Definition of Immune System (Immune)

The Immune system is the body's defense system, the word "Immune" comes from Latin and means "free from" so the system The immune system is in charge of keeping the body free of external or internal agents capable of producing alterations or diseases. On the other hand, Immune and Immunological share origin in Latin and Greek in terms of a form that is included together in a health framework that we address in this analysis.

For this system to work requires chemical signals on the membrane mobile of each and every one of the cells of the body there are substances of the type protein that are read by the cells of the immune system and act as a species personal brand, this allows you to recognize them as your own; all cell, microorganism, virus, battery, parasite or fungus that does not have this mark is recognized as foreign and becomes an antigen, because any antigen is foreign recognized as potentially dangerous so it is capable of initiating a series of events that constitute the immune response that aims to remove it.

Any external agent that enters the body constitutes an antigen, including donor organs, although they are not infectious agents. They are strange and the Immune System identifies them as foreign, producing the phenomenon known as transplant rejection, this also occurs With tumor cells, cancer causes cells to undergo changes that make them unrecognizable as their own by the System Immune.

In the so-called autoimmune diseases, such as rheumatoid arthritis, thyroiditis and lupus, among others, the Immune System for reasons that are not yet very clear recognizes some types of cells as foreign and initiates an immune response that leads to their destruction which produces their own manifestations diseases. Rheumatoid Factor, which is a laboratory test that is ordered to rule out the presence of arthritis, is an autoantibody.

The Immune System, unlike the other systems, is made up of a group of organs called lymphoid organs that include the lymph nodes and the lymphatic tissue located in the tonsils, adenoids and appendix, as well as by cells with the ability to move throughout the body, using for this the circulatory system.

The cells that make up the Immune System are of several types:

White blood cells: White Blood Cells or Leukocytes are cells found in the blood, they are of two main types: Neutrophils or Polymorphonuclear and the Lymphocytes. Lymphocytes are the most important cells of the Immune System and are of two types T lymphocytes Y B lymphocytes. T lymphocytes act by recognizing antigens, until the T lymphocyte gives the order it does not start any type of immune response, these lymphocytes are capable of recognizing up to 100 million antigens; B lymphocytes can also recognize antigens but they need the T lymphocyte to initiate the process, the B lymphocytes are the cells that produce antibodies or immunoglobulins that are the arsenal with which the immune system fights against antigens. Polymorphonuclear cells are vigilant cells, they are the first to activate when there is an infection and they are capable of attacking microorganismsUnlike Lymphocytes, Polymorphonuclear cells are nonspecific, they constitute the first line of defense while activating specific responses mediated by antibodies.

Monocytes: Monocytes are blood cells that, once activated, have the ability to leave the circulatory stream and pass to the tissues where they become In a cell called Macrophage, the term phage means to eat and this is precisely what this cell is capable of, once it comes into contact with a microorganism emits extensions or pseudopods that trap it by swallowing it, once inside the macrophage they are destroyed by the action of enzymes that digest them.

NK cellsThese cells get their name from their acronym in English: Natural Killers, which means natural killers. NK cells have specificity for infected cells or tumor cells, when they recognize them, they come into contact with them and trigger a reaction that begins their self-destruction process.

The immune response is a complex process that relates all these types of cells, for this it is necessary that there be an information system, once something strange or antigen Polymorphonuclear cells located in the bloodstream begin the neutralization process, which explains why white blood cells increase when there is a infection. Part of the antigens when they reach the lymph nodes through the circulation of a fluid called lymph, there they are capable of activating T Lymphocytes, which when recognize something strange they begin to replicate increasing their number which causes the ganglia near the place where the germs are to increase in size and inflame. Each T lymphocyte is specific for an antigen and replication gives rise to a series of clones that then pass into the blood where they release the Messenger substances that activate B lymphocytes, macrophages and NK cells to carry out the functions of each one of them. They, these chemical messengers are substances called cytokines that are of various types, they are also capable of activating some neurons thus putting the nervous system in knowledge of what is happening. Cytokines are capable of both activating and terminating the immune response, limiting the process.

When the functions of the immune system are not carried out correctly effective what is known as immunodeficiency occurs, which is a state pathological in which there is a greater predisposition to suffer infections, this can occur for several reasons, today the most frequent being infection by the human immunodeficiency virus or HIV, this is capable of affecting the lymphocytes that are the most important cells of this system since they are precisely the only ones capable of activating the immune response specific.