Deep Brain Structures 2 Flashcards
Brodemann area 4
-principal motor area
1/3 contribution to the corticospinal tract
brodemann area 6
-premotor area
what would be the result of a lesion to area 6?
loss of initiation of motor function
brodemann area 3-1-2
- postcentral principal sensory areas
- aka primary sensory strip
brodemann areas 5 and 7
-sensory association area
area 17
-principal visual cortex (striate)
areas 18-19
visual association areas
area 41
-primary auditory cortex
area 42
associative auditory cortex
area 22
- speech comprehension
- Wernicke’s area
area 44
- motor speech
- Broca’s area
nuclei of the thalamus
- dorsomedial nucleus (DM)
- VPM
- VPL
- pulvinar
- medial and lateral geniculate
- VA, VLo, VLc
- LP
- anterior nucleus
reminder for what the lateral and medial geniculate nuclei are for:
- lateral: vision
- medial: hearing
DM nucleus
- projects to
- receives from
- to: prefrontal cortex
- from: amygdaloid complex; temporal neocortex
what condition does a DM nucleus lesion mimic?
prefrontal lobotomy
Where does the LP nucleus project to?
superior parietal lobule
pulvinar
- projects to
- receives from
the pulvinar projects to and receives projections from:
- areas 18 and 19 (vision association)
- inferior parietal lobule
medial geniculate
- project to
- receives from
-to: areas 41 42
-from: lateral lemniscus and inferior colliculus
(goes on to transverse gyrus of heschel for hearing)
lateral geniculate
- projects to:
- receives from
- to: area 17 (vision)
- from: optic tract
VPM
- projects to
- receives from
- to: areas 3-1-2
- from: trigeminothalamic tracts
VPL
- projects to
- receives from
- to: areas 3-1-2
- from: medial lemniscus and spinothalamic tracts
VLo and VLc
- projects to
- receives from
- to: area 4 (primary motor)
- from: dentate nucleus, globus pallidus, substantia nigra
VA
- projects to
- receives from
- to: area 6 (premotor) and anterior insular cortex
- from: globus pallidus and substantia nigra
anterior nucleus
- projects to
- receives from
- to: cingulate gyrus
- from: mammillothalamic tract and fornix
lateral geniculate nucleus
- where
- function
- sits under thalamus
- sends out retinal projection to go on and form the optic N
- it’s projections go up and around lateral ventricles and optic radiation and end in area 17
what do crossing fibers in the optic chiasm “see”?
the bilateral temporal visual fields
right occipital lobe see what?
left visual field
calcarine sulcus
- the division of the inferior and superior visual field areas
- the inferior field is on top
- superior is on bottom
- in other words: the occipital lobe sees the world upside down
what are circumventricular organs?
- areas where the CSF-brain barrier doesn’t exsist
- allows for stuff in CSF to reach the nervous system
list the circumventricular organs
- area postrema
- neurohypophysis
- median eminence
- pineal gland
- ones he didn’t talk about: subcommissural organ, subfornical organ, organum vasculosum
area postrema
vomiting center
neurohypophysis
posterior pituitary
median eminence
forms the wall of the “funnel” that leads down to the posterior pituitary
pineal gland
- near superior and inferior colliculi
- primary secretion = melatonin but also 5-HT, NEPI, TRH, LHRH, SOM
what major function does the pineal gland play in lower phylogenetic animals?
gonadal hormone control
how do retinal projection travel?
- direct retinal projections to hypothalamus
- hypothalamus to pineal
- pineal secretions influence hypothalamus
what role does the pineal gland play in humans?
-exerts an inhibitory influence on gonads and reproductive system
what is the outcome of a tumor causing increased secretion of the pineal gland?
delayed pubescence
what is the outcome of a lesion and decreased secretion of the pineal gland?
precocious puberty
hypothalamus
- carries out the body’s reaction to the environment
- has many nuclei but not well defined functions like in the thalamus
notable nuclei of the hypothalamus
- mamillary bodies
- arcuate
- supraoptic
- paraventricular
- suprachaiasmatic
hypothalamic afferent
- limbic system (septal region)
- fornix (limbic)
- vagal sensory nuclei (related to satiety, PSNS)
- solitary nuclei
- thalamus
- somatic afferent from genitals and nipples
- retinal afferents to suprachiasmatic nucleus
- vasculature (SNS)
why is it significant that the hypothalamus is connected to somatic input from genitalia/nipples?
- hear your baby
- goes to medial geniculate
- projects to hypothalamus
- causes you to lactate
pathway of papez circuit
hippocampus –> fornix
–> mammillary bodies –> anterior thalamic nucleus –> cingulate gyrus –> back to hippocampus
overview of papez circuit
- you sense the environment in a physical sense
- received by cortex
- send to cingulate gyrus
- swings around into hippocampus (memory and sensory integration)
- sent back up through fornix
- ends in mammillary bodies (hypothalamus)
what happens at the mamillary bodies (hypothalamus) level of papez circuit?
-it attaches emotion to the input it received
-tells the body to have a certain reaction to the environment
(like when mcneill talked about giving me a rose…… eeeek!)
why is it beneficial for the papez circuit to be a continuous loop?
because the environment is constantly changing
hypothalamic efferents
- anterior thalamic nucleus
- BS and SC ANS centers: direct and indirect via reticular formation
- amygdoaloid nucleus
- midbrain reticular formation
