Which of the following bone structures is most concerned with hematopoiesis: Diaphysis, Bone marrow, Articular cartilage, or Epiphyseal disc?
Bone marrow, to be more precise red bone marrow, is the site of formation of cellular components of blood, i.e. Haematopoiesis.
Not all bone or their parts are hematopoietic. Irregular bones are all able to generate blood components, but shaft (diaphysis) of long bones are devoid of red marrow and hence not hematopoietic.
Epiphysis is the articular end of long bone, covered at the joint by articular cartilage. Epiphysis and diaphysis remain separated by a thin layer of epiphyseal cartilage in young, growing persons (replaced by epiphyseal line in adult). Such cartilages are not able to generate any blood component.