The immune system is a defense mechanism of the human body and animals that, through coordinated physical, chemical and cellular reactions, keeps the interior of the organism free of foreign and potentially toxic and infectious agents, such as viruses, bacteria and other microorganisms.
All these foreign bodies are called antigens. And they are counteracted by the body through the secretion of cells and defensive substances, such as different types of antibodies (white blood cells): cells whose mission is to detect, recognize and engulf these unwanted bodies to allow their subsequent expulsion from the body.
Other common responses of the immune system include inflammation (to isolate the affected area), fever (to make the body less habitable by invading microorganisms), among other possible responses.
The immune system is made up of various cells and organs of the body, from the organs that produce white blood cells, such as the spleen, bone marrow and various glands, but also the mucous membranes and other parts of the body that allow the expulsion or prevent the entry of blood cells. external agents.
Types of immune system
Two forms of the immune system are recognized:
- Natural immune system. Called innate or nonspecific, it is about defense mechanisms of the chemistry of life and that come with us at birth. They are common to almost all living beings, even the simplest and single-celled ones, capable of defending themselves by means of enzymes and proteins from the presence of parasitic agents.
- Acquired immune system. Typical of vertebrates and higher living beings, part of the specificity necessary to have cells totally dedicated to the defense and cleaning of the organism, interconnected with the natural system itself. This defensive mechanism adapts over time and “learns” to recognize infectious agents, thus presenting an immune “memory.” The latter is what vaccines are worth.
What can damage the immune system?
Despite its efficiency and coordination, not all diseases can be controlled and eliminated by the immune system alone. In some cases the antibodies are unable to identify or isolate the harmful agent, or even sometimes they are a victim of it. In these cases it is essential to take medications.
The same goes for autoimmune diseases, in which the immune system itself becomes a problem by attacking healthy cells or tissues, mistakenly identifying them as invaders.
When an organism presents a immune response slow or ineffective, we speak of an immunosuppressed individual or suffering from immunodeficiency.
The causes of this immune failure can be several, namely:
- Immunosuppressive diseases. Some agents that cause immunosuppressive diseases such as AIDS, precisely attack the white blood cells of the body, with such virulence that they do not allow their replacement at a sufficient rate to keep the body protected. The appearance of other congenital diseases, such as chronic granulomatous disease, produce similar scenarios despite the fact that they cannot be transmitted.
- Malnutrition. Severe dietary deficits, especially the lack of proteins and specific nutrients such as iron, zinc, copper, selenium and vitamins A, C, E, B6 and B9 (folic acid) have a direct impact on the quality of the response immune. Thus, people in a state of malnutrition or with a considerable nutritional deficiency are much more exposed to diseases than those who are better nourished.
- Alcohol, smoking and drug use. Excessive consumption of alcohol, tobacco, and drugs has a negative impact on the immune system, weakening it and leaving the body open for infection.
- Obesity. Obesity, especially in morbid cases, carries many health weaknesses, one of which is a considerable slowdown of the immune system.
- Radiation. One of the main effects of contamination of the human body by high doses of ionizing radiation is immunosuppression, due to the damage that these particles produce in the bone marrow. It is a phenomenon reported in unprotected operators of hazardous material, or victims of nuclear accidents such as Chernobyl.
- Chemotherapies. Radical drug treatments to deal with cancer or other incurable diseases are often so aggressive, given the nature of the substances used, that they subject the immune system to an extremely debilitating shock. That is why these treatments are usually accompanied by diets and other cares that allow to counteract this effect a little.
- Certain medications. Some medications are capable of reducing or moderating the body’s immune response, and therefore are used to deal with autoimmune conditions. However, misused can lead to a dangerous decrease in the body’s immune response. The indiscriminate use of antibiotics can also have an immunosuppressive effect on the body.
- Immunosenescence. This is the name given to the decrease in the effectiveness of the immune system that comes with advanced ages, usually after 50 years of age, and that is the product of a natural decline in the immune system.
- Lack of physical exercise. It has been proven that a physically active life, that is, with exercise routines, strengthens the immune system and optimizes its response. Sedentary life, on the other hand, tends to decrease and weaken the body’s immune response.
- Depression. A link between a person’s emotional state and their immune system has been proven, so that a depressed individual will present a much slower response than one with some zest for life.