Leukocytes also it would be wrong, as it still has a place to call balls, and even white. They are colorless, transparent lumps of irregular shape. An important feature of cells is their mobility. If you take a glass of blood smears and immediately examined under the microscope, you can see how leukocytes "creep" on the glass. Thus, they are like some kind of independent single-celled organisms within our body. However, leukocytes, as shown by research students I. P. Pavlova are managed in its work by the nervous system with the help of a whole number of humoral factors.
Blood in the blood is much smaller than a red blood cells. 1 mm3 contains 5-7 thousand of cells, i.e., the white "a " ball falls on 700-800 red. However, the value of leukocytes is also very large.
The discovery of the role of leukocytes belongs to a great Russian scientist I. I. Metchnikov, who in 1882 found that leukocytes "devour" trapped in the body of microbes, as well as various dying pieces of tissue in the body. Mechnikov called them so phagocytes (from the Greek. phages - eater and kytos - reservoir, here is the cell). This is one of the most important defenses. Approaching the microbe, leukocyte like bows, envelops its protoplasm and digesting enzymes your body. If penetrated the body, for example through the damaged skin, germs very strong, leukocytes masses perish in the struggle with this infection. Millions of their dead bodies form we all know pus. Occurs abscess an abscess. Having penetrated microbes thick shaft and protecting the rest of the body from infection, i.e., of blood poisoning, sepsis, leukocytes fiercely fight infection and often beat her.
If the body has got an infectionthat threatens to cause blood poisoning, the number of leukocytes quickly grows to 10-15 and even 25 thousand to 1 mm3. This can be observed in angina, pneumonia, suppurations RAS, etc., In such cases appears in the blood are not yet fully Mature white cells - the body throws to fight all the reserves. So, watching the blood picture, it is possible for a number of signs to see the progress of the body's fight against germs. Sometimes the blood analysis allows to reveal only just beginning or sluggish current disease, about which the patient did not know. Not casually modern medicine gives the analysis of blood of great importance. If the person is called "the mirror of the soul", that blood can be called "a mirror of health." By the way, today is a huge information to give not only the study of cells, but also subtle biochemical studies of plasma. Methods have been developed, allowing one drop of blood to explore many dozens of its ingredients.
When the body reason is deprived of cells, it dies quickly. So, were cases when people who consumed the grain that stood for the winter under the snow, ill severe angina, finally sunk into a deadly sepsis. It turned out that wintered grain contains poisons that destroy the cells. The body is deprived of his defenders, and the first infection, even not very strong, is fatal. One of the youngest diseases that appeared on a large scale after the tragedy of Hiroshima and Nagasaki, was named radiation sickness. The most vulnerable target for exposure was also leukocytes. Therefore, during the development of radiation illness, the body loses its ability to successfully fight with microbes.
Platelets - the third type of blood cell is even smaller than a red blood cells. 1 mm3 their blood contains about 300 thousand. The main feature of blood platelets is easy destructible, which plays a crucial role in the process of blood clotting. Why their destruction helping the blood clotting?