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20 Cards in this Set
- Front
- Back
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the brain receives ____% of cardiac blood output and consumes about ____% of oxygen used by entire body
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15% of cardiac blood and 20% oxygen
brain has high metabolic demand |
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what receives more blood flow: gray or white matter?
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gray! by 4x
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the brain is very aerobic! how many min of O2 deprivation before damage begins?
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4-5 min of O2 deprivation
10-15 min of glucose deprivation |
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Loss of consciousness occurs in less than ____ seconds after blood flow to brain has stopped
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15 seconds
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what is ischemia?
what level does cell death occur? |
ischemia (penumbra) is the restriction of blood vessels/blood flow to tissues.
occurs when blood flow drops below 20mL/min cell death below 10mL/min |
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brain arterioles ____when systemic BP rises and ____ when BP lowers
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constrict when BP rises
dilate when BP lowers |
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normal individuals: constant cerebral blood flow=
above or below these values, blood flow becomes what? |
60-150mm Hg
becomes pressure dependent (linear on chart) |
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hypertension shifts CBF/autoreg curve to the _____. autoreg can still funciton, but upper and lower limits shift, predisposes the patient to what?
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right
predisposes the patient to cerebral hypoperfusion and higher risk for stroke |
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increased neuronal firing results in a proportional increase in what?
in areas with high neuron activity, what is increased? what is this used for clinically? |
glucoseuse, O2 use, CO2 production.
blood flow is selectively increased in areas with high neuron acitivity. used for fMRI and PET |
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the internal carotid artery divides into the what?
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anterior cerebral and middle cerbral arteries
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the subclavian arteries give rise to what?
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the vertebral arteries, which join together to form the basilar artery--->posterior cerebral artery
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anterior circulation. what two arteries make it up?
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the anterior cerebral and the middle cerebral
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anterior cerebral artery (ACA) supplies where?
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medial side of each cerebral hemisphere and the frontal lobes
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the middle cerebral artery supplies where?
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lateral side of each cerebral hemisphere
large branches: front, parietal, temporal, occipital lobes small branches:deep white matter/diencephalic structures |
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posterior circulation is made up of what 2 arteries?
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the vertebral arteries and the basilar arteries
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vertebral arteries supply what?
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the meninges, falx, spinal arteries, and PICA (posterior inferior cerebellar artery)
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the basal arteries supply what? 2 subdivisions.
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long circumferential arteries: brain stem, AICA (anterior inferior cerbellar artery
posterior cerebral artery: medial aspect of cerebral hemispheres+ventral temporal lobes |
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the circle of willis allows for what?
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overlapping blood supply. connects anterior/posterior circulation.
collateral circulation-limits the extent of damage if there is a blockage. connects the posterior cerebral arteries, middle cerebral arteries, and left and right anterior cerebral arteries. |
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venous drainage in the brain. order?
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capillaries->superficial veins->deep veins->venous sinuses->internal jugular veins
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intracranial bleeds are characteristic on the _______ and the types of _____ that are involved.
epidural? subdural? subarachnoid? intracerebral? |
characteristic on the location and the type of vessels involved. put pressure on brain tissue
epidural=btw dura/skull-meningeal artery subdural=btw dura and arach-veins of dural sinuses subarach=cerebral arteries, blood in CSF intracerebral= |
