Cell types All blood cells are divided into three lineages. Red blood cells, which are also called erythrocytes, are the oxygen-carrying cells. Erythrocytes are functional, and are released into the blood. The number of reticulocytes, which are immature red blood cells, gives an estimate of the rate of erythropoiesis. Lymphocytes are the cornerstone of the adaptive immune system. They are derived from common lymphoid progenitors. The lymphoid lineage is composed of T-cells, B-cells, and natural killer cells. This is lymphopoiesis. Cells of the myeloid lineage, which include granulocytes, megakaryocytes, monocytes, and macrophages, are derived from common myeloid progenitors, and are involved in such diverse roles as innate immunity and blood clotting. This is myelopoiesis.
Cell types All. blood cells are divided into three lineages. Red blood cells, which are also called erythrocytes, are the oxygen-carrying cells Erythrocytes are functional, and are released into the blood. The number of reticulocytes, which are immature red blood cells, gives an estimate of the rate of erythropoiesis. Lymphocytes are the cornerstone of the adaptive immune system. They are derived from common lymphoid progenitors. The lymphoid lineage is composed of T-cells, B-cells, and natural killer cells. This is lymphopoiesis. Cells of the myeloid lineage, which include granulocytes, megakaryocytes, monocytes, and macrophages, are derived from common myeloid progenitors, and are involved in such diverse roles as innate immunity and blood clotting. This is myelopoiesis.