:check: Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification.
:check: This process includes the development of a cartilage model, its growth and development, development of the primary and secondary ossification centers, and the formation of articular cartilage and the epiphyseal plates
:check: Endochondral ossification begins with points in the cartilage called "primary ossification centers." They mostly appear during fetal development, though a few short bones begin their primary ossification after birth. They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones.
:check: Secondary ossification occurs after birth, and forms the epiphyses of long bones and the extremities of irregular and flat bones.
The diaphysis and both epiphyses of a long bone are separated by a growing zone of cartilage (the epiphyseal plate).
At skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure).
In the upper limbs, only the diaphyses of the long bones and scapula are ossified.
The epiphyses, carpal bones, coracoid process, medial border of the scapula, and acromion are still cartilaginous.