Biomedical Engineering Reference
In-Depth Information
Fig. 6.3
Bone reabsorption process
The bone-lining cells are inactive elongated and thin osteoblasts. These cells
remain inactive in the bone surface once the bone formation, or the bone
remodelling, has finished. However the bone-lining cells can be reactivated in
response to mechanical and/or chemical stimulation [
5
].
The osteocytes are mature cells derived from the osteoblasts. These cells can
be found inside the mineralized bone matrix occupying small chambers, called
lacunas. It are connected to each other by long cytoplasmic extensions, through
thin canals called canaliculi, which are used in the exchange of nutrients, forming
a complete and vast network. The osteocytes, through the canaliculi, conserve the
connection with the outer osteoblasts and have as primary purpose the preservation
of the surrounding mineralized bone matrix vitality. The osteocytes, using the
connections with the outer cells, act as local sensors of the mechanical and
chemical state of the bone and, in case of necessity, initiate the bone reabsorption
process from the surface [
6
,
7
]. These cells are affected directly by the damage in
