bone mineralization, viability

Question 0

amount of Ca released from bone daily?

Answer 0

400mg

Question 1

percent body calcium in bones?

Answer 1

99%

Question 2

primary regulators of Ca?

Answer 2

PTH, Vit. D

Question 3

daily Ca dietary requirement?

Answer 3

children 600mg

adults 1300mg

Question 4

percent body phosphate in bone?

Answer 4

85%

Question 5

synthetic form of PTH?

Answer 5

Teriparatide

Question 6

produces OPPOSITE effect of PTH?

Answer 6

Calcitonin

Question 7

age range of peak bone mass?

Answer 7

16-25 years old

Question 8

rate of bone loss after peak?

Answer 8

0.3-0.5% per year (2-3% menopausal), affects trabecular > cortical

Question 9

most common cause of hyperCa?

Answer 9

malignancy

Question 10

rickets/ osteomalacia

Answer 10

failure of mineralization

Question 11

most common form of rickets?

Answer 11

familial hypophosphatemic rickets (vitamin D resistance)

Question 12

osteoporosis WHO definition?

Answer 12

L2-L4 density 2.5 stdev less

mean density 1.0-2.5 stdev less

Question 13

brown tumors in bone?

Answer 13

hypercalcemia

Question 14

hypercalcemia histologic changes?

Answer 14

osteoblasts/clasts active on both sides of trabeculae (Paget’s)

Question 15

ortho tx of hypercalcemia?

Answer 15

mobilization, bisphosphonates, vit. D (5000 IU daily)

Question 16

rickets

Answer 16

failure of mineralization

Question 17

rickets signs

Answer 17

rachitic rosary

codfish vertebrae

Question 18

osteoporosis type of defect?

Answer 18

quantitative

Question 19

most affected bone type of osteoporosis?

Answer 19

cancellous

Question 20

type I osteoporosis

Answer 20

postmenopausal

Question 21

type II osteoporosis

Answer 21

age-related

Question 22

osteoporosis abnormal labs

Answer 22

none (xrays only for bone loss >30%)

Question 23

most accurate ‘special study’ for osteoporosis?

Answer 23

DEXA

Question 24

osteoporosis tx?

Answer 24

Ca 1000-1500mg

vit. D 400-800IU

Question 25

osteoporosis prophylaxis?

Answer 25

apt Ca intake, weight bearing, estrogen therapy

Question 26

osteomalacia type of defect?

Answer 26

qualitative (defect of mineralization)

Question 27

required for diagnosis of osteomalacia

Answer 27

transiliac biopsy (finding: widened osteoid seams)

Question 28

osteomalacia tx?

Answer 28

‘large doses’ of vit. D

Question 29

scurvy definition

Answer 29

vit. C deficiency (decrease in chondroitin sulfate - collagen - synthesis)

Question 30

scurvy clinical features

Answer 30

fatigue, gum bleeding, ecchymosis, joint effusions, iron deficiency

Question 31

scurvy histologic feature

Answer 31

calcification zone widening in physis

Question 32

pathophysiology of osteogenesis imperfecta

Answer 32

GLYCINE SUBSTITUTION in procollagen - failure in cross-linking

Question 33

effect of lead poisoning

Answer 33

alters chondrocyte response to PTH, TGF-beta (reduced bone density, short stature)

Question 34

osteopetrosis

Answer 34

failure of bone resorption; osteoclasts lack normal ruffled border

Question 35

malignant osteopetrosis (infantile)

Answer 35

‘bone within a bone’ on xray (no marrow)

Question 36

Paget’s disease etiology?

Answer 36

virus-like inclusion bodies in osteoclasts

Question 37

Paget’s disease ACTIVE phases

Answer 37

lytic, mixed, sclerotic

Question 38

Chandler’s disease

Answer 38

osteonecrosis of the femoral head in adults

Question 39

earliest study to yield positive results, highest specificity/sensitivity in osteonecrosis?

Answer 39

MRI

Question 40

osteochondrosis

Answer 40

traction apophyses (e.g., osgood-schlatter, legg-calve-perthes)