Unit 22 Flashcards
MD
sk m wasting/degen. progressive
what are 3 things cause MD
atrophy
necrosis of m. fiber
pseudohypertrophy
pseudohypertrophy
m tries to regen but CT and adipose is deposited instead of m.
which MD is most common
duchenne md
prevelance of duchenne md
1 in 3500 live male births
Et MD
monogenic, rescessive, x linked
how does MD pass
mother to son
why does md pass mom to son
mom has 2 x chrs, and if one is def and passes that one to son, since son only has 1 x, this is what mnfts
where is the def gene located in MD
short arm of x chr
how do we tell apart types of Md 5
m group age of onset genetics mode of inheritance progression/rate of disase
what does the def gene code for
dystrophin, a memb protein
where is dystrophin located
inner sarcolema of m cell
fx of dystrophin
attatches contractile filaments to points on the cell
where does dystrophin attach filaments to
eachother
sarcolema
ground matrix
when there is poor contractile protein attachment what happens to m fibers (step 1 patho)
necrosis with use
what happens when m fibers being to necros (step 2 patho)
attempt to regen and repair
what does attempted regen and repair of m cells cause (step 3 patho)
more necrosis
what does necrosis mean for m memb perm
change in permeability
what happens with the change in perm that occurs with def dystrophin
allows influx of Ca
what E is released when ca influxes into cells
enzymes (CK
what are filaments doing to themselves with contraction
injury
why does fibrofatty ct replace M
body is trying to restrict, limit and adapt to changes rt cell necrosis by attempting to inc m mass. body cant regen m so psuedohypertrophy
when does injury set in
with m use
what age do we normally see mnfts? why
2-3yo because at this age toddlers begin to utilize more m
what is the main mnfts of md
progressive m weakness or change in m action
what types of m does md affect
all, esp resp and cardaic
what does progession of md to to resp and cardiac fx
changes in breathing, CO, cardiomyopathy
why is there no contraction or rleaxation by m tissue in progressed md
psuedohypertrophic m cant contract/relax
what is important when begining dx for md
seperating this out from a n. issue
what do we look at for dx of md
voluntary movement
serum CK
biopsy
what do we analyze with vol movement
how much movement can they do alone
what do we keep in mind when looking at serum CK levels
levels inc with age
what confirms dx for md
biopsy
what do we look for in biopsy for md
defecttive dystrophin on sarcolemma
CT, adipose, Ca deposits
necrosis
tx
no cure
supportive and symptomatic
comfort
what is important to remember about the damage in md
irreversible
what is the most life threatening aspect in md
breathing
what type of exercises can we do with md pts? why is this problematic
breathing.
inc injury occurs with inc m use, but if we dont use the m at all -> total atrophy
what primary prevention measures can we do for md
carrier status assesment on mom prior to conception for def x chr
prenatal testing at 12 wks gest
