Cerebral cortex Flashcards
What is the Central sulcus also known as?
Central sulcus of rolando
What is another name for the lateral sulcus?
Sylvian Fissure
How much does the brain weigh?
1600 g in Males
1400 g in Females
With about 10-25 billion neurons in cerebral cortex.
Who was theodor Von Bishop?
19th century scientist claiming men are more intelligent than women because of brain weight.
The gray matter of the forebrain refers to…?
Cortex and the deep nuclei
What are the two principal cell types present in the neocortex?
Pyramidal and stellate cells
What are pyramidal cells?
Principal output neurons
Betz cells are the largest pyramidal cells.
What are stellate cells?
Also known as granular cells. Principal interneurons of Cortex.
What are the histology cell layers of the cortex?
- Plexiform (molecular) layer
- Outer granular layer (small pyramidal &stellate cells)
- Outer pyramidal cell layer
- Inner granular layer (densely packed stellate cells)
5 inner pyramidal cell layer/ ganglion cell layer (Betz cells & few stellate)
- Multiform cell layer
What are the six types of cortical neurons?
- Retzius-Cajal cells - only in most superficial layer
- Cells of Martinoti
- Basket cells
- Stellate cells (only in 4th layer!)
- Fusion cells - only in deepest layer
- Principal/pyramidal cells
Where are pyramidal neurons found
Layers 3 & 5
Where are granular neurons found?
In layers 2 & 4
Describe the cytoarchitecture of the brain
Cortex is organized into functional units (cortical columns) specialized to process specific inputs/outputs differing by function
What Is each cerebral hemisphere divided into?
5 lobes:
- Frontal
- Parietal
- Temporal
- Occipital
- Limbic
Cerebral white matter is made of three types of fibers…?
- Commissural- connect corresponding areas of both hemispheres
- Association fibers - Connect different parts of same hemisphere usually U-shaped
- Projection fibers - fibers to and from cerebral cortex
Commissural Fibers
- cross at midline
- mainly corpus callosum
- anterior commissure (connect temporal lobes)
- hippocampal commissure
Callostomy
- done on pts with severe epileptic seizures
- section corpus callosum to prevent discharge from reaching other hemisphere
- “split-brain”
Association fibers
Main bundles
- Arcuate fibers (u-fibers)
- Cingulum
- Arcuate Fasiculus (superior longitudinal)
- Inferior longitudinal Fasiculus
- Superior occipitofrontal Fasiculus
- Inferior occipitofrontal Fasiculus
- Uncinate Fasiculus
conduction aphasia
- damage to Arcuate Fasiculus connecting Wernicke’s and Broca’s areas.
- verbal output fluent, but misuse words
- language comprehension is normal but cannot repeat words or execute verbal commands
- aware of defect
Projection fibers
- concentrated in internal capsule and fan out as corona radiata
- establish many reciprocal connections
Composed of:
• anterior limb - anterior nucleus and cingulate gyrus, dorsomedial nucleus and prefrontal cortex, frontopontine fibers
• genu - fibers via VA and VL with premotor/motor cortex, corticobulbar fibers to cranial nerve nuclei
• posterior limb - VA and VL w/ premotor/motor. Corticospinal and corticobulbar. VPL and VPM to postcentral gyrus
• retrolentiform part - optic radiations
• sublentiform part
