Dougherty Part 1

Question 1

RANK receptor is found on what and what does it allow for

Answer 1

osteoclast precursor

allow for osteoclast generation and survival

Question 2

RANKL is found on what

Answer 2

osteoblast and marrow stroma cells

Question 3

M-CSF is secreted by what

Answer 3

osteoblast

Question 4

MCSF receptor is found on what and allows for what

Answer 4

osteoclast

allows for osteoclast generation and survival

Question 5

WNT is secreted from what

Answer 5

marrow stromal cells

Question 6

LRP5 and LRP6 are found on what and bind what and do what

Answer 6

osteoblast
bind WNT protein
activate beta-catenin
secrete osteoprotegrin (OPG)

Question 7

what does osteoprotegrin (OPG) do

Answer 7

blocks RANK

Question 8

from what and when is osteoprotegrin (OPG) secreted

Answer 8

from osteoblasts when WNT has bound LRP5 and LRP6

Question 9

the organic matrix of bone composition is mostly made up of what

Answer 9

Type 1 collagen

Question 10

what are the types of bone

Answer 10

woven bone (random collagen deposition)
lamellar bone (ordered collagen deposition)

Question 11

what are the types of lamellar bone

Answer 11

compact bone
spongy bone (calcinous)

Question 12

levels of what parallel osteoblast activity

Answer 12

osteopontin (osteocalcin)

unique to bone

Question 13

alkaline phosphatase is secreted from what

Answer 13

osteoblasts

Question 14

osteopontin activity is high in what

Answer 14

growing kids

Question 15

what type of bone resists forces in all directions

Answer 15

woven bone

Question 16

what bone has rapid growth and is found in healing fracture

Answer 16

woven bone

Question 17

woven bone in an adult is what

Answer 17

pathologic

Question 18

what is intramembranous ossification

Answer 18

bone formation direct form mesenchyme

appositional growth

Question 19

what is dysostosis

Answer 19

local problems in migration of mesenchyme and their condensation

Question 20

dysplasia is what

Answer 20

global defect in regulation of skeletal organogenesis

all bones are affected

Question 21

cleidocranial dysplasia has what pattern of inheritance and the defect

Answer 21

autosomal dominant

RUNX2 (CBFA1) transcription factor defect

Question 22

what is seen in cleidocranial dysplasia

Answer 22

short stature
abdominal clavicles
supernumerary teeth
Wormian bone

Question 23

Wormian bone is found in what

Answer 23

cleidocranial dysplasia

Question 24

achondroplaisa is a defect in what and has what inheritance pattern

Answer 24

FGFR3 point mutation- gain of function that inhibits cartilage growth
autosomal dominant
most common from paternal allele

Question 25

achondroplaisa is what type of defect

Answer 25

growth plate defect from paracrine cell defect

Question 26

what is seen in achondroplasia

Answer 26

``` short stature short proximal limbs normal trunk length enlarged head with building forehead depression root of nose normal longevity, intelligence, and reproductive status ```

Question 27

what is the defect in thanatophoric dwarfism is a defect in what

Answer 27

FGFR3 mutation- gain of function

Question 28

what is seen in thanantophoric dwarfism

Answer 28

``` cloverleaf skull micromelic short bowed limbs frontal bossing with macrocephaly small underdeveloped chest with bell-shaped abdomen diminished chondrocyte proliferation ```

Question 29

a gain of function in LRP5 is seen in what, with what inheritance pattern, and what happens

Answer 29

Osteopetrosis Type 1 autosomal dominant cannot up regulate osteoclasts

Question 30

Osteoporosis pseudoglioma syndrome is due to what

Answer 30

inactive LRP5

Question 31

what is seen in osteoporosis pseudoglioma syndrome

Answer 31

skeletal fragility | loss of vision

Question 32

what is "marble bone disease"

Answer 32

osteopetrosis

Question 33

osteopetrosis is due to what

Answer 33

reduced osteoclast bone resorption: cannot acidly pit (carbonic anhydrase II (CA2) deficiency defect in RANKL LRP5 gain of function

Question 34

erlenmeyer flask deformity (bulbous long bones) is seen in what

Answer 34

osteopetrosis

Question 35

what is seen in osteopetrosis

Answer 35

bone deposition replaces medullary cavity (extra medullary hematopoiesis) bulbous long bones (erlenmeyer flask deformity) narrow neural foramina brittle bones

Question 36

what is the spectrum of osteopetrosis

Answer 36

autosomal dominant benign to autosomal recessive "malignant"

Question 37

osteogenesis imperfecta aka brittle bone disease is due to what

Answer 37

Type 1 collagen | mutation of alpha1 or alpha 2 chains

Question 38

Osteogenesis Imperfecta Type I is what inheritance pattern and what is seen

Answer 38

autosomal dominant normal stature with less fractures after puberty blue sclerae from translucency of sclera hearing loss dentinogenesis imperfect from dentin defect

Question 39

osteoporosis is what

Answer 39

increased bone porosity and decreased mass

Question 40

what causes primary metabolic bone disease

Answer 40

senile postmenopausal idiopathic

Question 41

what in menopause leads to osteoporosis

Answer 41

increased expression of RANK, RANKL

Question 42

secondary metabolic bone disease is caused by what

Answer 42

``` drugs diabetes endocrine disorders malignancy liver GI disease ```

Question 43

what is the difference b.w osteopenia and osteoporosis

Answer 43

osteopenia- decrease bone mass | osteoporosis- osteopenia to the point of risk of fracture

Question 44

what is the low turnover variant of osteoporosis

Answer 44

senile osteoporosis

Question 45

what is the high turnover variant of osteoporosis

Answer 45

postmenopausal osteoporosis

Question 46

postmenopausal osteoporosis is caused by what

Answer 46

decreased estrogen leads to increased inflammatory cytokines this increases RANKL and decreases OPG osteoclast activity increases more than osteoblast

Question 47

how do you detect osteoporosis

Answer 47

Dual-energy absorptiometry

Question 48

in osteoporosis the cortex of the bone resembles what

Answer 48

cancellous bone