Eritropoesi

Eritropoesi is the process by which red blood cells, also known as erythrocytes, are produced. This vital physiological mechanism takes place primarily in the red bone marrow of adults. The process begins with a pluripotent stem cell, which differentiates into a myeloid progenitor. This progenitor then matures through several stages, including proerythroblast, basophilic erythroblast, polychromatophilic erythroblast, orthochromatophilic erythroblast, and reticulocyte, before finally becoming a mature erythrocyte.

The production of red blood cells is tightly regulated by a hormone called erythropoietin (EPO). EPO is produced mainly by the kidneys in response to low oxygen levels in the blood, a condition known as hypoxia. When oxygen levels fall, the kidneys release more EPO, which stimulates the bone marrow to increase red blood cell production. Conversely, when oxygen levels are normal or high, EPO production decreases. Other factors, such as iron, vitamin B12, and folic acid, are also essential for proper eritropoesi. Deficiencies in these nutrients can lead to anemia, a condition characterized by a reduced number of red blood cells or a decreased amount of hemoglobin. The lifespan of a red blood cell is approximately 120 days, after which they are removed from circulation, primarily by the spleen and liver.