Lec 7

Question 1

ontogenetic period of development

Answer 1

synapse formation and pruning
myelination and glial cell formation

Question 2

brain tumour (meningiomas)

Answer 2

between layers of meninges (protective layer) and are benign. only pain can cause is from the tumour putting pressure on other parts of brain.

Question 3

brain tumour (gliomas)

Answer 3

develop from glial cells and infiltrate through the brain.

Question 4

neuromas

Answer 4

tumour growing on one of cranial nerves

Question 5

metastatic tumour

Answer 5

grow from cancerous cells carried from other organs to brain via blood stream

Question 6

Stroke action plan

Answer 6

fast
face drooping
arm weakness
slurred language
time to call for help
also balance and vision problems

Question 7

cerebral haemorrhage

Answer 7

bleeding in brain, vessel ruptures causing blood to seep into neural tissue

Question 8

Aneurysn

Answer 8

balloon dilation form on wall of artery where elasticity is defective

Question 9

cerebral ischemia

Answer 9

blockage in blood vessel disrupting blood supply to brain.
Thrombosis = blood clot
embolism = blockage from larger vessel to smaller one lodged.
arteriosclerosis = thickening of artery walls and channels narrow, restrict blood flow

Question 10

what happens in ischemic stroke

Answer 10

blood vessel becomes blocked, neurons release excessive glutamate binding to NMDA receptor triggering excitatory response causing excess influx of positive ions to kill post synaptic neuron while spreading toxic cascade

Question 11

TBI

Answer 11

closed head TBI - contusions (bruised brain)
subdural hematoma - collection of blood between dura mater and arachnoid membrane
mild TBI- no physical evidence, loss of consciousness, confusion,
CTE - dementia and cerebral scaring from multiple mTBIs

Question 12

infections of the brain

Answer 12

Encephalitis - inflammation of brain
bacterial encephalitis - cerebral abscess (swollen area containing pus)
viral infections - rabies has affinity for neural tissue

Question 13

neurotoxins

Answer 13

mercury
lead
endogenous neurotoxins e.g. cortisol when stressed

Question 14

programmed cell death

Answer 14

apoptosis - genetic program for destroying themselves 1-2 days, orderly process
necrosis - passive cell death from injury, fast/disordered, neurons swell and break apart, cell scatters and can harm neighbouring cells

Question 15

neurological diseases

Answer 15

epilepsy - repeated seizures generated by chronic brain dysfunction
focal seizures - neurons fire together only in focused region of brain, causes synchronous firing
absence seizure - no convulsions, loss of consciousness, staring into space, usually in children

Question 16

parkinsons

Answer 16

degeneration of substantia nigra and deficiency in dopamine production. treated with L-dopa precursor to dopamine and can produce more to cover for deficiency

Question 17

multiple sclerosis

Answer 17

attack myelin in CNS
autoimmune disorder where immune attacks myelin sheath. glial cells cannot re-myelinate those cells. can leave scar tissue

Question 18

alzheimers disease

Answer 18

pathological change in brain.
neurofibrillary tangles - thread like tangles in Tau protein in cytoplasm on neurons
Particularly prevalent in amygdala and hippocampus
amyloid plaques - clump of scar tissue composed of degenerating neurons and beta-amyloid protein
neuron loss particularly in temporal lobe

Question 19

alzheimers stages

Answer 19

prodromal stage- mild cognitive impairment, anxiety, autonomy is reduced
dementia stage - progressive loss of memory, deficits in attention, and personality changes

Question 20

nervous system damage

Answer 20

no regrowth in CNS, adjacent neurons to the one who dies may also die.
In PNS axonal regrowth happens after injury

Question 21

PNS axonal regrowth

Answer 21

when nerve damaged without damaging Schwann cell sheaths, axons regenerate to correct targets, if Schwann cell sheaths are separated off cell, axons regenerate incorrect sheaths and reach incorrect targets, if sheath completely displaced from cell, there is no functional regeneration

Question 22

collateral sprouting

Answer 22

no regrowth in CNS, so adjacent neurons take up sites left open by spot where there is empty post synaptic neuron

Question 23

neural reorganisation

Answer 23

cells connected to dead cell will reorganise themselves to have connection to region originally dedicated to degenerate cells (e.g. rat getting whiskers cut off)

Question 24

release from inhibition with collateral sprouting

Answer 24

when one cell area in PNS overlaps with another is spot of inhibition, when one cell dies, not inhibited anymore and sprouts to the spot where the other cell used to be (e.g. Skin area A and B)

Question 25

Recovery from TBI

Answer 25

usually happens immediately after due to reduction of swelling or dissipation of blood, but is hard to tell as people adapt without knowing

Question 26

neurogenesis

Answer 26

stem cells produced in hippocampus and sub-ventricular zone, can migrate short distance and develop into neurons

Question 27

phantom limbs

Answer 27

amputees continue to have experience of limbs that were lost, may attempt to use limb that was lost