What is the term for the ends of long bones which contain red bone marrow?

• A. Epiphysis
• B. Diaphysis
• C. Metaphysis
• D. Periosteum

Answer: (A)

The ends of long bones are called epiphyses. This region houses red bone marrow, which is responsible for producing blood cells. In children, red marrow is abundant in the epiphyses; as we age, some red marrow in other parts of the bone may convert to yellow marrow, but the ends often still contain red marrow and continue to participate in hematopoiesis. The shaft of a long bone is the diaphysis, the area between the ends is the metaphysis (where growth occurs in developing bones), and the periosteum is the outer fibrous membrane covering the bone. So, the term for the ends that contain red bone marrow is epiphysis.