What happens and how immunity is formed in humans
Today the word “immunity” is heard. We all know that immunity must be enhanced, strengthened, strengthened. And when it weakens, we begin to hurt. And what is included in this concept? How, how, where is immunity formed?
Immunity – what is it?
The protection of our body from various pathogens: toxins, microbes, viruses – and this is immunity – is carried out by various organs. The main ones include bone marrow (red) and thymus (thymus gland), where lymphocytes are formed – the main cells of the immune system. B-lymphocytes are formed in the bone marrow, as well as precursors of T-lymphocytes, the latter differentiate (turn) into T-lymphocytes in the thymus.
Further, lymphocytes populate various organs – lymph nodes, tonsils, spleen. They also settle on the mucous membranes of the internal organs, forming lymphoid tissue. Lymphoid tissue is present in the intestines, genitourinary organs, bronchi, stomach, and esophagus.
Cellular and humoral immunity is distinguished.
Humoral is carried out by antibodies (they are also immunoglobulins) produced by B-lymphocytes. Antibodies act against pathogenic microbes alien to the body, mainly bacteria.
If immunity is weakened, it is difficult for a person to resist the disease
Cellular immunity uses T-lymphocytes (these are T-killers, T-helpers, etc.) and macrophages that act on viruses, cancer cells, foreign tissues.
In fact, the division is conditional. Cellular and humoral immunity acts together, complementing each other.
How does immunity
When a pathogenic microbe (antigen) enters our body, the immune system begins to fight it: a B-lymphocyte is activated, which is effective against this particular microbe. B-lymphocyte multiplies and produces cells of two types: plasmocytes that produce antibodies, and cells responsible for immunological memory. The latter retain information about a particular antigen, thereby creating acquired immunity.
Antibodies bind foreign agents, and they are affected by defense cells – T-killers, macrophages.
How is immunity formed. What types of immunity are
Immunity is congenital and acquired.
We all have an innate, genetically transmitted immunity to certain pathogens. This, for example, cattle plague – a person will never get this infection. We get this immunity from the mother in the womb along with blood, and then with mother’s milk.
We get acquired immunity at the first meeting with foreign agents.
How is immunity formed in a child?
When a baby first gets an infection or is vaccinated against it, protection is activated in his body, cells of the immune system are activated, they imprint a foreign antigen in his memory and produce certain antibodies directed against this infection. It is in this way that active natural (in case of illness) or artificial (during vaccination) immunity is formed.
The child needs vaccinations against certain diseases
When subsequently they encounter this microbe, the virus, it will be recognized and immediately destroyed.
That is why vaccination of children against the most serious, fatal diseases is necessary. It forms their immunity to infections, either permanent, lasting a lifetime (chickenpox), or temporary – for a certain period: long-term (diphtheria, tetanus – 10 years) and short-term (flu – year).
Many believe that immunity is created exclusively in childhood. Doctors are often asked the question: “How many years is immunity formed?”
The answer is active immunity to various pathogens is formed throughout a person’s life.
If we talk about the immune system, then it matures by 6-7 years. At this age, the child already has all the necessary lymphocytes in order to successfully resist infections. Up to this age, children’s immunity is still immature, so babies who attend kindergartens get sick so often.
Another type is passive immunity. It is formed when ready-made antibodies enter the body. This, for example, is the protection that is given to an infant with maternal colostrum containing antibodies.
Antibodies in the form of serum are administered prophylactically in case of danger of infection with a serious illness. For example, in case of injuries, when it is likely that bacteria that cause tetanus can enter the body, it is recommended to administer tetanus toxoid serum containing antibodies to the pathogen. This forms an artificial passive immunity. It begins to work immediately, from the moment of introduction of antibodies. But the immune memory is not created at the same time, so passive immunity soon ceases to exist.
And one more thing: active acquired immunity will work, provided that a person has innate immunity. With immunodeficiency, active immunity will not form, since the immune memory will not function.