Pathophysiology Two

Question 1

what is muscular dystrophy

Answer 1

a frequently fatal disease of muscle deterioration

Question 2

what do you need to know about Duchenne’s

Answer 2

• most common type
• boys!
• begins between 2-3 years old
• affects lower limbs first
• impacts heart and respiratory muscles later on

Question 3

what do you need to know about becker muscular dystrophy?

Answer 3

• ages 5-15 appear
• slower progression than DMD
• affects hips and pelvic area first
• causes muscle weakness in the heart for most

Question 4

T or F: DMD is an X linked recessive gene so it mostly affects females

Answer 4

F, is x linked recessive but mostly affects boys

Question 5

explain the science behind why DMD is bad

Answer 5

• 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

Question 6

what happens to the muscle fibers in myofibrillar myopathy

Answer 6

varied sizes

Question 7

what happens to the internal architecture in myofibrillar myopathy

Answer 7

• irregular
• aggregate proteins (similar to tau in alzheimers)
• vacuoles

Question 8

what happens to endomysium in myofibrillar myopathy

Answer 8

• increased connective tissue

Question 9

why is desminopathy bad

Answer 9

it can lead to dysfunctional cell adherence (think desmosomes in cardiac muscle cells) and muscle cell death

Question 10

what is desmin?

Answer 10

a protein that integrates the sarcolemma, Z disc, and nuclear membrane in sarcomeres and regulates sarcomere architecture

Question 11

what is the primary function for titin

Answer 11

• stabilize thick filament
• center thick filament between thin filaments
• prevent overstretching of the sarcomeres
• recoil carcomere like a spring after it is stretched

Question 12

______________ is the name for a defect in titin

Answer 12

titinopathy

Question 13

are titinopathies dominant or recessive?

Answer 13

both\

*can be inherited or a random mutation too

Question 14

a defect in actin or nebulin is called

Answer 14

nemaline myopathies

Question 15

purpose of nebulin

Answer 15

• wraps around actin and connects to Z-disc
• thin filament molecular reler
• regulates contractile force generation

Question 16

is nemaline myopathies dominant or recessive

Answer 16

can be either

Question 17

Adult onset ______- is progressive autoimmune based

Answer 17

nemaline myopathy

Question 18

strains

Answer 18

injury to muscle or tendons

Question 19

sprains

Answer 19

injury to ligaments

Question 20

two types of strains

Answer 20

acute or chronic

Question 21

how do you treat strains

Answer 21

PRICE

Question 22

what are the different grades of strains?

Answer 22

1, 2 3,

Question 23

characteristics of grade 1 muscle strain

Answer 23

• minor damage
• soreness and loss of function
• self-repair with rest and decreased usage

Question 24

characteristics of grade 2 muscle strain

Answer 24

• “tearing”, heavy damage
• intense pain, loss of motion, swelling, bruising
• rest, potential need for brace or casting
• seek medical assistanc eif symptoms are severe

Question 25

characteristics of grade 3 muscle strain

Answer 25

- total rupture - compromised stability - extreme pain, bruising and swelling, total loss of motion - surgical intervention required to reattach tissue

Question 26

what are risk factors for muscle strains

Answer 26

- sports (especially contact) - prior injury

Question 27

how do you prevent muscle strains

Answer 27

- 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

Question 28

what are symptoms of a muscle strain

Answer 28

- pain/tenderness - redness/bruising - limited motion - muscle spasms - swelling - muscle weakness - clicking or popping

Question 29

_______ is a subset of muscle strains

Answer 29

DOMS

Question 30

acute strains are due to _________ while chronic muscle strains are due to __________

Answer 30

one event daily wear and tear

Question 31

strains often occur at the __________

Answer 31

myotendinous junction

Question 32

strains occur when the energy the muscle is forced to absorb ________-- the strength of the tissue

Answer 32

exceeds

Question 33

what can you use to help diagnose a strain

Answer 33

diagnostic ultrasound

Question 34

how to treat muscle strains

Answer 34

- price - PT - immobiliation - surgical interventions - NSAIDS

Question 35

recovery of muscle strains depend upon ___________ and ___________

Answer 35

initial severity complexity