Non-specific defenses

innate mechanism

While waiting for the specific defenses to fulfill their role, they react to quickly protect the body against any foreign substance. They always act in the same way, regardless of the pathogen with which they come into contact.

Skin, mucous membranes and secretions

They prevent the penetration of the infectious agent into our body thanks to a barrier: skin, mucous membranes, bacterial flora, lysozyme, urine, mucus.

  • Keratin : Resists most weak acids and bases, bacterial enzymes, and toxins.
  • Mucous membranes : provide protection similar to that of skin.
  • Lysozime : Destroys bacteria found in saliva and tear fluid.
  • Urine : Inhibits bacterial growth and cleanses the lower urinary tract.
  • Mucus : traps microorganisms from the digestive and respiratory tracts.

Cellular and chemical defenses

These mechanisms are put in place if the external structures have not
were not sufficient to block the pathogen. Among these mechanisms
internal, we can cite:

  • Phagocytosis, whose main actors are macrophages found in most organs and circulating in the blood and lymph in search of cellular debris, metabolic waste, and foreign invaders. They bind to the bacteria to “eat” it via proteins and antibodies that attach to the bacteria to make it more “appetizing.”
  • The response of interferons , proteins from the cytokine family, they are secreted in response to the appearance of various antigens in the body (viruses, bacteria, parasites, etc.). An infected cell is unable to protect itself. On the other hand, before disappearing, it can produce a protein, interferon, which has the capacity to protect neighboring cells.
  • Diapedesis involves leukocytes which, in response to the detection of an attack, will slip between the cells in order to cause inflammation

Symptoms

  • Inflammatory response : Inflammation of tissues causing redness, swelling, heat, pain, and fever. This response is part of the immune system. It prevents the spread of toxic agents, eliminates cellular debris and pathogens, and initiates the repair process.
  • Complement system : This is a group of about twenty proteins that act in a sequential cascade, each one triggering the next step. The final step in the process involves making a hole in the bacteria's membrane so that it empties its contents and dies.
  • Fever : Body temperature is regulated at 37°C by a group of neurons in the hypothalamus, which acts as the body's thermostat. Fever speeds up our metabolism and promotes defense and repair reactions.

Specific defenses

acquired immunity

It adapts its attack to a specific antigen: it memorizes and recognizes the pathogens already encountered and therefore acts in a targeted and more effective manner.

The two main specific immune agents are B and T lymphocytes . Their outline is developed in the bone marrow: at this stage, they are still immature, that is to say, not programmed.

B lymphocytes

These are white blood cells synthesized in the bone marrow. They produce immunoglobulins (antibodies) that circulate in the blood and lymph. To activate, they need to come into direct contact with the antigen in question. Once activated, they will produce two different cell types. Plasma cells, which multiply to eradicate and prevent the spread of the pathogen (these will be eliminated by phagocytes along with the antigen), and memory cells, which will remain in our immune system, ready for a new attack.

T lymphocytes

Leukocytes play a major role in the adaptive response. They migrate via the circulation to the thymus to obtain their specific competence. Their action consists of secreting cytokines to destroy abnormal or diseased cells. There are several types of T lymphocytes, each with its own specificity and mode of action.

During our lifetime we produce 100 billion lymphocytes to protect the body against a large number of different antigens, but only a few thousand will be able to prove themselves against their specific antigen.

Immunity, why is it stuck?

  • Knowledge

    The programming

    We know that the general programming of living beings is found in their genetic code. Regarding immunity, we are born with certain aspects of nonspecific immune defense and are programmed to develop our specific defenses in contact with antigens encountered during our lives. A programming defect can cause autoimmune diseases.

    Who says programming also says possibility of deprogramming.

    We live in an increasingly hostile environment from an immune perspective. Many external factors can induce deprogramming, including both voluntary pollution (smoke, chemicals ingested through food and medications) and involuntary pollution such as stress.

  • The power

    Global energy

    We get our energy from a healthy lifestyle (diet, oxygenation, sleep, etc.). From food to energy, there are many processes which, if disrupted, no longer provide our body with the necessary energy.

    • Balanced diet
    • Good hygiene of life
    • Optimal oxygenation

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