hematopoézist

Hematopoiesis is the process by which all blood cells and platelets are formed. It is a continuous, complex process that occurs in the bone marrow of adult mammals. The origin of all blood cells is a multipotent stem cell, the hematopoietic stem cell (HSC). These HSCs are capable of self-renewal, meaning they can divide to produce more HSCs, ensuring a lifelong supply.

From HSCs, progenitor cells differentiate into various lineages. The myeloid lineage gives rise to red blood cells (erythrocytes), platelets (thrombocytes), and several types of white blood cells, including granulocytes (neutrophils, eosinophils, basophils) and monocytes. The lymphoid lineage produces lymphocytes, such as B cells, T cells, and natural killer (NK) cells. This differentiation is tightly regulated by a variety of growth factors and cytokines.

The production of red blood cells is called erythropoiesis, which is stimulated by the hormone erythropoietin. Thrombopoiesis produces platelets, regulated by thrombopoietin. Leukopoiesis encompasses the production of white blood cells, with different stimuli and regulators for each type. Disruptions in hematopoiesis can lead to various blood disorders, including anemia, leukemia, and other cytopenias.