the cerebrum Flashcards
where is broca’s area found
frontal lobe. LEFT hemisphere
what is the function of broca’s area
production of speech
where is the motor and pre motor cortex found
frontal lobe
where is the prefrontal cortex found
frontal lobe
what are the functions of prefrontal cortex
motor control, programming and planning, attention, memory, problem solving
what part of the frontal lobe is involved in personality, social behaviour, emotion?
orbital cortex
what is the function of the motor and pre motor cortex
primary and secondary levels of motor control, verbal fluency and design fluency
what are some functions of the temporal lobe
auditory, olfactory, visual association, memory, emotional and social
what makes up primary auditory cortex
Heschl’s gyrus
where is the auditory cortex found
superior part of temporal lobe
what is agnosia
loss of ability to recognise objects, people, sounds, shapes, smells etc
what does the parietal lobe integrate
spatial sense and navigation
what is the parietal cortex comprised of
somatosensory cortex and dorsal stream visual system
what is the postcentral gyrus responsible for
somatosensation
where is language processing associated with (lobe)
parietal lobe
what is the function of the anterior parietal lobe
postural sensation, tactile sensation
what can damage to ant parietal lobe result in
agraphism (inability to write), asterognosis (inability to recognise objects by touch)
what is Balint syndrome and what is it associated with
poor spatial processing, damage to the superior parietal lobe
what is conductive aphasia and what associated with
difficulty reading, writing etc inferior parietal lobe
what are some of the problems associated with the inferior parietal lobe
alexia (don’t understand written words), dyslexia, apraxia, asomatognosia (lack awareness body parts), spatial neglect
what is brodmann area 17?
primary visual cortex (V1- visual 1)
what happens if V1 is damaged (brodmann 17)
blindsight, eyes work but brain cant understand
what hemisphere is wernickes are on?
left
whats the difference between damage to brocas and wernickes?
brocas- speech production (aphasia); wernickes- speech comprehension affected
what happens in damage to angular gyrus
alexia (problems reading), agraphia (writing)
what happens in damage to the arcuate fasciculus
conduction aphasia, comprehension and production normal but word selection is impaired
what are the stages of sleep
stage 1 (light sleep), 2 (sleep), 3+4 (deep slow wave sleep), REM (dreaming)
what are used to investigate sleep
polysomnography: EEG, EMG, ECG, EOG, resp function, pulse oxymetry, brain activity, HR
what is the order of waveforms in EEG (small- largest)
sigma, theta, alpha, beta, gamma, miu
what waveform is when eyes are shut
alpha
what waveform is when eyes are open
beta
when going into stage 1 sleep what happens to the waveforms?
alpha disappears replaced by theta
what phenomena are seen in stage 2 to help in the winding down process
K complexes and sleep spindles (bursts of activity)
what are the brainwaves in stage 3 and 4 sleep?
sigma rhythm
what happens during REM
whole body is paralysed apart from the eyes (muscle atonia)
what brainwaves are present in REM
theta and beta
what can cause insomnia
drugs, stress, depression, brain injury, poor sleep hygiene
what can lead to excessive daytime sleepiness
not enough night time sleep, underlying disorder, circadian rhythm disorder, depression, structural brain lesion
what is narcolepsy
fall asleep at inappropriate times
what is present in narcolepsy
excessive daytime sleepiness, cataplexy (loss of muscle tone), sleep paralysis, hypnogogic hallucinations
what is narcolepsy associated with
HLA type- autoimmune disease
what is narcolepsy disagnosed with
multiple sleep latency test
what is narcolepsy treated with
amphatamines, modafinil. tca for cataplexy.
what is restless leg syndrome
irresistible urge to move body especially legs during sleep
what is restless leg syndrome associated with and how can treat
dopamine also common in those iron deficient. treat with iron supplements, dopamine agonists, L-DOPA
what are parasomnias, how are they classified?
abnormal behaviours, emotions, perceptions, dreams occur while falling asleep or upon arousal. REM and non REM
what are symptoms of non REM parasomnias?
confusional arousals, sleepwalking, sleep terrors, teeth grinding
what are symptoms of REM parasomnias?
