Pathophysiology Two Flashcards
what is muscular dystrophy
a frequently fatal disease of muscle deterioration
what do you need to know about Duchenne’s
- most common type
- boys!
- begins between 2-3 years old
- affects lower limbs first
- impacts heart and respiratory muscles later on
what do you need to know about becker muscular dystrophy?
- ages 5-15 appear
- slower progression than DMD
- affects hips and pelvic area first
- causes muscle weakness in the heart for most
T or F: DMD is an X linked recessive gene so it mostly affects females
F, is x linked recessive but mostly affects boys
explain the science behind why DMD is bad
- dystrophin is a protein that attaches actin to the extra-cellular matrix
- in DMD it’s too short and rips the myocyte membrane every time the muscle contracts and allows Ca+ to flow freely into the cell
- excess Ca+ activates too many proteases and breaks down the proteins
- this leads to elevated blood creatinekinase so less energy in the cell
what happens to the muscle fibers in myofibrillar myopathy
varied sizes
what happens to the internal architecture in myofibrillar myopathy
- irregular
- aggregate proteins (similar to tau in alzheimers)
- vacuoles
what happens to endomysium in myofibrillar myopathy
- increased connective tissue
why is desminopathy bad
it can lead to dysfunctional cell adherence (think desmosomes in cardiac muscle cells) and muscle cell death
what is desmin?
a protein that integrates the sarcolemma, Z disc, and nuclear membrane in sarcomeres and regulates sarcomere architecture
what is the primary function for titin
- stabilize thick filament
- center thick filament between thin filaments
- prevent overstretching of the sarcomeres
- recoil carcomere like a spring after it is stretched
______________ is the name for a defect in titin
titinopathy
are titinopathies dominant or recessive?
both\
*can be inherited or a random mutation too
a defect in actin or nebulin is called
nemaline myopathies
purpose of nebulin
- wraps around actin and connects to Z-disc
- thin filament molecular reler
- regulates contractile force generation
is nemaline myopathies dominant or recessive
can be either
Adult onset ______- is progressive autoimmune based
nemaline myopathy
strains
injury to muscle or tendons
sprains
injury to ligaments
two types of strains
acute or chronic
how do you treat strains
PRICE
what are the different grades of strains?
1, 2 3,
characteristics of grade 1 muscle strain
- minor damage
- soreness and loss of function
- self-repair with rest and decreased usage
characteristics of grade 2 muscle strain
- “tearing”, heavy damage
- intense pain, loss of motion, swelling, bruising
- rest, potential need for brace or casting
- seek medical assistanc eif symptoms are severe
characteristics of grade 3 muscle strain
- total rupture
- compromised stability
- extreme pain, bruising and swelling, total loss of motion
- surgical intervention required to reattach tissue
what are risk factors for muscle strains
- sports (especially contact)
- prior injury
how do you prevent muscle strains
- stretching
- warm ups
- be in shape for the sport, not use sport to get in shape
- regular conditioning can prevent workplace injuries in physically demanding occupations
what are symptoms of a muscle strain
- pain/tenderness
- redness/bruising
- limited motion
- muscle spasms
- swelling
- muscle weakness
- clicking or popping
_______ is a subset of muscle strains
DOMS
acute strains are due to _________ while chronic muscle strains are due to __________
one event
daily wear and tear
strains often occur at the __________
myotendinous junction
strains occur when the energy the muscle is forced to absorb ________– the strength of the tissue
exceeds
what can you use to help diagnose a strain
diagnostic ultrasound
how to treat muscle strains
- price
- PT
- immobiliation
- surgical interventions
- NSAIDS
recovery of muscle strains depend upon ___________ and ___________
initial severity
complexity
