Blood supply Flashcards
What % of the following does the brain use
a) Cardiac output
b) total body oxygen
c) total body glucose
a) 15%
b) 20%
c) 25%
What is average brain blood flow
46ml/100g/min
How many seconds of anoxia lead to unconciousness
20
Describe structure of arteries in the brain
Thin walled so easily blocked distorted or ruptured
Describe structure of veins in the brain
Thin walled so no muscles or elasticity to help return
What causes increased flow to the brain
Increased CO2
Reduced 02
What % change in CO2 is needed to double blood flow to the brain
70
Which arteries provide cerebral blood flow and in what proportion
80% from carotids
20% from vertebrals
2 common variations of the circle of willis
One posterior communicating small, one large
Anterior communicating large
What artery do striate come off and what do they supply
Internal capsule, lentiform nucleus etc
Come off middle cerebral
What artery supplies majority of lateral surface of brain
Middle cerebral artery
What does the basilar artery supply
Pons and cerebellum
What does the posterior cerebral artery supply
Inferior and medial aspects of temporal and occipital cortex
Thalamus and posterior internal capsule
Midbrain
What does the vertebral artery supply
Spinal cord
Dorsal medulla of brainstem (PICA)
Where do superficial cerebral veins cross
Subarachnoid space