loss of muscle atonia during REM, so patient acts out the dream. increased incidence in Parkinsons
what can treat REM parasomnia with
clonazepam
what is sleep apnoea
abnormal pauses in breathing or instances of low breathing during sleep
why does a person come out of deep sleep into a lighter state of sleep in sleep apnoea
due to the lack of oxygen
what can you use for the management of sleep apnoea
CRAP- continuous positive airway pressure
what sulcus divides the frontal and lateral lobes
central sulcus
what is another name for the lateral sulcus
sylvian fissure
what part of cortex is buried within neighbouring cortex
insula
what fissure can be seen from the basal surface dividing the 2 hemispheres?
longitudinal fissure
what passes through the lateral fissure
middle cerebral artery
what sulcus can be seen from the medial surface separating the occipital and parietal lobe
parieto-occipital sulcus
what connects the 2 hemispheres
corpus callosum
what are the segments of the corpus callosum
rostrum, genu, body, splenium
what connects the hippocampus and the hypothalamus (white matter)
fornix
what gyrus is associated with the primary motor cortex
pre central gyrus
what gyrus is associated with the primary sensory cortex
post central gyrus
what gyrus is associated with the primary auditory cortex
superior temporal gyrus
what sulcus is associated with the primary visual cortex
calcarine sulcus
what is the superolateral part of the brain supplied by
MCA
what is the medial surface of the brain supplied by
anterior and posterior cerebral arteries
what supplies the deep part of the brain
lots of tiny branches off of the circle of willis
where is brocas area found
directly in front of the primary motor cortex
what connects the 2 temporal lobes
anterior commissure
what happens as move further back on coronal sections of the brain
lentiform nucleus becomes smaller due to the thalamus (as go further back caudate nucleus becomes smaller)
is the thalamus medial or lateral to the internal capsule
medial
what does the posterior commissure connect?
medial longitudinal bundles
what happens if the posterior commissure is damaged
blurred vision
what is the equation for cerebral blood flow
perfusion pressure/ resistance
what is the perfusion pressure
mean arterial pressure- intracranial pressure
what is the difference between stroke and TIA
stroke symptoms >24 hours, TIA <24 hours
what are the types of stroke
ischaemic and hemorrhagic (15% of strokes)
what is the most common cause of ischaemic stroke
thromboembolism
other causes of ischaemia stroke
intracranial small vessel disease, embolism from the heart, haemodynamic failure, arterial vasospasm
what are the distributions of stroke
total anterior (17%), partial anterior (34%), posterior (24%), lacunar (25%)
what is the consequence of a total anterior stroke
hemiplegia contralat, hemanopia contralat, disturbance higher function
consequence of partial anterior stroke
motor/sensory deficit +/- hemanopia; or with new higher cerebral dysfunction; pure motor/sensory deficit
consequences of posterior stroke
brainstem features. hemanopia, cortical blindness. cranial nerve palsy. motor and sensory deficit
consequences of lacunar stroke
pure motor or sensory stroke; sensorimotor, ataxic hemiparesis
what are the causes of intracerebral hemorrhage
local vessel abnormalities eg hypertension, infarction; systemic factors eg drugs, trauma
what are the causes of a subarach hemorrhage
trauma or spontaneous- spont leads to rupturing of saccular aneurysm (berry); infection; vasculitis
what is a saccular aneursym
dilatation of artery at the base of the brain (congenital or acquired) no effect compressive or hemorrhagic
what is an aneurysm
weak area in a blood vessel wall causing the blood vessel to bulge out
the CBF stays constant over what BP
60-160 mmHg
what does a decrease in PaO2 lead to
increase CBF (modest)
what does an increase in PaCO2 lead to
increase CBF (potent)
what does an increase in Hct lead to
increase in PaO2 so a decrease in CBF
what is the constant ICP
5-15 mmHg
what are the main determinants of cerebral blood flow
arterial blood pressure, metabolic, chemical, neurogenic
how can ICP and mean arterial pressure be found
measure ICP directly. MAP = diastolic + 1/3 pulse pressure (difference between diastolic and systolic)
what leads to the intrinsic ability to maintain stability of blood flow
autoregulation
what is the CBF maintained at. what must ICP and MAP be
50mls/100g/min. ICP =10mmHg; MAP 60-150 mmHg
what does a change of 1kPa in PaCO2 result in for CBF
30% change CBF
when is there change in CBF wrt PaO2
when PaO2 < 7 kPa
what does cerebral vasculature most respond to
PaO2
which is more metabolically active grey or white matter
grey 4x as active
which has the least effect on CBF
neurogenic
