Bone Bitch

Front 1

HAP confers what traits to bone?

Back 1

hardness and resistance

Front 2

What makes up 85-90% of bone total proteins?

Back 2

type 1 collagen

Front 3

What makes up 10-15% of bone total proteins?

Back 3

noncollagenous proteins

Front 4

unique trait of fibronectin?

Back 4

only non collagenous protein that doesn't bind calcium

Front 5

what are the bone attachment molecules?

Back 5

1) fibronectin
2) thrombospondin
3) osteopontin
4) bone sialprotein

Front 6

fibronectin function:

Back 6

mediates cell attachment and bone cell spreading

Front 7

what produces fibronectin

Back 7

produced by osteoblast

Front 8

Thrombospondin function:

Back 8

mediates adhesion, not spread; binds calcium

Front 9

Osteopontin function:

Back 9

role in osteoclast attachment via integrin receptor; binds calcium;

Front 10

what produces Osteopontin?

Back 10

produced by osteoblasts and osteoclasts

Front 11

Bone sialoprotein function?

Back 11

role in osteoclast attachment? Role in binding calcium

Front 12

where is Bone sialoprotein found?

Back 12

In osteoblasts, osteocytes and recently in osteoclasts

Front 13

List the proteoglycans in bone:

Back 13

1) Chondroitin sulfate
2)Heparin sulfate

Front 14

function of Chondroitin sulfate:

Back 14

???

Front 15

structure of Chondroitin sulfate:

Back 15

attached to 3 separate core proteins - Versican - Decorin - Biglycan

Front 16

function of heparin sulfate:

Back 16

facilitates interaction of osteoblast with extra-cellular macromolecules

Front 17

function of osteocalcin

Back 17

Important signal in bone turnover and may act as a chemo-attractant to osteoclast precursors

-binds Ca

Front 18

what produces osteocalcin?

Back 18

osteoblasts

Front 19

what confers the Ca binding properties of osteocalcin?

Back 19

3-carboxyglutamic acid

Front 20

list the bone growth factors:

Back 20

1) fibroblast growth factors (FGFs)
2) insulin-like growth factors (IGFs)
3) transforming growth factor-ß molecules (TGF-ßs)
4) bone morphogenetic proteins (BMPs)
5) possibly platelet derived growth factor (PDGF)

Front 21

what synthesizes bone growth factors?

Back 21

1)cells of the osteoblast lineage
2) cells closely associated w/ bone
---chondrocytic cells
---endothelial cells
---fibroblasts

Front 22

what are the specific predominant growth factors in bone?

Back 22

IGF-II
TGF-3
IGF-I

Front 23

Alkaline phosphatase function:

Back 23

1) Used as an index of bone formation in serum

2) May also function in mineralization

Front 24

Osteonectin function:

Back 24

1) High affinity for binding ionic calcium and hydroxyapatite and collagen

2) May play a role as modulator of mineralization and function in tissue remodeling

Front 25

osteonectin structure

Back 25

phosphorylated glycoprotein

Front 26

most abundant NCP?

Back 26

osteonectin

Front 27

what are the cells of bone?

Back 27

1) OSTEOPROGENITORS
2) PRE-OSTEOBLASTS
3) OSTEOBLASTS
4) BONE LINING CELLS
5) OSTEOCYTES
6) OSTEOCLASTS

Front 28

OSTEOPROGENITORS function:

Back 28

Extensive proliferation: growth, repair, reorganization

Front 29

which bone cell is alkaline phosphatase negative?

Back 29

OSTEOPROGENITORS

Front 30

PRE-OSTEOBLASTS function:

Back 30

1) Limited proliferation and more differentiated

2) Release, RANKL (Receptor Activator Nucleofactor Kappa-B Ligand) and OPG

3) alkaline phosphatase positive

Front 31

osteoblast function:

Back 31

1. Synthesize bone (collagen type I & non collagenous proteins)
2. Strongly positive for alkaline phosphatase
Functions
3. Secretion of bone matrix (osteoid)
4. beginning of osteoid degradation
5. Osteoid resorption
6. Osteoclast stimulating factor(s)
• Least mitotic activity
• PTH receptor (activates osteoblast)

Front 32

which bone cell has the lease mitotic activity?

Back 32

osteoblast

Front 33

which bone cell has PTH receptor

Back 33

osteoblast

Front 34

parathyroid hormone activates which cell?

Back 34

osteoblast

Front 35

BONE LINING CELLS function:

Back 35

resting osteoblasts

Front 36

OSTEOCYTES function

Back 36

1) Important mechanosensory (mechanotransduction) role, maintain bone matrix
2) Form a syncytium through gap junctions between their processes: connexins

Front 37

OSTEOCLASTS function

Back 37

Bone resorption by osteoclast tightly coupled with bone formation by osteoblast

Front 38

OSTEOCLAST structure

Back 38

1) Large and multinucleated (4-20 nuclei)
2) Numerous large lysosomes, abundant mitochondria, well developed Golgi, some RER
3) Found in Howship’s lacunae (resorption bay)
4) Sealing/adhesion /circumferential zone: attachment to mineralized bone matrix
5) Ruffled border (microvilli): cell membrane thrown into many folds representing site of active resorption
6) Receptors for calcitonin, but not for PTH, Vitamin D3, or cytokines

Front 39

what prevents osteoclast formation?

Back 39

OPG

Front 40

function of calcitonin receptor on osteoclast?

Back 40

inhibits osteoclast

Front 41

precursor to osteoclast?

Back 41

monocyte

Front 42

What is primary spongiosa:

Back 42

initial immature (woven) trabeculae bone

Front 43

How long does each stage of bone remodeling last?

Back 43

Activation (1 week)
Resorption (2 weeks)
Reversal (1.5 weeks)
Formation (13.5 weeks)

Front 44

describe Parathyroid Hormone (PTH)

Back 44

increases blood calcium

1) Secretion stimulated by calcium decrease
2) Acts on kidney tubules to increase calcium resorption and decrease phosphate reabsorption
3) Activates vitamin D3

also induces osteoclast activity indirectly via osteoblast RANKL

Front 45

describe Vitamin D3

Back 45

involved in bone mineralization

Front 46

describe Calcitonin

Back 46

decrease calcium concentration in blood

1) Opposite effect of PTH
2) decrease osteoclast action and bone turnover

Front 47

function of Growth hormones

Back 47

proliferative cells of epiphyseal disk

Front 48

function of Thyroid hormones

Back 48

necessary for normal growth

Front 49

function of Glucocorticoids

Back 49

inhibition of bone resorption and collagen degradation

Front 50

function of Insulin

Back 50

direct effect on osteoblast

Front 51

function of Sex Steroids

Back 51

estrogen, androgens

Front 52

function of TGF

Back 52

stimulates precursor cells of osteoblast lineage and on bone collagen formation

Front 53

function of BMPs

Back 53

osteoinductive

Front 54

function of FGF

Back 54

neurovascularization and wound healing, stimulation of osteoblast precursor cells

Front 55

function of PDGF

Back 55

wound repair stimulates bone resorption and osetoblast precursors

Front 56

function of IGFI and IGFII

Back 56

increase bone collagen matrix and decrease collagenase levels

Front 57

Interleukins (IL-1, IL-6) function:

Back 57

osteoclast recruitment