Cortical organisation and function Flashcards
(38 cards)
What is gyri and sulci?
gyri are the folds/bumps
Sulci are the grooves/pits
How is the cerebral cortex organised?
-Into lobes
-Layers
-Columns
How is the cerebral cortex divided?
-divided into regions known as “brodmann areas”
-Based on cytoarchitecture (cell size, spacing/ packing density and layers)
-Areas shown to relate to function
What are the lobes of the brain?
-Frontal lobe
-Parietal
-Temporal
-Occipital
-Insular cortex
-Limbic
What is the function of the frontal lobe?
-Regulating and initiating motor function
-Language
-cognitive functions (executive function
[e.g. planning])
-attention
-memory
What is the function of the parietal lobe?
Sensation - touch, pain
sensory aspects of language
spatial orientation and self-perception
What is the function of the occipital lobe?
Processing visual information
What is the function of the temporal lobe?
Processing auditory information
emotions
memories
What is the function of the limbic lobe
Includes the amygdala, hippocampus, mamillary body, and cingulate gyrus
Concerned with learning, memory, emotion, motivation and reward
What is the function of the insular cortex
lies deep within lateral fissure
Concerned with visceral sensations (e.g. hunger/thirst) , autonomic control, and interoception, auditory processing, visual vestibular integration (e.g. motion sickness)
What is the grey matter of the cerebral cortex?
neuronal cell bodies and glial cells – around 85 billion of each
What is the white matter of the cerebral cortex?
Myelinated neuronal axons arranged in tracts
What are the 3 type of fibres that run through the white matter tracts?
- Association fibres (connect areas within the same hemisphere)
- Commissural fibres (Connect homologous structures in left and right hemispheres)
- Projection fibres (connect cortex with lower brain structures (e.g. thalamus, brain stem and spinal cord
What types of association fibres are there? what are their functions?
Short and long fibres:
1.Superior Longitudinal Fasciculus
(connects frontal and occipital lobes)
2.Arcuate Fasciculus -
(connects frontal and temporal lobes)
3.Inferior Longitudinal Fasciculus -
(connects temporal and occipital lobes)
4.Uncinate Fasciculus -
(connects anterior frontal and temporal lobes)
What type of commissural fibres are there?
- Corpus callosum
- Anterior commissure
What are the types of projection fibres?
-Afferent – towards cortex
-Efferent – away from cortex
-Deeper to cortex radiate as the corona radiata
-Converge through internal capsule between thalamus and basal ganglia
What is the internal capsule
A white matter structure for transmission of information to and from the cerebral cortex
what are the 2 types of cortices/ brodamann areas?
- PRIMARY cortices
Function predictable
Organised topographically
Symmetry between left and right - SECONDARY cortices:
function less predictable
not organised topographically
left-right symmetry weak or absent
What are the cortices of the frontal lobe? What type of information do they process?
Primary:
“primary motor cortex”
controls fine, discrete, precise voluntary movements.
Provides descending signals to execute movements.
Secondary: (there are 2)
1. “Supplementary”
Involved in planning complex movements (e.g.
internally cued)- like speech
2.”Premotor area”
involved in planning movements (e.g. externally cued)
What are the cortices of the parietal lobe? What type of information do they process?
Primary:
“Primary somatosensory cortex”
processes somatic sensations arising from receptors in the body (e.g. fine touch, vibration, two-point discrimination, proprioception, pain and temperature.)
Secondary:
“Somatosensory association”
Interpret significance of sensory information, e.g. recognizing an object placed in the hand. Awareness of self and awareness of personal space
What are the cortices of the occipital lobe? What type of information do they process?
Primary:
“primary visual”
Processes visual stimuli
Secondary:
“Visual association”
Gives meaning and interpretation of visual input
What are the cortices of the temporal lobe? What type of information do they process?
Primary:
“Primary auditory”
processes auditory stimuli
Secondary:
“Auditory association”
Gives meaning and interpretation of auditory input
What are the 3 other brodmann areas? what are they responsible for?
“Prefrontal cortex”
-attention
-adjusting social behavior
-planning
-personality expression
-decision-making
“Broca’s areas”
production of language
“Wernicke’s area”
Understanding of language
What issues would a frontal lobe lesion cause?
-changes in personality
-Inappropriate behaviour
