Muscle Pathology Flashcards
5 responses of muscle to injury
atrophy
hypertrophy
necrosis
regeneration
fibrosis
what is a denervation atrophy in the horse
laryngeal hemiplegia
left recurrent laryngeal n.
atrophy of left cricoarytenoideus dorsalis
signalment and pathogenesis of muscular dystrophy (Duchenne’s) in the dog
young male dogs
X linked dystrophin mutation that leads to marked necrosis (severest in diaphragm) & muscle loss
signalment and clinical sign of muscular dystrophy (Duchenne’s) in the cat
young male kittens
marked hypertrophy
bunny hopping gait
pathogenesis of malignant hyperthermia (porcine stress syndrome)
ryanodine receptor mutation > unregulated Ca channels > hypercontraction of all striated muscle > hyperthermia and lactic acidosis
pathogenesis of hyperkalemic periodic paralysis (HYPP)
horses
delayed Na channel inactivation > excess Na IC & K EC > hyperkalemia > myotonia
pathogenesis of equine polysaccharide storage myopathy (EPSSM)
what is a pathognomonic lesion of this
mutation in GSY1 > glycogen accumulation in type 2 muscle > muscle degeneration/necrosis
glycogen inclusion
pathogenesis of Myasthenia Gravis
what is it caused by?
what is a common clincial sign?
what test can you do?
inherit defect in ACh receptors at the NMJ > decreased contractions
thymoma
megaesophagus
tensilon test - give anti-AChE
pathogenesis of downer syndrome
cows
immobile recumbent animals
increased IM pressure > collagenous venous system > red infarct/ischemic necrosis
pathogenesis of compartment syndrome
chickens
vigorous musculature contraction
increased IM pressure > collagenous venous system > red infarct/ischemic necrosis
pathogenesis of Corynebacterium pseudotuberculosis
“Pigeon Breast/Fever”
organism in the soil contaminates wound or inoculation from insects > spreads to pectoral m > abscess
pathogenesis of C. septicum and C. perfringens
C. septicum - malignant edema
C. perfringens - gas gangrene
wound is contaminated with spores > toxins > local necrosis/toxemia > death
pathogenesis of C. chauveoi
black leg
spores ingestion > dormant in muscle until trauma > activation > myonecrosis/toxemia
pathogenesis of Actinonbacillus lignieresii
“wooden tongue”
focal trauma to tongue allows infiltration of actinobacillus > granulomatous inflam > regional lymphadenitis
what do Neospora caninum, Toxoplasma gondii, and Sarcocystis require
2 hosts - herbivore (intermediate/muscle) and predator (definitive/enteric)
sarcocystis can result in what type of myositis
eosinophilic myositis
hepatozoon americanum
definitive host?
transmission?
clinical sign?
brown tick
ingestion of tick
pyogranulomatous myositis & periosteal rxn (BONE AND MUSCLE CORRELATE)
what parasitic nematode is a “true parasite” that is zoonotic, high importance in pigs and cysts that are resistant to freezing and can survive for 20 yrs
trichonella spp.
what two parasites can humans acquire from consuming raw meat
trichonella spp
taenia solium & saginata “beef measles”
what is extertional rhabdomyolysis
myofiber damage from exercise stress as the primary cause, can also be due to EPSSM
common in horses
equine polysaccharide storage myopathy predisposes to what disease
extertional rhabdomyolysis
what is capture myopathy
wildlife species that undergo exertion, hyperthermia, lactic acidosis, myonecrosis and cardiac necrosis
what are the 2 types of equine post-streprtococcal myositis
purpura hemorrhagica (type III hypersensitivity)
autoAb against muscle in young quarter horses (type II hypersensitivity)
associated with S. equi equi
pathogenesis of canine masticatory myositis
autoAb against type 2M myosin (type II hypersensitivity)
eosinophillic plasmacytic myositis > compartmental syndrome > chronic atrophy/fibrosis (masseter and temporal mm)
