center of ossification

1. The site where bone begins to form in a specific bone or part of bone as a result of the accumulation of osteoblasts in the connective tissue.
2. The site where bone begins to form in the shaft of a long bone or the body of an irregular bone; primary ossification center.
3. The site where bone formation continues after beginning in the long shaft or body of the bone, usually in an epiphysis; secondary ossification center.
4. The site of earliest destruction of cartilage prior to bone formation; ossific center.