Q2 BONE and MUSCLE Flashcards
endochondral ossification
cartilage model, fetal long bones, bony collar, primary then secondary centers of ossification
intramembranous ossification
flat bones and healing later in life
4 zones of endochondral ossification at the epiphysis
resting, proliferative, hypertrophic, calcifying
two layers of periosteum
outer fibrous layer and inner osteogenic layer
type A and B synoviocytes
A are antigen presenting, B produce fluid
growth arrest lines
lines of thin bone parallel to the growth plate from times of nurtrient deficiency
growth retardation lattice
acquired impairment of osteoclastic resorption, area of increased bone density in the metaphysis (BVDV or distemper)
Osteopetrosis
bone density increase, but bone more fragile, red angus gene in cows, triangular radiodensities
wolffs law
tension = resorption and compression = formation
eburnation
smooth and shiny surface of subchondral bone after cartilage ulceration
pannus
granulation tissue arises from the synovial membrane and spreads over articular cartilage, can eventually fuse joint (ankylosis)
congenital cortical hyperostosis
piglets have thick forelimbs from abnormal periosteal bone formation
cause of chondrodysplasias
mutation in FGF4 causes downregulation of chondrocytes proliferation
spider lamb syndrome
FGFR3 usually limited growth, but mutation removes inhibition
osteochondroses
latens then manifesta then dissecans growing in severity
rickets and osteomalacia
vit D or phosphorus deficiency in growing animals also affects epiphyseal cartilage vs adult animals (causes nodular enlargement of costochondral junction)
fibrous osteodystrophy
caused by increased PTH, renal disease (hyperphosphatemia) or nutritional deficiency of Ca, all stimulate bone resorption, causes swelling of bone or teeth to move around in dog
hypertrophic osteodystrophy
disease of young dogs causes double physis line
exostosis and enostosis
bony growth projecting outward vs in the medullary cavity
hypertrophic osteopathy
progressive periosteal excessive bone formation often occurs secondary to thoracic masses
steps of fracture repair
granulation tissue in days, then primary callus of woven bone in weeks, then remodeling in lamellar bone in years
arthrogryposis
congenital contracture of a joint due to CNS damage usually caused by maternal intoxications (hemlock)
common bacterial joint inflammation (5)
E rhusiopathiae, trueperella, haemophilus, borrelia, mycoplasmas
cause of viral arthritis
caprine arthritis and encephalitis virus
types of muscle fibers
1 slow twitch
2A fast twitch and fatigue resistant
2B fast twitch but fatigued
exercise induced myonecrosis
“capture myopathy” resulting from tying up under stress
myositis ossificans
uncommon reaction of muscle to trauma causes osseus metaplasia
congenital muscular steatosis
denervation atrophy in the calf replaces muscle with fat
congenital muscular hyperplasia
inactiviation of the myostatin gene, which regulates muscle growth
malignant hyperthermia
unregulated release of calcium results in excessive contraction and heat, defect in the ryanodine receptor
glycogen storage disease type IV
caused by deficiency of GBE, abnormal glycogen called amylopectin accumulates within cells (PAS stain for glycogen)
myasthenia gravis
autoantibodies against acetylcholine receptor associated with thymic abnormalities
tick paralysis
tick toxins block release of ach
rhabdomyosarcoma
occur at young age in the neck or oral cavity
clostridial myositis
C septicum most common, causes gas gangrene necrosis
botulism
flaccid paralysis bc can’t use ach, can detect toxin in stomach contents?
immune mediated myositis
syndrome of severe acute rhabdo, cross reaction of streptococcal antibodies with muscle proteins, atrophy of paraspinal and gluteal muscles
protozoal myopathy
sarcocystis mostly incidental
ionophore toxicity
causes calcium overload and necrosis
EPSSM
point mutation in GYS1 gene allows abnormal accumulation of glycogen within myofibers, gluteal and hamstring stains with PAS
equine exertional rhabdo
widespread type 2 myofiber necrosis
most common endocrine disorder that causes muscle atrophy
PPID
sweeney vs stringhalt
unilateral scapular muscle atrophy due to suprascapular nerve compression, vs sporadic pelvic limb neuropathy maybe H radicata?
EMND
vitamin E deficiency causes affected muscles to turn yellow tan and gelatinous
blackleg in cattle
clostridium chauvoei from ingestion
wooden tongue
actinobacillus lignieresii
lumpy jaw
actinomyces bovis
eosinophilic myositis
green muscle discoloration from sarcocystis
most common degeneration toxicity in goats
honey medquite
myotonia in goats
defect in the skeletal muscle chloride channel
little parasite in pig muscle
trichinella spiralis
