Physio Test 2 - Motor System 2

Front 1

Basal ganglia

Back 1

components of feedback loops that regulation initiation and maintenance of planned movement, suppression of unwanted movement.

Front 2

Striatum

Back 2

input region of basal ganglia; caudate + putamen

Front 3

Pallidum

Back 3

output region of basal ganglia; globus pallidus (i and e) regulate limbs, SNr regulates eyes

Front 4

SNc

Back 4

domapinergic projections to striatum

Front 5

subthalamic nucleus

Back 5

projects to GP **only excitatory input to GPi (glutamic)

Front 6

Types of input to basal nuclei

Back 6

Cortical projections (excitatory, glutamic) and projections from SNc (dopaminergic, excitatory)

Front 7

Direct Pathway

Back 7

circuit goes directly from striatum to output region (GPi or SNr) promotes movement. key = inhibition of GPi allows activation of thalamus.

Front 8

Direct pathway - limbs

Back 8

excitatory dopamine (D1R) from SNc activates Striatum, which inhibits GPi, which disinhibits VA/VL of thalamus, activating frontal cortex and facilitating movement

Front 9

Direct pathway - eyes

Back 9

Striatum inhibits SNr, which inhibits Superior Colliculus

Front 10

thalamus

Back 10

gateway to cortical activation

Front 11

Indirect pathway

Back 11

Dop (D2R) from SnC inhibits striatum, which inhibits GPe, inhibits STN, activates GPi; inhibits thalamocortical neurons, inhibits movement. activation of GPi inhibits movement

Front 12

Medium spiny neurons

Back 12

Key neuron in striatum. Modulated by dopaminergic neurons from SNc; GABAergic and inhibits neurons in GP and SNr

Front 13

GPi role

Back 13

GPi is tonically active, suppressing VA/VL (gabaergic). When striatum activates, it inhibits GPi w/ GABA, so VA/VL can become active.

Front 14

GABA

Back 14

released by medium spiny neurons and output neurons of GPi

Front 15

Dopamine

Back 15

released by neurons in SNc, pro-movement. direct path - activates D1 receptors that increase camp; indirect path - activates D2 receptors that decrease camp. Dop is always excitatory

Front 16

Huntington's

Back 16

selective atrophy of medium spiny neurons in striatum; indirect path most effected early on (unwanted movement). personality change, movement disorder, progressive demensia. Autosomal Dom, trinucleotide repeat

Front 17

Parkinson's

Back 17

progressive loss of dopaminergic neurons in SNc leads to bradykinesia, low-freq resting tremor, sometimes cognitive decline.

Front 18

hemiballism

Back 18

unwanted flailing on one side of body due to lesion in STN. Removes excitation of GPi, which inhibits VA/VL. So VA/VL is less inhibited, leading to unwanted movement.

Front 19

Cerebellum

Back 19

error detection/correction system for movement. 50% of all neurons in CNS.

Front 20

Cerebrocerebellum

Back 20

lateral hemispheres that receive info from cerebral cortex and deal with complex skilled movement. Motor planning.

Front 21

spinocerebellum

Back 21

central hemispheres receives input from spinal cord, deal with movement of distal muscles. vermis deals w/ posture

Front 22

vestibulocerebellum

Back 22

Flocculus gets input from vestibular system; deals w/ eye movement

Front 23

4 key cerebellar functions

Back 23

motor planning, motor execution, gait and posture, eye movement

Front 24

deep cerebellar nuclei

Back 24

provide all output from cerebellum

Front 25

cerebellar peduncles

Back 25

tracts that contain all incoming and outgoing axons

Front 26

input via Middle cerebellar peduncle

Back 26

Info from contralateral cerebral hemisphere via pontine nuclei and middle cerebellar peduncle; crosses at midline. This is the largest source of input.

Front 27

input via Inferior cerebellar peduncle

Back 27

sensory from ipsilateral spinal cord, brainstem and vestibular nuclei. info from contralateral inferior olive.

Front 28

Ascending output from Cerebellum

Back 28

superior cerebellar peduncle to contralateral motor cortex via VA/VL of thalamus (motor planning). via dendate nucleus.

Front 29

Descending output from Cerebellum

Back 29

Cerebellar cortex >> deep cerebellar nuclei >> inferior peduncle >>( SC, Reticular formation) >> anterior white matter in SC >> LMN in ventral horn.

Front 30

output to reticular formation

Back 30

via inferior peduncle; postural responses

Front 31

output to Superior Colliculus

Back 31

via inferior peduncle. eye movement.

Front 32

output to vestibular nuclei

Back 32

via inferior cerebellar peduncle; balance; ** doesn't go through deep nuclei.

Front 33

Intention tremor

Back 33

Damage to cerebrocerebellum causes uncoordinated movements of the extremities.

Front 34

ataxia

Back 34

Damage to vermis causes gait ataxia with a characteristic wide-based, unsteady gait.

Front 35

dysarthria

Back 35

Patients may have obvious difficulty with cadence and smoothness of speech.

Front 36

nystagmus

Back 36

Damage to the vestibulo-cerebellum causes difficulty maintaining fixation, eyes drift form the target and then jump back with a corrective saccade.

Front 37

spinocerebellar ataxias

Back 37

most due to tri-nucleotide repeats; usually AD inheritance

Front 38

Friedrich's ataxia

Back 38

protein frataxin is abundant in mitochondria. degeneration of nerve tissue in SC that go to cerebellum, help direct arm/leg movement. unsteady gait, muscle weakness, speech difficulty, loss of coordination.

Front 39

MS and cerebellum

Back 39

inflow/outflow frequently damaged. intention tremor, gait ataxia, nystagmus are common.

Front 40

alcohol and cerebellum - acute effects

Back 40

DUI assesses cerebellar functions;

Front 41

alcohol and cerebellum - chronic effects

Back 41

marked atrophy of anterior lobule; gait disorder

Front 42

Blood flow and cerebellum

Back 42

blood flow (signalling activity) increases in cerebrocerebellum 1-2 seconds before movement and in vermis during movement.