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White blood cells (WBCs), also known as leukocytes, are a common topic of conversation when flu season starts. Since they are associated with the immune system, they are linked to fighting diseases and therefore essential for good health. White blood cells circulate in the blood stream so they are ready to attack infections in different areas of the body. When a particular area is being infected the white blood cells rush to this area and destroy the harmful substance.
White blood cells, which lack hemoglobin, are produced in the bone marrow and then stored in blood or lymphatic tissues, with about 7,000-25,000 white blood cells per cubic millimeter of blood.
There are five main types of white blood cells: neutrophils, eosinophils, basophils, monocytes, and lymphocytes; each serving a different purpose in our blood stream.
Neutrophils make up about fifty-eight percent of all white blood cells. These cells actually fight the infections in the body by ingestion (phagocytosis), however after ingesting the invader, neutrophils immediately die. They are the first responders to infections in and out of the body. They can attack invaders that they do not recognize specifically, but they know the invader is not supposed to be there.
Eosinophils kill parasites, but these cells, making up about two percent of all white blood cells, can produce allergic reactions. These cells, like neutrophils, can attack invaders it does not recognize specifically.
Basophils kill bacteria and even external parasites. They make up about one percent of white blood cells. Similarly to Eosinophils; Basophils can produce allergic reactions as well. They release histamine and heparin; both are blood used for blood thinning. Also like neutrophils and Eosinophils, Basophils can attack invaders they do not recognize specifically.
Monocytes destroy old and damaged cells in the body and can phagocytize cells leftover at the infection site. While they make up roughly four percent of white blood cells, they can change into different types of immune cells like macrophages and dendritic cells.
Lymphocytes, making up about four percent of white blood cells, direct the body’s immune system. They recognize and remember infections that enter the body. They can live for days, months, or years. Lymphocytes come in B-type and T-type. The B-type makes the circulating antibodies that are then secreted into bodily tissues. The T-type kills foreign cells and assists in killing invaders. These are the cell-mediated immunity cells. They also aid in the rejection of transplanted tissue and in fighting cancer.
Higher white blood cell count, called leukocytosis, is an indication of infection. Lower white blood cell count, called leukopenia, means the person is highly susceptible to illness. White blood cell count can be lower due to a weakened immunity, infections, or disorders in white blood cells. Extreme exercise, inflammation, injury or stress can cause white blood cells counts to spiral out of control.
While these cells are microscopic, without them in our body, we would be overridden with diseases and ultimately die. They each serve a specific purpose to defend our bodies against sicknesses.