What part of a long bone is primarily responsible for the production of new erythrocytes?

The primary function of red bone marrow is the production of new erythrocytes, or red blood cells. This specialized tissue is located in specific areas of certain bones, particularly in the axial skeleton and the ends of long bones, where it is actively involved in hematopoiesis, the process of blood cell formation. Red bone marrow contains hematopoietic stem cells, which can differentiate into various types of blood cells, including erythrocytes, leukocytes, and platelets.

Yellow bone marrow, in contrast, mainly serves as a storage site for fat and does not contribute to the production of blood cells. Cortical bone, or compact bone, provides strength and structure to the bone but is not involved in blood cell production. Spongy bone, while it contains some red bone marrow, is more related to the structure and support of the bone rather than the direct production of erythrocytes. Therefore, red bone marrow is the key site for erythrocyte formation in the body.