Basal ganglia Flashcards Preview

Year 1 Neuroanatomy > Basal ganglia > Flashcards

Flashcards in Basal ganglia Deck (27)
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1
Q

what are the roles of the basal ganglia?

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

what are the five basal ganglia?

A
  1. caudate nucleus 2. putamen 3. globus pallidus 4. subthalamic nucleus 5. substantia nigra or, corpus striatum + substantia nigra + subthalamic nucleus
3
Q

what makes up the lentiform nucleus?

A

putamen + globus pallidus

4
Q

what makes up the corpus striatum?

A

caudate + lentiform

5
Q

what makes up the striatum?

A

putamen + caudate nucleus

6
Q

the caudate is primarily concerned with what function?

A

cognitive

7
Q

the putamen is primarily concerned with what function?

A

motor

8
Q

what are the major inputs to the striatum?

A
  1. corticostriate 2. thalamostriate 3. nigrostriatal
9
Q

what are the outputs from the striatum?

A
  1. striatopallidal 2. striatonigral (pars reticulata)
10
Q

what are the inputs to the pallidum?

A
  1. striatopallidal 2. subthalamic fasciculus
11
Q

what is the thalamic fasciculus?

A
  1. the common tract joining the lenticular fasciculus + ansa lenticularis as they travel from the pallidum to the thalamus (VA and VL nuclei) 2. also carries cerebellar fibers to same nuclei
12
Q

what are the outputs from the pallidum?

A
  1. pallidothalamic 2. pallidosubthalamic 3. pallidonigral 4. thalamocortical
13
Q

what are the “reciprocal connections” of the basal ganglia?

A
  1. striatum - substantia nigra 2. pallidum - subthalamic
14
Q

what are the four loop circuits of the basal ganglia? what information do they convey?

A
  1. motor - UMNs of corticospinal, corticonuclear tracts 2. association - planning and direction 3. oculomotor - integration of eye movements and visual guidance 4. limbic - emotional and motivational
15
Q

what is the conserved pathway of the loop circuits of basal ganglia?

A

cortex - striatum - pallidum - thalamus

16
Q

what are the roles of the VA / VL and mediodorsal nuclei or the thalamus?

A
  1. VA / VL - relay signals related to movement 2. mediodorsal - relay signals to frontal and limbic cortex
17
Q

what is the direct pathway through the basal ganglia? what is the result?

A
  1. facilitates flow of information through the thalamus 2. results in greater excitation of cortex, and voluntary movement (due to release of the thalamus from the tonic pallidal inhibition)
18
Q

what is the indirect pathway through the basal ganglia? what is the result?

A
  1. decreases activity in the thalamus 2. lessens excitatory output to the cortex, and tonically suppresses inappropriate movements (also terminates volitional movements)
19
Q

what is the “input gate” to the basal ganglia?

A

striatum

20
Q

what is the “output gate” from the basal ganglia?

A

pallidum

21
Q

what serves as the interface between the basal ganglia and the cortex?

A

thalamus

22
Q

is the thalamus excitatory or inhibitory to the cortex?

A

excitatory

23
Q

is the pallidum excitatory or inhibitory to the cortex?

A

inhibitory

24
Q

what is the proximate cause of Parkinson’s disease?

A

death of dopaminergic cells in pars compacta of substantia nigra

25
Q

what is athetosis?

A

slow, involuntary, convoluted, writhing movements of fingers, hands, toes, and feet

26
Q

what is hemiballismus?

A

appearance of flailing, ballistic, undesired movements caused primarily by a decrease in activity in the subthalamic nucleus

27
Q

what is the nucleus accumbens?

A

when the caudate nucleus and putamen come together