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Its connections

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Connections of thalamusy Anterior nucleus

Afferent Fibres

mamillothalamic tractHypothalamus

Cingulate gyrus

Efferents

to cingulate gyrus

Function Relay station for hippocampalimpulses .concerned with emotional tone andmechanism ofrecent memory

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Medial(Dorsomedial) Nucleusy Afferents from hypothalamus,frontal lobe ofarea

6(premotor area),corpus striatum and other thalamic

nucleiy Efferents to same parts from which afferents are

received

y Function Relay station for visceral

impulses,somatic and olfactory information andrelation ofthis information to ones feelings

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Lateral Nucleusy Afferents from precuneus and superior

parietal lobule

from ventral and medial nuclei ofthalamus

Efferents

to precuneus and superior parietal lobule

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VentroAnterior(VA)y Afferents from globus pallidus(subthalamic

fasciculus)

y Efferents to area 6 and 8 ofcortex(frontal eye fieldarea)

y Function Relay station for striatal impulses

y This nucleus is connected to reticular

formation,substantia nigra,corpus striatum,premotorcortex and thalamic nuclei.it influences activities ofmotor cortex

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Ventrolateral(VL)y Afferents from cerebellum dentato thalamic and

rubrothalamic fibres

y Efferents to motor area 4 (motor area)and 6(premotorarea)

y Function Relay station for cerebellar impulses

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Ventroposterolateral(VPL)y Afferents medial and spinal lemnisci

y Efferents to post central gyrus (area 3,1,2)

y Function relay station for exteroceptive(touch,painand temperature) and proprioceptive impulses frombody except face

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Ventroposteromedial(VPM)Afferents trigeminal lemniscus and gustatory pathway

Efferents to postcentral gyrus(3,1,2)

Function Relay station for impulses from face andgustatory pathway

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Intralaminar nucleiy Afferents reticular formation ofbrain

stem,spinothalamic and trigeminothalamic tracts

y Efferents to all parts ofcerebral cortex through otherthalamic nuclei and to corpus striatum

y Function participate in arousal reactions

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Midline nucleiy Afferents reticular formation ofbrain stem

y Efferents to all parts ofcerebral cortex

y Function participate in arousal reactions

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Reticular nucleusy Afferents cerebral cortex and reticular formation

y Efferents other thalamic nuclei and cerebral cortex

y Function through it cerebral cortex regulatesthalamic activity.participates in arousal mechanism

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Important neuronal loopsy Thalamic nuclei(except reticular nuclei)

y Different parts ofcerebral cortex

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Between cerebellum and basal

nucleiy This is cerebellar-rubro-thalamic-cortical-ponto-

cerebebellar pathway

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contdy Cortical-striatal-pallidal-thalamic-cortical loop

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Functions of thalamusy Integeration ofsensory input except smell.olfaction is

integrated at a lower level with taste and othersensations ,relayed to thalamus via mammillothalamictract from amygdaloid complex and hippocampus.

y Thalamus can appreciate crude sensation but cortex isrequired for interpretation ofsensation based uponpast experience

y Dorsomedial nucleus is concerned with subjectivefeeling states

y Intralaminar nuclei are concerned with level ofalertness andconsciousness.