Cerebral Hemispheres Flashcards
What is a sulcus?
A dip
What is a gyrus?
An elevation
What is a fissure?
A larger dip
Where are grey and white matter found?
Grey = on the surface White = inside
What is the basal ganglia?
Collection of neuronal cell bodies buried in the white matter
What is the role of the corpus callosum?
Connects the 2 hemispheres
What is the role of the frontal lobe?
Motor function
Intellect
What is the role of parietal lobe?
Somatosensory
What is the role of the occipital lobe?
Vision
What is the role of the temporal lobe?
Hearing
Smell
Which part of the cerebral hemisphere is sensory and which is motor?
Posterior = sensory Anterior = motor
What are the medial portions of the cerebral hemisphere responsible for?
Storage and retrieval of processed information (limbic system)
What is area 4 of the brain?
Precental gyrus: primary motor cortex
Somatotopic representation of contralateral half of body
What area is the inferior frontal gyrus?
Area 44, 45 = Broca’s area of motor speech
What is the function of the prefrontal cortex?
Cognitive functions of higher order - intellect, judgement, prediction, planning
What is areas 3,1, 2 in the postcentral gyrus?
Primary sensory area
General sensations from contralateral half of body
What is the role of the superior parietal lobule?
Interpretation of general sensory information and conscious awareness of contralateral half of body
What is the role of the inferior parietal lobule?
Interface between somatosensory cortex and visual and auditory association areas
In dominant hemisphere - contributes to language functions
What is areas 41,42 in the superior temporal gyrus?
Primary auditory cortex
Where are the auditory association areas found?
Posterior to 41, 42 in dominant hemisphere (Wernick’es area)
Crucial for understanding of spoken word
What is the role of the inferior surface of the temporal lobe?
Receives fibres from olfactory tract - conscious appreciation of smell
What is area 17?
Primary visual cortex
Where is the primary visual cortex?
Medial surface of the occipital lobe on either side of the calcarine sulcus
What is areas 18,19?
Visual association cortex
What is the limbic lobe involved in?
Memory
Emotional aspects of behaviour
What makes up the limbic lobe?
Cingulate gyrus
Hippocampus
Parahippocampal gyrus
Amygdala
What is Broca’s area?
Motor speech area
What is Wernicke’s area?
Auditory association area - necessary for recognition of spoken word (dominant hemisphere)
What is aphasia?
Problem with speech due to damage to one or more speech areas in the brain
What occurs in Broca’s aphasia?
Understands speech Misses small words Aware of difficulties in speech Frontal lobe damage Weakness/paralysis on one side of body
What occurs in Wernicke’s aphasia?
Fluent speech New meaningless words Can't understand speech Not aware of mistakes Temporal lobe damaged No paralysis
What are commisural fibres?
Connect corresponding areas of the 2 hemispheres (corpus callosum)
What are association fibres?
Connect 1 part of the cortex with another
May be short or long
What are projection fibres?
Run between cerebral cortex and various subcortical centres
Pass through corona radiata and internal capsule
Where is the internal capsule found?
Narrow area between thalamus and caudate nucleus medially and the lentiform nucleus laterally
What is the basal ganglia made up of?
Caudate nucleus
Putamen
Globus pallidus
What do the caudate nucleus and the putamen receive?
Input from motor cortex, premotor cortex and from thalamus
‘Input regions’
What are the output regions?
Globus pallidus
Substantia nigra
What is the main function of the basal ganglia?
Help to regulate initiation and termination of movements
