Defense Of The Organism From Infection

During life, man has acquired successful defense mechanisms against infection. These mechanisms exist in the organism even before contact with pathogenic microorganisms, and in each of them the organism resists in a similar way.

This form of defense, which is a set of all hereditary factors that prevent the entry and penetration of microorganisms into a macroorganism, is called nonspecific defense or resistance.

Some infectious diseases affect only certain animal species. Thus, poultry is resistant to tetanus and does not suffer from this disease.

In contrast to nonspecific defense, only in vertebrates there is a specific defense (resistance) or immunity based on the ability of the immune system to produce antibodies (antibodies) involved in humoral immunity in contact with an antigen (pathogenic microorganism or parasite).

Humoral immunity is antibody-mediated immunity. Antibodies are formed after an antigen enters the body, either free, soluble or bound to the surface of a particle.

One part of the molecule performs a recognition function, i.e. it binds non-covalently reversibly with its antigen, and the other part involves nonspecific mechanisms for antigen destruction and removal.

If non-specific defense is not sufficient, specific defense begins to act, and then both forms of resistance are more effective in defending the macroorganism from infection. The same goes for humoral and cellular immunity.