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A nucleated red blood cell (NRBC), also known by several other names, is a red blood cell that contains a cell nucleus. Almost all vertebrate organisms have hemoglobin -containing cells in their blood, and with the exception of mammals , all of these red blood cells are nucleated. [ 1 ]
Red blood cells (RBCs), referred to as erythrocytes (from Ancient Greek erythros ' red ' and kytos ' hollow vessel ', with -cyte translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, [1] erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O 2) to the body tissues ...
Overall, there are four main types of akaryocytes discovered: Erythrocytes, commonly known as red blood cells, are concave-shaped cells responsible for gas exchange, and the transfer of nutrients throughout an organism. Red blood cells are classified as akaryocytes because they lack a cell nucleus after they have fully developed.
Red blood cells are the most abundant cell in the blood, accounting for about 40–45% of its volume. Red blood cells are circular, biconcave, disk-shaped and deformable to allow them to squeeze through narrow capillaries. They do not have a nucleus. Red blood cells are much smaller than most other human cells.
In the process of erythropoiesis (red blood cell formation), reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells. Like mature red blood cells, in mammals, reticulocytes do not have a cell nucleus.
[1] [2] They also occur on platelets, but not on red blood cells. Their function is to display peptide fragments of proteins from within the cell to cytotoxic T cells; this will trigger an immediate response from the immune system against a particular non-self antigen displayed with the help of an MHC class I protein.
The nucleus was the first organelle to be discovered. What is most likely the oldest preserved drawing dates back to the early microscopist Antonie van Leeuwenhoek (1632–1723). He observed a "lumen", the nucleus, in the red blood cells of salmon. [97] Unlike mammalian red blood cells, those of other vertebrates still contain nuclei. [98]
an orthochromatic or late normoblast. At this stage the nucleus is expelled before the cell becomes; a reticulocyte. (These cells still contain RNA and are also called "immature red blood cells") The cell is released from the bone marrow after Stage 7, and so in newly circulating red blood cells there are about 1% reticulocytes.