Cerebral cortex and blood supply Flashcards
which gyrus in the frontal lobe contains the primary motor cortex?
central
where is the primary somatosensory cortex located?
postcentral gyrus
What would be the effect of stimulating the motor hand area during awake craniotomy?
Contralateral involuntary hand movement
what lobe is the auditory cortex found?
temporal lobe
what does the insula lie over?
basal ganglia
Why would unilateral temporal lobe infarction not cause contralateral deafness?
The auditory projections from the ear go to both sides of the brain (partially crossed)
Function of Brocas area
expressive aspects of speech
function of wernickes area
comprehension
blood supply to brocas and wernickes area
middle cerebral artery
What are the clinical features of Broca’s dysphasia?
The key thing is that it is NON-FLUENT. The patient’s speech is hesitant, with word-finding difficulty, naming difficulty (anomia) but they are aware of the problems and often very frustrated. Trying to write down their throughts is no help: they can’t write either because the problem is with language itself (grammar, synatax) not just “speech”.
What are the clinical features of Wernicke’s dysphasia?
The key thing is that it is FLUENT. Patients may produce nonsense words (neologisms), word substitutions etc. and may be unaware that they are talking nonsense, probably because they are not able to self-monitor their own speech output.
what does the cingulate gyrus surround
corpus callosum
what sulcus does the primary visual cortex lie in?
calcarine sulcus
What visual field defect would result from infarction of the lingual gyrus?
Contralateral superior quadrantanopia- vision loss in one quarter of visual field (if the lesion is inferior to the calcarine sulcus, the deficit is superior in the visual field – because the visual projection is upside down)
What is the anatomical basis of “macular sparing”?
The macula lutea with its fovea centralis (for acute, central vision) is represented in both temporal poles so that damaging one hemisphere is not enough to abolish central vision; also the polar region is supplied by two different vascular territories (medial and posterior cerebral arteries) so, again, blocking just one vessel is not enough to abolish central vision.
