Kasvulevyyn

Kasvulevyyn, often referred to as the epiphyseal plate in English, is a layer of hyaline cartilage found in the long bones of children and adolescents. It is located between the epiphysis (the end of the bone) and the diaphysis (the shaft of the bone). This cartilaginous region is responsible for the longitudinal growth of bones.

Within the kasvulevyyn, chondrocytes (cartilage cells) undergo mitosis, proliferating and forming new cartilage. This newly formed cartilage is then mineralized and replaced by bone tissue through the process of endochondral ossification. As long as the kasvulevyyn remains active, bones continue to lengthen.

The growth of the kasvulevyyn is regulated by hormones, primarily growth hormone and sex hormones. Estrogen and testosterone play a crucial role in the maturation and eventual closure of the growth plates. When puberty is complete and hormonal levels change, the cartilage in the kasvulevyyn is fully replaced by bone, and longitudinal bone growth ceases.

Injuries to the kasvulevyyn, known as growth plate fractures, can occur in children and adolescents. These injuries are significant because they can disrupt normal bone growth, potentially leading to limb length discrepancies or deformities. The treatment and prognosis of such fractures depend on the location and severity of the injury, as well as the child's age.