I came across this terminologies while reading;
" Why red blood cell has no nucleus? "
Here's the answer:
While in the bone marrow, the developing red blood cells are nuclear. They include in order of maturity, the prorubricyte, rubricyte and metarubricyte (being the most matured). Just before being released from the bone marrow, the metarubicyte discard their nuclei.Therefore rbc in most domestic animal (except birds) are anuclear, biconcave, discoid cells.
Hence, with no nucleus, the number oxygen's molecule that can bind to the haemoglobin can be increased up to 4 molecules for each red blood cells.
Erythrocyte maturation diagram
Sources: Veterinary Medical Terminologies 2nd edition, Saunders Elsevier
