Epiphyysi

Epiphyse is a term used in anatomy and medicine that refers to the expanded ends of a long bone. These end portions are typically made of spongy bone and are covered by articular cartilage, which facilitates smooth movement at joints. Each long bone has two epiphyses: a proximal epiphysis, which is closer to the center of the body, and a distal epiphysis, which is farther away.

In growing individuals, the epiphysis is separated from the shaft of the bone (the diaphysis) by a layer of hyaline cartilage called the epiphyseal plate, also known as the growth plate. This is where longitudinal bone growth occurs as new bone is formed on the diaphyseal side of the plate. Once growth is complete, usually in late adolescence or early adulthood, the epiphyseal plate ossifies and fuses with the diaphysis, becoming the epiphyseal line.

Fractures that occur at the epiphyseal plate in children are known as epiphyseal fractures or Salter-Harris fractures. These are significant because they can disrupt bone growth, leading to limb length discrepancies or deformities. The term epiphyse is also used in the context of the pineal gland (epiphysis cerebri), a small endocrine gland in the brain that produces melatonin.