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

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