Thalamus Flashcards
Diencephalon structures
- thalamus
- hypothalamus
- epithalamus
Thalamus
Gateway to cerebral cortex; sorts, edits, and relays ascending input
Hypothalamus
Controls autonomic nervous system and endocrine system
Epithalamus
Pineal gland (body) extends from posterior border and secretes melatonin
Thalamus impulses
- impulses from hypothalamus for regulating emotion and visceral function
- impulses from cerebellum and basal nuclei to help direct motor cortices
- impulses for memory or sensory integration
Thalamus main function
Mediates sensation, motor activities, cortical arousal, learning, and memory
Anatomy of the thalamus
- internal medullary lamina: dense thick band of fibers formed by tracts running between masses
- anterior nuclei
- medial nuclei
- lateral nuclei
Anterior nuclei
Collection of nuclei at the rostral end of the dorsal thalamus:
- anteroventral nucleus
- anteromedial nucleus
- anterodorsal nucleus
Anterior nuclei connections
Limbic system, mamillary bodies, cingulate gyrus, and hippocampus
Anterior nuclei function
Emotional behavior and memory
Medial nuclei function
- affective behavior
- decision making
- judgement
- memory
- stimulates anxiety and dread
Limbic thalamus
Comprised of anterior nuclei and mediodorsal nuclei
Limbic thalamus lesions
- produce emotional disorders and some long-term memory loss
- severe anxiety: bilateral dorsomedial nuclear lesions or severing frontal lobe connections
Lateral nuclei
- sensory and motor
- medial and lateral geniculate
Lateral posterior and pulvinar nucleus
Receives afferent fibers from superior colliculus and has recripocal connections to the superior parietal lobe