Hematopoiesis (blood cell formation)

Hematopoiesis (blood cell formation) begins in the bone marrow which produces red blood cells and white blood cells. Red blood cells take about 2-3 weeks to mature. In the process of their development, they lose their nucleus and eventually even ribosomes. They become massively filled with hemoglobin. They lack mitochondria and rely entirely on glycolysis for ATP production. Myeloblasts develop into various white blood cells. Lymphblasts develop into lymphocytes. Immature T cell lymphocytes are “trained“ to recognize invaders by the thymus. Find diagrams, notes, and practice questions at