In details

White blood cells


The white blood cells or leukocytes It is the body's defense cells that destroy foreign agents, such as bacteria, viruses and toxic substances that attack our bodies and cause infections or other diseases.

Leukocyte is a compound word of Greek origin meaning “white cell”: leuco means "white" and quote, "Cell".

Leukocytes are the main agent of our body's defense system, also called immune system. In the blood, there are various types, of different shapes, sizes and core shapes. They are: neutrophils, monocytes, basophils, eusinophils, lymphocytes.

The leukocytes are larger than the red blood cells, however their amount in the blood is much smaller. When the body is attacked by viruses or bacteria, the number of leukocytes increases significantly. They act in defense of the organism in two ways:

  • Phagocytosis - In this process, the defense blood cells encompass, digest and destroy invading microorganisms. Phagocytosis is a word composed of Greek origin, formed by phage, meaning "eat, digest", and I quote "cell".
  • Antibody production - Antibodies, special proteins, counteract the action of toxic substances produced by invading beings or present in foods and various substances.

O pus What usually accumulates at the site of a wound is formed by the set of leukocytes, dead microorganisms, and also the fluid that comes out of the capillaries at the infected points, causing swelling.


Electron microscopy showing red blood cells (in red) and a white blood cell (in white).

The lifespan of leukocytes or white blood cells varies. In a period of intense action in defense of the organism, they last hours and even days.