creierul 2 Flashcards
What is the cerebral cortex?
Highly folded layered sheet of neurones
Forms the outer surface of the cerebral hemispheres
Brownish grey matter covering the white matter
grey matter - the cortex
white matter - the axons that connect the cortex to other regions of the brain
Statistics about the cerebral cortex
the cortex makes up about 76% of human brain volume
about 2/3 of the cortex is found in the folds
What are the 3 phylogenetic categories of the cerebral cortex?
- Archicortex
- Paleocortex
- Neocortex
What is the archicortex?
Oldest
composed of 3 layers of neuronal cell bodies
found mostly in olfactory cortex and hippocampus
What is the paleocortex?
3 layers
also olfaction related
What is the neocortex?
Only present in mammalian brains
2-4mm thick
Comprised of 6 distinct layers
Makes up nearly all of cortical matter in humans
Associated with higher brain functions (memory, attention, intentional movement and language)
What is the temporal lobe?
Includes primary auditory cortex
Contains areas for high-level visual processing, such as object and facial recognition
Contains Wernicke area (language comprehension)
What is the occipital lobe?
Nerve signals related to vision are relayed by thalamus to occipital lobe
If you become blind by damaging your eyes, you continue to experience visual imagery
If you become blind due to occipital lobe damage, you lose the capacity for visual imagery and cease to have visual dreams
The occipital cortex is home to primary visual cortex (V1) and secondary visual areas (V2) and other parts of the visual cortex (V3, V4, V5)
Primary visual cortex receives signals directly from the thalamus
What is the parietal lobe?
Somatosensory
Related to sensing the body (touch and location)
What is the frontal lobe?
Region of the brain most closely linked with higher-order psychological functions, including the sense of self
It includes:
- primary motor cortex (production of voluntary movements)
- premotor cortex (planning and guidance of movements)
- prefrontal lobe (foreplanning and personality)
What are association areas?
Areas of cerebral cortex outside the primary areas
E.g auditory association area and visual association area
What is the role of the cortex?
receive signals from the subcortical structures
send signals within itself
send signals back down via the axons of nerve cells
What are the different types of connectivity fibres?
Association fibres
Commissural fibres
Projection fibres
What are association fibres?
Connect areas within the same hemisphere
They include:
- arcuate
- uncinate
- cingulate
- superior and inferior and longitudinal
- superior and inferior occipital
What are commissural fibres?
Connect equivalent areas in the 2 hemispheres
They are:
- corpus callosum
- anterior commissure
- posterior commissure
