1b// Cerebral Vasculature and Cerebrovascular disorders Flashcards
why is the brain vulnerable if blood supply is impaired?
6% of liver glucose, 10-20% of all cardiac output - 20% of all body O2 consumption despite being only 2% of body weight
what are the main blood supplies for the brain?
vertebral arteries
internal carotid arteries from common carotid
what is the main cerebral branch of the internal carotid artery?
middle cerebral artery
what artery sits on the pons?
basilar artery
what artery connects the posterior cerebral artery and the middle cerebral artery?
posterior communicating artery
what artery connects the anterior communicating cerebral artery and middle cerebral artery?
anterior cerebral artery
what do the vertebral arteries connect to form?
basilar artery
Label.
Circle of Willis
where is the confluence of sinuses?
at the base of the occipital bone, medially.
what does the sigmoid sinus eventually become?
internal jugular vein
Describe the venous drainage of the brain.
cerebral veins–> venous sinuses in the dura mater–> internal jugular vein
Label.
What are the 4 types of haemorrhages?
extradural
subdural
subarachnoid
intracerebral
What is an extradural haemorrhage?
trauma, immediate clinical effects (arterial, high pressure)
on skull
What is a weak spot for an extradural haemorrhage?
pterion
truma leads to a burst in the middle meningeal artery
What is a subdural haemorrhage?
trauma, can be delayed clinical effects (venous, lower pressure)
Dura mater
What is a subarachnoid haemorrhage?
ruptured aneurysms
in subarachnoid space
what is an intracerebral haemorrhage?
spontaneous hypertensive
in brain
what is a cerebrovascular accident (CVA)? And what are the types?
rapidly developing focal disturbance of brain function of presumed vascular origin and of >24hr duration
thrombo-embolic (85%) or haemorrhage (15%)
majority of strokes are thrombo-embolic
What is a transient ischaemic attack?
“rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours”
what is an infarction?
degenerative changes after losing blood supply/occlusion of an 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 a blood clot
what is an embolism?
plugging of small vessel by material carried from larger vessels e.g thrombi from the heart, atherosclerotic debrias from the internal carotid, air, fat