eritropoezi

Eritropoieza, also known as erythropoiesis, is the biological process through which new red blood cells (erythrocytes) are produced in the body. This process primarily occurs in the red bone marrow, which is found within certain bones such as the pelvis, vertebrae, and sternum. Erythropoiesis is essential for maintaining adequate oxygen transport throughout the body, as red blood cells contain hemoglobin, a protein responsible for oxygen binding.

The process begins with hematopoietic stem cells, which differentiate into erythroid progenitor cells under the influence of specific growth factors. The key hormone regulating erythropoiesis is erythropoietin (EPO), mainly produced by the kidneys in response to hypoxia (low oxygen levels). Erythropoietin stimulates the proliferation and differentiation of erythroid precursor cells, accelerating red blood cell formation.

During erythropoiesis, precursor cells undergo several maturation stages, including proerythroblasts, basophilic erythroblasts, polychromatic erythroblasts, and orthochromatic erythroblasts, before ejecting their nuclei to become reticulocytes. Reticulocytes enter the bloodstream and mature into fully functional erythrocytes within a day or two.

Regulation of erythropoiesis involves feedback mechanisms sensitive to oxygen levels and blood quality. Disorders related to erythropoiesis include anemia, characterized by a deficiency of red blood cells, and polycythemia, which involves excessive red blood cell production. Overall, erythropoiesis is vital for ensuring sufficient oxygen delivery and maintaining systemic homeostasis.