Bone remodeling, formation, and growth Flashcards
What two processes are in balance for bone remodeling
reabsoprtion by the osteoclasts and bone formation by the osteoblasts
What is bone remodeling and when does it occur
it start when skeletal growth has reached adult size and it is the renewable of bone
What hormone is crucial to maintaining the balance of bone remodeling
estrogen
How does estrogen effect bone remodeling
it signals the osteoblasts to release OPG
What does OPG do
binds to RANKL
Why does OPG bind to RANKL
so that there is less free floating RANKL to bind to RANK
What does RANKL bind to if it doesnt bind with OPG
RANK
What is RANK
a recceptor on osteoclasts that bind to RANKL
What happens when RANKL binds to RANK
it signals the osteoclasts to reaborb bone
So what happens if we get less estrogen
there is less OPG being produced by osteoblasts so therefore there are more free floating RANKL to bind to RANK on the osteoblast, causing more reasorption than formation of bone
What disease can form without a balanced bone remodeling
osteoporosis
and possibly rheumatoid arthritis
What are the hormone that control the hormonal control of bone formation
PTH
calcitonin
Vit D
What does PTH cause the release of
calcium from the bone
How does PTH cause calcium preservation in the kidneys
it increases reabsorption of calcium and reduces reabsroptiion of phosphate
What does calcitonin do
lowers serum calcium levels by inhibiting osteoclasts, reducing reabsorption in the kidney
