thalamus, hypothalamus and limbic system Flashcards
(32 cards)
what is the white matter found next to the thalamus ?
internal capsule
what is the main job of the thalamus ?
sensory relay except for the olfactory nerve
consciousness
sleep
and alertness
what are the main thalamic nuclei ?
ventral postromedial VPM
ventral postrolateral VPL
lateral geniculate nucleus LGN
medial geniculate nucleus MGN
ventral lateral VL
what is the info , input and output associated with the VPL ?
info - all sensory except olfactory
input - from medial leminiscus , posterior column and spinothalamic
output - somatosensory cortex
what is the info , input and output of the VPM ?
info : sensory face and taste
input : trigeminal and gustatory
output : somatosensory cortex
what is the info, input and output of the LGN ?
info: vision
input: CN 2
ouput : calcarine sulcus
what is the info , input and output of MGN ?
info : hearing
input : superior olive and inferior colliculus of tectum
output : temporal lobe- auditory cortex
what is the info , input and output associated with VL ?
info: motor
input : baal ganglia
output : motor cortex
what is a lacunar stroke ?
stroke of the small vessels of the brain, affecting the deep structures of the brain
what is the thalamic syndrome ?
affection of the thalamus usually due to a lacunar stroke where the VPL is mainly affected
what is the presentation associated with thalamic syndrome ?
contralateral sensory loss
can lead to thalamic pain syndrome many months after the occurence of the stroke
where is the hypothalamus found ?
below the thalamus
what are the hypothalamic functions ?
autonomic control
temperature regulation
water balance
pituitary control
what are the areas of the hypothalamus and what are the associated functions ?
lateral - hunger - anorexia
ventromedial - satiety - hyperphagia and obesity
anterior - cooling - hyperthermia
posterior - heating - inability to thermoreulate
suprachiasmatic - circadian rhythmn
what is the association between fever and the hypothalamus ?
release of pyrigens like IL6 and TNF alpha allow for the productions of prostaglandin E2 though the anterior portion of the hypothalamus - allowing for a fever to happen
what are the hormones released by the hypothalamus ?
TRH
CRH
GHRH
GnRH
what are the inhibitory effects of prolactin and somatostatin ?
somatostatin decreases GH release
prolactin release inhibits dopamine release
what is the prolactin feedback ?
an increase in prolactin results in decreased GnRh release
where are ADH and oxytocin released ?
ADH - released form supraoptic nucleus
oxytocin - paraventricular nucleus
where is leptin secreted from and what is the effect of it on the hypothalamus ?
from adipocytes
lateral HT - responsible for hunger is inhibited by leptin
ventromedial HT - is stimulated by leptin
you feel more full with an increase in leptin release
what is a craniopharyngioma ?
most common childhood - supratentorial
rare form of tumor arising from rathke’s pouch , where there is pressure on the optic chiasm
what are the findings associated with crangiopharyngoma ?
Cholesterol crystals found in “motor oil”-like fluid within tumor
associated with bitemporal hemaniopia
what is the limbic system responsible for ?
emotion , long term memory loss
smell and behavioural modulation
what are the famous 5 Fs associated with the limbic system ?
feeding
fleaing
fighting
feeling
sex
