Basic Science 1

Front 1

a protein encoded by the SOST gene in

osteocytes

inhibits osteoblastic bone formation by blocking the WNT pathway

Back 1

sclerostin

Front 2

binds and inhibits RANKL to decrease bone

resorption

Back 2

osteoprotegerin

Front 3

most abundant non collagen bone protein.

secreted by osteoblasts

fx: increases bone formation

Back 3

osteocalcin

Front 4

Family of at least 19 secretedproteins that are key regulators of earlyskeletal development .

Bind frizzled G protein coupled receptors and LRP6

Back 4

WNT

Front 5

Cleidocranial dysplasia, what is the absent transcription factor?

Back 5

RUNX2/CBFA

Front 6

increases bone resorption

secreted by osteoblasts

binds RANK on osteoclast

Back 6

RANKL

Front 7

Transcription factor involved in mesenchymal stem cell differentiation into adipocytes

Back 7

PPARy2

Front 8

area on the limb bud that directs longitudinal growth of the limb.

Back 8

Apical ectodermal ridge

Front 9

directs radio-ulnar growth on the limb bud

Back 9

Zone of polarizing activity

Front 10

secreted by ZPA

Back 10

Sonic hedgehog

Front 11

A tumor may secrete this substance which

activates osteoblasts to produce RANKL, thus

increasing bone destruction via osteoclast

induced bone resorption

Back 11

PTHrP

Front 12

secreted by the parafollicular cells of the thyroid gland to reduce bone resorption

directly binds osteoclast to decrease activity

Back 12

Calcitonin

Front 13

cytokine which influences hematopoietic stem cells to differentiate into macrophages,

osteoclasts, or other related cell types

Back 13

M-CSF

Front 14

the substance on the surface of osteoclasts that let them attach to bones

Back 14

Integrin

Front 15

This is on the osteoclast, and it binds vitronectin (on the bone surface) at the RGD sequence

Back 15

AvB3

(AvB3 is an integrin)

Front 16

major proteolytic enzyme that digests organic matrix at ruffled border

Back 16

Cathepsin K

Front 17

secreted by osteoclasts to lower the Ph (utilizing carbonic anhydrase) and increases the solubility of hydroxyapatite crystals

Back 17

Tartrate resistant acid phosphatase

Front 18

monoclonal Ab toward RANKL

binds and inhibits RANKL, decreasing osteoclast activity

Back 18

Denosumab

Front 19

this factor attracts inflammatory cells via

chemotaxis in fx healing.

Back 19

PDGF (in fracture healing)

Front 20

bmp used for open tibial shaft fx treated with an IMN within 14 days of fracture

and single level ALIF from L2-S1 in degenerative disc disease

Back 20

rhBMP-2

Front 21

bmp used for tibial nonunion

Back 21

rhBMP-7

Front 22

glycoprotein that binds calcium

Back 22

osteonectin

Front 23

this BMP is not osteogenic

it increases chondrogenic markers

Back 23

BMP-3

Front 24

most abundant PG in tendons

binds to collagen

Back 24

decorin

Front 25

binds to hydroxyapatite

creates boundary lubrication

Back 25

lubricin

Front 26

3 transcription factors that are required for bone formation

Back 26

β-catenin, Runx2, and Osterix (Osx)

3 BONE BROs

Front 27

PPaRy

Back 27

Adipocytes

Adipocytes are SliPPaRy

Front 28

Sox9

Back 28

Cartilage

Cartilage sox

Front 29

What cell makes sclerostin?

Function of sclerostin?

Back 29

Osteocyte makes sclerostin

sclerostin inhibits osteoblasts=decreased bone formation

Front 30

2 important receptors on osteoblasts?

Back 30

VitD

PTH

Front 31

PTH utilizes what cellular signaling in the osteoblast? What is the benefit?

Back 31

adenylyl cyclase.

This allows for coupling of bone formation in the osteoblast and bone resorption in the osteoclast

(Osteoblast makes type one collagen and also makes RANKL which turns on osteoclasts)

Front 32

What happens when calcitonin binds to an osteoclast?

Back 32

Overall: inhibition of bone resorption.

this is through Protein kinase A

Front 33

What happens when RANKL binds to an osteoclast?

IL-6?

Back 33

Both induce increased bone resorption

Front 34

Integrins on the osteoclast bind ____on the bone.

Back 34

vitronectin

(Arg-gly-ASP or RGD sequence)

Front 35

disease with cathepsin K mutation

Back 35

pyKnodysostosis

Front 36

Wolff's law vs Heuter-Volkman law?

Back 36

Wolff's: Remodeling occurs in response to mechanical stress on the bone

HV: Compressive forces inhibit longitudinal growth of bone, tension stimulates it

Front 37

High blood calcium level= thyroid gland releases calcitonin. What happens in bone, kidneys, gut?

Back 37

Bone: Stimulates calcium deposition

Kidneys: Reduces Ca uptake

Gut: reduces Ca uptake in the gut

Front 38

Low blood calcium level= PT releases PTH. What happens in bone, kidneys, gut?

Back 38

Bone: PTH stimulates OB to make RANKL which increases osteoclast activity and bone resorption

Kidneys: increases Ca resorption in kidneys, PO4 is excreted more. Also, increased Vit D is produced

Gut: increases calcium uptake in gut (vit D)

Front 39

2 types of renal osteodystrophy from impaired renal function?

2 types of Renal osteodystrophy?

Back 39

1. Decreased production of Vit D (decreased Calcium absorption)

2. Decreased PO4 excretion

A. High turnover - high PTH

B. Low Turnover - Normal PTH

Front 40

Familial rickets

Back 40

MC form

PHEX gene

Normal calcium

Can't absorb phosphate (phosphate leaks out in urine)

Front 41

Hereditary Vit D dependent rickets

Back 41

AR inheritance type 1, vit d 1 alpha hydroxylase

can't convert inactive -> active Vit D

AD Type 2 defect in intracellular receptor

Total baldness

Front 42

XLD rickets?

Back 42

Vitamin D resistant rickets

aka X-linked hypophosphatemia

Front 43

function of decorin?

Back 43

regulates tendon diamter, forms cross links between fibrils in a tendon, which transfers loads

Front 44

Bone tendon attachment : 4 steps

Back 44

Tendon

fibrocartilage

Mineralized fibrocartilage (sharpey's)

Bone

Front 45

mnemonic for C spine level injury and wheelchair required or transfers allowed

Back 45

C4 Puff

C5 Hands (hand controls)

C6 Slides (manual with slide board)

C7 on my own (7 letters)

Front 46

Energy expenditure % above baseline with the following amputations:

a: unilateral BKA

b: Bilateral BKA

c: unilateral AKA

d: Bilateral AKA

Back 46

a 9% (if long BKA) 25% (if short BKA)

b 40%

c 50-65%

d 280%

Front 47

s1q3t3

Back 47

ekg changes in PE

s wave in lead 1

q wave in lead 3

t wave inversion lead 3

Front 48

5 levels of evidence

Back 48

Level I includes randomized clinical trials.

Level II includes prospective cohort studies.

Level III includes case control studies AND retrospective cohort studies.

Level IV includes case series.

Level V evidence includes expert opinion, case reports, and personal observation.