bone soft tissue Flashcards
achondroplasia hot terms
activating mutation of FGFR3 constituitively inhibiting chondrocyte differentiation. dwarfism with macrocephaly. failure of epiphysial cartilage formation. most common form of dwarfism. AD trait.
what is the mental status and life span of achondroplasia?
normal.
what does Vit C deficiency cause? how does this affect the bones?
scurvy. it inhibits the function of osteoblasts and causes abnormal collagen formation. wound healing and bone growth are impaired. there is also widespread capillary bleeding.
scoliosis?
abnormal lateral curvature of the spine that usually affects adolescent girls.
kyphosis
abnormal anteroposterior curvature of the spine.
how to treat scoliosis
putting braces on the back to appropriately apply pressure to the spine, moving it back into proper alignment.
osteochondroma hot terms
defect of skeletal growth from the ring of ranvier in the growth plate. cartilage-capped, bony, stalked osteochondroma. surrounded by a fibrous perichondrial membrane.
hereditary multiple osteochondromatosis
most common inherited AD trait MSK disorder. loss of EXT1/2 gene function. dwarfism can result in severe cases.
hemihypertrophy etiology and risks
where one growth plate is stimulated excessively. one limb will become longer than the other. children are at increased risk for neoplasm.
osteoporosis hot terms
abnormally dense bone. chalk-like and brittle. marble bone or albers-schonberg is rare inherited disease of abnormally dense bone. block-like, radio dense bone.
who gets the autosomal dominant form of osteopetrosis and who gets the AR? what is the difference in severity?
adults get the AD, children get the recessive. the childhood form is more severe.
what is the function of the gene for the AD osteopetrosis and the AR?
AD: osteoclast proton pump.
AR: carbonic anhydrase II.
why is carbonic anhydrase needed to lay down bone?
it isn’t. but it is required for osteoclasts to remodel bone. they need an acidic environment to elevate the calcium/
what happens to hematopoiesis in osteopetrosis?
there is replacement of the marrow cavity with osteoclasts and extensive fibrosis. can cause anemia or pancytopenia. there will be extra medullary hematopoiesis
osteogenesis imperfect hot terms
defect in collagen type I. type I OI is the less severe type. AD trait multiple fractures, blue sclera, hearing abnormalities. thin, delicate, abnormally curved bones. decreased cortical thickness and trabecular bone. misshapen blueish-yellow teeth.
stature in OI
unaffected.
what happens as a child with OI gets older.
the fractures become farther apart and less severe.
what causes the blue sclera in OI
the underlying choroidal veins are apparent.
type II OI
lethal. perinatal, AD inheritance.
type III OI
one of the most devesatiting, with growth abnormalities deformation, AD. blue sclera at birth, but white shorty after.
type IV OI
same as I, but with white sclera.
collier disease ( multiple endochondromatosis)
asymmetric, multiple cartilaginous tumors that lead to bony deformities. tumor-like masses of abnormally arranged cartilage. tumors present in the metaphyses. as growth continues the tumors settle in the diaphysis. PTHR1 gene. PTH is involved in this syndrome.
what are the phases of bone reparation?
inflammatory, reparative and remodeling
characteristics of reactive bone formation?
suburst pattern or onion-skin patterning. can be either woven or lamellar. this is intramembranous bone because it is derived from the periosteum or the endosteal tissue.
heterotropic ossification
bone formation in extraskelatal sites. not associated with any metabolic disorder. genetic, post traumatic, neurogenetic, and as distinct reactive lesions (myositis ossificans.
metastatic calcification
occurs with hypercalcemia or hyperphosphatemia and predisposes other tissues to deposition.
dystrophic calcification
abnormal or damaged tissues
myositis ossificans
dystophic calcification of muscle due to trauma, occurs in young persons and often mimics cancer. usually of the lower limbs. exhibits the zonation effect, in which there is peripheral maturity but central immaturity of the formed bone. this clearly indicates a reactive process
langerhans cell histiocytosis
general term for three distinct disorders 1.) eosinophilic granuloma, 2.) hand-schuller christianson disease. 3.) letterer-siwe disease. the histological appearance of all three is identical. collections of large, eosiniophilic phagocytes with convoluted or grooved nuclei. there are birbeck granules. punched out lytic bone lesions within the flat bones (skull) and there are lesions within the metaphyses and diaphysis, periosteal callus with no reactive bone/
triad of hand-schuller christianson
lytic bone lesions (skull, etc), diabetes insipidus, exophthalmos. floating teeth on XR due to granulomatous inflammation and resorption of the jaw bone.
letterer-siwe
fail to thrive in children, cachetic, hepatosplenomegaly, LAD, anemia, leukopenia and thrombocytopenia. scattered seborrheic skin lesions.
what is the main characteristic that distinguishes osteomalacia from osteoporosis
milkman looser syndrome or pseudofractures. they are exaggerations of osteoid seams.
clinical features of osteomalacia
nonspecific muscle aches and pains, diffuse. poorly localized bone pain and tenderness. spine, pelvis and proximal extremities.
rickets clinical features
apathetic, irritable, short-attention spans, buddha posture, flat skull with prominent frontal bones. rachitic rosary chest. is a grossly beaded appearance of the costral chondral junctions. outward curvature of the sternum. overall musculature is weak and represents a potbelly. short limbs, bowing of the legs and forearms. 1
osteitis fibrosa
histological changes of hyperparathyroidism, pagets disease, and even accelerated osteoporosis.
renal osteodystrophy
in chronic renal failure there is a decreased GFR, decreased clearance of phosphate. this drives the calcium concentration down. combined with tubular injury there is a decreased Vit D output and thus decreased calcium further. thus the PT undergoes secondary hyperPTism and can even undergo tertiary.
