What is a stroke?
A stroke is similar to how a heart attack stops the blood going to the heart -but for the brain. So like a ‘brain attack’ or a sudden ‘strike’ to the brain. Depending where the blood is stopped from getting to in the brain, depends on what effect it’ll have on the person. Once deprived of blood and therefore oxygen, parts of the brain begin to die after only a few minutes and so a stroke is classed as a medical emergency.
Causes of stroke
Ischaemic– blood vessel blocked by clot, stopping flow. Most common 85% cases. Clot could be due to narrow arteries, clot in artery, or clot travelling from somewhere else to the brain. Brain area that dies is called an infarct… ‘the naughty clot “schemes” to injure the brain’
Haemorrhagic-blood vessel ruptures and blood leaks out. 15% cases. The leaking blood building up also causes extra pressure inside the skull. Leak could be due to high blood pressure or a weakened/bulging blood vessel wall (‘aneurysm’)…‘haemorrhage of blood’
Where the brain dies dictates which abilities will be lost. The right side of the brain controls the left side of the body, and vice versa.This means an injury to the left side will affect movement in the right side of the body.
The different areas of the brain control different tasks:
Frontal lobe (front)
- initiation and motivation
- voluntary movement
- appropriate socialising & interactions with others
- Broca’s area -produce spoken language
Parietal lobe (top middle strip: like saddle on a horse on the prairies, you experience a lot of unusual sensations as you ride through the desert like heat, smells, sore bum etc!)
- perception: processing sensation from touch/pressure/temp/pain
- Wernicke’s area-understand received language: spoken & written
Occipital lobe (back: why a blow to back of the head often affects vision)
- processing visual input from eyes
Temporal lobes (front either side:where your temples are located, a lot of old artefacts are stored (memory) and labelled (different things identified) in an old temple)
- distinguishing different smells & sounds apart
- visual & verbal memory (for words & names)
Cerebellum (bottom underneath, Latin for ‘little brain’)
- controls smooth (involuntary) muscles like gut or maintaining balance
Brain stem (stick at bottom, joining onto spinal cord)
- basic life support functions eg breathing, heart