Brainscape's Knowledge GenomeTM

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


See full index

B3 CAI > Basal Ganglia > Flashcards

Basal Ganglia Flashcards

1
Q

define disinhibition

A

the inhibition of an inhibitor

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

what are the basal ganglia?

A

a collection of nuclei (points of synapse) within the cerebral hemispheres, involved in the control of voluntary movement posture

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

other than voluntary movement and posture, what else are the basal ganglia involved in?

A

selection of motor programs, attention, reward-related behaviour and other functions such as emotion

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

what two things is the striatum composed of?

A

caudate nucleus and putamen

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

what 3 things is the pallidum made up of?

A

globus pallidus internus, globus pallidus externus, substantia nigra pars reticulata

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

what 3 things is the lentiform nucleus made up of?

A

putamen, globus pallidus internus, globus pallidus externus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the corpus striatum made up of?

A

caudate nucleus, putamen and globus pallidus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what do a given set of basal ganglia look after?

A

the contralateral side of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the basal ganglia motor circuit arranged in a loop with?

A

the thalamus and motor cortexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what would we lack without the basal ganglia circuit?

A

fine control of motor activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the basal ganglia circuit do?

A

monitor motor activity and bring about corrective actions to either promote wanted movements or to inhibit unwanted movements

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

what is the effect of the basal ganglia circuit on the thalamus?

A

output of the basal ganglia inhibits the thalamus

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

what is the effect of reduced output of the basal ganglia

A

the basal ganglia are less able to inhibit the thalamus and thus movement is promoted, as activity of the thalamus will excite the motor cortexes

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

describe the circuit in the basal ganglia circuit that increases the output of the basal ganglia

A

this would increase inhibition of the thalamus and thus there would be a reduction in the amount of movement

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

where are the nuclei within the basal ganglia circuit located?

A

forebrain, diencephalon and midbrain

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

what is the direct pathway of the basal ganglia?

A

neurons pass from the striatum to the globus pallidus internus and SNPR to the thalamus and onto the cortex

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

what is the indirect pathway of the basal ganglia?

A

neurons pass from the striatum to the globus pallidus externus to the subthalamic nucleus to the globus pallidus internus and SNPR to the thalamus and onto the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does the basal ganglia consist of?

A

putamen, globus pallidus, caudate nucleus and can also include the subthalamus nucleus and substantia nigra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where are the basal ganglia nuclei located?

A

within the cerebral hemisphere, diencephalon and midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how do nuclei appear on cross sections of the brain?

A

as darker areas as they are considered to be gray matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe the caudate nucleus

A

large, follows the curve of the lateral ventricle and connects with the putamen anteriorly

22
Q

what do the left and right thalami represent?

A

an organised collection of sensory, visual, auditory, limbic and motor-associated nuclei

23
Q

what is the internal capsule?

A

a dense collection of myelinated neurons passing to and from the cerebral cortex

24
Q

where do efferent neurons from the thalamus project to?

A

the ipsilateral cerebral cortex

25
Q

which nucleus of the thalamus can be separated into different parts?

A

the ventral posterior nucleus, which can be seperated into the VPL and VPM

26
Q

what monitors the intended actions of the motor cortexes with the actual output of that action in the periphery?

A

the cerebellum via proprioceptive inputs from muscles/ligaments/tendons

27
Q

what is the most commonly used model as to how the basal ganglia function?

A

the Alben and De Jong model

28
Q

what does the Alben and De Jong model state?

A

normal basal ganglia output is maintained by balanced activity of the direct and indirect pathways, with a shift in favour of the direct pathway promoting wanted movements and a shift in favour of the indirect pathway inhibiting unwanted movements

29
Q

what are the direct and indirect pathways very simply?

A

direct - excitatory and promotes movement

indirect - reduces unwanted movement

30
Q

what is one of the core regions affected in Parkinson’s Disease?

A

the substantia nigra (a degeneration of the nigrostriatal neurons will reduce the dopamine release onto the striatum which means a reduction of excitation of the direct pathway within the striatum)

31
Q

what does a reduction in the activation of the striatum lead to?

A

this will reduce the inhibition of the GPI and SNPR, which will in turn increase the activity of the GPI and SNPR, and thus the thalamus, meaning the thalamus is less able to excite the cortex and thus reduce movement

32
Q

how does dopamine release from the SNPC promote movement?

A

it will increase the activity of the direct pathway and reduce the activity of the indirect pathway

33
Q

how are the indirect and direct pathways in the striatum separate?

A

dopamine acts on D1 or D2 receptor within the striatum (D1 causes excitation and D2 causes inhibition)

34
Q

what is the pathogenesis of Huntington’s Disease in the early stages?

A

the striatal neurones degenerate, reducing the activity of the indirect pathway, leading to an inbalance between the direct and indirect pathway, with the direct pathway more able to inhibit the GPI and SNPR, reducing the inhibition of the thalamus meaning the thalamus is more able to activate the cortex and promote movement

35
Q

what type of disorder is Huntington’s Disease?

A

a pro-kinetic disorder characterised by excessive and unwanted movements

36
Q

what can disorders of the basal ganglia result in?

A

imbalance of the direct and indirect pathways resulting in either hyperkinetic (Huntington’s) and hypokinetic (Parkinson’s) disorders

37
Q

what is the effect on the GPI in hyperkinetic disorders?

A

reduced activity of GPI (e.g. Huntington’s Disease)

38
Q

what is the effect on the GPI in hypokinetic disorders?

A

increased activity of the GPI (e.g. Parkinson’s Disease)

39
Q

What receptor does dopamine act on in the direct pathway?

A

D1 receptors in the striatum

40
Q

What receptor does dopamine act on in the indirect pathway?

A

D2 receptors in the striatum

41
Q

What does the striatum do?

A

In direct pathway, inhibits Globus Pallidus Internus + SNPR. In indirect pathway, inhibits globus pallidus externus.

42
Q

What does the cortex do?

A

Excite striatum

43
Q

What does the Globus pallidus internus + SNPR do?

A

Inhibits thalamus

44
Q

What does thalamus ventral anterior/lateral nucleus do?

A

Excites cortex (via pre/supplemental motor)

45
Q

What does Globus pallidus externus do?

A

Inhibits Subthalamic nucleus

46
Q

What does subthalamic nucleus do?

A

Excites Globus pallidus internus + SNPR

47
Q

What are the different groups of basal ganglia and where are they located?

A

striatum (caudate nucleus + putamen)

pallidum (globus pallidus internus, globus pallidus externus, substantia nigra pars reticulata)

lentiform nucleus (putamen, globus pallidus internus, globus pallidus externus

subthalamic nucleus

substantia nigra pars compacta

48
Q

Label this diagram

A
49
Q

Label this diagram

A
50
Q

Label this diagram

A
51
Q

Draw out the direct pathway

A
52
Q

Draw out the indirect pathway

A

B3 CAI (13 decks)

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