Chap. 3- Cerebrum Flashcards
(33 cards)
What are the three phylogenetic sections of cerebrum?
Neocortex
Proisocortex
Allocortex - archicortex and paleocortex
What is included in paleocortex?
Basal part- Olfactory bulb, olfactory peduncle, olfactory tubercle and piriform lobe
Septal part- subcallosal area, diagonal gyrus, tel septum
What is included in the archicortex?
Hippocampus formation- subiculum, hippocampus and dentate gyrus
What is included in the proisocortex?
Transitional cortex between isocortex and allocortex
Comprises cingulate gyrus and parahippocampal gyrus
What does the neocortex comprise of?
Frontal, parietal, temporal, occipital
What are the six layers of the neocortex?
- Molecular
- Outer granular
- Outer pyramidal
- Inner granular
- Inner pyramidal
- Multiform layer
Molecular layer
Dendrites and nuclei (few; neuroglia and cajals horizontal cells)
Outer granular layer
Excitatory interneurons that project from entorhinal cortex to hippocampus
Outer pyramidal layer
Projects to other cortical areas as associative and commissural fibers
Inner granular layer
Excitatory interneurons
Inner pyramidal layer
Projects to subcortical regions- basal nuclei, brainstem, spinal cord
Receives thalamocortical fibers
Multiform layer
Projects to metathalamus
What are the basal nuclei?
Caudate, accumbens, lenticular, Claustrum and amygdala
What makes up the lenticular nuclei
Putamen and globus pallidus
What comes from the lateral striated body?
Caudate and putamen
What does the caudate and putamen nucleus receive and where does it project?
Both form striated body
Cortical axons and projects to the palladium and substantia nigra
What does the palladium receive and when does it project to?
Receive axons from stated body and project to thalamus and subthalamus
Medial- endopeduncular nuc facilitates movements
Lateral- inhibits them
What happens when sensory info reaches cerebral cortex?
Excitatory fibers activate the striated body and this projects to pallidum, medial portion activates thalamus and lateral inhibits it
These activate dopaminergic neurons of pars compacta of substantia nigra to inhibit basal nuclei
What are the three differences in function of basal nuclei and cerebellum?
- Basal nuclei receive afferents from entire cerebral cortex and cerebellum only from sensorimotor
- Basal nuclei receive connections from brainstem and none from SC, cerebellum receives many from SC
- Efferent from basal nuclei to motor and prefrontal and cerebellum just to motor
What are the association fibers in the white matter of the cerebrum’?
- Superior long fasciculus- frontal cortex to parietal and occipital
- Inferior long fasciculus- occipital with temporal
- Uncinate - frontal with temporal
- Subcallosal - fronto-occipital
- Cingulum- band of fibers located in cingulate gyrus and is main afferent to parahippocampal gyrus
What is the most extensive band of projection fibers?
Internal capsule, these extend to the cerebral cortex in a fan like fashion and make corona radiata
What fibers form the rostral crus of internal capsule?
Located between caudate and lenticular
Corticopontine
Thalamocortical
Corticothalamic
Caudadoputaminal
What fibers form the genu of the internal capsule?
Located between rostral and caudal crus Corticonuclear
Corticoreticular
What fibers form the caudal crus of internal capsule?
Located between thalamus and lenticular
Corticopontine
Corticospinal
Corticorubral
Corticothalamic
Thalamocortical
And optic and acoustic radiation
