Thalamus Flashcards
What is the main purpose of the thalamus?
Relay and integration station for information en route to the cortex
What are the major derivatives in the adult brain of the telencephalon?
What are the associated cavities in the mature brain?
- Cerebral hemispheres, including corpus striatum
- Lateral ventricle
What are the major derivatives in the adult brain of the diencephalon?
What are the associated cavities in the mature brain?
- Thalamus
- Hypothalamus
- Third ventricle
What are the major derivatives in the adult brain of the mesencephalon?
What are the associated cavities in the mature brain?
- Midbrain
- Cerebral aqueduct
What are the major derivatives in the adult brain of the metencephalon?
What are the associated cavities in the mature brain?
- Pons
- Cerebellum
- Upper portion of fourth ventricle
What are the major derivatives in the adult brain of the myelencephalon?
What are the associated cavities in the mature brain?
- Medulla oblongata
- Lower portion of the fourth ventricle
Identify the structure indicated by the arrow

Pinneal gland
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Posterior commissure
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This section is too far anterior to include the thalamus

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This section is so far posterior that only a small part of the thalamus is present

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All nuclei of the thalamus send fibres to the cerebral cortex except one. Which nucleus is the exception?
What is its function?
Reticular nucleus
Inhibits other thalamuc nuclei - possible role in suppressing sensory input to the cortex in sleep.
Describe the reticular nucleus of the thalamus
- Thin sheet of grey matter on the lateral surface of the thalamus.
- Sends inhibitory fibres to all of the nuclei of the thalamus.
Identify the structure indicated by the arrow

Ventral anterior nucleus of the thalamus
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Lateral dorsal nucleus of the thalamus
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Ventral lateral nucleus of the thalamus
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Lateral posterior nucleus of the thalamus
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Ventral posterior nucleus of the thalamus
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Pulvinar of the thalamus
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Medial geniculate body of the thalamus
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Lateral geniculate body of the thalamus
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Internal medullary lamina of the thalamus
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Mediodorsal nucleus of the thalamus
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Massa intermedia of the thalamus (also known as interthalamic adhesion)
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Anterior nucleus of the thalamus
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Centromedian nucleus of the thalamus
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Ventral posterior nucleus of the thalamus
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Parafasicular nucleus of the thalamus
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Mediodorsal nucleus of the thalamus
Which thalamic nuclei are included in the intralaminar group?
What is this group responsible for?
- Centromedian nucleus
- Parafasicular nucleus
- Arousal from sleep
- Sensation of pain
Extensive connections to the cortex
Which thalamic nuclei are included in the ventral group?
What is this group responsible for?
- Ventral posterior nucleus - relay centre for somatosensation.
- Ventral lateral nucleus - relay in cerebellar and basal ganglia circuits to the motor and premotor cortex.
- Ventral anterior nucleus - same as ventral lateral ^
- Lateral geniculate body - relay for vision
- Medial geniculate body - relay for audition
Which thalamic nuclei are included in the lateral group?
What is this group responsible for?
- Pulvinar
- Lateral dorsal nucleus
- Lateral posterior nucleus
- Extensive connections to the cortex. May be important for iInterpretation of visual stimuli, among other functions
Which thalamic nuclei are included in the medial group?
What is this group responsible for?
- Anterior nucleus - input to cingulate gyrus, part of circuit of papez and important in memory.
- Mediodorsal nucleus - input to prefrontal cortex, involved in decisions based on predictions and memory.
Which input does the ventroposteromedial nucleus of the thalamus send to the somatosensory cortex?
Sensory input from the head
Which input does the ventroposterolateral nucleus of the thalamus send to the somatosensory cortex?
Sensory input from the body
Which input does the lateral geniculate body have and to where?
Input from the optic nerves to the primary visual cortex
Which input does the medial geniculate body have and to where?
Input from auditory system to the auditory cortex
Which input goes from the thalamic nuclei to the motor cortex?
- Ventrolateral nucleus sends input to the motor cortex from the cerebellum.
- Ventroanterior nucleus sends input to the motor cortex from the basal ganglia.
What is the mediodorsal nucleus of the thalamus responsible for?
- Emotion and subjective responses
- Integration with sensory information
- Connects to:
- Prefrontal gyrus
- Hypothalamus
- Other thalamic nuclei
- Also receives output from these same regions
What is the anterior nucles of the thalamus responsible for?
- Memory
- Instinctive behaviour
- Connects with the limbic system - mainly via the cingulate gyrus and hypothalamus.
- Also receives input from these regions
What are the intralaminar nuclei of the thalamus responsible for?
- Influences level of consciousness and alertness
- Connects with several other thalamic nuclei and so projects widely to the cortex.
- Receives input from the reticular formation and spinal sensory systems.
What is the reticular nucleus of the thalamus?
Thin covering over the lateral part of the thalamus
