Question

Describe the life cycle of an erythrocyte. Start with its creation in the marrow and finish off with the recycling of its components.

Answer 1

Production of erythrocyte is called as erythropoiesis

In bone marrow the production starts with stem cells

1) stem cells

2) Proerythroblast

3) Early erythroblast - ribosome synthesis takes place

4) Late erythroblast - hemoglobin accumulation occurs

5) Normoblast

6) reticulocyte - remains in bone marrow for 1-3 days and enter blood circulation , It doesn't have nucleus

7) Erythrocyte - final stage

RBC life span is about 120 days and then it becomes old erythrocyte and taken by macrophage of liver , spleen and bone

Cycling takes by degradation of RBC into haem and globin

1) globin is converted into amino acids and used

2) haem is converted in iron and bilirubin

Iron is used in erythropoises

Bilirubin is excreted as urobilinogen