Cerebral Cortex I Flashcards
Sylvian fissure
Separates the temporal lobe from the frontal and parietal lobes.
Central sulcus
Everything in front of this is frontal lobe, behind it is parietal lobe. Found between 2 vertical gyri
Gyri associated with the central sulcus
Precentral (motor) gyrus
Postcentral (sensory) gyrus
3 major horizontal Gyri in frontal lobe? In temporal lobe?
Both are Superior, middle, and inferior
2 divisions of the parietal lobe
Superior lobule
Inferior lobule
Separated by interparietal sulcus.
Gyrus next to corpus collusum
Cinguate gyrus. Goes on to become the Hippocampul gyrus.
Gyrus which splits occipital lobe
Calcarine fissure
General role of cerebral cortex
Analyzes, plans and initiates response.
Reticular system for cerebral cortex.
“Wakes brain up” Turns it on to adjust its level of responsiveness.
Types of cortex
(1) Neocortex (most of cortex)
(2) Archicortex
(3) Paleocortex
Most of the neurons of the brain are where?
Cerebellum
Pyramidal cells of Neocortex
Projection cells out of cerebral cortex. 80% of the neocortex cells.
Give rise to the axons which leave the cortex, and go to other parts of the brain.
Alost all of the output of the cortex is (excitatory or inhibitory?)
Excitatory
Non-pyramidal cells of neocortex
Axons don’t project out. They still in the cerebral cortex and influence pyramidal cells
Granular areas vs Agranular areas
Granular- small neurons
Agranular- large pyramidal cells
The pyramidal cells usually sit in cell layer
V
Most of the input that enters brain, enters via layers…
2, 3, and 4
Columns which are adjacent to each other…
Have similar function at a cellular level
Association bundles or fasiculi
Connect parts of the back of the cerebrum to parts in the front. These tracts are similar to a highway.
Fibers travel in both directions and none are discrete point-to-point.
Primary neocortical areas
(1) Primary (P) motor– precentral gyrus (4)
(2) P. Somatosenory– postcentral gyrus (3, 1, 2)
(3) P. Visual– calcarine (17)
(4) P. Auditory– transverse temporal gyrus (41)
Unimodal association areas
Similar to primary neocortical areas. Analyze information and extract more from it.
Adjacent to primary cortical areas.
Higher level of analysis.
Multimodel association areas
High level intellectual functions.
Sends converging inputs and may respond to multiple stimuli.
Parieto-occipital-temporal region
Multimodal association area of cortex in which information related to sight, sounds and feeling are integrated.
There is no topographic distribution affiliated. One point could be for finger and a point right next to it could be for the opposite knee.
Neglect
Caused by injury to right inferior parietal lobule. Contralateral.
Ex. Vision is intact, but their minds neglect certain parts of the field
Apraxia can be caused by…
Injury to the left parietal area
Prefrontal area of the Multimodal association area
Executive Functions: Planning, insight, foresight and basic aspects of personality.
Memory, and Decision Making.
Dorsolateral component of Prefrontal area
Important for working memory, attention and logical aspects of problem solving
Ventromedial component of Prefrontal area
Has extensive limbic connections and are more important for emotional aspects of planning and decisions.
All cortical areas receive Corpus Callosum commissural fibers EXCEPT (just name the major exception)…
Temporal lobe connections which travel through the ANTERIOR COMMISSURE
Disconnection syndromes
Often result from white matter damage that interferes with cerebral connections.
Major Example: Alexia without Agraphia. Person cannot read, but they can write.
Language is centered in which hemisphere of the brain?
Left
Brokese– Motor (production of words)
Werneke’s– Sensory (what you hear and see, getting transmitted into what you say)
