37 Cerebral hemisphere 1 Flashcards
__________ separates the frontal and parietal lobes.
Central sulcus
Name the main cortices in the frontal cortex from anterior to posterior.
- prefrontal association cortex
- premotor cortex
- primary motor cortex
Name the main cortices in the parietal lobe from anterior to posterior.
- primary somatosensory cortex
2. posterior parietal cortex
Name important structures in the occipital lobe.
Primary visual cortex, associated visual areas
Name the important structures in the temporal lobe.
Primary auditory areas, associated auditory areas
List 3 association cortices.
What is the main function of association cortices?
- Limbic cortex
- Parietal-temporal-occipital cortex
- Prefrontal cortex
- store old information, process new and old information to make a new decision
Afferents and efferents of prefrontal cortex?
Afferents:
- parietal-temporal-occipital cortex
- high-order sensory cortex
Efferents
- parietal-temporal-occipital cortex
- premotor cortex
Name the 6 layers of the cortex covered by pia mater.
Layer 1-3: association/ commissural layers
Layer 4: afferent layer
Layer 5-6: efferent layers
What is the afferents of layer 4 sensory cortex?
inputs from ventral posterior thalamic neuron
What is the flow of information from layer 4 ?
Layer 4 > synapse with stellate cells > layers 2 and 3 > layer 1 + some associated fibers (AF)
In sensory cortex, layer __ is/are very thick.
In motor cortex, layer ____is/are very thick.
4;
5 & 6
Where is the thickest areas in the brain?
Limbic system in Temporal cortex
Briefly describe the flow of vision from the retina to the primary visual cortex.
Nasal retina > contralateral lateral geniculate nucleus;
Temporal retina > Ipsilateral lateral geniculate nucleus
(thalamus)
> optic radiation > primary visual cortex
Name the long association fibers tracts.
- Superior longitudinal fasciculus
- Inferior longitudinal fasciculus
- Uncinate fasciculus
Occipital cortex to frontal cortex is connected by the ____________, which is responsible for ______________ in our brain.
arcuate fasciculus;
language processing
The anterior limb of IC is surrounded by?
lateral: GP + putamen
medial: head of caudate nucleus
The posterior limb of IC is surrounded by ?
lateral: GP + putamen
medial: thalamus
What fibers are present at the posterior limb of IC? Lesion of which artery is related?
Corticospinal fibers (+ corticopontine) at posterior limb; middle cerebral artery (lateral striae: both anterior and posterior limb) + anterior choroidal artery
What fibers are present at the anterior limb of IC? Lesion of which artery is related?
Cortico-oculumotor fibers (+corticopontine)
supplied by medial striate artery from anterior cerebral artery
What fibers are present at the genu of IC? Lesion of which artery is related?
Corticonuclei/ corticobulbar fibers;
supplied by middle cerebral artery; lesion > UMNL
Area 4 is the?
Precentral gyrus, Primary motor area
Afferents of area 4?
- somatosensory cortex,
- cerebellum,
- premotor cortex,
- supplementary motor area (corpus striatum)
Efferents of area 4?
corticospinal tract (80%)
corticostriate pathway
corticobulbar tract (CN motor nuclei)
corticothalamic tract
Face and hand have greater areas in the cortices because?
They are areas requiring larger number of muscles/ more neurons to produce muscle movements
Area 6 is?
Where is its location?
Supplementary motor areas (medial surface) and premotor area (lateral surface)
- anterior to area 4
Function of supplementary motor area?
Lesion? (ipsilateral/bilateral)
Initiate movement ;
Ipsilateral lesion: akinesia: difficulty in initiating movement;
Bilateral lesion: total skinesia: total lack of initiation, muscle tone maintained
Afferents and efferents of supplementary motor area?
Afferents: prefrontal cortex, basal ganglion (via VL), contralateral supplementary motor area
Efferents: primary motor area, corticospinal tract
Function of premotor area?
contain motor programmes, motor routines
Afferents (under control of?) and efferents of premotor area?
Afferents: prefrontal cortex, basal ganglion (via VL), posterior parietal cortex (area 7, visual)
Efferents: primary motor cortex, RF, corticospinal tract
Area 8 is? Main function?
Frontal eye field (in front of premotor area);
voluntary saccadic eye movement towards opp hemi-visual field.
Route of area 8.
FEF > PPRF (paramedian pontine reticular formation) > contralateral CN3 and ipsilateral CN6
What is area 1,2,3a, b?
Primary somatosensory cortex
What is area 5?
Somatosensory association cortex
Posterior parietal cortex is area ____.
7
What is stereognosis? Which brain parts are involved?
Ability to recognize 3D object with one’s hand;
dorsal column > relayes to VPLN > primary somatosensory cortex > somtatosensory association cortex > able to form picture of what u are holding
Posterior parietal cortex is the ______________center in the brain to external stimuli.
What is the neural route in searching objects of interest?
Attention;
object at contralateral visual hemifield > activate cell columns in posterior parietal cortex > increase resting firing rate and cell columns in frontal eye field and premotor cortex > saccadic eye movements and reaching movements
Hemineglect is caused by?
- Lesion of posterior parietal cortex especially on the RIGHT > contralateral visual neglect, delayed and inaccurate saccades and reaching movements;
- Lesion of the inferior parietal lobule > ignore opposite side of body unless attention is drawn to it
Posterior parietal cortex is dominated in the ______ hemisphere.
right
Inferior parietal lobule is area ______ and it is responsible for _______________.
40;
attention to internal environment
Supramarginal gyrus is part of the?
Inferior parietal lobule
_________________
contains a body schema, for awareness of existence and spatial relationships of body parts. Lesion of this area will cause?
Inferior parietal lobule (area 40);
Lesion: hemineglect, ignore the opposite side of the body unless attention is drawn to it
Right hemisphere is for ________________ in vision.
recognition of spatial relationships
Left hemisphere is for ________________ in vision.
recognition of visual details
Area 39 is?
Main function?
Angular gyrus;
initiates learned movements of some complexity
Connections of the angular gyrus?
- premotor area
- prefrontal cortex
- motor cortex
Angular gyrus is dominant on the _______ side. Lesion will cause?
Left;
Ideomotor apraxia - failure to perform a learned movement on request.
Angular gyrus is at the _________lobe, and it sends information to the premotor areas via _______________fasciculus.
parietal;
superior longitudinal
