Which cell is not produced in the bone marrow?

Which cell is not produced in the bone marrow?

• A. Lymphocytes
• B. Erythrocytes
• C. Neutrophils
• D. Eosinophils

Answer: (A)

Hematopoiesis mainly happens in the bone marrow, but lymphocytes have a different maturation path. While their precursors originate there, the final, functional lymphocytes mature in lymphoid organs, especially T lymphocytes in the thymus (and B cells within lymphoid tissues, with maturation often described as occurring in primary lymphoid organs). Because of this, mature lymphocytes are not produced in the bone marrow in the same way as other blood cells like red cells or granulocytes. Erythrocytes, neutrophils, and eosinophils complete their maturation in the bone marrow and are released as mature cells, whereas lymphocytes finish their development outside it, which is why they are identified as not being produced there.

Hematopoiesis mainly happens in the bone marrow, but lymphocytes have a different maturation path. While their precursors originate there, the final, functional lymphocytes mature in lymphoid organs, especially T lymphocytes in the thymus (and B cells within lymphoid tissues, with maturation often described as occurring in primary lymphoid organs). Because of this, mature lymphocytes are not produced in the bone marrow in the same way as other blood cells like red cells or granulocytes. Erythrocytes, neutrophils, and eosinophils complete their maturation in the bone marrow and are released as mature cells, whereas lymphocytes finish their development outside it, which is why they are identified as not being produced there.