in microscopic world, countless vibrant erythrocytes, red blood cells, traverse circulatory system, tirelessly carrying

microcytes ironrich heme erythrocytes hematopoiesis hemoglobin oxygenation erythrocyte medical macrocytes hematologist iron cell anemia bloodstream rbcs normocytic oxygencarrying bloodrelated erythropoiesis blood hematocrit health capillaries morphology hematology red lifespan hypochromic ai generated