Blood Cells

Among other constituents, blood is made up of white and red blood cells. The white ones are called leucocytes. They attach themselves to the different tissues in the body where they play a defensive role by attacking and killing foreign microorganisms. The red blood cells, or erythrocytes, are the cells without a nucleus in the shape of a lentil that can be distorted. They can therefore easily circulate in all the small vessels. Their role is to transport oxygen. Men have approximately 5 million per square millimetre and women approximately 4.5 million. Our bodies are constantly making new ones (their lifetime is approximately 120 days) since they have no nucleus and cannot reproduce.