Cerebral Cortex Flashcards
What is the cerebral cortex embryologically derived from??
The Telencephalon
What are the subdivisions of the cerebral cortex?
Archicortex (3 layers)
Paleocortex
Neocortex (6 layers)
4 major lobes and 2 subdivisions of the cerebral cortex:
Frontal lobe Parietal lobe Temporal lobe Occipital lobe Insular lobe Limbic lobe
Which arteries supply the cerebral cortex?
ACA MCA PCA Anterior communicating Posterior communicating
What is the major venous drainage of the cerebral cortex??
Sagittal sinus, Inferior sagittal sinus, Straight sinus, Transverse sinus, Sigmoid sinus, which drain into internal jugular veins
What are the six cellular layers of the cortex?
Layer I: Molecular layer Layer 2: External Granular layer Layer 3: External Pyramidal layer Layer 4: Internal Granular layer Layer 5: Internal Pyramidal layer Layer 6: Multiform layer
What are the major cell types in the cerebral cortex?
Pyramidal cells and Non-pyramidal cells
Areas 3, 1, 2
Primary somatosensory cortex
Area 4
Primary motor cortex
Area 17
Primary visual cortex
Area 41 and 42
Primary Auditory cortex
Areas 44 and 45
Motor area of speech (Broca’s); mostly dominant in L hemisphere
Lesion of Areas 3, 1, 2 (Primary somatosensory cortex)
Contralateral loss of somesthetic sensation
Lesion of Area 4 (Primary motor cortex)
Contralateral spastic paralysis
Lesion of Area 17 (Primary visual cortex)
Contralateral hemianopia
If restricted to upper or lower banks of Calcarine fissure –> contralateral inferior or superior quadrantanopia
Lesion of Area 41, 42 (Primary auditory cortex)
Bilateral lesions lead to loss of hearing
Lesion of Area 44 and 45 (Broca’s area)
Dominant side (left) --> motor aphasia, Broca's aphasia, or expressive aphasia Non-dominant side (right) --> difficulty expressing emotional aspect of language
Association cortical areas of the parietal lobe
Posterior parietal lobe: polymodal convergence
Superior parietal lobule: areas 5 and 7
Inferior parietal lobule: supramarginal gyrus (area 40) and Angular gyrus (area 39)
Lesion of association cortical areas of parietal lobe
Dominant (usually left) hemisphere –> astereognosis (area 40) aphasia, alexia and agraphia (area 39)
Non-dominant (usually right) hemisphere –> spatial distortion, contralateral neglect
Association cortical areas of the occipital lobe
Secondary visual cortex: area 18 or V2
Association cortical areas: V3, V4, etc
32 visual areas in primate cortex
Lesion to association cortical areas of occipital lobe
A variety of visual defects
Association cortical areas of temporal lobe
Wernicke’s area: posterior part of superior temporal gyrus (area 22): language comprehension (dominant on the left)
Lesion to association cortical areas of temporal lobe
Wernicke’s area (dominant hemisphere) –> sensory aphasia, Wenicke’s aphasia, receptive aphasia
Wernicke’s area (non-dominant hemisphere) –> difficulty in comprehending the emotional aspect of language
Cortico-cortical connections within the same hemisphere and between two hemispheres
Short association fibers
Long association fibers
Callosal fibers
General functional significance of the cerebral cortex
Perception of special sensations (somatic, visual, auditory, olfaction)
Planning and execution of voluntary movements
Emotions and behavior
Mental functioning
Memory
Dysfunctions of cerebral cortex
Usually caused by vascular hemorrhage, thrombosis or tumor
Symptoms related to specific regions of cortex affected
