Haematopoiesis(fromGreek, "blood" and "to make"; alsohematopoiesisin American English; sometimes alsohaemopoiesisorhemopoiesis) is the formation ofbloodcellular components. All cellular blood components are derived fromhaematopoietic stem cells. In a healthy adult person, approximately 10111012new blood cells are produced daily in order to maintain steady state levels in the peripheral circulation.[1][2]Contents[hide] 1Haematopoietic stem cells (HSCs) 2Locations 2.1Extramedullary 2.2Other vertebrates 3Maturation 3.1Determination 3.2Growth factors 3.3Transcription factors 3.4Myeloid-based model 4See also 5References 6Further reading 7External links