Osteocyte

Osteocyte
Transverse section of a bone
Illustration showing a single osteocyte
Details
LocationBone
Identifiers
Latinosteocytus
MeSHD010011
THH2.00.03.7.00003
FMA66779
Anatomical terms of microanatomy

An osteocyte, an oblate shaped type of bone cell with dendritic processes, is the most commonly found cell in mature bone. It can live as long as the organism itself.[1] The adult human body has about 42 billion of them.[2] Osteocytes do not divide and have an average half life of 25 years. They are derived from osteoprogenitor cells, some of which differentiate into active osteoblasts (which may further differentiate to osteocytes).[1] Osteoblasts/osteocytes develop in mesenchyme.

In mature bones, osteocytes and their processes reside inside spaces called lacunae (Latin for a pit) and canaliculi, respectively.[1] Osteocytes are simply osteoblasts trapped in the matrix that they secrete. They are networked to each other via long cytoplasmic extensions that occupy tiny canals called canaliculi, which are used for exchange of nutrients and waste through gap junctions.

Although osteocytes have reduced synthetic activity and (like osteoblasts) are not capable of mitotic division, they are actively involved in the routine turnover of bony matrix, through various mechanosensory mechanisms. They destroy bone through a rapid, transient (relative to osteoclasts) mechanism called osteocytic osteolysis. Hydroxyapatite, calcium carbonate and calcium phosphate is deposited around the cell.

  1. ^ a b c Tate, M. L.; Adamson, J. R.; Tami, A. E.; Bauer, T. W. (2004). "Cells in Focus, The osteocyte". International Journal of Biochemistry & Cell Biology. 36 (1): 1–8. doi:10.1016/S1357-2725(03)00241-3. PMID 14592527.
  2. ^ Buenzli, Pascal R.; Sims, Natalie A. (2015-06-01). "Quantifying the osteocyte network in the human skeleton". Bone. 75: 144–150. doi:10.1016/j.bone.2015.02.016. ISSN 1873-2763. PMID 25708054.