Flashcards in Cerebral Cortex Deck (54):
What percentage of our cerebral cortex is neocortex?
What are the layers of the neocortex?
outer granular layer
outer pyramidal layer
inner granular layer
inner pyramidal layer
What is a homotypical cortex? What is it characteristic of?
displays all six layers equally
What is a heterotypical cortex?
includes all six layers but some are more developed than others
What is heterotypical agranular cortex? What is it characteristic of?
outer and inner pyramidal layers expanded
granular layers less developed
What is heterotypical granular cortex? What is it characteristic of?
outer and inner granular layers expanded
pyramidal layers less developed
Brodmann's area: Sensory: Primary cortex
1, 2, 3
Brodmann's area: Sensory: Higher order
Brodmann's area: Visual: Primary
Brodmann's area: Visual: Higher order
Brodmann's area: Auditory: Primary
Brodmann's area: Auditory: Higher order
Brodmann's area: Association cortex
19, 21, 22, 37, 39, 40
Brodmann's area: Ideational speech area
21, 22, 37, 39, 40
Brodmann's area: Motor speech area
Brodmann's area: Motor: Primary cortex
Brodmann's area: Motor: Premotor area
Brodmann's area: Motor: Frontal Eye Fields
Brodmann's area: Prefrontal cortex
What % of corticospinal and corticobulbar fibres originate from primary motor cortex? from premotor cortex? from parietal lobe?
30% primary motor
What is an apraxia?
inability to perform learned, skilled voluntary movements int eh absence of paralysis
may result from lesions affecting the premotor area
Which parts of the body are represented to a much larger proportion on the motor homunculus?
hand and face (areas require more control of fine motor movements)
What are projection fibres
fibres passing from one level of the CNS to a higher or lower level
eg internal capsule
What are commissural fibers
interconnect opposite sides of the brain
eg corpus callosum
What are association fibres
interconnects regions of the cerebral cortex within a hemisphere (eg cingulum of the limbic system)
What does the anterior limb of the internal capsule include?
reciprocal connections: anterior and dorsomedial thalamic nuclei, frontal & cingulate cortical areas
descending projections: from frontal lobe to pontine nuclei
What does the posterior limb of the internal capsule include?
reciprocal connections: ventral anterior, ventral posterior, VPM, VPL; cortex of frontal & parietal lobes
What pathway passes through the retrolenticular and sublenticular portions of the internal capsule?
visual pathway connecting lateral geniculate body with visual cortex (occipital lobe)
What pathway passes through the sublenticular portions of the internal capsule only?
Auditory pathway connecting medial geniculate body with temporal lobe
It is thought that the external and extreme capsule contain what types of fibres
external: projection fibres from cortex to putamen
The claustrum is reciprocally connected to the
The lateral ventricles are associated with what region of the brain
The anterior horn of the lateral ventricles extend into what lobes
The posterior horn of the lateral ventricles extend into what lobes
The inferior horn of the lateral ventricles extend into what lobes
What is the trigone of the lateral ventricles?
The region where the anterior horn, posterior horn and inferior horn come together.
What cavity is associated with the diencephalon?
The third ventricle is continuous with the lateral ventricle through what
The third ventricle is continuous with the fourth ventricle through what
What cavity is associated with the pons and medulla?
The fourth ventricle opens into the __ via the ____
subarachnoid space via the two lateral foramina of Luschka and the medial foramen of Magendi
What is a homotypical cortex? Where is it found?
Cortex where all six layers of the neocortex are more or less the same.
What cell types are found in molecular layer?
mainly incoming axons and dendrites of more deeply placed cells
What cell types are found in external granular layer?
pyramidal & granular (stellate) cells
What cell types are found in external pyramidal layer?
What cell types are found in internal granular layer
granule (stellate) cells
What cell types are found in multifom layer?
fusiform & pyramidal cells
What is granular heterotypical cortex? Where is this found?
layers II & IV expands
primary visual, auditory and somatosensory cortices
What are the layers of the neocortex from I-VI?
II - external granular
III - external pyramidal
IV - internal granular
V - internal pyramidal
VI - multiform
What is agranular heterotypical cortex? Where is this found?
layers III and V predominate
primary motor cortex
In the heterotypical granular cortex, both internal and external granular layers are thickened. Why the internal more than the external?
sensory thalamic nuclei terminate preferentially in layer IV (internal granular layer)
Why is the primary visual cortex also called the striate cortex?
stria Gennari enters visual cortex from lateral geniculate body of thalamus
Primary motor cortex can be recognized by the presence of what types of cells int he internal pyramidal layer?
cells of Betz