Cortical Organisation and Function Flashcards
What does the cerebral cortex cover?
The entire surface of the brain
How is the cortex oganised?
Into lobes
What are folds on the cortex called?
Gyri and sulci
How many layers does the cortex have?
6
What are the main roles of the frontal lobe?
Regulating/initiating motor function, language, cognitive functions, attention, memory
What does the primal frontal lobe do?
Controls fine discrete and precise voluntary movements
What does the supplementary frontal lobe do?
Planning movements (that are externally cued)
What are the main roles of the parietal lobe?
Sensation (touch and pain)
Sensory aspects of language
Spatial orientation and perception
What does the primary somatosensory cortex do?
Processes somatic sensations eg fine touch, vibration, proprioception etc
What does the somatosensory association do?
Interprets significance of sensory info eg recognising an object placed in your hand
What is the main role of the occipital lobe?
Processing visual information
What does the primary visual cortex do?
Processes visual information
What does the visual association do?
Gives meaning and interpretation of visual inout
What is the main role of the temporal lobe?
Processing auditory information, emotions, memories
What does the primary auditory cortex do?
Processes auditory stimuli
What does the auditory association do?
Gives meaning and interpretation of auditory input
What is included in the limbic lobe?
Amygdala, hippocampus, mammillary body, cingulate gyrus
What is the main role of the limbic lobe?
Learning, memory, emotion, motivation, reward
Where is the insular cortex found?
Deep in the lateral fissure
What does the insular cortex do?
Concerned with visceral sensations, autonomic control, auditory processing
What is grey matter made of?
Neuronal cell bodies and glial cells
What is white matter made of? How is it arranged?
Myelinated neuronal axons arranged in tracts
What type of fibres connect areas in the same hemisphere?
Association fibres
What is the name of the association fibre that connects the frontal and occipital lobes?
Superior longitudinal fasciculus
What is the name of the association fibre that connects the frontal and temporal lobes?
Arcuate fasciculus
What is the name of the association fibre that connects the temporal and occipital lobes?
Inferior longitudinal fasciculus
What is the name of the association fibre that connects the anterior frontal and temporal lobes?
Uncinate fasciculus
What type of fibres connect homologous structures in the left and right hemispheres?
Commissural fibres
What do association fibres connect?
Areas within the same hemisphere
What do commissural fibres connect?
Homologous structures in the left and right hemispheres
What are the 2 main commissural fibres?
Corpus callosum and anterior commissure
What type of fibres connect the cortex with structure in the lower brain?
Projection fibres
What do projection fibres do?
Connect the cortex with structures in the lower brain
Where do afferent projection fibres go?
Towards the cortex
Where do efferent projection fibres go?
Away from the cortex
Describe how the primary and secondary cortices are different?
Primary cortex has a predictable function, secondary cortex has a less predictable function
Primary cortex is organised topographically, secondary isn’t
In the primary cortex there is symmetry between the left and the right, in the secondary symmetry is weak or absent
What is the role of Broca’s area?
Speech production
What is the role of Wernicke’s area?
Understanding language
What changes do frontal lobe lesions cause?
Changes in personality and inappropriate behaviour
What changes do parietal lobe lesions cause?
Contralateral neglect, a lesion in the right hemisphere will cause a lack of awareness on the left side which includes extra-personal space
What changes do temporal lobe lesions cause?
Agnosia (inability to recognise things)
What resection may be performed to cure epilepsy? What does this cause?
Parts of temporal lobe, cause anterograde amnesia (inability to form new memories)
What changes do Broca’s area lesions cause?
Expressive aphasia= poor production of speech but normal comprehension
What changes do Wernicke’s area lesions cause?
Receptive aphasia= poor comprehension of speech but production is normal
What is the difference between expressive and receptive aphasia?
Expressive= speech production is impaired but comprehension is normal Receptive= speech comprehension is impaired but production is normal
What changes does lesion in primary visual cortex cause?
Blindness in the corresponding part of the visual field
What changes does lesion visual association cause?
Deficits in interpretation of visual info eg prosopagnosia (inability to recognise familiar faces or learn new ones)
What do PET scans show in brain imaging?
Blood flow to different areas of brain
What does fMRI show in brain imaging?
Amount of blood oxygen in an area of the brain
What does EEG measure in brain imaging?
Electrical signals produces by the brain
What does MEG measure in brain imaging?
Magnetic signals produced by the brain
