Kõhrplaatide

Kõhrplaatide, often translated as cartilage plates, are areas of hyaline cartilage found in growing long bones. These plates are crucial for longitudinal bone growth. They are located between the epiphysis, the expanded end of a long bone, and the diaphysis, the shaft of the bone. Within the kõhrplaatide, chondrocytes, or cartilage cells, actively divide and produce new cartilage matrix. This process, known as interstitial growth, causes the cartilage plate to lengthen.

As new cartilage is formed on the epiphyseal side of the kõhrplaatide, older cartilage on the diaphyseal side undergoes calcification and is eventually replaced by bone tissue through the process of endochondral ossification. This continuous process effectively pushes the epiphysis further away from the diaphysis, resulting in an increase in the overall length of the bone.

The growth of kõhrplaatide is regulated by hormones, particularly growth hormone and sex hormones. These plates are present throughout childhood and adolescence. Once puberty is complete and skeletal maturity is reached, the kõhrplaatide ossify, meaning the cartilage is completely replaced by bone. This fusion of the epiphysis and diaphysis marks the cessation of longitudinal bone growth. Injuries to kõhrplaatide, especially during the growth years, can lead to premature closure of the plate and result in stunted bone growth, a condition known as a growth plate fracture.