bone histology

Question 0

confers STIFFNESS (high:stiff:cortical, low:elastic:cancellous)

Answer 0

Young’s modulus of elasticity

Question 1

COMPACT bone; 80% of skeleton

Answer 1

CORTICAL bone

Question 2

law of remodeling according to LINES OF STRESS?

Answer 2

Wolff’s law

Question 3

is transcription factor for: mesenchymal cells - osteoblast

Answer 3

RUNX2

Question 4

maintains bone; 90% of mature skeleton

Answer 4

osteocytes

Question 5

antiseptics toxic to osteoblasts?

Answer 5

hydrogen peroxide, betadine, bacitracin

Question 6

action of PTH?

Answer 6

stimulate OSTEOCLAST activity

Question 7

lineage of OSTEOCLAST?

Answer 7

MACROPHAGE

Question 8

action of BISPHOSPHONATES?

Answer 8

INHIBIT osteoclast - ANABOLIC effect

Question 9

NITROGEN-CONTAINING bisphosphonate?

Answer 9

1000-fold ANABOLIC potency (zoledronic acid, alendronate)

Question 10

IN BONE DEV’T: osteoprogenitor cells - LOW strain, HIGH O2 tension

Answer 10

osteoblasts/WOVEN bone

Question 11

IN BONE DEV’T: osteoprogenitor cells - INTERMEDIATE strain, LOW O2 tension

Answer 11

CARTILAGE

Question 12

IN BONE DEV’T: osteoprogenitor cells - HIGH strain

Answer 12

fibrous tissue

Question 13

bone collagen type?

Answer 13

type I

Question 14

ORGANIC component % of bone dry weight?

Answer 14

40%

Question 15

collagen % of organic component?

Answer 15

90%

Question 16

decreases solubility, increases strength of collagen?

Answer 16

cross-linking

Question 17

most abundant NON-COLLAGENOUS bone protein?

Answer 17

OSTEOCALCIN

Question 18

INORGANIC component % of bone dry weight?

Answer 18

60%

Question 19

primary composition of bone INORGANIC component?

Answer 19

calcium hydroxyapatite

Question 20

bone TENSION stimulates?

Answer 20

RESORPTION (osteoclasts)

Question 21

bone COMPRESSION stimulates?

Answer 21

FORMATION (osteoblasts)

Question 22

law of BONE GROWTH (compressing inhibits, tension stimulates)

Answer 22

Hueter-Volkmann law

Question 23

% cardiac output received by bone?

Answer 23

5-10%

Question 24

bones with LOW blood supply?

Answer 24

scaphoid, talus, femoral head, odontoid

Question 25

bone's 3 sources of blood?

Answer 25

NUTRIENT artery, METAPHYSEAL-EPIPHYSEAL system, PERIOSTEAL system

Question 26

arterial flow in MATURE bone?

Answer 26

centrifugal

Question 27

arterial flow in FRACTURED/ IMMATURE bone?

Answer 27

centripetal

Question 28

MAJOR determinant of bone healing?

Answer 28

blood flow

Question 29

effect of nail REAMING?

Answer 29

devascularization

Question 30

effect of LOOSE-FITTING nails?

Answer 30

spares cortical perfusion

Question 31

enlarges diameter of bone in growth and forms periosteal callus?

Answer 31

CAMBIUM (inner periosteum)

Question 32

composition of RED marrow?

Answer 32

water 40% fat 40% protein 20%

Question 33

composition of YELLOW marrow?

Answer 33

water 15% fat 80% protein 5%

Question 34

types of bone formation?

Answer 34

enchondral, intramembranous, appositional

Question 35

ENCHONDRAL bone formation?

Answer 35

BONE REPLACES CARTILAGE (e.g. embryonic/ longitudinal growth, fracture callus)

Question 36

what are the 2 growth plates?

Answer 36

PHYSIS (horizontal), | EPIPHYSIS (spherical)

Question 37

physeal cartilage zones: RESERVE zone

Answer 37

lipid, glycogen, proteoglycan storage

Question 38

physeal cartilage zones: PROLIFERATIVE zone

Answer 38

longitudinal growth

Question 39

physeal cartilage zones: HYPERTROPHIC zone

Answer 39

maturation, degeneration, calcification (rickets, MPS)

Question 40

INTRAMEMBRANOUS bone formation?

Answer 40

WITHOUT CARTILAGE (e.g. flat bones, distraction osteogenesis, young amputations)

Question 41

APPOSITIONAL bone formation?

Answer 41

bone enlargement (width), remodeling