ossification

1. The natural process of bone formation.
2. 1. The hardening or calcification of soft tissue into a bonelike material.
   2. A mass or deposit of such material.
3. 1. The process of becoming set in a rigidly conventional pattern, as of behavior, habits, or beliefs.
   2. Rigid, unimaginative convention.

The process of creating bone.

The transformation of fibrous tissue or cartilage into bone. In long bones, special cells (osteoblasts) carry out the process in three main stages: first, a framework of collagen fibres is laid down; then a cementing polysaccharide is produced; finally, calcium salts are deposited in the cement. A bone is unable to elongate any further after ossification is completed. Exercise and an adequate diet (especially with respect to calcium and vitamin D) are essential for proper ossification. Weight-bearing exercise can increase the width, density, and strength of bone, but not its final length. See also intramembranous ossification, Wolff's law.

Formation of or conversion into bone or a bony substance.

• biceps brachii o. — causes a progressive lameness of the shoulder joint of the horse. The calcification of the tendon can be identified radiologically.
• o. center — a locus in an epiphysis or other part of a bone at which ossification commences and from which it spreads over the entire section. Radiological examination can detect the appearance of each ossification center and this is of assistance in aging.
• dural o. — occurs in large and giant breed dogs. Detected radiographically, most commonly in the lumbar and cranial and caudal cervical areas, but rarely produces clinical signs. Called also ossifying pachymeningitis.
• ectopic o. — see ectopic mineralization.
• enchondral o. — ossification that occurs in and replaces cartilage.
• o. groove — located at the physeal end of the perichondrial ring of long bones. It supplies chondrocytes to the physis for the diametric growth of the bone. Called also groove of Ranvier.
• intramembranous o. — the formation of bone directly from fibrous tissue without the use of a cartilaginous model, e.g. as occurs in the parietal and frontal bones.
• lateral cartilage o. — see sidebone.
• retarded enchondral o. — the ossification of cartilage in growing large dogs may be retarded and, at the distal ulnar growth plate, resembles premature closure of the plate; the characteristic lesion is a cone of uncalcified cartilage in the growth plate.

Look up ossification in Wiktionary, the free dictionary.

Ossification is a medical term that is synonymous with bone tissue formation. Endochondral ossification and intramembranous ossification are two processes resulting in the formation of normal, healthy bone tissue.^[1] Heterotopic ossification is a process resulting in the formation of bone tissue, that is often atypical, at an extraskeletal location. Calcification is a medical term that is often confused with ossification. Calcification is synonymous with the formation of calcium-based salts and crystals within cells and tissue. Calcification is a process that occurs during ossification, but not vice versa.

Evolution

Several hypotheses have been proposed for how bone evolved as a structural element in vertebrates. One hypothesis is that bone developed from tissues that evolved to store minerals. Specifically, calcium-based minerals were stored in cartilage and bone was an exaptation development from this calcified cartilage.^[2] However, other possibilities include bony tissue evolving as an osmotic barrier, or as a protective structure.

See also

• Bone healing
• Calcification
• Dystrophic calcification
• Ossicone
• Mechanostat
• ossification in da ed ini

References

1. ^ Caetano-Lopes J, Canhão H, Fonseca JE (2007). "Osteoblasts and bone formation". Acta reumatológica portuguesa 32 (2): 103–10. PMID 17572649. 
2. ^ Donoghue PC, Sansom IJ (2002). "Origin and early evolution of vertebrate skeletonization". Microsc. Res. Tech. 59 (5): 352–72. doi:10.1002/jemt.10217. PMID 12430166. 

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v • d • e Musculoskeletal system · connective tissue: bone and cartilage (TA A02.0 · GA 2.86-95) Cartilage perichondrium · fibrocartilage callus · metaphysis cells (chondroblast · chondrocyte) types (hyaline · elastic · fibrous) Bone Ossification intramembranous · endochondral Cycle osteoblast · osteoid · osteocyte · osteoclast Types cancellous · cortical Regions subchondral bone · epiphysis · epiphyseal plate/metaphysis · diaphysis · Condyle · Epicondyle Structure osteon / Haversian system · Haversian canals · Volkmann's canals · connective tissue (endosteum · periosteum) · Sharpey's fibres · enthesis · lacunae · canaliculi · trabeculae · medullary cavity · bone marrow Shapes long · short · flat · irregular · sesamoid bone and cartilage navs: anat/physio/dev, noncongen/congen/neoplasia, symptoms+signs/eponymous signs, proc

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