vörösvértesttermelés

Vörösvértesttermelés, also known as erythropoiesis, is the process by which red blood cells are produced. This vital biological function primarily occurs in the red bone marrow of adult mammals. The process is tightly regulated, with the hormone erythropoietin (EPO) playing a central role. EPO is mainly produced by the kidneys in response to low oxygen levels in the blood, a condition called hypoxia.

The development of a red blood cell is a complex, multi-stage process that begins with a hematopoietic stem cell. This stem cell differentiates into a myeloid progenitor cell, which then further develops through several intermediate stages, including the proerythroblast, basophilic erythroblast, polychromatophilic erythroblast, orthochromatophilic erythroblast, and finally, the reticulocyte. During these stages, the cell undergoes significant changes: it shrinks in size, extrudes its nucleus and most of its organelles, and accumulates hemoglobin, the protein responsible for oxygen transport.

Once the reticulocyte is released from the bone marrow into the bloodstream, it matures into a fully functional red blood cell within one to two days. The lifespan of a red blood cell is approximately 120 days. After this period, they are removed from circulation by macrophages, primarily in the spleen and liver, a process known as eryptosis. The components of the old red blood cells, particularly iron, are then recycled for new erythropoiesis, ensuring a continuous supply of oxygen-carrying cells.