Thalamus

Question 1

Diencephalon structures

Answer 1

• thalamus
• hypothalamus
• epithalamus

Question 2

Thalamus

Answer 2

Gateway to cerebral cortex; sorts, edits, and relays ascending input

Question 3

Hypothalamus

Answer 3

Controls autonomic nervous system and endocrine system

Question 4

Epithalamus

Answer 4

Pineal gland (body) extends from posterior border and secretes melatonin

Question 5

Thalamus impulses

Answer 5

• 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

Question 6

Thalamus main function

Answer 6

Mediates sensation, motor activities, cortical arousal, learning, and memory

Question 7

Anatomy of the thalamus

Answer 7

• internal medullary lamina: dense thick band of fibers formed by tracts running between masses
• anterior nuclei
• medial nuclei
• lateral nuclei

Question 8

Anterior nuclei

Answer 8

Collection of nuclei at the rostral end of the dorsal thalamus:
- anteroventral nucleus
- anteromedial nucleus
- anterodorsal nucleus

Question 9

Anterior nuclei connections

Answer 9

Limbic system, mamillary bodies, cingulate gyrus, and hippocampus

Question 10

Anterior nuclei function

Answer 10

Emotional behavior and memory

Question 11

Medial nuclei function

Answer 11

• affective behavior
• decision making
• judgement
• memory
• stimulates anxiety and dread

Question 12

Limbic thalamus

Answer 12

Comprised of anterior nuclei and mediodorsal nuclei

Question 13

Limbic thalamus lesions

Answer 13

• produce emotional disorders and some long-term memory loss
• severe anxiety: bilateral dorsomedial nuclear lesions or severing frontal lobe connections

Question 14

Lateral nuclei

Answer 14

• sensory and motor
• medial and lateral geniculate

Question 15

Lateral posterior and pulvinar nucleus

Answer 15

Receives afferent fibers from superior colliculus and has recripocal connections to the superior parietal lobe

Question 16

Ventral posterior lateral (VPL)

Answer 16

• Dorsal column medial lemniscus tract
• spinothalamic tract

Question 17

Ventral lateral

Answer 17

Cerebellothalamic tract

Question 18

Medial geniculate

Answer 18

• Represents the thalamic relay station of the auditory pathway
• receives input from auditory system
• cochlear nuclei and inferior colliculus
• projects to temporal lobe
• aids with auditory perception

Question 19

Lateral geniculate

Answer 19

• Represents thalamic relay station of the visual pathway
• receives input from retina
• projects to occipital lobe for visual perception
• species difference

Question 20

Motor thalamus

Answer 20

• ventral lateral and ventral anterior nuclei of the lateral mass
• input: extrapyramidal (involuntary) motor centers—> basal ganglia, substantia nigra, cerebellum
• projections: motor cortisol areas of the frontal lobe

Question 21

Sensory thalamus

Answer 21

• ventral posterior medial
• ventral posterior lateral
• medial geniculate body
• lateral geniculate body

Question 22

Sensory thalamus tracts

Answer 22

• VPL nucleus: somatosensory input from the body
• VPM nucleus: input from the head

Question 23

Cognitive thalamus

Answer 23

• pulvinar: modulate cortical synchrony needed for perception; attention and emotional processing
• lesions: loss of mental life and awareness of surroundings

Question 24

Thalamic disorders

Answer 24

• stroke/lesion
• unconsciousness
• sleep disorders
• aphasia
• movement disorders
• pain syndrome
• korsakoff syndrome

Question 25

Pineal gland

Answer 25

- produces melatonin - input: parasympathetic - output: secretory neuroendocrine organ

Question 26

Sleep regulation in pineal gland

Answer 26

- retina projects to the suprachiasmatic nucleus of the hypothalamus; light —> inhibition, dark —> activation - info transmitted through a multisynaptic pathway - melatonin released into the bloodstream