Immunity: on guard of health
If a person often suffers from coldsdiseases or feels a general weakness and lethargy, the familiar immediately make a verdict - weakened immunity, you need to drink vitamins, herbs or something else. Of course, in the bulk, these are people who have no idea of the immune status of the organism and the entire complex system operating inside the person. But the wrong and unreasonable interference in the work of the immune system is unacceptable. In this case, often there are diseases of the immune system, its hyperactivity (for example, autoimmune diseases) or vice versa immunodeficiencies.
The concept of immunity
In the general sense of the word, immunity is a special systemthe biological mechanisms by which the body recognizes and destroys foreign cells. The work of this system is aimed at providing three main functions:
• Protection. That is resistance to infections.
• Homeostasis. Removal of cells of the body that have worn out and ceased to perform their functions.
• Control. Ability to recognize and destroy mutant and tumor cells.
Forms of immunity:
1. Congenital and acquired (acquired during life).
2. Natural (occurs after a meeting with the causative agent of the infection) and artificial (the result of immunization, ie vaccinations).
3. Active (produced by the body) and passive (obtained from the outside)
4. Non-sterile (the causative agent of infection is present in the body) and sterile (the pathogen is absent)
5. Cellular (nonspecific immunity, represented by the compliment system, adhesion molecules, etc.) and humoral (represented by antibodies).
6. Antibacterial, antiviral, antitoxic, etc.
Features of immunity in newborn children
Children's immunity is characterized by immaturityimmune response and its naivety. The first means that the immune system responds poorly or does not respond at all to the invasion of the infection. Second, that the organism of a young child had not previously experienced an infection. The newborn has exclusively congenital nonspecific immunity. This is why breastfeeding is so important. It's only with the mother's milk that a child receives antibodies - immunoglobulins, which provide him with sufficient immune protection. And if we strengthen immunity on our own, the newborn child can not do this.
Protective barriers to the body
In the human body, everything is arranged in such a way that, having overcome one barrier, the infection immediately encounters the next.
• Skin and mucous membranes. In addition to the barrier function, the skin has bactericidal activity, the ability to kill bacteria. This is promoted by gastric juice, lysozyme in saliva, tear fluid, and also normal microflora (for example, bifidobacteria in the intestine). It prevents colonization of the organism by extraneous pathogenic microflora.
• Phagocytosis and compliment system. Special cells - phagocytes (monocytes, macrophages, basophils, etc.) absorb germs and genetically foreign material. However, some microbes (viruses) are capable not only of not dying, but also of multiplying inside phagocytes. For example, the influenza virus, the causative agent of gonorrhea, etc. However, even if phagocytosis has not been successful, the phagocytes trigger further immune responses. Compliments are special proteins, which are activated only when the infection enters the body. An active compliment triggers the process of inflammation and destruction of microbes.
• Inflammation and fever. Reactions aimed at worsening the conditions for the reproduction of microbes.
• The barrier from the lymph nodes. Here, microbes are retained and exposed to the previous and subsequent link.
• Interferons and killers. Special glycoproteins and lymphocytes, rapidly included in the immune response. Interferons actively act on viruses, T-killers and natural killers on tumor cells.
All of the above constitute a systemnonspecific immunity. If the infection or tumor can not be destroyed, specific immunity comes into play, that is, the system of immunoglobulins - antibodies. However, they need time to mature.
Author: Dmitry Plotnikov
