Human Brain and Behaviour
➢ Mid-term: Friday, Nov 4 from 3 – 5pm
➢ Vascular Disorders
Things that go wrong with blood supply
Cerebro-Vascular Accident (CVA) – Stroke
Asevere interruption of blood supply to the brain
Brain does not stay alive for very long without blood supply and glucose (within minutes)
Get to the hospital instantly
Adisruption in blood supply (blockage)
Ageneral insufficient supply of blood
Whenever this happens, death of the brain tissue
When severe – causes an infarct = which means dead or dying tissue
This blockage of blood flow can be very fast, immediate (more common) or even slow
Most of the damage is irreversable
However, blockage of blood supply can happen over time – especially during old age due to
What happens during stroke depends on which artery is blocked and also the larger the artery the
more massive the damage is going to be.
• Entire cerebral artery damage = damage to the frontal lobes
Avery slow reduction in the brain supply which causes an accumulation of small amounts of
damage rather than stroke which is sudden and quite dramatic
Bruised tissue, some cells are dying and some are not
Softening of brain tissue – tends to occur more in the elderly
You get aschemia (not enough blood supply) but it's temporary.
People have migraine headaches may sometimes get this. They usually get a loss of vision in a
particular part of their visual field.
Caused by the musculature on the outside of the blood vessels contracting – reducing blood
supply to the brain – temporary since migraines do go away. Reduction is not enough to kill
neurons but it doesn't allow them to work very well, causing part of visual field to disappear.
Migraines are caused by pain in the blood vessels, not pain in your head.
These attacks can be caused by migraines but what causes sudden blockage/obstruction?
• Alocally formed blockage in the artery which can be caused by blood clots.
• But blood clots can dissolve quite quickly
• 2) Embolism
• Something is going on in another part of the body – cholesterol forming somewhere else
but breaks away and then ends up getting to the brain and blocking it. • 3)Arterio-sclerosis
• Slow blockage due to cholesterol – in the elderly
• Ablood vessel inside the brain that bursts – internal bleeding
• Can be found in younger people but mostly in the elderly
• If it's small and causes death in an area – it's still referred to as a stroke
• Bleeding inside the brain
• Bleeding in the space between the skull and the brain
• NOT bleeding inside the brain
• CSF all gets squeezed to one side
• The bleeding puts pressure on the brain
• But since its not inside the brain, you won't have any damage to the brain – you can drain it
out. But if you let it go and allow it to get to the brain stem, it may result in brain
• As we mature, the blood vessels get a little more fragile
• Acollection or a mass of enlarged abnormal blood vessels
• Happens before you're born
• Blood vessels didn't form properly – abnormal
• By themselves are not serious – but they interfere with blood supply sometimes
• They are inherently weak – not strong as regular blood vessels
• They often just burst on their own
• You may live with these vessels for your whole life and be fine but they could burst at
• An expansion of a weakened part of a blood vessel
• Vascular Dialation caused by problems in the elasticity of the blood vessel.
• Having a weak spot in blood vessel.
• If aneurism bursts inside brain its a cerebral hemmhorage and if it burts outside then it
would be a subdoral hema