What is the definition of epiphyses in long bones?

The definition of epiphyses in long bones refers specifically to the end parts of the bones that initially grow separately from the shaft. Epiphyses play a crucial role in the growth and development of long bones, especially during childhood and adolescence. They are made up of spongy bone that is surrounded by a thin layer of compact bone and are involved in joint formation. The existence of a growth plate, or epiphyseal plate, at the junction between the epiphysis and the diaphysis (the shaft) allows for the longitudinal growth of the bone.

In contrast, the protective covering on the outer surface of the bone is known as the periosteum, which does not define the epiphysis. The hollow shaft of a long bone refers to the diaphysis, which contains the medullary cavity housing bone marrow. The portion containing yellow bone marrow corresponds primarily to the medullary cavity found in the diaphysis, again unrelated to the definition of epiphyses. Understanding this foundational aspect of bone structure is essential for comprehending how growth and development occur and how these areas contribute to the overall function of the skeletal system.