Cerebral cortex Flashcards
Lecture 5
telencephalon (cerebral hemisphere)
1) cerebral cortex
2) basal ganglia
3) hippocampus and amygdala
lobes of cerebral cortex
frontal, parietal, occipital, temporal, limbic, insula
diencephalon
thalamus, hypothalamus, epithalamus, pineal gland
brainstem
midbrain, pons, medulla
central sulcus
separates pre-central and post-central gyrus
parieto-occipital sulcus
separates parietal and occipital lobes
lateral fissure
separates frontal, parietal, and temporal lobes
cingulate sulcus
limbic lobe is below (cingulate gyrus)
callosal sulcus
separates corpus callosum from cingulate gyrus
calcarine fissure
separates upper and lower visual field information, in occipital lobe
circular sulcus
traces around insula
longitudinal cerebral fissure
separates hte left and right lobes of the brain sagittally
transverse cerebral fissure
separates cerebrum from cerebellum, diencephalon, and brainstem
Neocortex layer I
molecular layer
- horizontally arranged fibers
- input/output: dendrites and axons from other layers
Neocortex layer II
external granular layer
- mostly interneurons, some pyramidal cells
- input/output: cortical-cortical connections
Neocortex layer III
external pyramidal layer
- mostly pyramidal cells, association axons
- input/output: cortical-cortical connections
Neocortex V
internal pyramidal layer
- mostly large pyramidal cells including Betz cells in primary motor cortex
- input/ouput: subcortical structures other than thalamus
Neocortex layer VI
multiform layer
- mixture of cells, axons project to thalamus
- output: thalamus
Neocortex layer IV
internal granular layer
- mostly stellate cells, some pyramidal cells
- input: thalamus
association fibers
fibers that stay in the same region of the brain (stay within cerebrum)
pyramidal cells
- most numerous neurons in neocortex
- soma is pyramid shaped (apex, base)
- excitatory
- Betz cells are a subtype of pyramidal cells only found in primary motor area of frontal lobe
- fusiform-shaped pyramidal cells have an elongated soma and project to the thalamus
non-pyramidal cells
1) basket
- stellate in shape, axons run horizontally
- inhibitory (GABA)
2) horizontal cells
- only in layer I, axons run horizontally
- inhibitory (GABA)
3) stellate or granular cells
- interneuron, multiple processes
- excitatory
projection fibers
fibers that go to other regions of the brain or nervous system (CNS)
- cortical info via the internal capsule
- thalamocortical (IV) and corticothalamic fibers (VI)
commisural fibers
fibers connecting left and right cerebral hemispheres
- corpus callosum: permits transfer of info between hemispheres
- anterior and posterior commissure
boundaries of frontal lobe
- in front of central sulcus
- above lateral sulcus/fissure
- external to cingulate sulcus
gyri of frontal lobe
- precentral gyrus
- superior frontal gyrus
- middle frontal gyrus
- inferior frontal gyrus
- anterior paracentral lobule
- gyrus rectus
- orbital gyri
boundaries of parietal lobe
- behind central sulcus
- above lateral sulcus/fissure
- in front of parieto-occipital sulcus
- external to cingulate sulcus
gyri of parietal lobe
- postcentral gyrus
- superior parietal lobule
- inferior parietal gyrus (supramarginal gyrus and angular gyrus)
- intraparietal gyrus
- precuneus
- posterior paracentral lobule (extension of postcentral gyrus)
boundary of occipital lobe
- behind occipito-parietal sulcus
gyri of occipital lobe
- lateral occipital gyri
- cuneus
- lingual gyrus
- occipitotemporal (fusiform) gyrus
boundaries of temporal lobe
- below lateral sulcus/fissure
- in front of parieto-occipital sulcus
- below cingulate sulcus
gyri of temporal lobe
- superior temporal gyrus
- middle temporal gyrus
- inferior temporal gyrus
- occipitotemporal (fusiform) gyrus
- lingual gyrusb
boundary of limbic lobe
callosal sulcus to cingulate sulcus
gyri of limbic lobe
- cingulate gyrus
- parahippocampal gyrus (uncus)
- paraterminal gyrus
- subcallosal area
primary cortices
areas of the cortex most directly linked to the rest of the world
association cortices
areas adjacent to primary areas
frontal lobe functional areas
- primary motor cortex
- premotor cortex
- supplementary motor cortex
- Broca’s area (speech)
- prefrontal cortex
primary motor cortex
- motor movement
- input: premotor area, somatosensory areas, VL thalamus
- output: pyramidal system
- precentral gyrus
premotor cortex
- anterior to primary motor cortex
- planning/intention of movement
- input: cortical areas, VL thalamus
- ouput: primary motor cortex, pyramidal system
supplementary motor area
- control of complex movements which require temporal organization
- input: many cortical areas, VL thalamus
- output: primary motor cortex, pyramidal system, reticular formation in brainstem
frontal eye fields
- voluntary eye movements (saccades)
- input: othoer eye fields
- output: PPRF
prefrontal cortex
- decision making, working memory, personality
- input: widespread cortex, DM thalamus
- output: widespread
parietal lobe functional areas
- primary sensory cortex
- comprehension of language areas
- spatial orientation and attention areas
primary somatosensory cortex
- postcentral gyrus
