basal ganglia Flashcards
(110 cards)
1
Q
The corpus striatum is situated lateral to the thalamus and is almost completely divided by a band of nerve fibers
A
internal capsule
2
Q
Globus pallidus plus putamen
A
Lentiform nucleus
3
Q
Caudate nucleus plus lentiform nucleus
A
Corpus striatum
4
Q
Caudate nucleus plus putamen
A
Neostriatum (striatum)
5
Q
Amygdaloid nucleus
A
Amygdaloid body
6
Q
large C-shaped mass of gray matter
A
caudate nucleus
7
Q
large and rounded and forms the lateral wall of the anterior horn of the lateral ventricle
A
head of the caudate nucleus
8
Q
- long and narrow and is continuous with the head in the region of the interventricular foramen
- forms part of the floor of the body of the lateral ventricle
A
body of the caudate nucleus
9
Q
- long and slender and is continuous with the body in the region of the posterior end of the thalamus
- follows the contour of the lateral ventricle and continues forward in the roof of the inferior horn of the lateral ventricle
- terminates anteriorly in the amygdaloid nucleus
A
tail of the caudate nucleus
10
Q
A vertical plate of white matter divides the nucleus into a larger, darker lateral portion
A
putamen
11
Q
A vertical plate of white matter divides the nucleus into a inner lighter portion
A
globus pallidus
12
Q
paleness of the globus pallidus is due to the presence of a high concentration of
A
myelinated nerve fibers
13
Q
form the main sites for receiving input to the basal nuclei
A
caudate nucleus and the putamen
14
Q
forms the major site from which the output leaves the basal nuclei
A
globus pallidus
15
Q
Corpus Striatum Afferent Fibers
A
- corticostriate
- thalamostriate
- nigrostriatal
- brainstem striatal fibers.
16
Q
- All parts of the cerebral cortex send axons to the caudate nucleus and the putamen
- Each part of the cerebral cortex projects to a specific part of the caudate—putamen complex
- Glutamate is the neurotransmitter
A
corticostriate fibers
17
Q
of the thalamus send large numbers of axons to the caudate nucleus and the putamen
A
thalamostriate fibers
18
Q
- send axons to the caudate nucleus and the putamen and liberate dopamine at their terminals as the neurotransmitter.
A
nigrostriatal fibers
19
Q
- Ascending fibers from the brainstem end in the caudate nucleus and putamen and liberate serotonin at their terminals as the neurotransmitter
- inhibitory in function
A
brainstem striatal fibers
20
Q
Corpus Striatum Efferent Fibers
A
striatopallidal and striatonigral fibers.
21
Q
- pass from the caudate nucleus and putamen to the globus pallidus
- y—aminobutyric acid (GABA) as their neurotransmitter
A
striatopallidal fibers
22
Q
- pass from the caudate nucleus and putamen to the substantia nigra
- use GABA or acetylcholine as the neurotransmitter, while others use substance P
A
striatonigral fibers
23
Q
- pass from the caudate nucleus and putamen to the globus pallidus
- have GABA as their neurotransmitter
A
Globus Pallidus Afferent Fibers; Striatopallidal fibers
24
Q
connected to the putamen
A
head of the caudate nucleus
25
connected to the caudate nucleus
amygdaloid nucleus
26
lies in the roof of the lateral ventricle.
