Thalamus

What is the anterior nuclear group surrounded by that divides the thalamus into large nuclear groups?

internal medullary lamina

Where does the VPMpc sensory information come from and what tracts are associated?

taste information; solitary tract

What does the diffuse connection nuclei consist of?

ventral anterior nucleus and intralaminar nuclei

What is the medial nuclear group of the thalamus composed of?

dorsal medial nucleus

What are the subdivisions of the diencephalon?

epithalamus, hypothalamus, thalamus (dorsal thalamus), subthalamus (ventral thalamus)

Where does the VPM sensory information come from and what tracts are associated?

face; all subdivisions of trigeminal nucleus

What are the afferent and efferent connections of the Intralaminar Nuclei of the diffuse connections?

1. reticular formation, spinothalamic tract (afferent) -> IL -> basal ganglia (efferent) 2. Basal ganglia (afferent) -> IL -> wide regions of cerebral cortex (efferent)

What are the afferent and efferent connections of the Dorsal Medial of the limbic system?

Afferent connections: amygdala/olfactory Efferent connections: prefrontal cortex

What are the afferent and efferent connections of the Ventral Anterior of the motor system?

Afferent connections: basal ganglia Efferent connections: supplementary motor area (SMA)

What are the afferent and efferent connections of the Anterior nuclear group of the limbic system?

Afferent connections: mammillary body (via MMT) and hippocampal formation (via fornix) Efferent connections: cingulate gyrus of limbic system

What are the afferent and efferent connections of the Lateral Dorsal of the limbic system?

Afferent connections: medial parietal and limbic regions Efferent connections: medial parietal and post cingulate cortex of the limbic system

What are the afferent and efferent connections of the Dorsal Medial of the motor system?

Afferent connections: substantia nigra Efferent connections: frontal eye fields

What are the afferent and efferent connections of the Pulvinar of the sensory system?

Afferent: Association cortex and superior colliculus Efferent: widespread regions of cortex and visual association cortex Association cortex -> Pul -> widespread regions or cortex Superior Colliculus -> Pul -> visual association cortex

What are the afferent and efferent connections of the medial geniculate body of the sensory system?

Afferent: inferior colliculus Efferent: primary auditory cortex and secondary auditory cortex

What are the afferent and efferent connections of the lateral geniculate body of the sensory system?

Afferent: retinal ganglion cells (crossed: 1, 4, 6; uncrossed: 2,3,5) Efferent: primary visual cortex

What are the afferent and efferent connections of the Lateral Posterior of the sensory system?

Afferent: superior parietal lobule Efferent: superior parietal lobule

Which relay nuclei are associated with the limbic system?

Anterior nucleus, lateral dorsal nucleus, dorsal medial nucleus

What is the pathway of the olfactory system?

CNI -> olfactory bulb -> olfactory cortex -> amygdala -> thalamus (DM)

What do lesions of the VA/VL usually result in?

Contralateral motor: ataxia or choreoatheotoid movements

T/F: All thalamic nuclei only participate in only one function.

False: Some thalamic nuclei participate in more than one function.

All systems project to the thalamus to get to the cerebral cortex except which system?

Olfactory system

What is the primary blood supply of the thalamus?

Posterior communicating and Posterior cerebral arteries

What is the posterior nuclear group of the thalamus composed of?

Pulvinar (Pu), Lateral Geniculate Body (LGB), Medial Geniculate Body (MGB)

What structure does the VLa receive information from involving motor function and what does it project to?

Same as VA: basal ganglia; motor planning area in the cerebral cortex (supplementary motor cortex)

What do lesions of the VPL/VPM usually result in?

Sensory deficity: complete hemianesthesia

What are the afferent and efferent connections of the Thalamic nuclei of the subcortical connections?

Thalamic nuclei (afferent) -> RETICULAR -> Thalamic Nuclei (efferent)

T/F: All thalamic nuclei receive input from at least one extrathalamic source.

True

T/F: Lesions of the thalamus usually involve multiple structures.

True

What is the Ventral Lateral Nucleus divided into?

VLa (anterior) and VLp (posterior)

What are the afferent and efferent connections of the Ventral Lateral (VLa and VLp) of the motor system?

VLa: basal ganglia (afferent), SMA (efferent) VLp: cerebellum (afferent), lateral premotor cortex and primary motor cortex (efferent)

What are the afferent and efferent connections of the Ventral Posterior (VPL, VPM, VPMpc) of the sensory system?

