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Bone Response to Damage (view source)
Revision as of 13:59, 28 September 2007
, 13:59, 28 September 2007no edit summary
***"Random weave" which is only a normal feature in the foetus
***"Random weave" which is only a normal feature in the foetus
***In adults it is a sign of a pathological condition (e.g. fracture, inflammation, neoplasia)
***In adults it is a sign of a pathological condition (e.g. fracture, inflammation, neoplasia)
**Lamellar bone:
**'''Lamellar bone''':
***Orderly layers which are much stronger than woven bone
***Orderly layers which are much stronger than woven bone
***Two main types:
***Two main types:
===Periosteum and blood supply===
===Periosteum and blood supply===
*Specialised sheath of connective tissue covering bone except at the articular surfaces
*Inner layer
**Merges with the outer layer of bone
**Contains osteoblasts and osteoprogenitor stem cells
*Damage to the periosteum invokes a hyperplastic reaction of the inner layer
*The blood supply to the mature bone enters via the periosteum
Bone development
===Bone development===
*Two main types of bone development:
**'''Endochondral ossification''' (cartilage model)
***Long bones mainly
***Vascularised
***Developed centres of ossification
****Primary (diaphyseal)
****Secondary (epiphyseal)
**'''Intramembranous ossification'''
***Flat bones mainly (e.g. skull)
***Mesenchymal cells differentiate into osteoblasts
***No cartilage precursor template
Physis
Physis