tail of the caudate nucleus
27
terminates anteriorly in the amygdaloid nucleus
tail of caudate nucleus
28
All parts of the cerebral cortex send fibers to
the caudate nucleus and putamen
afferent corticostriate fibers to the corpus striatum
29
The neurons in the substantia nigra send axons
to the putamen
nigrostriatal fibers
30
Some of the striatopallidal fibers have GABA as
the neurotransmitter
efferent fibers of the corpus striatum
31
precede the activities of the motor cortex concerned with discrete movements of the hands and feet
globus pallidus
32
The caudate nucleus and the putamen form the
neostriatum
33
lies medial to the apex of the globus pallidus
internal capsule
34
basal nuclei are formed of ___
gray matter
35
lies lateral to the thalamus
corpus striatum
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made up of the caudate nucleus and the lentiform nucleus
corpus striatum
37
divided into the head, body, and tail
caudate nucleus
38
forms part of the floor of the body of the lateral ventricle
body of the caudate nucleus
39
lies lateral to the anterior horn of the lateral ventricle
head of the caudate nucleus
40
neurotransmitter at the nerve endings of the corticostriate fibers to the corpus striatum
glutamate
41
neurotransmitter at the nerve endings of the nigrostriatal fibers
Dopamine
42
inhibitory in function
nigrostriatal fibers
43
caused by a reduction in the release of dopamine within the corpus striatum
Parkinson disease
44
pass from the caudate nucleus to the substantia nigra
striatonigral fibers
45
influences movements of the entire body
globus pallidus
46
when the discharge patterns of the basal ganglia become excessive
effect on motor systems is to produce abnormal slowing of movements
47
result of which is the presence of abnormal, involuntary movements that occur during periods of rest
- form of disorder is called dyskinesia
reduced output
48
caudate nucleus and putamen
neostriatum
49
globus pallidus
paleostriatum
50
two additional nuclei
subthalamic nucleus and substantia nigra
51
The primary regions of the basal ganglia that serve as afferents (receiving areas) are
caudate nucleus and putamen
52
- The principal inputs from the primary motor, secondary motor, and primary somatosensory regions of cortex are directed to the
- somatotopically organized
- receive sensory and motor inputs that are associated with different parts of the body
putamen
53
- receives inputs from cortical association regions, frontal eye fields, and limbic regions of cortex
- receive more varied and integrated cortical inputs, is likely involved with cognitive aspects of movement, eye movements, and emotional correlates of movement
caudate nucleus
54
The neostriatum also receives an indirect source of cortical input. The source of this input is the ___ of the thalamus
centromedian nucleus
55
This nucleus receives afferent fibers primarily from the motor cortex and projects its axons topographically to the putamen as ___
thalamostriate fibers
56
involuntary movements during periods of rest
dyskinesia
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slowness of movement
bradykinesia
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lack of movement
akinesia
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- impaired initiation of movement, bradykinesia, and increased muscle tone
- loss of dopamine inputs into the part of the striatum
hypokinetic disorders
60
- involuntary movements at rest
- movements are typically rhythmic tremors at approximately 3 to 6 Hz
- “pill-rolling” tremor involving the fingers, hands, and arm
parkinson disease
61
- tremor disappears when the patient begins a voluntary movement
- reduced number of spontaneous movements
- bradykinesia
Parkinson’s disease
62
- Postural adjustments are awkward
- display slower than normal movements
- loss of facial expression, monotonous speech, and marked increases in muscle tone to both the flexors and extensors of the same limb, producing rigidity
parkinson disease
63
reduction in spontaneous facial expressions and eye blinking
akinesia
64
- loss of the dopamine-containing neurons of the pars compacta of the substantia nigra
- exhibit reduced amounts of norepinephrine and serotonin elsewhere in the brain
parkinson disease
65
passes through the blood-brain barrier, and as a precursor of dopamine, it is converted to dopamine in the brain
L-3, 4-hydroxyphenylalanine (L-DOPA)
66
dopamine-decarboxylase inhibitor
carbidopa
67
drug containing both L-DOPA and carbidopa
Sinemet
68
- toxic to dopamine neurons and that environmental toxins may play a role in the development of this disorder
- induce Parkinson’s disease is that it provided investigators with an important experimental tool by which this disorder can be studied in a systematic manner
1-methyl-4-phenyl-1, 2, 3, 6-tetrahydro- pyridine (MPTP)
69
- embryonic tissue containing dopamine neurons are transplanted directly into the neostriatum
- dopamine-containing cells then grow sprouts, synthesize, and release dopamine onto neostriatal neurons, where they serve to increase dopamine levels
transplantation
70
wild, uncontrolled movements of the distal musculature, which appear as abrupt and jerky
chorea
71
inherited autosomal dominant illness with the genetic defect located on the short arm of chromosome 4
huntington's disease
72
- Violent involuntary ballistic movements of the limbs contralateral to the lesion characterize ___
- proximal musculature is typically involved, but choreiform (irregular, jerky) movements of the distal musculature usually in the upper extremity may also be present
