Erythrocytes (or red blood cell) are one of the main components in the blood along with leukocytes, platelets and plasma. Every second, 2-3 million red blood cells are created. These are made from the haemopoetic pluripotent stem cells in the bone marrow.
Erythrocytes contain no nucleus or mitochondria, which gives the cell more space so that it can contain more haemoglobin. The more haemoglobin present in the cells, the more oxygen each red blood cell is able to transport, therefore erythrocytes are able to carry out their function more effectively.
The lack of nuclei or mitochondria gives mature red blood cells their biconcave disc shape, which gives the cell a higher surface area to volume ratio, aiding diffusion and increasing the cell's ability to absorb oxygen. More oxygen is, therefore, able to diffuse into the cell at any one time.
Red blood cells also have a role in determining blood types. There are four main blood groups: A, B, O and AB. These are caused by different antigens and different sugars attached to the surface of the erythrocyte.
A blood group contains N-acetyl-galactosamine whilst B blood group contains just galactosamine.
- ↑ Blood Groups and Red Cell Antigens, Dean.L., -http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=rbcantigen