Hematopoiesis refers to what process?

• A. Formation of plasma proteins
• B. Blood cell production from stem cells
• C. Destruction of old blood cells
• D. Oxygen transport in plasma

Answer: (B)

Hematopoiesis is the formation of blood cells from hematopoietic stem cells. This lifelong process occurs mainly in the bone marrow and gives rise to all blood cell types, including red blood cells, white blood cells, and platelets, through differentiation along the myeloid and lymphoid lineages. It is regulated by growth factors like erythropoietin, thrombopoietin, and colony-stimulating factors that guide how stem cells mature into specific blood cells. This differs from making plasma proteins, which occurs mainly in the liver and plasma cells; from destroying old blood cells, which is a clearance process; and from oxygen transport in plasma, which is carried by hemoglobin inside red blood cells rather than by plasma itself.