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Bone Response to Damage (view source)
Revision as of 08:06, 10 October 2007
, 08:06, 10 October 2007no edit summary
***Promoted by growth factors
***Promoted by growth factors
***Have receptors for PTH
***Have receptors for PTH
****They contract in response -> space for osteoclasts to attach
**'''Osteocytes'''
**'''Osteocytes'''
***Osteoblasts that have become surrounded by mineralised bone matrix
***Osteoblasts that have become surrounded by mineralised bone matrix
***Regulate composition of bone fluid
***Regulate composition of bone fluid
**'''Osteoclasts'''
**'''Osteoclasts'''
***Large, often multinucleated cells
***Histologically:
***Acidophilic cytoplasm
****Large, often multinucleated cells
****Acidophilic cytoplasm
***Derived from haematopoietic stem cells
***Derived from haematopoietic stem cells
***Responsible for bone resorption (have a brush border for this)
***Responsible for bone resorption
****Firstly dissolve mineral followed by collagen
****Use brush border for this
***Sit in bone surface depression - '''Howship's lacuna'''
***Sit in bone surface depression - '''Howship's lacuna'''
***Do <u>not</u> have receptors for PTH
***Have receptors for calcitonin
****Involute their brush border in response
****Detach from bone surface
*'''Matrix''':
*'''Matrix''':
**Osteoid
**Osteoid