block 6 lecture 1 localisation and function Flashcards
what happens in fMRI?
put person in machine ask them to look at some thing record what part of the brain lights up
what is a PET scan?
introducing radioactively labelled substance, take scan at rest, take scan while doing something and observe additional uptake or substance
where is the cortex thinnest?
visual cortex
where is the cortex thickest?
primary motor cortex
what does the map of the map of the different histological layers show?
different cell types
what is the main blood supply to the brain?
carotid arteries and vertebral arteries
what are the vertebral arteries branches of?
subclavian
where does the left common carotid come from?
aortic arch
where does the right common carotid come from?
branches from the right braqchiocephalic artery
what does the bifurcation of the common carotid arteries gives rise to?
the internal and external carotid arteries
what does the external common carotid artery supply?
face and scalp
what does the internal common carotid artery supply?
brain
what do the vertebral arteries join to form?
basal arteries
what does the basal artery give rise to?
pontine, inferior cerebellar, superior cerebellar, posterior cerebral arteries
what does the internal carotid bifurcate into?
anterior and middle cerebral arteries
where do lesions of the primary motor, somatosensory or visual areas present?
controlaterally
what happens in a primary motor lesion?
controlateral hemiparesis
what is controlateral hemiparesis?
half weakness
what happens in a primary somatosensory lesion?
controlateral hemianasthesia
what is controlateral hemianasthesia?
half lack of sensation
in hemiaopia where is the lesion?
controlateral primary visual area
what is hemiaopia?
lack of visual field on one side
where is thinking done most commonly?
right hemisphere
where is language done most commonly?
left hemisphere
where is spacial orientation done most commonly?
right hemisphere
what does heisphere dominance refer to?
which of your hemispheres is responsible for language comprehension
why do unilateral lesions in language only last a period of time?
other hemisphere assumes the function
a lesion at area 4 results in what?
facial paralysis
a lesion in area 6 leads to?
hyperflexior - excessive tendon reflex
what happens if you get a lesion at region 8?
cant move eyelids to the opposite side
where is the motor region?
everything anterior to the central sulcus
what is posterior of the central sulcus?
sensory: parietal, occipital, temporal lobes
what do you get if you lose the primary sensory areas 3 1 and 2?
loss of touch, pressure and proprioception controlaterally
what do you get if you lose secondary sensory area?
pain
what is tactile agnosia?
ability to identify something by touch
what do you get if you have lesion in area 40?
contralateral heminnoglect
what is hemioneglect?
dont care about the other side of the body
what is aplaxia?
ability to perform skilled movements you could do before
what is the area that causes contralateral aplaxia?
40
what do you lose at area 39?
alexia, dyslexia and agraphia
what is agraphia?
the ability to write language
what happens in Brocas?
you can understand language but cant speak it
in Brocas where is the lsion?
posterior inferior frontal lobe
what happens in Werinckles?
can speak but you cant understand
where is the auditory area?
on temporal operculum
why is the primary auditory area not visible?
in the sulcus
how is hearing found in the brain?
bilaterally - each ear is represented on both hemispheres
what is cranial nerve 8?
vestibulocochlear nerve
what supplies primary sensory and motor cortexs, Brocas, Wernicas, premotor, primary auditory and language areas?
medial cerebral artery
what is a direct continuation of the internal carotid?
medial cerebral artery
how does the medial cerebral artery supply the basal ganglia, internal capsule and thalamus?
lateral striate arteries
what happens if you get a stroke of the middle cerebral artery?
lesion of upper motor neurons contralaterally
what does a lesion of the prefrontal cortex cause?
changes in personality, concentration, abstract thought and forsite
what artery supplies the prefrontal cortex?
middle cerebral artery and anterior cerebral artery
what does the anterior cerebral artery supply?
medial aspect of the hemisphere - corpus calosum
what happens in stroke of the anterior cerebral artery?
contralateral upper motor neuron hemiplegia and hemiparesis
contralateral hemianasthesia
prefrontal cortical lesion - forsite…
where is the primary visual area?
occipital lobe
where does the calcerine sulcus run to?
apex of the occipital lobe
what are the gyri on either side of the calcerine sulcus?
primary occipital areas
what do association area do in relation to vision?
link vision to memory
