Anatomy and function of cerebral hemispheres* Flashcards
Explain the structure of the cerebral hemispheres?
It is highly folden so that it has a large surface area can be packed into a small space. It contains a rim of grey matter and a core of white matter.
What are the clefs separating each area in the cerebral hemispheres called?
Sulci.
What are the raised separating each area in the cerebral hemispheres called?
Gyri.
What does the cerebral cortex consist of?
Neuronal cell bodies, dendrites and synapses. There is a mass of nerve fibres beneath the cortical surface.
What is in the white matter of the cerebral cortex?
It consists of axons bundled together as tracts running in three directions.
What are the three tracts (fibre types) ?
- Association fibres connect different areas in the same hemisphere.
- Commissural fibres - linking left and right hemispheres.
- Projection fibres - connect cortex with other areas of the CNS to motor/sensory tracts.
Where does auditory stimuli project?
To the auditory cortex in the temporal lobe.
Where does the visual stimuli project?
To the visual cortex in the occipital.
Where does the somatosensory stimuli project?
To the somatosensory cortex in the parietal lobe.
What happens if the motor cortex is damaged or diseased?
It will produce spastic paralysis of the contralateral muscles controlled by the area of the cortex affected and hyperflexia of the muscles.
What happens if the sensory cortex is damaged or diseased?
Produces loss of sensation (anaesthesia) from corresponding part of body projecting to the damaged or diseased area of cortex.
What do the areas of cortex outside the primary areas do?
The rest of the cortex is designated as the association cortex (rather than language processing).
What do secondary association areas do?
They integrate signals received in the primary areas.
What is the prefrontal association cortex concerned with?
Mood and personality.
What is the prefrontal association cortex concerned with?
Mood and personality.
What happens if the prefrontal association cortex is damaged?
Patients may:
- have a short attention span
- unaware of turn-taking
- ignore questions
- aggressive
- sensory neglect of their interpersonal space.
- puerile jocularity - laughing inappropriately
- inability to understand complex ideas.
What is broca’s area involved in? and what if it is damaged?
- language execution
- damage causes brocas aphasia with few words.
What is wernicke’s area involved in? and what if it is damaged?
- Language comprehension.
- Being unable to understand or reply meaningfully.
What happens if the parietal cortex is damaged?
It will effect clients skills and behaviour but is dependent on which side of brain is affected because of laterality of function.
What does the left hemisphere deal with?
Symbolic function - logic, language, maths.
What does the right hemisphere deal with?
Visuospatial function - facial recognition, artistic ability, pattern recognition, 3D problems.
What happens if the posterior association cortex is damaged?
It can cause:
- apraxia - inability to make functional movements when motor systems are still intact.
- agnosia - inability to interpret sensory information although the relevant sensory systems are intact.
What happens if the left parietal cortex is damaged?
Left-right confusion.
Alexia – impairment of reading.
Agraphia – impairment of writing ability.
Anomia – inability to name objects
What happens if the right parietal cortex is damaged?
Sensory inattention to the left side of the environment.
Dressing apraxia – inability to dress properly especially obvious on the left side of the body.
Constructional apraxia – inability to draw simple figures and shapes.
