The immune response is a complex reaction of the body to antigenic activity. The basic phenomenon of immunity is a reaction whose quality is determined by the specificity of the antigen, external factors, and the reactivity of the body. The immune response is three-stage, it is possible only with the ability of a macroorganism to recognize an antigen, to develop an effector that can demonstrate effectiveness in a particular case.
general information
The immune response is a sequence of complex biological processes that occur in the immune system. Their task is to respond to a dangerous antigen. The reaction is possible primary, forming when the antigen is in the human body for the first time, secondary - appearing when the situation repeats.
The first phase of the reaction is inductive, the macroorganism recognizes the antigen. At the cellular level, resources are coordinated, then the cells actively multiply and differentiate. The next step begins when the cells of the immune response are active against harmful structures. Analyzes help determine the results of a response response.
Case Nuances
If the immune response is the initial reaction of the body, it does not encounter a harmful structure, the inductive stage in duration is on average weekly. The secondary reaction is usually faster - about three days or even less. This is due to the effectiveness of cell memory.
The immune response is a reaction of the mutual influence of antigen-presenting cell structures, in medicine called macrophages, and antigens. Macrophages can express antigen determinants on the cell surface, thereby obtaining data on the structure and directing it to the periphery of the immune system. It is in this area that T-helpers are generated.
Process development: and then?
The body's immune response is of three options: at the cellular level, humoral, tolerant.
At the cellular level, the reaction is assigned to T-lymphocytes. Effector structures capable of killing antigen cells are formed. They may have a direct toxic effect at the cellular level, others work through the production of lymphokines. These elements are involved in the processes of mutual reactions involving cells. The cellular immune response proceeds with the participation of T-helpers, which increase the strength of the reaction, and T-suppressors, which have the opposite effect.
Continuing the topic
Considering the types of immune response, it is necessary to pay attention to the humoral. Cell structures of type B are responsible for it. Antigen data is transmitted to T-helpers, which send information to class B lymphocytes. Their task is to create an analogue of antibody-producing cell structures. In the process of response, structural elements are converted into plasma, capable of secreting immunoglobulins. These compounds have an inherent effect, the characteristics of which are determined by the variety of the object of invasion.
Antibodies formed during the reaction can react with antigens. This leads to the production of a specific complex that activates the defense. It is able to initiate the activity of a complementary system. Its mutual influence with the participation of mast cells gives rise to degranulation, therefore, the primary immune response, the secondary is accompanied by the formation of numerous inflammatory mediators. In the role of these substances in the macroorganism (in humans), serotonin and histamine are played.
Last option
If the primary, secondary immune response is triggered by the ingestion of a small amount of antigen, immunity tolerance is recorded. Internal defense systems recognize invasion but do not start cell generation processes. Tolerance is not peculiar to humoral immunity.
Features of the response of the body
Specificity is inherent in the immune response - perhaps this is the main and most significant quality of the reaction. The body interacts only with a specific agent. It is called the antigen. Another important ability is potentiation. If a certain antigen regularly enters the body, the response to it becomes stronger over time.
A distinctive feature of the immune response is immunological memory. This term reflects the ability to quickly identify an antigen when it is re-introduced into the body and give a stronger response to it. Such a memory is often observed, even if an extended time period elapses between cases of invasion.
Immunity: why is it needed?
The immune system is responsible for antigenic homeostasis. In the terminology accepted in science, immunity is called immunity to a certain type of pathological microscopic life forms and products of their vital activity, as well as poisons generated by animals. The immune system is involved in the identification and destruction of a variety of cellular structures - bacteria and viruses, parasitic, protozoa, fungal, and tumor. The immune response that arises from this is a reaction to invasion.
Evolution is a feature inherent in any life form, but it is especially pronounced if we observe microorganisms. The properties of microscopic life forms are constantly being improved, and the formation of immunity of different species turned out to be the only effective response from macroorganisms. However, immunity is not the only thing that protects a person. A significant role is played by factors that do not allow invasion. For example, the penetration of pathological microflora into the human body is hampered by epithelial cilia, skin, mucous membranes, as well as the high acidity of the gastric environment.
Types of immunity: what are there?
It is customary to distinguish two types: individual, species. The latter is inherent in some kind of animals. Since a person also has such a quality, we are not afraid of pathologies that are dangerous for some life forms - say, a dog’s plague. For a similar reason, animals are not afraid of certain diseases that are dangerous (even deadly) to humans. Species immunity is due to the microstructural level, it is transmitted between generations within the species.
The individual receives an individual type of immunity during its life; it cannot be inherited. This is formed if a person is experiencing infection, poisoning. A number of diseases after themselves give a stable immunity, with other pathologies it is not observed. In particular, if you get gonorrhea, the immunity after recovery will be weak, after a short time completely disappears. At the next contact with the pathogen, the individual is likely to become ill again. But chickenpox, once transferred, leaves behind immunity for life, so you will not have to get sick again.
What does it depend on?
The duration of immunity depends on the immunogenicity of the pathogen, that is, its ability to activate the immune response. If an individual becomes infected and becomes ill, it receives natural active immunity. If a vaccine was received, immunity will also be active, but artificial. Both reaction classes are the longest possible.
Relatively short-lived immunity is formed when an infant receives antibodies from the mother's body during the period in the womb. These antibodies are the key to the health of the baby in the first few months after birth. The immunity obtained in this way is passive, and by virtue of its origin is considered natural.
Passive artificial can be obtained if an injection of serum was performed in which antibodies against some microscopic life form or poisonous compound are present. The effectiveness of the injection lasts for several weeks, after which it completely disappears.
Sterility: is it relevant?
Allocate sterile immunity and not being such. Resistance to pathogens is formed if a person has suffered an infection. During the response of the body, the main percentage of pathological life forms is destroyed, but microbes are not always excreted without a trace. In some cases, a certain amount is stored in the body. Such pathogens are not characterized by reproduction, aggression. The condition is called non-sterile immunity, provided by a low concentration of the pathogen in the human body. This case is fraught with the danger of relapse if the immune system weakens. Locating, defeating a disease is usually quite simple, because internal systems at the cellular level know how to deal with a problem.
Sterile immunity is a condition where the pathogen is eliminated without a trace. It is formed upon receipt of the vaccine. This appears, for example, if a person develops hepatitis A against the background of infection with the virus.