They do have nucleus at an earlier life of their life cycle, and
they are called erythoblast in the bone marrow. Their nucleus were
extruded when they reach the blood vessels to allow more space for
carriage of nutrients, gases and toxic products.
Compared with other cells, these red blood cells are better known
as red blood corpuscle (particles) and they are more flexible, soft
and elastic making them have the ability to crawl, creep, navigate
and negotiate any smallest tunnel possible.
