Cerebral Cortex Flashcards
What is a nucleus?
Collection of neuron cell bodies in the CNS
What is a tract?
Collection of axons in the CNS
What is a ganglion?
Collection of neuron cell bodies in the PNS
Which part of the brain is the largest?
Cerebrum
What percentage of brain mass does the cerebrum make up?
83%
What functions does the cerebrum control?
Higher functions such as conscious thoughts and intellectual functions
What type of information does the cerebrum process?
Somatic sensory and motor information
What embryonic structure does the cerebral cortex develop from?
Telencephalon
Which embryonic structure acts as a pivot for cerebral hemispheres to rotate around?
Insula
What does the embryonic structure, the insula, do for cerebral hemisphere development?
Acts as a pivot for the hemispheres to rotate
At what gestation are frontal, parietal, occipital, and temporal lobes identifiable?
~14 weeks gestation
Which lobes of the cerebrum are identifiable at 14 weeks gestation?
Frontal, parietal, occipital, temporal
Which sulci are identifiable at around 28 weeks gestation?
Lateral, central, calcarine
At what gestation are the lateral, central, and calcarine sulci identifiable at?
~28 weeks
What is grey matter composed of?
Neuron cell bodies
What is white matter composed of?
Fibre tracts, neuron axons
Where is grey matter found in the cerebrum?
Cerebral cortex and basal nuclei
Where is white matter found in the cerebrum?
Deep in cerebrum to cerebral cortex, surrounding basal nuclei
What allows the cerebral cortex to have such a large surface area?
Sulci and gyri
What is the total surface area of the cerebral cortex?
Around 2200cm^2
Of the total surface area of the cerebral cortex, what proportion is the general surface area?
1/3
Of the total surface area of the cerebral cortex, what proportion is hidden in the sulci?
2/3
What range of thickness is there for the cerebral cortex?
1.5mm to 3mm
Where is the cerebral cortex at its thickest?
Over the crest of convolution
Where is the cerebral cortex at its thinnest?
At the bottom of sulci
What is the weight of the cerebral cortex?
600 grams
What percentage of the total brain weight is composed of the cerebral cortex?
40%
What are three types of white matter fibers visible in the cerebrum?
Commissural fibers, association fibers, and projection fibers
What are commissural fibers?
White matter fibers that connect the right and left cerebral hemisphere cortices.
Where is the largest bundle of commissural fibres found?
Corpus callosum
What are association fibers?
Connect regions of the cerebral cortex within one hemisphere
What are the two subtypes of association fibers?
Arcuate and longtitudinal
What do arcuate association fibers do?
Connect adjacent gyri
What do longitudinal association fibers do?
Connect distant gyri in different lobes
What are projection fibres?
White matter fibers that leave the cerebral white matter
What structure do projection fibers form?
Internal capsule
Which white matter fibers form the internal capsule?
Projection fibers
What are the two categories of projection fibers?
Corticofugal and corticopedal
What are corticofugal projection fibers?
White matter fibers that leave the cerebral white matter and terminate in the basal nuclei, brainstem, or spinal cord
What are corticopedal projection fibers?
White matter fibers that originate in the thalamus and terminate in the cerebral cortex
What functional area is Brodmann’s area 4?
Primary motor cortex
What Brodmann’s area is the primary motor cortex?
Brodmann’s area 4
What functional area is Brodmann’s area 17?
Primary visual cortex
What Brodmann’s area is the primary visual cortex?
Brodmann’s area 17
What Brodmann’s areas are the primary sensory cortex?
1, 2, and 3
What functional area is represented by Brodmann’s areas 1, 2, and 3?
Primary sensory cortex
What Brodmann’s areas represent the primary auditory cortex?
41, 42
What functional area is represented by Brodmann’s areas 41 and 41?
Primary auditory cortex
What functions does the frontal lobe control?
Decision making, voluntary movement control
What functions does the parietal lobe control?
Sensory and spatial information processing
What function does the occipital lobe control?
Vision
What functions does the temporal lobe control?
Memory processing and integration with emotion and sensation
What is the function of Broca’s area?
Speech production
Which lobe is Broca’s area found in?
Frontal
Which hemisphere is Broca’s area found in?
Left usually
What is the function of Wernicke’s area?
Speech comprehension
What lobe is Wernicke’s area found in?
Temporal
Which hemisphere is Wernicke’s area usually found in?
Left
Where is Broca’s area located?
Inferior frontal gyrus
- pars triangularis
- pars orbitalis
- pars opercularis
What Brodmann’s area is Broca’s area located in?
44/45
Where is Wernicke’s area located?
Posterior superior temporal gyrus
What Brodmann’s area is Wernicke’s area located in?
22
Which gyrus hosts the primary motor cortex?
Precentral gyrus
What functional area is housed in the precentral gyrus?
Primary motor cortex
Which gyrus hosts the primary sensory cortex?
Postcentral gyrus
Which functional area is housed in the postcentral gyrus?
Primary sensory cortex
What is the prefrontal cortex?
Most anterior part of the frontal lobe
Which functional areas is the prefrontal cortex anterior to?
Primary motor and premotor areas
What functions is the prefrontal cortex important for?
Intellect
Planning
Reasoning
Mood
Conscience
Predicting consequences accurately
Judgment
Which part of the prefrontal cortex ‘lights up’ on imaging during active thinking?
Dorsolateral prefrontal cortex
What behavioural changes occurred to Phineas Gage following an accident that destroyed majority of his left frontal lobe?
Started to exhibit inappropriate behaviours in social settings, permanently lost inhibitions, marked personality changes, epilepsy
What did Phineas Gage’s accident reveal about the frontal lobe?
It is involved in personality
What was prefrontal leucotomy also known as?
Frontal lobotomy
What conditions were treated with frontal lobotomies?
Psychiatric and neurological conditions
What did a prefrontal lobotomy involve?
Drilling a hole into the side of the skill and inserting a leucotome to disrupt brain tissue
What did a transorbital lobotomy involve?
Inserting a leucotome through bone behind the eyes
What risks were associated with lobotomies?
Severe physical and intellectual disability, seizures, cognitive impairment
What are association areas in the brain?
Brain region that receives input from more than one sensory modality
The abundance of what brain regions determines intellectual capacity?
Association areas
What does the abundance of association areas determine?
Intellectual capacity
How do association areas aid our perception?
Enable us to interact with our environment effectively whilst supporting abstract thinking and language
What function does the association area in the parietal cortex have?
Responding to stimuli in both external and internal environment
What function does the association area in the temporal cortex have?
Identifying nature of stimuli
What function does the association area in the frontal cortex have?
Planning appropriate responses to stimuli
The combination of association areas allows for what higher-order function?
Cognition
What is the term for functional differences between left and right hemispheres?
Hemispheric lateralisation
What is hemispheric lateralisation?
Functional differences between left and right hemispheres
In most people, which cerebral hemisphere is the dominant hemisphere?
Left hemisphere
What does the left hemisphere control as the dominant hemisphere (for most people)?
Reading, writing, math, decision-making, logic, speech and language
What does the right cerebral hemisphere control (for most people)?
Recognition of faces and voices, visual/spatial reasoning, emotion
