebellar cortex

Question 39

cortico-olivocerebellar pathway

Answer 39

cerebral cortex inferior olivary nuclei climbing fibers cerebellar hemisphere via inferior cerebellar peduncle

Question 40

cortico-reticulocerebellar pathway

Answer 40

cerebelar cortex recticular formation mossy fibers cerebellar hemisphere via middle and inferior cerebellar peduncle *middle and inferior peduncle *terminates ipsilateral cerebellar cortex

Question 41

peduncles and termination: corticopontocerebellar - cortico-olivocerebellar - cortico-reticulocerebellar -

Answer 41

corticopontocerebellar - middle peduncle contralateral cortico-olivocerebellar - inferior peduncle contralateral cortico-reticulocerebellar - inferior & middle peduncle ipsilateral

Question 42

Answer 42

Question 43

Answer 43

Question 44

Answer 44

Question 45

Answer 45

Question 46

efferent pathways from cerebellum (2)

Answer 46

rubrospinal tract cerebellovestibular tract

Question 47

where do efferent pathways originate from of the cerebellum?

Answer 47

the four deep cerebellar nuclei *via superior cerebellar peduncle

Question 48

Efferent tracts originate from the four deep cerebellar nuclei and travel mainly via the

Answer 48

superior cerebellar peduncle

Question 49

The tracts of the fastigial nucleus travel via the

Answer 49

inferior cerebellar peduncle

Question 50

cerebellorubral tract pathway

Answer 50

Globose & emboliform nuclei → superior cerebellar peduncle → red nucleus → rubrospinal trac *tone of contralateral skeletal muscles

Question 51

cerebellothalamic tract pathway

Answer 51

Dentate nucleus → superior cerebellar peduncle → thalamic nuclei → primary motor cortex *Contralateral motor coordination

Question 52

Cerebellovestibular tract pathway

Answer 52

Fastigial nucleus → inferior cerebellar peduncle → bilateral vestibular nuclei → vestibulospinal tract *Coordination of balance and saccadic ocular movements

Question 53

from the vestibular nuclei, output is transmitted via (2)

Answer 53

* The vestibulospinal tracts to spinal motor neurons, which control postural muscles. * Brainstem circuits involved in the vestibulo-ocular reflex (VOR) for stabilizing gaze

Question 54

Answer 54

Question 55

Answer 55

Question 56

Answer 56

Question 57

Answer 57

Question 58

basal ganglia are a group of nuclei that lie where?

Answer 58

beneath the cortex

Question 59

basal ganglia are a group of ___ that lie beneath the cortex

Answer 59

nuclei

Question 60

Basal ganglia are a group of nuclei. These structures form a network of WHAT to regulate motor, cognitive, and emotional functions?

Answer 60

*input, output, and modulatory components* to regulate motor, cognitive, and emotional functions.

Question 61

components of the basal ganglia (4)

Answer 61

striatum globus pallidus subthalamic nucleus substantia nigra

Question 62

components of the striatum (basal ganglia) - 3

Answer 62

* Caudate nucleus * Putamen * Nucleus accumbens

Question 63

components of the globus pallidus (basal ganglia)

Answer 63

* Globus Pallidus Externus (GPe) * Globus Pallidus Internus (GPi)

Question 64

components of the substantia nigra (basal ganglia)

Answer 64

* Substantia Nigra Pars Compacta (SNc) * Substantia Nigra Pars Reticulata (SNr)

Question 65

Caudate nucleus: Putamen: Nucleus accumbens:

Answer 65

Caudate nucleus: planning and executing movement Putamen: movement regulation Nucleus accumbens: interface between limbic system and basal ganglia (motivation/reward processing)

Question 66

globus pallidus interna vs externa (role)

Answer 66

interna: Major output nucleus of basal ganglia; inhibits the thalamus to regulate movement external: Relay and modulator in the indirect pathway; inhibits the STN and other nuclei

Question 67

globus pallidus interna vs externa (direct/indirect)

Answer 67

interna: direct/indirect externa: indirect

Question 68

globus pallidus interna vs externa (output targets)

Answer 68

interna: thalamus, brainstem externa: subthalamic nucleus, globus pallidus interna

Question 69

Answer 69

Question 70

Subthalamic Nucleus (STN), an excitatory structure in the basal ganglia that uses ___

Answer 70

glutamate

Question 71

Substantia Nigra Pars Reticulata (SNr): Uses ___ to inhibit unwanted signals, helping control eye movements and muscle activity for smooth, purposeful actions

Answer 71

GABA

Question 72

Substantia Nigra Pars Compacta (SNc): Releases ____ to regulate emotions, learning, motivation, and decision-making, linking reward signals to motor actions.

Answer 72

dopamine

Question 73

hormones? Subthalamic Nucleus (STN): Substantia Nigra Pars Reticulata (SNr): Substantia Nigra Pars Compacta (SNc):

Answer 73

Subthalamic Nucleus (STN): glutamate Substantia Nigra Pars Reticulata (SNr): GABA Substantia Nigra Pars Compacta (SNc): dopamine

Question 74

basal ganglia functional circuitry (function) Direct pathway: Indirect pathway:

Answer 74

Direct pathway: Facilitating movement Indirect pathway: Inhibiting unwanted movements.

Question 75

The balance of activity between the direct and indirect pathways is modulated by ___

Answer 75

dopamine

Question 76

basal ganglia direct pathway main function

Answer 76

increase in motor activity (excitatory)

Question 77

pathway of the basal ganglia direct pathway

Answer 77

Motor cortex activation → glutamate release → striatum stimulation → GABA release → inhibition of Gpi → inhibition of GABA release → thalamus disinhibition → premotor cortex stimulation → muscle activation → ↑ movement

Question 78

basal ganglia direct pathway excitatory or inhibitory?

Answer 78

excitatory

Question 79

basal ganglia indirect pathway excitatory or inhibitory?

Answer 79

inhibitory

Question 80

function of basal ganglia indirect pathway

Answer 80

decrease motor activity *modulation of the disinhibitory effect of the direct pathway

Question 81

sequence of basal ganglia indirect pathway

Answer 81

Motor cortex activation → glutamate release → stimulation of striatum → GABA release → inhibition of Gpe → inhibition of GABA release → ↓ inhibition (activation) of subthalamic nucleus → glutamate release → stim. of substantia nigra (pars reticularis) & Gpi → GABA release → inhibition of thalamus → inhibition of premotor cortex → deactivation of muscles → ↓ movement

Question 82

Degeneration in Nigrostriaital pathway =

Answer 82

decreased dopamine

Question 83

Parkinson’s Disease

Answer 83

* Overactivity of the indirect pathway * Reduced stimulation of the direct pathway *Loss and impairment of melanated dopaminergic neurons *substantia nigra is NOT dark

Question 84

symptoms of Parkinson's Disease (6)

Answer 84

* Initial symptom is typically a tremor in fingers or hands * Bradykinesia- slowed movement * Stiff/rigid muscles * Gait abnormalities * Posture instability * Loss of automatic movements

Question 85

Huntington disease

Answer 85

Degeneration of striatum

Question 86

Huntington's disease symptoms (6)

Answer 86

* Mood changes * Cognitive decline * Movement problems * Chorea- random spasmastic movements * Difficulty speaking and swallowing * Huntington’s is always fatal, there is no cure