The process by which bone is formed, renewed, and repaired, starting in the embryo and continuing throughout life. There are 3 main situations in which ossification occurs: bone growth, during which new bone forms at the epiphyses (ends) of bones; bone renewal as part of normal regeneration; and bone repair following a fracture. In newborn babies, the diaphysis (shaft) has begun to ossify and is composed mainly of bone, while the epiphyses are made of cartilage that gradually hardens. In children, growth plates produce new cartilage to lengthen the bones, and further bone forms at secondary ossification centres in the epiphyses. By the age of 18, the shafts, growth plates, and epiphyses have all ossified and fused into continuous bone.
Ossification |
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