Cerebral Cortex II HY Flashcards
layers of the cortex
I: Molecular layer II: External granule layer III: External pyramidal layer IV: Internal granule layer V: Internal pyramidal layer VI: Polymorphic layer
granular = small pyramidal = large
agranular cortex is dominated by _________ cells
agranular cortex is dominated by LARGE PYRAMIDAL cells
granular cortex is dominated by ________ cells
granular cortex is dominated by SMALL cells
cortex functions
- integrates all sensory modalities
- plans/executes all motor activity, speech, and volitional action
- enables abstract thought, emotion, creativity
- controls attention :: modulates its own activity and focus
thalamic sensory and relay nuclei —> what cortical layer?
layer IV (internal granule)
input from intrathalamic nuclei —> what cortical layer?
layer VI (polymorphic)
intracortical input —> what cortical input?
layers II/III (external granule/pyramidal)
cortical layers that receive input
II/III: external granule/pyramidal --intracortical input IV: internal granule ---thalamic sensory/relay nuclei VI: polymorphic ---thalamic nuclei
cortical layers that have outputs
III: external pyramidal layer ---other cortical areas V: internal pyramidal layer ---striatum, brainstem, spinal cord VI: polymorphic ---thalamus
cortical layer III has output to __________
cortical layer III has output to OTHER CORTICAL AREAS
cortical layer V has output to __________
cortical layer V has output to STRIATUM, BRAINSTEM, SPINAL CORD
cortical layer VI has output to __________
cortical layer VI has output to THALAMUS
association fibers
intracortical white matter tracts
-stay within same hemisphere
Main:
- superior longitudinal fasciculus
- cingulum
- amygdalofugal pathway
commissural fibers
intracortical white matter tracts
-project from 1 hemisphere to the other
Main:
- corpus callosum
- anterior commissure
corpus callosum
- type of commissural fiber
- massive intracortical white matter tract
- contains 200-250 million axons
anterior commissure
- type of commissural fiber
- connects the temporal lobes
- 1/10 size of corpus callosum
superior longitudinal fasciculus
- a main association fiber
- connects frontal with posterior
- contains ARCUATE fasciculus: connects brain regions involved in generation/comprehension of language
arcuate fasciculus
- within the superior longitudinal fasciculus (association fibers)
- connects brain regions involved in generation/comprehension of language
cingulum
- a main association fiber
- forms nearly a complete circle
- from cingulate to parahippocampal gyrus
amydalofugal pathway
- a main association fiber
- connects amygdala with thalamus, hypothalamus, basal forebrain, brain stem, septal nuclei, nucleus accumbens
cortical columns are ______
cortical columns are MICROCIRCUITS
-many connections with other neurons in same column (and within columns)
cortical columns process sensory input _________
cortical columns process sensory input TOPOGRAPHICALLY
-area of visual field corresponds to region in cortex
direction-sensitive neurons
- type of functional organization
- some neurons only become active when light moves across the visual field in a certain direction
- due to the connections that each neuron makes with nearby neurons, and the excitatory/inhibitory nature of those connections
-converge with other neurons to integrate info into more complex things (recognize familiar faces/scenes/threats)
“columnar microcircuits work together to engender cellular behavior”
fusiform gyrus
- activated during facial recognition
- higher order cortical center
prosopagnosia
- “face blindness”
- disruption of circuits in fusiform gyrus
what happens if you stimulate the fusiform gyrus with an electric current?
- prosopagnosia (face blindness)
- “face metamorphosed”
