Cerebral Hemispheres Flashcards
what is the basal ganglia?
collection of neural cell bodies buried in the white matter
what is the gyrus of the brain?
elevation either side of the sulci
where is the median longitudinal fissure?
in between the two hemispheres
what is the fissure between the cerebral hemispheres and the cerebellum?
the transverse fissure
what is the corpus callosum?
broad band of nervous tissue connecting the two cerebral hemispheres
where is the central sulcus?
between the frontal lobe and the parietal lobe (with the precentral sulcus and postcentral sulcus either side of it)
where is the lateral sulcus?
on the lteral part of the hemisphere between the temporal lobe and the frontal lobe
what separates the parietal hemispheres and the occipital hemispheres?
the Prieto-occipital sulcus
where is the cingulate sulcus?
on the median wall of the cerebral cortex separating the cingulate gyrus from the from the frontal and parietal lobes
what is the insula?
> area of the cerebral cortex
it is part of the temporal lobe
overlapped by sides of the deep cerebral sulcus in each hemisphere
what lobe of the brain coordinates muscles, higher mental functions and intellect?
the frontal lobe
what lobe of the brain is somatosensory (touch, temperature, pain)?
parietal lobe
what part of the brain is for hearing and smell?
the temporal lobe
what part of the brain is for vision?
the occipital lobe
what are the medial portions of the cerebral hemispheres for?
storage and retrieval of processed information.
what is the difference between primary and associated areas?
primary area is where the information first goes to then it is passed on to an association area which makes sense of the information
what is the precentral gyrus?
this is part of the frontal lobe (area 4) -primary motor cortex- that is somatotopic representation of the contralateral, half of the body
what is the inferior frontal gyrus?
brocas area of motor speech
what does the prefrontal cortex do?
it organises all muscles movement, higher order intellect and predicts and judges
what is the cortical homunculus?
distorted representation of the human body that is based on a neurological map of the areas, and proportions of the brain dedicated to processing motor functions, or sensory functions, for different parts of the body.
what is the post-central gyrus?
areas 3,1,2- primary sensory area- that receives general sensations from the contralateral half of the body
name the lobules and gyruses making up the parietal lobe
> post central gyrus
superior parietal lobule
inferior parietal lobule
what is the function of the superior parietal lobule?
interpretation of general sensory information and conscious awareness of the contralateral half of the body
what is the function of the inferior parietal lobule?
interface between the somatosensory cortex and visual and auditory association areas. contributes to language function in the dominant hemisphere
what can a parietal lobe lesion cause?
> hemisensory neglect
right-left agnosia
acalculia
agraphia
what is the primary auditory cortex?
the superior temporal gyrus in the temporal lobe
what is wernicks area?
> it is the auditory association area that is crucial for understanding the spoken word
temporal lobe,
unilateral in the dominant hemisphere
from where does the inferior surface of the temporal lobe receive fibres from?
the olfactory tract
where is the primary visual cortex?
on the medial surface of the occipital lobe either side of the calcrine sulcus
what makes up the occipital lobe?
> primary visual cortex
> visual association cortex
what makes up the limbic lobe?
> cingulate gyrus
hippocampus (medial aspect of the temporal lobe)
parahippocampal gyrus
amygdala
what aspects of behaviour does the limbic lobe involve?
the memory and emotional aspects of behaviour
what is aphasia?
problem with speech due to damage to one or more speech areas of the brain
describe brocas aphasia
> understands speech > misses small words > aware of speech difficulties > frontal lobe damage > weakness and paralysis of one side of the body
describe wernickes aphasia
> fluent speech with new meaningless words > cant understand speech > doesn't know of mistakes > damage to temporal lobe > no paralysis
name the three types of myelinated axon fibres
> commisural fibres
association fibres
projection fibres
what are commissural fibres?
fibres connecting corresponding areas of the two hemispheres (corpus callosum)
what are association fibres?
fibres connecting one part of the cortex with the other (can be short and long)
what are projection fibres?
fibres running between the cerebral cortex and various subcortical centres (they pass through the corona radiate and internal capsule)
what is tractography?
recent 3D modelling technique mapping functional white matter tracts using data collected using MRI.
what is the internal capsule made of?
projection fibres passing to and from the cerebral cortex
where is the internal capsule?
narrow area between the thalamus and caudate nucleus medially, and lentiform nucleus latterally
what supplies the internal capsule with blood?
he middle cerebral artery
what makes up the basal ganglia?
> caudate nucleus
putamen
globus pallidus
what are the subcortical nuclei?
collection of neural cell bodies deep within each cerebral hemisphere
what part of the midbrain is functionally part of the basal ganglia?
substantia nigra
which basal ganglia has a tail?
caudate nucleas
which is more medial the globus pallidus or the putamen?
the globus pallidus
what forms the lentiform nucleas?
the globus pallidus and the putamen
name structures and ganglia form the most medial to the most lateral starting at the third ventricle
> third ventricle > (lateral ventricle) > thalamus (posterior) and caudate nucleus (anterior) > internal capsule > lentiform nucleas
what basal ganglia receive information from the premotor cortex, motor cortex and thalamus?
input regions
> caudate nucleus
> putamen
what basal ganglia are output regions (receiving information from the input regions)?
Globus pallidus
substantia nigra
where does the globus pallidus primarily project to?
thalamus
what is the major function of the basal ganglia?
regulate initiation and termination of movements
