What is the term for immature red blood cells?

The term for immature red blood cells is reticulocytes. These cells are the direct precursors to mature erythrocytes, or red blood cells, and they typically enter the bloodstream during and after the process of erythropoiesis, which occurs in the bone marrow. Reticulocytes contain remnants of ribosomal RNA, which gives them a mesh-like appearance when stained and viewed under a microscope, distinguishing them from fully mature erythrocytes.

This stage is crucial because the presence of reticulocytes in the bloodstream can indicate the level of red blood cell production in the bone marrow. Normally, reticulocytes make up about 1-2% of the total red blood cell count in healthy individuals, and higher levels can suggest increased production in response to anemia or blood loss. Therefore, understanding the role of reticulocytes is important in evaluating overall blood health and diagnosing various conditions.