4-Basal Nuclei

Question 1

function

Answer 1

1. inhibit involuntary movements at rest
2. facilitate voluntary movements

Question 2

inhibited movements

Answer 2

1. tremors- rhythmi, distal extremities
2. chorea- random jerky
3. tics- brief action preceded by irresistable urge

Question 3

facilitated movements

Answer 3

1. starting movements- getting up chair, start walking
2. keeping/maintaining- speed of action
3. stopping an action- stop and turn

Question 4

major nuclei of basal

Answer 4

1. caudate nucleus
2. putamen
3. globus pallidus/pallidum
4. subthalamic nucleus
5. substantia nigra

1-3 = corpus striatum, 2 + 3 = lentiform nucleus

Question 5

striatum =

Answer 5

putamen + caudate nucleus

more functional description NOT short term for corpus striatum

Question 6

input to striatum

Answer 6

1. corticostriate fibers
2. nigrostriate fibers (substantia nigra)
3. thalamostriate fibers

nigrostriate has dopamine neurons, lose in parkinsons

Question 7

output from striatum

Answer 7

1. striatopallidal fibers
2. striatonigral fibers

Question 8

input to pallidum

Answer 8

1. striatopallidal
2. subthalamic nucleus

Question 9

output from pallidum

Answer 9

1. pallidothalamic fibers aka thalamic fasiculus = lenticular fasiculus + ansa lenticularis + subthalamic fasiculus

to VA/VL nuclei (motor)

Question 10

closed motor loop sequence

Answer 10

1. supplementary motor cortex
2. caudate nucleus and putamen (striatum) input gate
3. globus pallidus/pallidum + substantia nigra output gate
4. ventral lateral (VL) nucleus of thalamus
5. repeat

Question 11

open motor loop

input into closed loop

Answer 11

1. somatosensory cortex
2. primary motor cortex- execution
3. premotor cortex- orientation

all feed into closed loop/striatum via corticostriate fibers

Question 12

closed association loop

Answer 12

1. prefrontal cortex- plan and decide
2. striatum
3. pallidum
4. thalamus- VA (ventral anterior), dorsomedial nucleus

Question 13

open association loop/input

Answer 13

1. premotor cortex (orientation)
2. posterior parietal cortex (visual guidance)

Question 14

oculomotor closed loop

Answer 14

1. frontal eye field-visual tracking
2. striatum
3. pallidum
4. VA + dorsomedial nucleus thalamus OR superior colliculus for reflexes

Question 15

oculomotor open loop

Answer 15

input from
1. prefrontal cortex- plan and decide
2. posterior parietal cortx- visual guidance

Question 16

limbic closed loop

Answer 16

1. anterior cingulate gyrus + orbitofrontal cortex
2. striatum (ventral, nucleus accumbens)
3. pallidum
4. VA + dorsomedial nucleus thalamus

Question 17

limbic open loop

Answer 17

1. medial and lateral temporal lobe
2. hippocampus-memory
3. amygdala- fear, emotions
4. entorhinal area- olfactory

Question 18

direct pathway

Answer 18

striatum > substantia nigra
and back

general excitation of basal nuclei (hyperkinesia)

Question 19

indirect pathway

Answer 19

pallidum > subthalamus via subthalamic fasciculus

inhibitory to basal nuclei (hypokinesia)

Question 20

thalamus is what to cortex

Answer 20

excitatory

Question 21

pallidum is waht to thalamus

Answer 21

inhibitory

Question 22

why no paralysis

Answer 22

bc no tracts are going to muscles