Cerebral vasculature Flashcards
what % of cardiac output does brain use
10-20%
what % of o2 consumption does brain use
20%
what % of liver glucose does brain use
66%
what are the two sets of vessels supplying brain
internal carotid artery - comes through carotid canal
vertebral artery - comes through foramen magnum
what do the two vertebral artery fuse to form
basillar artery
what does basillar artery divide into
2 posterior cerebral arteries
what is the main branch of the internal carotid artery
middle cerebral artery
what is advantage of having circuit of vasculature in brain
theoretical chance of flow from other side
how does blood drain from brain
from cerebral veins into venous sinuses in dura mater to internal jugular vein
what is the fold of dura that passes down between two hemispheres
falx cerebri
what is the name given to the sinus which comes straight down from brain into confluence of sinuses
vein of galen
what sinus drains into internal jugular vein
sigmoid sinus
what is an intracranial haemorrhage
bleeding within cranial cavity
what are the 4 types of intracranial haemorrhage
extradural
subdural
subarachnoid
intracerebral
what is an extradural haemorrhage
usually due to trauma e.g injury to pterion
immediate clinical affects
can strip dura away from skull - is an arterial bleed and causes high pressure
is a surgical emergency!
what is a subdural haemorrhage
can be due to trauma
delayed clinical effects
venous bleed
lower pressure
what are subarachnoid haemorrhages
found at circle of willis
ruptured aneurysyms
what are intracerebral haemorrhages
found inside brain
spontaneous hypertensive
what is another name for stroke
cerebrovascular accident
what is the definition of a stroke
rapidly developing focal disturbance of brain function of presumed vascular origin and over 24hr duration
what % of stroke is caused by thrombo embolic
85%
what % of stroke is due to haemorrhage
15%
what is a transient ischaemic attack
rapidly developing focal disturbance of brain function of presumed vascular origin and over 24hr duration
what is an infarction
degenerative changes which occur following occlusion of artery
what is cerebral ischaemia
lack of sufficient blood supply to nervous tissue resulting in permanent damage if blood flow is not restored quickly
what is a thrombosis
formation of blood clot
what is an embolism
plugging of small vessel by material carried from larger vessel
e.h thrombi from heart/atherosclerotic debris
what are some signs of stroke
impaired speech
face lopsided
cannot raise arms
what are the risk factors for stroke
age hypertension cardiac disease smoking diabetes mellitus
what can stroke in anterior cerebral artery cause
paralaysis of contralateral structures
leg>face,arm
disturbance of intellect, executive function and judgement (abulia)
loss of appropriate behaviour
what can stroke in posterior cerebral artery cause
visual deficits
homonymous hemianopia
visual agnosia
what can stroke in middle cerebral artery cause
= classic stroke symptoms contralateral hemiplegia arm>leg contralateral hemisensory deficits hemianopia aphasia if left sided lesion
