White blood cells or leukocytes: what they are and functions

The white blood cells (known as this is the color they present to the microscope, not containing pigments) or leukocytes consist of a set of blood cells, which stand out as the cellular effectors of the immune response of our body.

That is to say, they intervene and participate very actively in the defense of the organism against infectious agents (antigens) or foreign substances. And they make up, therefore, about 1% of the total blood volume in the body of a healthy adult person.

It is, as we shall see, a fundamental element in the basic blood analysis that we perform routinely every so often, mainly because the number of leukocytes in the blood can be a sign or indicator of disease or pathology.

In this way, when we are faced with a high number of leukocytes in the blood, it is a medical condition known by the name ofleukocytosis, while its decrease below the lower limit, is medically known under the name ofleukopenia.

What are white blood cells or leukocytes?

The white blood cells, also known medically with the name of leukocytes, consist of a type of blood cell that we find fundamentally both in the bloodstream and in the different lymphatic tissues, and that are produced both in the bone marrow and in the lymphatic tissue.

They are produced from the hematopoietic stem cells, which consist of multipotential cells that we find in the bone marrow, known in turn with the name of hemocytoblast (precursor cell ultimately of the different blood cells).

They are part of the immune system of our body, and as we will know in the next section, among other important functions are responsible for fight infections and diseases. That is, they are executors of the immune response of our own body.

Main functions of white blood cells or leukocytes

We could say that white blood cells are essential blood cells for our health, especially for our immune system.

In fact, precisely circulate through the blood to fight infections or foreign bodies, although being a fundamental part of the immune defenses of our body, sometimes can also attack the normal tissues of the body.

The origin of the different forms of leukocytes is produced from stem cells of the bone marrow, although they also originate in the lymphatic tissue.

Characteristics of white blood cells or leukocytes

They are characterized by being mobile cells, which are found in the blood, and form the cellular fraction of the different figurative elements of the blood.

Although not only circulate through blood vessels, since through a mechanism called diapedesis can move outside and have contact with the tissues of the interior of the body.

As for their life time, it varies from a few hours, to months and even up to reaching years.

Classification of white blood cells or leukocytes

Leukocytes with nuclei without lobules (mononuclear)

  • Lymphocytes: are the leukocytes of smaller size. React to foreign materials; To put it in some way, we can consider them as high hierarchy in the immune system, being the ones in charge of specific or acquired immunity.
  • Monocytes: type of white agranulocyte globules, is the largest. They are generated in the bone marrow and, through the blood, migrate to different organs and tissues such as the lungs, liver, spleen, bones or lymph nodes. Its function is to eat different microorganisms or cellular debris.

Leukocytes with lobed nuclei (polymorphonuclear)

  • Neutrophils: granulocyte type, is the most abundant of the blood of the human being. It has a short period of life (of hours or few days), and its main function is that of fungal and bacterial phagocytosis (that is, they surround them with their cytoplasmic membrane and introduce them to the cellular interior).
  • Basophils: it is the least abundant in the blood. They are responsible for the beginning of the allergic response, through the release of histamine and serotonin in low concentrations, having an active participation in the immune response.
  • Eosinophilic: derived from the bone marrow, before migrating to the tissues they have a half-life in the blood of 3 to 4 days. They are responsible for the pathogenesis of allergic diseases and the death of parasites.

As we can see, depending on the type of leukocyte or white blood cell in front of which we find ourselves, it will have a series of main functions.Therefore, it is appropriate to know what they are and how they are classified to discover what those basic functions are.

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