27: Physiology Of Bone Flashcards
Function of organic components of bone
Contributes to flexibility and tensile strength of bone
Seven organic components of bone
- Collagen
- Osteonectin
- Osteocalcin
- proteoglycans
- sialoproteins
- osteopontin
- thrombospondin
major organic component of bone
collagen
osteonectin and osteocalcin: 2 functions
hydroxyapatite crystallization, Ca binding
what do sialoproteins, osteopontin, and thrombospondin do?
mediate osteoclast adhesion to bone surface
proteoglycan function
bind GFs
two main inorganic bone components
hydroxyapatite, mineral salts (Calcium phosphate, calcium carbonate, K, Mg)
osteocyte function
regulation of osteoblasts and osteoclasts by releasing paracrine factors
Major stimulator and inhibitor of osteoclast differentiation
Stimulator: RANKL
Inhibitor: OPG
TGF-B: two functions
- Osteoblast stimulation
2. Increased OPG production
BMP function
Potent osteoblast inducer
rhBMP-2
Clinical use for fracture healing and spinal fusion
RANKL function
Osteoclast activation
Osteoprotegerin (OPG)
Mock receptor for RANKL -> prevents osteoclast activation
FGFs (fibroblast GFs): two functions
- Osteoblast proliferation
2. Enhance callus formation during fracture repair