Diencephalon- Thalamus and hypothalamus Flashcards
What does the diencephalon and mostly thalamus do?
receives ascending sensory info,
processes the info,
relays it to the CORTEX
Where are the 2 thalami located?
one on each side of 3rd ventricle
what are the 6 nuclear subdivisions of thalamus?
- Anterior group
- medial group
- lateral group
- Metathalamic group
- intralaminar group
- reticular coat
what are the fiber layers of the thalamus?
internal and external medullary laminae
what is the anterior group related to?
limbic system
what is the medial group related to?
what is the main nucleus in this group?
prefrontal cortex
-Dorsomedial nucleus
what is the lateral group related to?
What are the two main tiers in this group?
somatosensory & motor areas
- Dorsal tier
- ventral tier
what is in the dorsal tier?
pulvinar
what is in the ventral tier?
VPM, VPL, VL, VA (nuclei relaying sensory and motor info)
what is the metathalamic group related to?
lateral and medial geniculate nucleus
What is the intralaminar group related to?
centromedian nucleus related to RF
what is the Reticular coat related to?
gathers efferent thalamic info
what are the subcortical afferents to thalamic nuclei?
- sensory pathways
- basal ganglia
- cerebellum
- RF
T/F: the thalamus is the chief integrating sensor of all sensory info.
T
What sensations for conscious perception is the thalamus involved in?
All sensations except olfaction
what other roles does thalamus play in?
- alertness, and attention
- emotion, pain, agreeableness)
what are 3 functional groupings of thalamic nuclei?
- cortical relay nuclei
- association nuclei
- nonspecific nuclei
what does cortical relay nuclei do?
receive sensory info,
relays it to cortex
what does association cortex do?
inter thalamic connections
where does association cortex project to?
What does it include?
- frontal and medial lobes
- pulvinar
what does nonspecific nuclei do?
- behavioral arousal , sleep
what occurs with thalamic pain syndrome?
can’t distinguish between irritating or painful stimulus
what cortical areas are heightened with this central sensitization of pain? (thalamic pain syndrome)
- thalamus
- cingulate gyrus (limbic or emotion)
- parietal lobe
- prefrontal cortex
what is hyperalgesia or allodynia?
clinical representation of thalamic pain syndrome
How does stimulus threshold change?
- elevated for tactile and position sense
- lowered for nociceptive stimuli
what happens at threshold?
- sensations are exaggerated, exceptionally unpleasant
- pin prick leads to severe burning pain
T/F: theres no spontaneous pain, while exaggerated its linked to a real stimulus
F
T/F: there is emotional instability and pseudo bulbar effect
T
What is the hypothalamus responsible for?
homeostatic influences necessary for life
cardiorespiratory, thermoregulation, metabolic, water resorption, digestive activity
How are hypothalamus’ responsibilities manifested?
control of pituitary gland, ANS
Hypothalamus acts in a _______ manner receiving afferent visceral info and is influenced by ________ and ________
- reflexive
- limbic system
- prefrontal cortex
What are the UMN of the ANS?
Autonomic control areas
-ant., lateral, ventromedial hypothalamus
what emotional reactions is the hypothalamus involved in?
embarrassment
fear
anxiety
