Problem 4 Flashcards
Histological organization of the cortex
- Neocortex
- -> 6 layers, whereas older version had 3 layers:
Paleocortex= Olfactory bulbs Architocortex= Hippocampus
- Major neuronal cell types
- -> pyramidal + granular neurons - Cytoachitecture
- -> organized into functional units
Functional units
Refer to columns specialized to process specific inputs + outputs
–> broadmann found areas with different histological organizations, penciled established that these areas correlate with functionally different areas
Subcortical fibre bundels
Relay info to + from specific brain areas
–> depends on their classification as
a) association
b) commissural
c) projection fibers
Association fibres
Interconnect cortical areas within a hemisphere
eg.: short ones connect to adjacent gyri; long ones to more distant ones
Superior longitudinal fasciculus
Association fibre
Spreads out from anterior FL to posterior PL + OL, and connects the overlying cortex of the
a) frontal
b) parietal
c) occipital lobes
–> arcuate fibre is an important subset
Inferior occipitofrontal fasciculus
Association fibre
Located below the insula and runs from the
a) frontal
b) temporal
c) occipital lobes
AND: interconnects them
–> uncinate fasciculus is an important subset
Superior occipitofrontal fasciculus
Association fibre
Located superior + adjacent to corpus callosum
–> interconnects
a) frontal
b) parietal
c) occipital lobes
Cingulum
Located within the limbic lobe
–> interconnects areas of the limbic cortex (=those above limbic system)
=> subset of SOF fibers
Commissural fibres
Connect similar functional areas between the hemispheres
–> enables coordination of cortical activity across the hemispheres
Corpus callosum
Commissural fibre
Largest cortical commissure, that connects the
a) 2 PLs
b) posterior parts of FLs
AND: as their fibers enter the hemispheres they can reach out to all parts of the cortex
Anterior commissure
Connects the
a) anterior temporal lobes
b) olfactory bulbs
Posterior commissure
Located in the midbrain and connects the pretectal nuclei
Projection fibres
Travel to + from the cortex
- via or from the Thalamus
- -> to descend to brainstem, basal ganglia or SC - and come from the corona radiata and converge into the internal capsule
Anterior limb
Located between the caudate + lenticular nucleus
–> part of Internal capsule
Posterior limb
Located between the thalamus lenticular nucleus
–> part of internal capsule