Nervous Damage 1 Flashcards
what are the different types of neurones?
sensory, interneurons and motor neurons
what are the fast causes of damage to the nervous system?
traumatic events such as strokes, epilepsy, infections, inflammation
what are the slower causes of damage to nervous system?
accumulate damage over time causing neurodegeneration
what causes varying effects of acute brain injuries?
the cause, location, severity and the wing of brain affected
what is a traumatic brain injury?
it is a process rather than an event and can be secondary rather than primary
what are the 4 mechanisms of traumatic brain injury?
brain contusion, increased intracranial pressure, diffuse axonal injury and strokes
what is a brain contusion?
cell death accompanied by haemorrhage, a bruise on the brain
where does contusions occur?
at a site distant from the point of impact
what is increased intracranial pressure?
an increase in components inside the skull which increases pressure
what components contribute to pressure inside the skull?
venous volume, arterial volume, brain and CSF
what is the first to be put under pressure in the brain?
CSF, venous blood then arterial blood and then brain tissue
what is brainstem herniation?
brain tissue is forced down through the foramen magnum and compresses the brain stem
what is a subfalcine herniation?
a hernia in the curtain of dura mater between the left and right cerebral hemispheres
what is a transtentorial herniation?
hernia in dura mater that covers the cerebellum
what effects does herniation have on brain tissue?
diffuse swelling and expansion of brain tissue into ventricles and widening and flattening of gyri
what is diffuse axonal injury?
damage to axons of neurones
how is diffuse axonal injury caused?
shearing of axons in the white matter tracts
where is the most common site of DAI?
where grey and white matter meet
what occurs at the point of damaged axon in DAI?
everything downstream of axon dies and connections lost and there is loss of function
what are the mechanical pressures that cause acute damage?
encephalitis, meningitis, brain tumours, abscesses
what is the definition of a stroke?
loss of blood supply to some or all of brain causing a cerebral deficit for more than 24 hours
what is it classified as if the cerebral deficit is less then 24 hours?
transient ischaemic attack
how are ischaemic attacks causes?
blockages that are thrombotic or embolic
what is a haemorrhagic stroke?
decreased oxygen as blood leaking into the brain and not capillary network
