Practice question

Hematopoiesis throughout adult life depends on rare hematopoietic stem cells located in bone marrow endosteal and perivascular niches near sinusoids. These CD34 positive, lineage negative, Sca1 positive cells self-renew and generate common myeloid and common lymphoid progenitors that sequentially produce erythrocytes, platelets, neutrophils, monocytes, B and T lymphocytes. Transplantation of single HSC can reconstitute entire blood system of lethally irradiated recipients, demonstrating multipotency. Totipotent cells form extraembryonic tissues, neural stem cells generate glia and neurons, mesenchymal cells generate bone and stroma, not hematopoietic lineages robustly.