THE CELLS
Osteoprogenitors:
(Osteo =bone; pro= precursor; genitor= produce)
- They are indifferentiated cells
that will undergo mitosis and develop into osteoblasts.
They are found on the surfaces of bones and
bone cavities containing blood vessels and bone marrow.
Osteoblasts:
(Osteo =bone; blast= germ)
- They are derived fom osteoprogenitor cells.
Osteoblasts build bones: they are also found on the
surfaces of bones and
bone cavities containing blood vessels and bone marrow.
There, they secrete the matrix.
Osteocytes:
(Osteo =bone; cyte= cell)
- They make the majority of the bone cells
and are found embedded in the bone matrix. Osteocytes derive from osteoblasts:
osteoblasts are found on the surface of bones - as they secrete matrix, they surround
themselves with the material and become "walled up" in the matrix - then, they stop secreting matrix and
become osteocytes. Osteocytes do not secrete bone matrix: they only maintain the matrix
surrounding them in good condition.
Osteoclasts:
(Osteo =bone; clast= destroy)
- They are located on the surfaces of bones and
bone cavities containing blood vessels and bone marrow.
They destroy the matrix
(the destruction of bone matrix is called bone resorption).
This function of the osteoclasts is important in the development,
growth, maintenance and repair of bone. Osteoclasts are quite
different from the other types of bones cells. They have several nuclei and
are believed to be differentiated monocytes.
