Cerebral Cortex Flashcards
Inputs to Cerebral Cortex
Thalamus
Outputs of Cerebral Cortex
Thalamus
BG
Br stem
spinal cord
Cerebral Cortex is embryologically derived from the
telencephalon
Cerebral Cortex can be subdivided into
Archicortex (3 layers), Paleocortex, and Neocortex (6 layers)
Four major lobes and 2 subdivisions of cerebral cortex
Frontal lobe, parietal, temporal, occipital
insula and limbic are subdivisions
Limbic lobe includes:
cingulate gyrus, parahippocampal gyrus and hippocampus
Three poles of cerebral cortex
frontal, occipital, temporal
Blood supply to the cortex
Anterior cerebral, middle cerebral, posterior cerebral, anterior communicating and posterior communicating arteries and circle of willis
Major venous drainage is via the
superior Sagittal sinus, Inferior sagittal sinus, Straight sinus, Transverse sinuses, and Sigmoid sinuses, which drain into the Internal jugular veins.
Major venous drainage is via the superior Sagittal sinus, Inferior sagittal sinus, Straight sinus, Transverse sinuses, and Sigmoid sinuses, which drain into the
Internal jugular veins.
Archicortex is made of the ________ and _______ has 3 layers
(hippocampus and dentate gyrus)
Layer I
molecular layer
Layer II
External granular layer
Layer III
External pyramidal layer
Layer IV
Internal granular layer
Layer V
internal pyramidal layer
Layer VI
multiform layer
Myelinated axons run in _______bands and ______ bundles.
horizontal
vertical
Major cell types in cortex
Major cell types: Pyramidal cells and Non-pyramidal cells.
Functional units of cortex are columns and modules:
each column will….
extend through the 6 layers that share simular fnxs
Functional columns form modules in various cortical areas, especially the
primary somatosensory, visual, and auditory cortices.
Columns of cortical neurons are interconnected ……
within the same hemisphere and between the
two hemispheres
Areas 3, 1, 2 (Postcentral gyrus):
Primary somatosensory cortex
Areas 4 (Precentral gyrus):
Primary motor cortex
Area 17 (Cuneus and Lingual gyri):
Primary visual cortex
Areas 41 and 42 (Transverse gyri of Heschl):
Primary auditory cortex
Areas 44 and 45 (part of the Inferior frontal gyrus):
Motor area of speech (Broca’s area); mostly
dominant in the left hemisphere
Primary somatosensory cortex
somatotopic organization (contralateral)
sensory homunculus
great representation of face and hand
lower limb representation is medial
Lesion in the primary somatosensory cortex
contralateral loss of somesthetic sensation
Primary Motor cortex information
somatotopic organization is contralateral
motor homonuculus
greater representation of face and hand
lower limb is represented medially
Lesion in the primary mortor cortex
contralateral SPASTIC paralysis
Primary visual cortex:
visuotopic organization
Central visual field; most posterior while peripheral visual field is most anterior
verticle meridian at the border of area 17 and 18
Horizontal meridian will bisect horizontally
Central visual field is :
most posterior while peripheral visual field is most anterior
Horizontal meridian will bisect
horizontally
Lesion of primary visual cortex
see contralateral hemianopia and if restricted to upper or lower banks of the calcarine fissure–> contralateral inferior or superior quadrantanopia
Primary auditory cortex
tonotopic orgnization, biaural respresentation
Lesion in the primary auditory cortex
bilateral lesions lead to loss of hearing
Broca’s area:
Broca’s area is motor area of speech and dominant of the left side
Lesion on left side of broca
motor aphasia, Broca’s aphasia or expressive aphasia
Non-dominant (right) side lesion of Broca’s
difficulty in expressing emotional aspect of language
Prefrontal cortex is made up of
Dorsolatearl prefrontal cortex
ventromedial prefrontal cortex
Fnx of dorsolateral prefrontal cortex
working memory
Fnx of ventromedial prefrontal cortex
limbic
Main functional areas of frontal cortex
Primary motor cortex premotor cortex supplementary motor area frontal eye field Broca's area prefrontal cortex
Association cortical areas of parietal lobe
Posterior parieta lobe
superior parietal lobule
Inferior parietal lobule: supramarginal gyrus and angular gyrus
Lesion of left hemisphere in the association cortical areas of the parietal lobe
astereognosis, aphasia, alexia and agraphia
Association cortical areas of occipital lobe
secondary visual cortex
Assocation cortical areas
32 visual areas in primate cortex
Lesion in the association cortical area of the occipital lobe
variety of visual deficits
Association cortical areas of temporal lobe
Wernickes area: posterior part of superior temporal gyrus: languange comprehension (dominant on left)
Lesion in wernickes area–association cortical areas of temporal lobe
sensory aphasia, wernickes aphashia or receptive aphasia
Lesion in non-dominant hemisphere–
difficulty in comprehending the emotional aspect of language
Lesion of supramarginal gyrus
astereognosis
Lesion of angular gyrus
alexia and agraphia
Tumor in the cerebral cortex is usually of
gial origin
Dysnfnx in the cerebral cortex is usually caused by
vascular hemorrhage, thrombosis, tumor
General fnx of the cerebral cortex
Perception of special sensations: somatic, visual, auditory, olfaction
planning and execution of voluntary mvmnts
emotions/behavior
mental fnx
memory
