Ossifikaatiovyöhyke
Ossifikaatiovyöhyke refers to the physis, also known as the growth plate or epiphyseal plate, in long bones. This is a cartilaginous layer found within the bone where longitudinal growth occurs. During childhood and adolescence, chondrocytes within the ossification zone proliferate and mature, eventually undergoing ossification to form new bone tissue. This process is responsible for increasing the length of the bone. The ossification zone is located between the proliferative zone and the calcified cartilage zone. It is characterized by the hypertrophy of chondrocytes and the deposition of calcium salts, which are then invaded by blood vessels and osteoblasts from the metaphysis to lay down new bone. Once skeletal maturity is reached, the cartilage in the physis is completely replaced by bone, and the growth plate closes, ceasing further longitudinal growth. Injuries to the ossification zone, such as fractures involving the growth plate, can lead to growth disturbances and deformities.