Metaphysis is the region of a long bone located between the epiphysis and the diaphysis. It plays a crucial role in bone growth during childhood and adolescence, as it contains the growth plate, or epiphyseal plate, where new bone tissue is formed. This area is responsible for the lengthening of bones as a person grows. In adults, the metaphysis becomes less active as the growth plates close, leading to the cessation of bone lengthening. The metaphysis is also important for the distribution of blood vessels and nutrients to the bone, contributing to overall bone health and maintenance throughout life.