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Flashcards in Thalamus Deck (121):
1

What are the 4 parts of the thalamus?

- Epithalamus
- Subthalamus
- Hypothalamus
- Dorsal thalamus

2

Which part of the thalamus is connected to the pineal gland?

Epithalamus

3

What is the function of the pineal gland?

- Secretes melatonin
- Develop sex organs
- Limbic system

4

What are the 3 portions of the epithalamus?

- Habenular trigone and nuclei
- Pineal body
- Striate medularis

5

What structure does the epithalamus form the roof of?

The 3rd ventricle

6

What is the subthalamus?

- Border between thalamus and midbrain just rostral to substantia nigra

7

What part of the thalamus is referred to generally when people refer to the thalamus?

- Dorsal thalamus

8

What systems does the epithalamus link?

- Link between limbic system in forebrain and other parts of the brain

9

What substances is the habenula nucleus involved in releasing?

- Neuromodulators
- Dopamine
- Norepinephrine
- Serotonin

10

What is the main function of the subthalamus

Regulating movements produced by skeletal muscles

11

What other important structures related to movement is the subthalamus connected to?

- Basal ganglia
- Substantia nigra

12

Where is the subthalamus located?

Between dorsal thalamus and hypothalamus

13

What makes up a majority of the subthalamus? What other gray matter and tracts are involved?

Subthalamic nucleus
Also:
- Zona incerta
- Subthalamic fasciculus
- Lenticular fasciculus
- Ansa lenticularis

14

What is the major function of the hypothalamus?

Homeostatic control

15

Through what 2 systems does the hypothalamus maintain homeostasis? What other system is it involved in?

- Autonomic nervous system
- Endocrine through pituitary

- Limbic system

16

How long is the dorsal thalamus from anterior to posterior? How long is the thalamus from ventral to dorsal?

- 3cm AP
- 1.5 cm VD

17

What are the 2 regions of the dorsal thalamus?

- Allothalamus
- Isothalamus

18

Which part of the thalamus is older phylogenetically?

Allothalamus

19

Which part of the thalamus is newer phylogenetically?

Isothalamus

20

Which portion of the thalamus makes up its bulk?

Isothalamus

21

What are the 3 structures making up the allothalamus?

- Afferents from amygdala
- Centre-median parafascicular complex
- Intralaminar region

22

What are the 4 functions of the dorsal thalamus?

- Relay and integration of sensory information
- Focus attention and maintain conciousness
- Relay and integrates motor information
- Perception of low grade pain

23

What is the only sensory information that does not synapse directly on the thalamus before the cortex?

Smell

24

What are the 2 relay motor nuclei?

- Ventral anterior
- Ventral lateral

25

What are the 3 relay sensory nuclei?

- Ventral posterior
- Lateral geniculate
- Medial geniculate

26

What is the limbic relay nucleus?

Anterior

27

What are the main features of relay nuclei?

- Reciprocal connections with specific areas of cortex
- Relay information from long ascending tracts or from basal ganglia, cerebellium/ other motor nuclei

28

What effect with an ablation of specific cortical areas have?

- Degeneration of the relay nucleus to that specific area.

29

What are the 4 thalamocortical radiations, and what lobes to they project to?

Central: Frontal and Parietal (mostly parietal)
Optic: Occipital
Auditory: Temporal
Anterior: Frontal

30

What tracts synapse on the ventral posterior lateral nucleus?

- Nucleus gracilis
- Nucleus cuneatus
- Dorsal horn of spinal cord/ spinothalamic tract

31

What tracts synapse on the ventral posterior medial nucleus?

- Trigeminal sensory nuclei

32

To what structure in the cortex do the ventral posterior nuclei project to?

Primary somatosensory cortex

33

What structures synapse on the lateral geniculate body of the thalamus?

- Ipsilateral temporal hemiretina
- Contralateral nasal hemiretina
In reticular formation:
- Raphe nuclei
- Locus coeruleus
- Other areas in pons & medulla

34

What structure does the lateral geniculate nucleus project to in the cortex?

Primary visual cortex

35

What structure synapses on the medial geniculate body?

Inferior colliculus

36

Where does the medial geniculate synapse in the higher centers?

Primary auditory cortex

37

What structures synapse on the ventral lateral nucleus?

- Ipsilateral globus palldius & substantia nigra
- Contralateral dentate nucleus
- Spinothalamic tract & vestibular nuclei
- Precentral motor cortical area

38

What is the target structure if the ventral lateral nucleus of the thalamus?

