Task 4 - Cerebral Cortex Flashcards
Cerebral cortex lobes
Frontal Parietal Temporal Occipital Limbic
Subcortical fiber bundles
Connect cortical areas:
- Association fibers
- Commissural fibers
- Ascending/descending projection fibers
Histological Cortex Organization
Organized in layers: Neocortex: 6 layers I-VI -> enables thought Older cortical areas only 3 layers: -paleocortex -archicortex
Paleocortex
Olfactory bulb, uncus, anterior commissure
Archicortex
Hippocampus, dentate gyrus
Pyramidal Neurons
- in layers III and V
- triangular structure: 1 apical dendrite and abundant dendritic trees coming from cell body
- main output cells of cortex: project into other brain regions and spinal cord
Granular Neurons
- in layers II and IV
- stellate neurons
- shorter axons, smaller dendritic trees
- remain in cortex
- > main interneurons of cortex
Layer I
Molecular layer
contains neuronal processes
Layer VI
Multiform layer
contains output neurons
Agranular Cortex
Mainly contains pyramidal neurons projecting to lower motor neurons (e.g. primary motor cortex)
-> not many granular neurons
Granular Cortex
Mainly contains granular neurons processing sensory information (e.g. primary sensory cortex)
-> few pyramidal cells
Cytoarchitecture
Cortex is organized into functional units
- > cortical columns
- columns specizalized to process specific inputs or outputs (depends on function)
Cortical layers
I: molecular layer II: external granular layer III: external pyramidal layer IV: internal granular layer V: Internal pyramidal layer VI: Multiform layer
Subcortical fiber bundle function
Relay information to and from specific brain areas
Association fibers
Interconnect areas within one hemisphere:
- short association fibers: connect areas in adjacent gyri
- long association fibers: connect areas more distant from each other
Commissural fibers
Connect cortical areas of one hemisphere with the same ones in the opposite hemisphere
-> enables coordination of cortical activity across hemispheres
Anterior commissure
Connects anterior temporal lobes and olfactory bulbs with each other