case 6 Flashcards
glia
insulate support and nourish
neurons
sense change convey info and communicate.
macroglia
oligodendrocytes, shwann cells, astrocytes (fibrous in white matter, protoplasmic in grey, absorb K glutamate and GABA, radial glial are precursers)
microglia
macrophages of CNS
axonal transport
movement of proteing from soma to axon by axoplasmic flow. into vesicles by golgi apparatus in soma, kinesin carries it down the path by ATP. movement from soma to axonal end anterograde. Dyenin is used.
wallerian degeneration
nerve fibre damaged, degenerates.
MS
disease characterised by inflamation demyelination and gliosis. PNS spared.
signs and symptoms
tingling, numbness, muscle weakness, ataxia, dysarthria and dysphargia. nystagmus, optic neuritis or dyplopia. pain. bladder difficulties. depression. diplopia may result from internuclear ophthalmoplegia INO or palsy of 6th cranial nerve.
epidemiology
more common in women. 1 in 800. 20-40 yrs. inc higher latitudes. Vit D deficiency. HLA on chromasome 6 genetic predisposition. hygiene hypothesis. Herpes and Epstein Barr virus.
relapse remitting
remission when symptoms dont worsen. common optic neuropathy brainstem demyelination and spinal cord lesions.
inflamation
BBB prevents entry T cells, usually occludin and claudin form tight junctions, in inflamation BBB compromised. allow macrophages and lymphocytes that attack myelin.
relapse
mainly TH1 and TH17. IL12 differenciates Th cells into inflam Tcells. Overproduction of IL12 in MS. cant destuinguish normal from problem myelin. lesions most common in ON, CC, cerebellum, BS, BG, SC. TH1 secrete IFNy which activate macrophages. TH17 recruit leukocytes.
diagnosis
2 or more episodes that reflect pathology of CNS for 24h seperated by month. MRI, inc in vasc permeability from breakdown of BBB detected by leakage of gadolinium Gd. Evoked potentials test-electrical activity of brain detect slowing. CSF-elevated IgG, oligoclonal bands detected electrophoresis. breakdown products of myelin.
treating acute relapse
antiinflamatory, methylprednisolone, 1g/day 3 days. prednisone 500g for 5 days.
preventing relapse
B interferon SCI, inhibit prevent block t cells.
Glatiramer acetate/copaxane/copolymer-bind MHC 2, compete MBP, SCI.
Fingolimod/Gilenya-sphingosine 1phosphate receptor modulator, tablet o.5mg, lymphocytes cant leave lymph.Used RR
Natalizumab/tysabri-a4b1 interact with VCAM1, inhibits this so lymphocytes cant bind and enter BBB,
alemtuzumab-anti CD52 monoclonal antibody IV once yearly. depletes T and B cells.
Teriflunomide-blocks pyrimidine synth by inhibit DHODH so T cells.
BG 12-activate Nrf 2 pathway dec inflamation.
MDD
have to have one of little interest in doing things, feeling depressed. and 3 other ticks elsewhere. leadaing cause disability. more common in woman. high suicide. neg cognitions of self world and future. recurrence is norm. progressive-kindling hypothesis-episodes more easily triggered.
genetics
short/short greater risk. Long long lesser risk. seratonnin reuptake gene.
types of neurons
unipolar and pseudopolar are sensory neurons. bipolar are interneurons, multipolar are motor neurons. in PNS sympathetic are myelinated parasympathetic are un. in CNS usually unmyelinated.
axonal transport
axoplasmic flow, soma to axon anterograde transport using kinesis. Retrograde transport use dyenin.
electronic potential
non propogated. smaller as spreads down membrane.
action potentials
propogated. use electronic potentials to trigger. constant amplitude.
resting membrane potential
Na K ATPase pump. Dec external Na reduces size of AP but little effect on RMP. Inc external K dec RMP. Ca bind to Na channels, their pos charge alter electrical state of channel altering voltage level to open, Dec Ca inc excitability of nerve.
how is GABA terminated
uptake into the pre-synaptic neurone and glial cells
how is Dopamine terminated
breakdown by synaptic enzymes, MOA B and COMT and taken up but dat
