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The immune system

The human body is usually in a constant war due to the interaction with multiple agents. Specifically, the battle is waged between antigens and antibodies, which are microscopic elements that, on the one hand, try to protect the organism, while on the other, they try to spread diseases.

In other words, the organism battles against external threats in order to protect itself. The main responsible for acting as a barrier or protective shield is what is known as the immune system.

This is composed of a set of cells and organs that function as a unit against the threat. Consequently, the immune system is responsible for preventing pathogenic microorganisms from being installed and adversely affecting the organism, through diseases.

It should be noted that the immune system develops progressively, depending on the different stages of human growth. Once it reaches maturity, the immune system is able to expand its range of scope.

Faculties of the immune system

The immune system
  1. Recognition of microbes of diverse origin (since they make a first contact with the organism) which leads to the production of specific cells to act against them.
  2. Distinction between those molecules that are external to the body and their own. Thanks to this, the immune system manages to prevent the molecules from attacking themselves.
    • This aspect varies in those people who suffer from autoimmune diseases, whose immune system is not able to identify when they are particles of their own or external to the body.

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How is the functioning of the immune system?

With regard to the functioning of the immune system, it is characterized by acting harmoniously. In this way, the cells, molecules, tissues and organs that compose it, do not interfere with each other when facing a threat.

Immunocompetent organs

All these organs are the precursors of immune two types of lymphocytes; whose cellularity (or proportion) is essential for the functioning of the immune system in any pathological situation that the body faces.

Subdivision of lymphocytes

The immune system
  • T lymphocytes.
  • B lymphocytes

T lymphocytes mature in the thymus and are responsible for producing effector molecules against antigens throughout the body. These molecules must always act together with other cells of similar function, such as cytotoxic lymphocytes and killer cells , also known as NT cells (natural killer).

On the other hand, B lymphocytes are essential for the immune system (in a mature and virgin state), since they are the ones that will face each of the antigens for the first time, consequently releasing the protective antibodies.

The immune response is divided into two large groups

  • Innate immunity.
  • Acquired immunity.

Innate immunity

The immune system

This acts immediately against microorganisms and does not depend on the type of antigen that is present .

It represents the first phase of defense against invading pathogenic particles and establishes a number of elements that serve as a physical, chemical and biological barrier, these being the skin and mucous membranes, together with all their cellularity.

These elements are those that prevent pathogens from establishing themselves from the moment they are presented to the antibodies. This is due to the cell lines they contain, they detect foreign agents according to their antimicrobial activity, initially.

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Acquired immunity

The immune system

It refers to that response that unlike innate, it does depend on the type of antigen that is present and is characterized by having immunological This refers to the fact that after the first contact with an antigen, the second time the antibody is present, it can recognize it and attack it in a specific way.

The mechanism of function of acquired immunity is totally specific , given that each pathogen induces an individual response after being exposed to the cells of the immune system.

The speed and efficiency with which the acquired This allows to certify how optimal is the immunological memory of each organism and how to respond permanently to it.

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Both types of immunity work interdependently ; that is, they complement each other, which gives a dynamic of collaboration. Then, through the immune cells present in organs, mucous membranes and lymphoid tissues, the two types of

This is the way in which the immune system functions properly, whose objective is to protect the body in the presence of any infectious agent. Whether they are viruses, bacteria, fungi or parasites.


Leticia Cedillo Barrón, Moisés López González and Benito Gutiérrez Castañeda. Science Magazine 2015. Mexico

The immune system