Thalamus Flashcards
What embryonic structure is the thalamus derived form?
Diencephalon
What makes up the epithalamus and brief function of each?
habenular nucleus (limbic), pineal gland (melatonin) post. commissure (connect pretectal and other nuclei bilat)
What divides the thalamus into anterior, lateral, and medial groups?
internal medullary lamina
What is the narrow band of laminated fibers that lie lateral to the thalamus called?
external medullary lamina
What makes up the ventral thalamus?
reticular nucleus and ventral LGN
What lies between the external medullary lamina and the internal capsule?
reticular nucleus of the thalamus (part of ventral thalamus)
What makes up the subthalamus and what is its function?
zona incerta and subthalamic nucleus involved in basal ganglia and extrapyramidal functions
4 parts of the hypothalamus
- Hypothalamic Nuclei
- Infundibulum (stalk)
- Hypophysis (pituitary)
- Hypophyseal portal system
Functions of the thalamus
- Sensory relay to the cortex
- Motor activities
- Sensory integration
- Emotional/affective info
- Papez circuit (limbic)
- Alertness, arrousal, sleep
- direct cortical feedback
Thalamic syndrome is generally caused by a lesion or tumor of which nuclei?
VPL
What are the sx of thalamic syndrome?
- Transitory contralateral hemianalgesia
- Painful sensation contralateral
- Later, pain by pressure, touch, vibration
- Eventual dysesthesia (unproved pain)
pain threshold is often raised but once overcome pain has strong emotional overtones
Afferent/Efferent/Function of anterior nucleus of the thalamus?
mamillary body/ cingulate gyrus/ limbic (Papez)
Afferent/Efferent/Function of VA?
globus pallidus/ premotor cortex (6)/ motor fxn
Afferent/Efferent/Function of VL?
dentate nucleus of cerebllem/ motor and premotor cortex 4/6)/ motor fxn
Afferent/Efferent/Function of VPL?
dorsal medial lemniscus/ somatosensory (3,1,2)/ somatic sensation of the body
