Thalamus

Front 1

Major Thalamic Nuclei

Back 1

1. Anterior
2. Mediodorsal
3. Centromedian
4. Pulvinar
5. Ventral tier nuclei
A. ventral anterior
B. ventral lateral
C. Ventral posterior; i. ventral posterolateral
ii. ventral posteromedial
6. Metathalamus
7. Reticular nucleus of thalamus

Front 2

Anterior Nucleus

Back 2

- INPUT: mamillary nucleus
- TRACT: mamillothalamic
- OUTPUT: cingulate gyrus
- FUNCTION: part of Papez circuit of emotion of limbic

Front 3

Mediodorsal nucleus

Back 3

LOTS of intralaminar connections
- INPUT: amygdala, substantia nigra & temporal neocortex
- OUTPUT: reciprocally connected to prerontal cortex
- TRACT:
- FUNCTION: expression of affect, emotion & behaviour
memory (lost if destroyed) - Werncke Korsakoff Syndrome

Front 4

Centromedian Nucleus

Back 4

largest intralaminar nucleus, recip. connected to 1o motor cortex
- INPUT: GP
- OUTPUT: Striatum (CN & Putamen) & diffusely to entire neocortex
- TRACT:
- FUNCTION

Front 5

Pulvinar

Back 5

largest thalamic nucleus
- INPUT: l & m geniculate bodies & superior colliculus
- OUTPUT: recp. connections with the assoc. cortex of parietal, occipital & posterior temporal lobes
- TRACT:
- FUNCTION: intergration of visual, auditory & somesthetic input
- destruction may result in sensory dysphasia

Front 6

Ventral Anterior nucleus

Back 6

- INPUT: GP & Substantia Nigra
- OUTPUT: diffusely to prefrontal cortex, orbital cortex & premotor cortex
- TRACT:
- FUNCTION

Front 7

Ventral Lateral

Back 7

- INPUT: cerebellum (dentate), GP, SN
- OUTPUT: motor cortex, supplementary motor cortex (BA 6)
- TRACT:
- FUNCTION

Front 8

Ventral Posterior Nucleus;
2 subnuclei; VPL & VPM

Back 8

2 subnuclei; VPL & VPM
- termination point for GSA & SVA (taste)

Front 9

VPL

Back 9

- INPUT: spinothalamic tract & ML
- OUTPUT: sensory cortex
- TRACT:
- FUNCTION

Front 10

VPM

Back 10

- INPUT: trigeminothalamic tracts
- OUTPUT: sensory cortex
- TRACT:
- FUNCTION
GUSTATORY pathway orginates in solitary nucleus & projects via central tegmental tract to VPM & then gustatory cortex (postcentral gyrus BA 3b). Taste Pathway is ipsilateral

Front 11

Metathalamus

Back 11

LGN: visual relay.
INPUT: retina via optic tract
OUTPUT; 1o visual cortex

MGN: auditory relay nucleus
INPUT: brachium of inferior colliculus
OUTPUT: 1o auditory cortex (BA 41, 42)

Front 12

Reticular Nucleus of Thalamus

Back 12

surrounds the thalamus as a thin layer of GABAergic neurons, lies between the extramedullary lamina & IC
- INPUT: excitatory from corticothalamic & thalamocortical fibres
- OUTPUT; inhibitory to thalamic nuclei

Front 13

Thalamus BS

Back 13

1. Post. communicating aa
2. Post. cerebral aa.
3. Anterior choroidal aa (LGN)

Front 14

Internal Capsule

Back 14

- layer of white matter separate the caudate & thalamus medially from the lentiform (GP & P) nucleus laterally
A. anterior limb; between caudate & lentiform
B. genu; contains corticobulbar fibres
C. posterior limb; between thalamus & lentiform. COntains, CsT, sensory (pain, temp, touch), visual & auditory radiations

Front 15

Internal Capsule BS

Back 15

1. anterior limb; medial striate branches of anterior cerebral a & lateral striate from MCA
2. genu; direct branches off ICA or pallidal branches of Ant. Choroidal a
3. Post. limb; Ant. choroidal a & branches off MCA