Question

What are the steps involved in Erythropoiesis?

Answer 1

Erythropoiesis ('erythro-red and poises’ formation) is the process by which red blood cells (erythrocytes) are produced. The formation of red blood cells takes place in the red bone marrow.

The following steps are involved in the Erythropoiesis:

1. Pronormoblast / proerythroblast – It is the earliest recognizable cell in the marrow
2. Basophilic (early) normoblast
3. Polychromatic (intermediate) normoblast
4. Orthochromatic (late) normoblast
5. Reticulocyte

Answer 2

Following are the steps involved in the erythropoiesis:

1. PROERYTHROBLAST
2. BASOPHILL ERYTHROBLAST
3. POLYCHROMATOPHIL ERYTHROBLAST
4. ORTHOCHROMATIC ERYTHROBLAST
5. RETICULOCYTE
6. ERYTHROCYTES

The first cell of the Red Blood Cell series is the PROERYTHROBLAST. Because of excessive stimulation, large amount of these cells are formed from the CFU-E (Colony Forming Unit-E) Stem cells.
After the formation of the PROERYTHROBLAST it divides multiple times, forming mature red blood cells. The first cell formed is called as BASOPHILIC ERYTHROBLAST. These, cells are called as Basophilic as they stain Basic dyes. The cell at this stage contains very little Hemoglobin. In next generations the cells get filled with Hemoglobin to about 34%, & the size of nucleus shrinks. Finally, the nucleus is absorbed & extruded from the cell. Even, the endoplasmic reticulum also gets absorbed. The cell of this stage is called as RETICULOCYTE. It is called reticulocyte because it still contains the Basophilic Material, consisting of remaining of Golgi apparatus, Mitochondria & few other Cytoplasmic Organelles. During the stage of Reticulocyte the cells passes from Bone Marrow to the Blood Capillaries. This action is called as the Diapedesis (passing through pores of capillary membrane).

Any remaining Basophilic Material in the Reticulocyte normally gets disappear within 1 to 2 days, and then the cell is said to be Matured Erythrocyte.