What is a Leukocyte?

Leukocyte is actually the official medical term for the white blood cells. "Leukos" means white and "cytos" means cell. The leukocytes, or white blood cells are "in charge' of both the short-term and the long-term protection and defense in the human body. The leukocyte is one of the three components of the blood.

When a person's body is faced with an invasion of a bacteria or virus, the polymorphonuclear leukocyte comes to the rescue. This white blood cell (WBC) has an irregular lobe-like appearance in the very nucleus of the cell. The most common form of the polymorphonuclear is called the neutrophil. These cells will appear and be elevated when there is an acute inflammation or infection occurring in the body. This is also the cell that is the most predominant cell found in pus.

There is another form of leukocyte that is not quite as common as the polymorphonuclear cell, as it shows up in areas of the body when certain types of allergic reactions occur. This is called the eosinophile. If a doctor were to take a sample of mucus from someone who was having a "hay fever" like reaction, this type of white blood cell would be present in abundance.

The lymph nodes of the body also produce a type of leukocyte called the lymphocyte. This white blood cell gets involved when there are more chronic types of infections and inflammations. Often this type of leukocyte will appear in an area or region after the polymorphonuclear cells have already been trying to defend against the attack of the bacteria or virus causing an infection.

Since doctors and medical specialists are able to not only identify the leukocytes, or white blood cells, in a persons body, but are also able to differentiate between the various types of leukocytes - taking blood and body fluid samples and testing for elevated levels of these cells is a reliable way to help to identify and diagnose various illnesses and infections. Leukocytes can also appear and be tested in urine and mucus samples, and when they appear, doctors will want to do further investigation to identify where the infection or inflammation may be located within the body. Some infections, such as a urine or bladder infection, may not present any symptoms in some cases and testing for the presence of leukocytes can help doctors provide treatment before the condition worsens.