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RUSVM Large Animal Medicine I 2017 > Muscle > Flashcards

Flashcards in Muscle Deck (96)
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1

Enzyme activities to assess muscle damage

Creatine kinase (CK)
Aspartate aminotransferase (AST)
Lactate dehydrogenase (LDH)

2

What is Serum CK a sensitive indicator for?

myonecrosis in both skeletal and heart muscle

3

When does Serum CK activity increase?

Increased within hours of a muscle insult and peaks within 4-6 hours after injury

4

When can CK elevate?

training
transport
strenuous exercise

5

What enzyme has high activity in skeletal and cardiac muscle as well as Liver, RBCs, and other tissues?

AST

6

When is the peak time for AST levels after an insult?

24 hours

7

What do elevations in CK and AST reflect?

recent or active myonecrosis

8

What do elevations of CK reflect?

myonecrosis is likely going on

9

What do elevated AST and decreasing or normal CK levels indicate?

Myonecrosis not continuing

10

Elevations in LDH specify what?

rhabdomyolysis
myocardial necrosis
hepatic necrosis

11

What tests assess concurrent renal disease?

Urine specific gravity
White blood cell count
Protein content
Red Blood cell count
Evaluation of cast formation

12

What does a positive Hemastix test in the absence of hemolysis or RBCs in urine indicate?

Myoglobinuria

13

Exercise Challenge test

15 mins of slow trot with CK activity sampled before and 4-6 hours after

14

What do elevations of greater than 5-fold CK indicate?

exertional rhabdomyolysis

15

Electomyography

to detect spontaneous or evoked potentials of neurogenic or myogenic

16

What do horses with abnormalities show on electromyography?

Spontaneous electrical activity
Fibrillation potentials: spontaneous firing of muscle fibers
Positive sharp waves
Myotonic discharges: bursts of complex high-frequency potentials
Complex repetitive discharges

17

What are EMG and NCVs used to classify?

classify the disease Neuropathic or Myopathic

18

Use of Nuclear Scintigraphy

ID some forms of muscle damage
area of deep muscle damage

19

How does Nuclear Scintigraphy work?

Technetium 99 m methylene diphosphonate is taken up in inflamed and damaged muscle

20

How is muscle fiber disruption seen on Ultrasonography?

hypoechoic area with loss of the normal fiber striation

21

How do es a defect in muscle/hematoma appear on ultrasonography?

Hypoechoic

22

How does increased connective tissue or loss of muscle appear on ultrasonography?

Hypoechoic

23

How does mineralization or gas pockets appear on ultrasonography?

Hyperechoic shadowing artifacts

24

"Sweeney"

suprascapular nerve is damaged and muscle over the scapula are atrophied

25

How long does it take for denervation to result in 50% muscle mass loss?

2 - 3 week period

26

What are the causes of Atrophy?

Denervation
Disuse
Malnutrition and cachexia
Immune-mediated myositis

27

HYPP

Hyperkalemic Periodic Paralysis

28

What causes HYPP?

inherited defect in the skeletal muscle sodium channel

29

What type of trait is HYPP?

Autosomal dominant

30

What does HYPP cause?

Abnormal skeletal muscle membrane excitability leads to episodes of myotonia, muscle contraction, and paralysis