- Primary motor cortex
- Supplementary motor area

39

What part of the ventral lateral nucleus does the globus pallidus synapse on?

Anterior part

40

What part of the ventral lateral nucleus does the cerebellar/ vestibular nuclei and the spinal cord synapse on?

Posterior part

41

What part of the ventral lateral nucleus does the substantia nigra nucleus synapse on?

Medial part

42

What structures synapse on the ventral anterior nucleus?

- Ipsilateral globus pallidus
- Substantia nigra
- Premotor cortex
- Frontal eye field

43

What structure does the ventral anterior nucleus project to?

- Premotor cortex
- Supplementary motor cortex

44

What structures synapse on the anterior nuclear group of the thalamus?

- Mammillary body of hypothalamus via mammillothalamic tract

45

What structures in the cortex does the anterior nuclear group project to?

- Anterior limbic area
- Cingulate gyrus
- Parahippocampal gyrus

46

What system is the anterior nuclear group a part of?

- Limbic system

47

What does the anterior nuclear group help to control?

- Alertness
- Emotion

48

What does the anterior nuclear group help acquire?

Memory

49

What information do the association nuclei help to process?

- Emotional
- Memory

50

What do association nuclei help to integrate?

Different types of sensation

51

Do the association nuclei receive direct inputs from long ascending tracts?

- No

52

What is another name for multimodal nuclei?

Association nuclei

53

Where do the association nuclei project to in the cortical areas?

Association cortical areas

54

What are the 3 nuclei of the association nuclei?

- Dorsomedial
- Pulvinar
- Lateral posterior

55

What are the 2 portions of the dorsomedial nuclei?

- Parvo cellular
- Magno cellular

56

What are the functions of the parvo cellular nucleus?

- Affective behavior
- Memory and integration of somatic visceral activities

57

What symptoms will result from a lesion to the parvo cellular nuclei?

- Flat emotional state transient memory loss
- Anterograde amnesia

58

What is the function of the magno cellular nuclei?

Relay nuclei for smell

59

What is the function of the pulvinar nuclei?

Vision

60

What is the function of the lateral posterior nuclei?

- Form complex links between subcortical visual areas with association cortical visual areas

61

What structures synapse on the lateral dorsal nucleus?

- Happocampal formation
- Pretectal area
- Superior colliculus

62

What structures does the lateral dorsal nucleus synapse on?

- Cingulate gyrus
- Visual association cortex

63

What structures synapse on the lateral posterior nucleus?

Superior colliculus

64

What structures does the lateral posterior nucleus synapse on?

- Parietal lobe
- Temporal lobe
- Occipital association cortex

65

What structures synapse on the pulvinar nucleus?

- Pretectal area
- Superior colliculus
- Retinas

66

What areas does the pulvinar nucleus synapse on?

- Association area of paretotemporal cortex
- Visual areas in occipital and posterior temporal lobe

67

What structures synapse on the medial nuclear group?

- Hypothalamus
- Amygdala
- Other thalamic nuclei
- Prefrontal cortex

68

What structures does the medial nuclear group synapse on?

- Prefrontal cortex
- Post parietal cortex
- Limbic structures

69

What is the function of the lateral dorsal nucleus?

- Memory
- Interpretation of visual stimuli

70

What is the function of the lateral posterior nucleus?

Interpretation of visual and other stimuli

71

What is the function of the pulvinar nucleus?

- Visual
- Perception
- Cognition
- Memory

72

What is the function of the medial nuclear group?

Integration of:
- Emotion
- Thought
- Judgement

73

What are the 3 non-specific nuclei?

- Reticular
- Intralaminar
- Midline (nucleus Reuniens)

74

How are the cortical projections of the non-specific nuclei connected to the cortex?

- Diffuse, widespread indirect

75

From where do the non-specific nuclei receive input?

- Reticular formation
- Other areas of neural axis

76

What do non-specific nuclei help to regulate?

- Conciousness
- Arousal
- Attention

77

What is the function of the intralaminar nuclei?

- Cortical activation
- Sensorimotor integration

78

What structures synapse on the intralaminar nuclei?

- Brainstem RF
- STT
- Cerebellar nu
- Pallidum

79

What structures do the intralaminar nuclei synapse on?

- Frontal lobes
- Parietal lobes

80

What is the function of the midline nuclei?

