# Hematopoiesis --- **Hematopoiesis**, (or sometimes **hemopoiesis**, **hematogensis**, or **hemogenesis**) is the how all the different types of [[blood|blood cells]] are formed. "Hemo-" for "blood" and "-poiesis" for "plyable" or "making". **Hematopoietic stem cells**, also called **hemocytoblasts** are [[stem cell|stem cells]] found in red [[bone marrow]] that have the potential to differentiate into any of the blood cells. Once the blood cells reach their final form, they leave the marrow and travel to the [[circulatory system]] where they get to work, or (in the case of some WBCs) head to another place where they can mature. Hemocytoblasts can recieve one of two different signals that make it differentiate into a common *myeloid* progenitor or a common *lymphoid* progenitor, themselves both more specific stem cells. ![[hematopoiesis .png]] The **common myeloid progenitor** can make both [[red blood cells]], megakaryocytes (which produce [[platelets]]) and the cells of the [[innate immune system]] such basophils, neutrophils, eosinophils and macrophages. The **common lymphoid progenitor** makes cells that we associate with the [[adaptive immune system]] such as NKCs, T-cells and B-cells. ___