The Cerebral Hemispheresebral Hemispheres Flashcards
is the posterior part of the cerebral hemisphere sensory or motor?
sensory
is the anterior part of the cerebral hemisphere sensory or motor?
motor
function of the medial portion of the cerebral hemisphere
storage and retrieval of processed information
function of the precentral gyrus
Primary Motor cortex – somatotopic representation of contralateral half of body (motor homunculus)
function of the inferior frontal gyrus
Broca’s area of motor speech
function of the prefrontal cortex
cognitive functions of higher order- intellect,judgement, prediction,planning
function of the post central gyrus
Primary sensory area.Recieves general sensations from contralateral half of body. Somatotopic representation (sensory homunculus).
function of the superior parietal lobule
Interpretation of general sensory information (sensory association area) and conscious awareness of contralateral half of body.
function of the inferior parietal lobule
Interface between somatosensory cortex and visual and auditory association areas. In dominant hemisphere, contributes to language functions.
what happens when there is a parietal lobe lesion
hemisensory neglect
Right-left agnosia
Acalculia
Agraphia
what areas are present in the temporal lobe
Superior Temporal gyrus
Auditory association areas
Inferior surface
function of the superior temporal gyrus
Primary auditory cortex areas 41, 42
function of the auditory association areas
posterior to 41,42. In dominant hemisphere – Wernicke’s area. Crucial for understanding of spoken word. Has connections with other language areas.
function of the inferior surface of the temporal lobe
recieves fibres from olfactory tract – concious appreciation of smell.
what is on the medial surface of the occipitl lobe, on either side of the calcarine sulcus?
primary visual cortex
what is the majority of the occipital lobe?
visual association cortex, (areas 18,19) concerned with interpretation of visual images.
the medial surface of the cerebral hemisphere has areas which together form…
functional limbic lobe
what is the function of the functional limbic lobe?
involved in memory and emotional aspects of behaviour
what does the limbic lobe include?
It includes the cingulate gyrus, the hippocampus (medial aspect of temporal lobe), parahippocampal gyrus, and the amygdala ( subcortical grey matter close to temporal pole)
what are the language areas of the brain?
Broca’s area
Wernicke’s area
what is the brocas area?
motor speech area
what is the wernickes area?
auditory association area necessary for recognition of the spoken word. Is in the dominant hemisphere
what is aphasia?
problem with speech due to damage to one or more speech areas in brain.
what happens to the brain to someone with brocas aphasia
Understands speech Misses small words Aware of difficulties in speech
Damage to frontal lobe
Weakness/paralysis of one side of body
what happens to someone with wernickes aphasia
Fluent speech, with new meaningless words, can’t understand speech, doesn’t know of mistakes
Damage to temporal lobe
No paralysis
what are the three types of myelinated axon fibres bundled into tracts in white matter?
commisural fibres
association fibres
projection fibres
function of commisural fibres
connect corresponding areas of the two hemispheres. (Corpus callosum)
function of association fibres
connect one part of the cortex with the other. They may be short or long
function of prjection fibres
run between the cerebral cortex and various subcortical centres. They pass through the corona radiata and the internal capsule.
what is tractography?
technique that maps functional white matter tracts using data collected using magnetic resonance imaging (MRI).
what is the internal capsule made up of?
projection fibres passing to and from the cerebral cortex
function of the internal capsule
It derives blood supply from the middle cerebral artery and is frequently affected in a stroke.
where do the subcortical neuclei lie?
deep within each cerebral hemisphere
what is the basal ganglia made up of?
caudate nucleus, putamen and globus pallidus
regarding basal ganglia:
which is the one with the tail?
caudate
regarding basal ganglia:
what texture does the putamen have?
has a hard shell
regarding basal ganglia:
what is the one with a pale globe?
Globus pallidus
regarding basal ganglia:
The hard shell + the globe form a lens like structure. WHat is this called?
Lentiform nucleus
regarding basal ganglia:
what is the black substance?
Substantia nigra (this lies in the midbrain!)
what is lateral to the internal capsule?
lentiform nucleus made up of the putamen laterally and globus pallidus medially.
what is lying in the wall of the lateral ventricle?
caudate nucleus
what is lying beside the third ventricle?
thalamus (diencephalon)
what is lateral to the caudate and thalamus?
internal capsule
what is lateral to the internal capsule?
lentiform nucleus made up of the globus pallidus medially and putamen laterally
what are the input regions of the basal ganglia?
caudate nucleus and the putamen are the ‘input regions’ receiving input from the motor cortex, premotor cortex, and from thalamus.
what are the output regions of the basal ganglia?
globus pallidus and the substantia nigra.
what is the function of the basal ganglia?
help regulate initiation and termination of movements.
Because they play a role in controlling the motor system they are often referred to as the “extrapyramidal system