- Part of limbic system
- Memory
- Arousal

81

What structures synapse on the midline nuclei?

- Brainstem RF
- Hypothalamus
- STTT
- Midbrain

82

What structures do the midline nuclei synapse on?

- Hippocampal formation
- Amygdala
- Nucleus accumbens
- Cingulate gyrus

83

What is the function of the reticular nucleus?

- Inhibitory modulation of thalamocortical transmission

84

What structures synapse on the reticular nucleus?

- Collateral of thalamocortical
- Corticothalamic
- thalamostriatal
- Pallidothalamic fibers

85

What strucutre does the reticular nucleus synapse on?

The body of the thalamus

86

What is the major artery of the thalamus?

Thamogeniculate artery

87

What artery does the tuberothalamic artery branch off of?

- The posterior communicating

88

What artery does the posterior choroidal artery branch off of?

- Posterior cerebellar

89

What artery does the thalamogeniculate artery branch off of?

Basilar

90

What artery does the thalamoperforating artery branch off of?

Basilar

91

What artery supplies the posterior thalamus?

Thalamoperforating artery

92

What artery supplies anterior area of the thalamus and the geniculate bodies?

Thalamogeniculate

93

What artery supplies the medioanterior portion of the lower half of the thalamus?

Posterior choroidal artery

94

What artery supplies the anterior area of the thalamus?

Tuberothalamic artery

95

What % of thalamic infarcts are of the anterior area?

12 %

96

In what % of people is the tuberothalamic artery missing?

33 %

97

How is personality altered by a tuberothalamic artery?

- Withdrawn
- Disorientation in time and place
- Euphoria
- Lack of insight
- Apathy

98

What non-personality effects result from a tuberothalamic region?

Impairments of:
- Recent memory
- New learnings
- Disoriented

99

What % of infarcts occur in the paramedian area?

35 %

100

What nucleus is typically affected by a lesion to the paramedian area of the dorsal thalamus?

Dorsomedian nucleus

101

What impairments result from a lesion to the paramedian area?

- Neuropsychological distrubances in arousal and memory
- Confusion
- Agitation
- Aggression
- Apathy
- Speech problems (soft speech)
- Dysprosody (difficulty speaking)

102

What arteries are severed in an inferolateral dorsal thalamus lesion?

Thalamogeniculate arteries

103

What % of thalamic infarcts are in the inferolateral area?

45 %

104

What symptoms may result from an inferolateral area?

- Ataxia
- Contralateral somatosensory sensation impairment
- Intractable/ affective pain

105

What % of thalamic infarcts are in the posterior area?

8 %

106

What symptoms result from a lesion to the posterior dorsal thalamus?

- Hypoesthesia (decreased sensitivity to light/ other sensations)
- Spatial neglect
- Homonymous horizontal sectoranopsia (loss of vision in a portion of the visual field)

107

What is thalamic sydrome?

Blockage in thalamogeniculate artery

108

What typically precedes thalamic syndrome?

Numbness in the affected side

109

What is the numbness of thalamic syndrome replaced by?

Varying burning and tingling sensations

110

What can accompany the burning and tingling of thalamic syndrome?

Hypersensitivity; dysaesthesias or allodynia

111

What are less common symptoms of thalamic syndrome?

Severe ongoing pain with little or no stimuli/ motor problems

112

What fibers make up the anterior limb?

- Anterior thalamic radiation
- Frontopontine and other corticofugal fibers

113

What fibers make up the posterior limb?

- Corticopontine and other corticofugal(corticothalamic) fibers
- Superior thalamic radiation (includes somatosensory radiation)
- Corticospinal tract

114

What radiation projects from the medial geniculate nucleus?

Auditory radiation (inferior thalamic peduncle)

115

What radiation projects from the lateral geniculate nucleus?

Optic radiation (posterior thalamic peduncle)

116

What 3 motor tracts make up the internal capsule?

- Corticospinals
- Corticobulbars
- Corticopontocerebellar

117

From what lobe does the internal capsule originate?

The frontal lobe

118

What 2 nuclei do the fibers forming the anterior limb of the internal capsule pass between?

- Caudate nucleus
- Lentiform nucleus

119

What structures do the fibers making up the posterior limb of the internal capsule pass between?

- Thalamus
- Lentiform nucleus

120

What limb does the medial geniculate pass through?

The posterior limb

121

What is the intersection of the anterior and posterior limb of the internal capsule near the interventicular foramen termed?

Genu of the internal capsule