Bone Physiology

Question 1

Alkaline Phosphate

Answer 1

ALP
Marker of bone formation 
Activated by OSTEOBLASTS 
Made in Liver and bone 
elevated in Pagets, hyperpartathyroidism etc also measured in osteoporosis 
high in children

Question 2

Osteocalcin

Answer 2

Specific marker for bone formation, released by osteoblasts

high in children
low in osteomalacia and rickets

Question 3

Procollagen peptiedes (OINP

Answer 3

Marker of bone formation, correlate with increased bone density

Question 4

Urinary hydroxyproline

Answer 4

marker of bone resorption

from collagen degradation

Question 5

NTX or CTX

Answer 5

marker of bone resorption

Question 6

Primary osteoporosis

Answer 6

increased bone fragility conferring risk of fx

Found in older men and women, not secondary to any other cause

Question 7

Secondary osteoporosis

Answer 7

increased bone fragility conferring risk of fx

secondary to other causes of osteoporosis such as GC exs

Question 8

Tx for osteoporosis

Answer 8

antiresorbtives such bisphosphonates

anabolics such as intermittent PTH injections

Question 9

Osteomalacia

Answer 9

(Rickets=pediatric)
disorders in mineralization of the organic matrix
associated with decreased Vit D an low Pi
decreased bonde density, increased fx risk, and bowing of long bones

Question 10

Paget’s Disease

Answer 10

Excessive osteoblast activity and hyperactive bone remodeling

can be asymptomatic until X ray, elevated ALP

can cause bone pain, deformity, fx

enlarged bones can cause tingling due to pinched nerves

tx=bisphosphinates–>decrease bone resorption–>because things are coupled would decrease bone formation

(there is currently no drug that directly inhibits bone formation)

Question 11

Osteogenesis imperfecta

Answer 11

brittle bone diseases that occur due to mutations in collagen

lead to bone fx and deformity, wide range of severity, especially in wormian bones

Question 12

OI type I

Answer 12

AD disease with decreased collagen PRODUCTION

delayed fontanelle closure, bone fragility. short stature, blue scerae, joint laxity, hearing loss

improves into adolescence

osteopenia and fx common

Question 13

OI type II

Answer 13

EXTREME bone fragility

causes infantile death secondary to respiratory problems

Question 14

Osteopetrosis

Answer 14

marble bone disease due to decreases osteoclast activity–>disorganized bone structure

increased fx risk

Question 15

bisphosphonates

Answer 15

inhibits osteoclast activity, decreases bone resorption,

Question 16

Intermittent PTH

Answer 16

at low doeses acts to activate osteoblasts and is anabolic