9. Higher cortical function Flashcards
How many layers is the cerebral cortex arranged into?
6 layers
- containing cells bodies and dendrites i.e. cortex is grey matter
Where are most of the inputs to the cortex from?
From the thalamus and other areas of the cortex
- also from the reticular formation
What is the function of the reticular formation?
maintaining cortical activation (consciousness)
What type of cells are the outputs from the cortex carried in?
Pyramidal neurones
What type of neurons are upper motor neurones?
Pyramidal cells
Where do outputs from the cortex go? (3)
- Outputs can be projection fibres going down to brainstem and cord (e.g. upper motor neurones)
- Outputs can be commissural fibres going between hemispheres (e.g. corpus callosum)
- Outputs can be association fibres connecting nearby regions of cortex in the same hemisphere (e.g. arcuate fasciculus)
What are the general functions of the frontal lobe?
- motor (primary motor cortex)
- expression of speech (Broca’s area)
- behavioural regulation/judgement
- cognition
- eye movements (Contain the frontal eye fields)
- continence
Which parts of the frontal lobes are responsible for behavioural regulation and cognition?
Pre-frontal cortex
Which part of the frontal lobe is responsible for continence?
paracentral lobules
what can damage to the frontal lobe lead to?
o contralateral weakness o expressive dysphasia o impulsive, disinhibited behaviours e.g. sexual inappropriateness, aggression o difficulty with tasks such as complex problem solving, including calculation o problems with conjugate gaze and other eye movement disturbances o urinary incontinence
What are the general functions of the parietal lobes?
- sensory (primary sensory cortex)
- speech comprehension (Wernicke’s area)
- body image and awareness of external environment
- Calculation and writing
- (contain superior optic radiations)
Which parietal lobe is usually responsible for body image and awareness?
Right
What does body image and awareness of external environment relate to?
Seems to be involved with acknowledgement that things (including the body) exist
What does damage of the right parietal lobe lead to?
Neglect
What is neglect syndrome?
Neglect syndrome is when a patient neglects half of space following an injury to the parietal cortex on one side of the brain (contralateral sides?)
- only eat one side of food, shave one side of face etc.
what can damage to the parietal lobe lead to?
o contralateral anaesthesia affecting all modalities
o receptive dysphasia
o neglect.
o affect calculation ability
o contralateral inferior homonymous quadrantanopia
What are the general functions of temporal lobe?
- hearing (primary auditory cortex)
- olfaction (primary olfactory cortex)
- memory
- emotion
- (contain the inferior optic radiations)
Where are the primary auditory and olfactory cortex located?
Auditory: superior temporal lobe
Olfactory: inferiomedial (uncus)