- lesion has been found to be discrete and localized within the subthalamic nucleus
hemiballism
73
- variant of choreiform movement
- slow, writhing movements of the extremities
athetosis
74
- sustained muscle contractions of the limb, axial, or cranial voluntary muscles, resulting in abnormal postures and repetitive or twisting movements
Dystonia
75
movements produce severe torsion of the neck or shoulder girdle, causing an appearance of a rhythmic shaking of the head, this form of dystonia is referred to as
torsion tremor
76
damage to the neostriatum and, possibly, the cerebral cortex
athetosis and dystonia
77
- Involuntary movements of the tongue and face characterize
- repetitive chewing movements, and the tongue irregularly moves in and out of the mouth
tardive dyskinesia
78
- block dopaminergic transmission
- blockade results in dopamine D2 receptor hypersensitivity
haloperidol (Haldol)
79
- primary features of this disorder are motor and vocal tics
- subsides in early adulthood or subside but reappear again at a later period and persist throughout life
- dysfunctions of the caudate nucleus and its linkage with the prefrontal cortex
Tourette Syndrome
80
brief, sudden involuntary movements of different parts of the body
motor tics
81
sounds that are irritating in pitch, compulsive expression of obscenities, repetition of words, and repeating words of others
vocal tics
82
compulsive expression of obscenities
coprolalia
83
repetition of words
palilalia
84
blocks dopamine D2 receptors, has been shown to be an effective treatment for Tourette syndrome
Haloperidol
85
A patient presents with violent involuntary ballistic movements that are jerky and irregular and mainly involve the upper extremity on one side of the body
The lesion was most likely located in the
Subthalamic nucleus
86
A patient presents with violent involuntary ballistic movements that are jerky and irregular and mainly involve the upper extremity on one side of the body
The motor dysfunctions characteristic of this disorder can best be accounted for in terms of loss of:
Excitatory input to the medial (internal) pallidal segment
87
A patient presents with reduced facial expression, spontaneous movements (slower than normal) that are revealed most clearly when walking, monotonous speech, an increase in muscle tone in the arms, and a rhythmic tremor (4 to 7 Hz) in the fingers, including a pill-rolling tremor
This disorder can be directly linked to loss of:
Dopaminergic inputs to the neostriatum
88
A patient presents with reduced facial expression, spontaneous movements (slower than normal) that are revealed most clearly when walking, monotonous speech, an increase in muscle tone in the arms, and a rhythmic tremor (4 to 7 Hz) in the fingers, including a pill-rolling tremor
Which of the following pharmacological treatment strategies would be most appropriate for this patient?
L-3, 4-hydroxyphenylalanine (L-DOPA) plus a dopa-
mine-decarboxylase inhibitor (Sinemet)
89
A 55-year-old man was recently diagnosed with Hunting- ton’s disease. This disorder may best be understood in terms of the loss of which substance with which result?
Gamma aminobutyric acid (GABA) in the neostriatum,
reduction of neostriatal inhibition on the lateral (external) pallidal segment
90
Huntington’s chorea (hyperkinetic disorder; loss of GABA in neostriatum)
Neostriatum
91
Disruption of indirect pathway
Globus pallidus (lateral segment)
92
Disruption of output to thalamus and cerebral cortex
Globus pallidus (medial segment)
93
Parkinson’s disease (hypokinetic disorder; loss of dopamine in neostriatum)
Substantia nigra
94
Hemiballism
Subthalamic nucleus
95
Disruption of feedback circuit from basal ganglia to cerebral cortex
Ventrolateral, ventral anterior, and centromedian nuclei of thalamus
96
* Group of subcortical nuclei
* Primarily for motor control by providing a feedback mechanism to the cerebral cortex for the initiation and control of motor responses
basal ganglia
97
- habit hub
- plays an important role in motor control
dorsal striatum
98
- reward hub
- plays key roles in emotions & learning via connections with hippocampus, amygdala, and prefrontal cortex
ventral striatum
99
- paleostriatum / dorsal pallidum
- triangular shaped
globus pallidus
100
- acts to tonically inhibit the ventral lateral nucleus & ventral anterior nucleus of thalamus
- restricts movement initiation & prevents unwanted movements
- output nucleus; sends information to thalamus
globus pallidus internus (GPi)
101
- functions as central hub in the basal ganglia for processing motor & non-motor information
- intrinsic nucleus; relay for information
globus pallidus externus (GPe)
102
- control conscious & proprioceptive movements
globus pallidus
103
NEOSTRIATUM AND GLOBUS PALLIDUS
Primary neurotransmitter:
GABA
104
NEOSTRIATUM AND GLOBUS PALLIDUS
Direct Pathway:
neostriatum -> medial (internal) pallidal segment -> thalamus -> cerebral cortex
105
NEOSTRIATUM AND GLOBUS PALLIDUS
Indirect Pathway:
neostriatum -> lateral pallidal segment -> subthalamic nucleus -> medial pallidal segment -> cerebral cortex
106
GLOBUS PALLIDUS AND SUBTHALAMIC NUCLEUS
Pathway:
lateral segment of globus pallidus -> subthalamic -> medial segment of globus pallidus
107
GLOBUS PALLIDUS AND SUBTHALAMIC NUCLEUS
Neurotransmitter:
glutamate
108
NEOSTRIATUM AND SUBSTANTIA NIGRA
Pathway:
pars reticula -> thalamus -> superior colliculus -> pars compacta
109
NEOSTRIATUM AND SUBSTANTIA NIGRA
Neurotransmitters:
dopamic
110
uncontrolled movements, unsteadiness, clumsiness, loss of balance, slurred speech, and trouble swallowing and eating
huntington's disease
