Neuro - Cortical Orgnisation + Function Flashcards
What is the microscopic organisation of the cerebral cortex?
6 layers + many columns
How was the cerebral cortex organised by cytoarchitecture?
52 regions
What does frontal lobe do?
→ regulating + initiating motor function → language → cognitive functions → attention → memory
What does parietal lobe do?
→ sensation, touch, pain
→ sensory aspects of language
→ spatial orientation
→ self - perception
What does occipital lobe do?
→ processes visual info
What does Temporal lobe do?
→ processes auditory info
→ emotions
→ memories
What makes up the limbic lobe?
→ amygdala
→ hippocampus
→ mamillary body
→ cingulate gyrus
What does limbic lobe do?
→ learning
→ memory
→ emotion motivation
→ reward
Where does the insular cortex lie?
Deep within lateral fissure
What does insular lobe do?
→ visceral sensations, → autonomic control, → interoception, → auditory processing, → visual- vestibular integration
What matter makes up the cerebral cortex?
Grey + white matter
What is grey matter?
Neuronal all bodies + glial cells
What is white matter?
Myelinated neuronal axons
What do white matter tracts do?
Connect cortical areas
What are the 3 types of fibres that make up white matter tracts?
→ association
→ commissural
→ projection
What do association fibres do?
connect areas within the same hemisphere
What do commissural fibres do?
Connect homologous structure in left + right hemispheres
What do projection fibres do?
Connect cortex with lower brain structures (e.g. thalamus, brain stem and spinal cord)
What are the 2 types of association fibres? What’s more common?
Short + long
→ short
What does the superior longitudinal fasciculus do?
Long, connects frontal and occipital lobes
What does the arcuate fasciculus do?
connects frontal and temporal lobes
What does the inferior longitudinal fasciculus do?
connects temporal and occipital lobes
What does the uncinate fasciculus do?
connects anterior frontal and temporal lobes
What are 2 examples of Commissural fibres?
→ corpus callosum
→ anterior commissure
Where do afferent + efferent projection fibres do?
→ efferent = away from cortex
→ afferent = towards cortex
Where do the projection fibres converge?
internal capsule between thalamus + basal ganglia
What are 3 main features of primary cortices?
→ Function predictable
→ Organised topographically
→ Symmetry between left and right
What are 3 main features of secondary / association cortices?
→ Function less predictable
→ not organised topographically
→ weak or absent symmetry between left and right
What are the 3 main motor areas of the frontal lobe?
Which one is primary and secondary?
→ primary
→ supplementary (secondary/association)
→ premotor (secondary/association)
What does the primary motor cortex do?
→ controls fine, discrete, precise voluntary movements.
→ Provides descending signals to execute movements.
What does the supplementary area do?
Involved in planning complex movements (e.g. internally cued)
What does the premotor area do?
involved in planning movements (e.g. externally cued)
What are the 2 main sensory cortices of the parietal like? Which one is primary and secondary?
→ primary somatosensory
→ somatosensory association
What does the primary somatosensory cortex do?
processes somatic sensations arising from receptors in the body
(e.g. fine touch, vibration, two-point discrimination, proprioception, pain and temperature)
What does the somatosensory association area do?
→ Interpret significance of sensory information, e.g. recognizing an object placed in the hand.
→ Awareness of self + awareness of personal space
What are the 2 main cortices of the occipital lobe?
What do they do?
→ primary visual cortex = processes visual stimuli
→ visual association = gives meaning + interpretation of visual input
What are the 2 main cortices of the temporal lobe?
What do they do?
→ primary auditory cortex : processes auditory stimuli
→ auditory association : gives meaning + interpretation of auditory input
Where is the prefrontal cortex located? What does it do?
Frontal lobe → attention → adjusting social behaviour → planning → personality expression → decision making
Where is the Broca’s area located? What does it do?
Frontal lobe, Usually only left hemisphere
→ production of language + speech
Where is the wernicke’s area located? What does it do?
Temporal lobe
→ understanding language
How do frontal lobe lesions present?
→ Changes in personality
→ Inappropriate behaviour
How do parietal lobe lesions present?
→ Contralateral neglect
→ Lack of awareness of self on opposite side to lesion
→ Lack of awareness of opposite side to lesion of extrapersonal space
How do temporal lobe lesions present?
→ Lateral leads to agnosia, inability to recognise
→ Medial = anterograde amnesia
How do Broca’s area lesions present?
Expressive aphasia – poor production of speech, comprehension intact
How do Wernicke’s area lesions present?
Receptive aphasia – poor comprehension of speech, production is fine
How do primary visual cortex lesions present?
blindness in the corresponding part of the visual field
How do visual association lesions present?
→ deficits in interpretation of visual information
→ e.g. prosopagnosia: inability to recognise familiar faces or learn new faces (face blindness)
How does a PET scan assess cortical function?
→ positron emission tomography
→ blood flow directly to a brain region
How does a fMRI scan assess cortical function?
→ functional MRI
→ looks at amount of blood oxygen in a brain region
What is an EEG?
electroencephalography
What is an MEG?
magnetoencephalography
How does an EEG assess cortical function?
measures electrical signals produced by the brain using event-related or evoked potentials
How does an MEG assess cortical function?
measures magnetic signals produced by the brain using event-related or evoked potentials
