neural damage Flashcards
what is the efferent tract
sensory
what is the afferent tract
motor
what is myelin
- fatty tissue
- oligodendrocytes in the CNS
what is microglia
- CNS monocytes
what are astrocytes
- control blood brain barrier
what are the different types of glia
- astrocytes
- oligodendrocytes
- microglia
what are the neurones in the PNS
- myelinating Schwann cells
- satellite cells
what is the function of oligodendrocytes precursor cells
make new myelin if there is any damage
what is myelin
- fatty sheath around nerve fibres
- oligodendrocytes wrapped around each other
what is the function of nodes of ranvier
- gap between wrap of myelin
- where electrical signal is sent between as this is where neurones are
oligodendrocytes in CNS structure
- each multiple internodes
- can be multiple
- extend outwards
Schwann cells in PNS structure
- entire cell sits on axon
- each cell is an internode
- sit on nerve fibre and wrap themselves
what is demyelination
loss of myelin due to diseases eg MS
what is the result of demyelination
- impaired neurological function
- visual and gait deficits
- reduced conduction
what different factors can damage the nervous system
- traumatic
- developmental
- neurodegenerative
what is neurodegerneration
loss/ deterioration of neural cells/ circuitry
what causes neurodegeneration
- genetic, age trauma
- Alzheimer’s, Parkinson’s, Huntington’s
what are the consequences of neurodegeneration
- dementia
- disordered movement
- psychiatric disturbance
- paralysis
- pain
what are the cellular and molecular bases of neurodegeneration
- cell failure
- non-specific tissue damage
- accumulation of toxic molecules
- inflammation
- demyelination
- neuronal apoptosis
how does the CNS change in aging
- prevents growth
- becomes more stable
- unneeded neurones are pruned away
why is myeline removed
it can be inhibitory to the synapses
what are the symptoms of multiple sclerosis
- weakness
- fatigue
- depression
- cognitive disturbances
- chronic pain
- bouts of dizziness
what is MS
- demyelinating disease
- loss of oligodendrocytes
- sensory, motor and visceral deficits
what are the structural changes in dementia
- loss of synapses
- loss of neurons
- brain is noticeably shrunken
what are the effects of dementia
- behavioural disturbances
- psychological disturbances
- impaired language/ understanding
- irreversible decline in mental function
what causes aggression in dementia
- altered brain function
- secondary to frustration, irritation, anxiety
- frustration from cognitive impairment
what is an ischemic stroke
blockage to the blood vessels in the brain causing ischemia
what is haemorrhagic stroke
bleeding vessels in the brain
what is a TIA
an ischaemic stroke where symptoms fully resolve
what are some stoke mimics
- seizures
- infections
- migraine
what is diabetic peripheral neuropathy
nerve damage in the peripheries as a result of chronic hyperglycaemia exposure
what are the symptoms of diabetic peripheral neuropathy
- numbness, tingling in feet
- burning/ stabbing/ shooting
- muscle weakness and twitches
- sores/ ulcers
what effect does hyperglycaemia have on Schwann cells
- mitochondrial dysfunction
- affects NADPH oxidase causing an inflammatory signal
what is the microvascular damage from hyperglycaemia
- capillary basement membrane thickening
- loss of pericyte coverage
- endothelial hyperplasia
what is the neuronal damage from hyperglycaemia
- demyelination
- axon loss distally
- myelinated fibre density reduction
what causes shingles
- chickenpox virus
- remains dormant until reactivated
what are the effects of shingles
infects nerves in the surrounding skin and cause blisters
what are the types of periodic paralysis
- hypokalaemic periodic paralysis
- hyperkaliaemic periodic paralysis
what is hypokalaemic periodic paralysis
- decreased serum potassium levels
- sudden onset of flaccid paralysis
- risk of aspiration
what is hyperkalaemic periodic paralysis
- increase in serum potassium levels
- sudden onset of flaccid paralysis
- risk of aspiration
what is hypokalaemic periodic paralysis management
prophylactic oral potassium
what is hyperkalaemic periodic paralysis
diuretics to reduce potassium