VPL: medial lemniscus spinothalamic tract (afferent), somatosensory cortex (efferent) VPM: Principal Sensory Nucleus of V (afferent), somatosensory cortex (efferent) VPMpc: Solitary Nucleus (afferent), Parietal Operculum (efferent)

What are the relay nuclei that are associated with motor function?

Ventral Anterior Nucleus, Ventral Lateral Nucleus, Dorsal Medial Nucleus

What are the 3 parts of the Ventral Posterior Nuclei that are involved in somatic (and visceral related) functions?

Ventral posterior lateral (VPL), ventral posterior medial (VPM), ventral posterior medial parvocellular (VPMpc)

What are the relay nuclei that are associated with sensory functions?

Ventral posterior lateral, lateral geniculate nucleus, medial geniculate nucleus, dorsal medial nucleus, pulvinar

What do lesions of the LGN usually result in?

Visual field defects: contralateral homonymous hemianopsia

What does the thalamus receive inputs from?

all sensory systems that ascend to the cerebral cortex (except olfaction), systems dealing with motor activities, ascending systems that maintain consciousness, limbic system

What structure does the Dorsal Medial Nucleus receive information from in the limbic system and what does it project to?

amygdala; prefrontal cortex (play role in emotion)

What does the intralaminar nuclei (diffuse connections) receive from and what does it project to?

ascending systems maintaining consciousness and spinothalamic tract; widespread projections to cerebral cortex

What sensory information does the medial geniculate nucleus receive sand what does it project to?

auditory information via lateral lemniscus; auditory cortex

What structure does the Dorsal Medial Nucleus receive information from involving motor function and what does it project to?

basal ganglia; frontal eye fields of the cerebral cortex (assist in integrated eye movements)

What structure does the Ventral Anterior Nucleus receive information from involving motor function and what does it project to?

basal ganglia; motor planning area in the cerebral cortex (supplementary motor cortex)

Where does the VPL sensory information come from and what tracts are associated?

body; spinothalamic tracts and dorsal column

What structure does the VLp receive information from involving motor function and what does it project to?

cerebellum; motor planning area (Lateral Premotor Cortex) and directly to the Primary Motor Cortex

What kind of connections does the reticular nucleus of the subcortical nucleus have?

diffuse local connections that do not project to the neocortex

What sensory information does the lateral geniculate nucleus receive what does it project to?

direct visual information from eye via ganglion cells of retina, optic nerve, and optic tract; visual cortex

What do lesions of the CVA, nuclei processing somatic sensations and/or intralaminar nuclei usually result in?

intractable pain

What does the ventral anterior nucleus (diffuse connections) receive from and what does it project to?

intralaminar nuclei; diffuse projections to frontal lobe

What structure does the Lateral Dorsal Nucleus receive information from in the limbic system and what does it project to?

limbic subcortical regions; cingulate gyrus

What do the medially located nuclei of the thalamus associate with?

limbic system

What is the main role of the Dorsal Medial Nucleus?

limbic system

What structure(s) does the Anterior Nucleus receive information from in the limbic system and what does it project to?

mammillary bodies and hippocampal formation via fornix; cingulate gyrus

What do the anterior nuclei of the thalamus associate with?

motor functions

What sensory information does the dorsal medial nucleus receive sand what does it project to?

olfaction; olfactory cortex

What are the functional categories of the thalamic nuclei?

relay nuclei, diffuse connection nuclei, subcortical nuclei

Which thalamic nuclei does not project to the cerebral cortex?

reticular nuclei

What are other thalamic nuclei?

reticular nuclei and middle nuclei

What does the subcortical nuclei consist of and what does it form?

reticular nucleus; shell around the body of the thalamus

What do the posterior nuclei of the thalamus associate with?

sensory regions of cortex

What is the lateral nuclear group of the thalamus divided into?

small dorsal tier of nuclei: lateral dorsal and lateral posterior) large ventral tier of nucleus: ventral anterior nucleus (VA), ventral lateral nucleus (VL), ventral posterior nucleus (VP)

What is the intralaminar nuclei composed of?

small nuclear groups embedded within the internal medullary lamina (i.e. centromedian)

What sensory information does the pulvinar receive and what does it project to?

visual information (probably auditory and somatic sensory as well); secondary visual corices