Page 200 - Atlas of Histology with Functional Correlations

In this process, all blood cells originate from a common stem cell in the red

bone marrow that is self-renewing. Because this stem cell type can produce all
blood cell types, it is called the pluripotential hematopoietic stem cell (Fig.
6.1). Pluripotential stem cells, in turn, produce two major cell lineages that form
the pluripotential myeloid stem cells and pluripotential lymphoid stem cells.
Before maturation and release into the bloodstream, the stem cells from each

lineage undergo numerous divisions and intermediate stages of differentiation
before full maturation. Hematopoiesis is regulated by numerous growth factors,
which activate and control blood cell formation. These growth factors influence

different cell lineages and induce proliferation, differentiation, maturation and
release the blood cells from the bone marrow into the blood. Erythropoietin, a
protein substance produced by kidney cells, stimulates the proliferation and
production of erythroid (RBC) progenitor cells. Thrombopoietin, also produced
by kidneys, stimulates megakaryocyte differentiation and platelet formation.

Granulocyte-stimulating factor and monocyte-stimulating factor stimulate
the formation of the cells of granulocyte and monocyte lineages. Different
interleukins are responsible for development and function of B and T

lymphocytes.

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