What organs does the human immune system consist of? What is the immune system and how does it work

The immune system is a set of organs, tissues and cells, the work of which is aimed directly at protecting the body from various diseases and at the extermination of foreign substances that have already entered the body.

It is this system that is an obstacle to infectious agents (bacterial, viral, fungal). When the immune system fails, the likelihood of developing infections increases, this also leads to the occurrence of autoimmune diseases, including multiple sclerosis.

Organs that make up the human immune system: lymph glands (nodes), tonsils, thymus gland (thymus), bone marrow, spleen and intestinal lymphoid formations (Peyer's patches). They are united by a complex circulation system, which consists of ducts connecting The lymph nodes.

Lymph node- This is an oval-shaped formation from soft tissues, 0.2-1.0 cm in size and contains a large number of lymphocytes.

The tonsils are small collections of lymphoid tissue located on either side of the throat.

The spleen is an organ that looks very much like a large lymph node. The functions of the spleen are diverse: it is both a filter for blood, and a storage for its cells, and a place for the production of lymphocytes. It is in the spleen that old and defective blood cells are destroyed. This organ of the immune system is located in the abdomen under the left hypochondrium near the stomach.

Thymus gland (thymus) located behind the chest. Lymphoid cells in the thymus proliferate and "learn". In children and young people, the thymus is active, the older the person, the more passive and smaller this organ becomes.

Bone marrow- This is a soft spongy tissue located inside the tubular and flat bones. The main task of the bone marrow is the production of blood cells: leukocytes, erythrocytes, platelets.

Peyer's patches these are concentrations of lymphoid tissue in the walls of the intestine, more specifically, in the appendix (vermiform appendix). However leading role plays the circulation system, consisting of ducts that connect the lymph nodes and transport lymph.

Lymph fluid (lymph) is a colorless liquid that flows through lymphatic vessels, it contains many lymphocytes - white blood cells involved in protecting the body from disease.

Lymphocytes are, figuratively speaking, the "soldiers" of the immune system, they are responsible for the destruction of foreign organisms or their own diseased cells (infected, tumor, etc.). The most important types of lymphocytes are B-lymphocytes and T-lymphocytes. They work together with other immune cells and do not allow foreign substances (infectious agents, foreign proteins, etc.) to invade the body. At the first stage of development of the human immune system, the body "teaches" T-lymphocytes to distinguish foreign proteins from normal (own) proteins of the body. This learning process takes place in the thymus gland in early childhood, since at this age the thymus is most active. When a child reaches puberty, his thymus decreases in size and loses its activity.

Interesting fact: for many autoimmune diseases, for example, when multiple sclerosis, the immune system the patient "does not recognize" the healthy tissues of his own body, treats them as foreign cells, begins to attack and destroy them.

The role of the human immune system

The immune system appeared along with multicellular organisms and developed as an assistant to their survival. It unites organs and tissues that guarantee the protection of the body from genetically foreign cells and substances coming from environment. In terms of organization and mechanisms of functioning, immunity is similar to the nervous system.

Both of these systems are represented by central and peripheral organs capable of responding to different signals, have a large number of receptor structures and specific memory.

The central organs of the immune system include the red bone marrow, thymus, and the peripheral organs include the lymph nodes, spleen, tonsils, and appendix.

The leading place among the cells of the immune system is occupied by leukocytes. With their help, the body is able to provide different forms immune response upon contact with foreign bodies for example, the formation of specific antibodies.

History of Immunity Research

The very concept of "immunity" in modern science introduced by the Russian scientist I.I. Mechnikov and the German doctor P. Ehrlich, who studied defensive reactions body in the fight against various diseases primarily infectious. Their joint work in this area was even noted in 1908. Nobel Prize. A great contribution to the science of immunology was also made by the work of the French scientist Louis Pasteur, who developed a method of vaccination against a number of dangerous infections.

The word "immunity" comes from the Latin "immunis", which means "pure from something." Initially, it was believed that the immune system protects us only from infectious diseases. However, the studies of the English scientist P. Medawar in the middle of the twentieth century proved that immunity provides protection in general from any alien and harmful interference in the human body.

Currently, immunity is understood, firstly, as resistance to infections, and secondly, as responses organism, aimed at the destruction and removal from it of everything that is alien to it and poses a threat. It is clear that if people did not have immunity, they simply could not exist, and it is precisely its presence that makes it possible to successfully fight diseases and live to old age.

The work of the immune system

The immune system has developed long years human evolution and acts like a well-oiled mechanism. It helps us fight disease and harmful environmental influences. The tasks of immunity include recognizing, destroying and bringing out both foreign agents penetrating from the outside and decay products formed in the body itself (during infectious and inflammatory processes), as well as exterminating pathologically changed cells.

The immune system is able to recognize many "aliens". These include viruses, bacteria, toxic substances vegetable or animal origin, protozoa, fungi, allergens. Among the enemies, she also includes those that have turned into cancer cells, and therefore their own cells that have become dangerous. The main purpose of immunity is to provide protection against intrusions and maintain integrity internal environment organism, its biological identity.

How is the recognition of "outsiders"? This process takes place at the genetic level. The fact is that each cell carries its own, inherent only to this specific organism genetic information (you can call it a label). It is her immune system that analyzes when it detects penetration into the body or changes in it. If the information matches (the label is present), then it’s your own, if it doesn’t match (the label is missing), then it’s someone else’s.

In immunology, foreign agents are called antigens. When the immune system detects them, they immediately turn on defense mechanisms, and the struggle begins against the "stranger". Moreover, for the destruction of each specific antigen, the body produces specific cells, they are called antibodies. They fit antigens like a key to a lock. Antibodies bind to the antigen and eliminate it, so the body fights the disease.

allergic reactions

One of the main immune reactions a person is a state of increased body response to allergens. Allergens are substances that contribute to the occurrence of the corresponding reaction. Allocate internal and external factors provocateurs of allergies.

External allergens include some food products(eggs, chocolate, citrus), various chemical substances(perfumes, deodorants), medicines.

Internal allergens - own cells, usually with altered properties. For example, during burns, the body perceives dead tissues as foreign, and creates antibodies for them. The same reactions can occur with the stings of bees, bumblebees and other insects.

Allergies develop rapidly or sequentially. When an allergen affects the body for the first time, the immune system produces and accumulates antibodies with hypersensitivity to him. When the same allergen enters the body again, allergic reaction, for example, skin rashes, swelling, redness and itching appear.

Education: Moscow medical institute them. I. M. Sechenov, specialty - "Medicine" in 1991, in 1993 " Occupational diseases", in 1996 "Therapy".

Components of the immune system

The structure of the organs of the immune system is quite complex and is only slightly inferior to how the nervous system is built. Its central organs are:

1. Red and yellow bone marrow. Its purpose is to be responsible for the hematopoietic process. spongy substances short bones contain red brain. It is also found in the spongy components of flat bones. Tubular bones in their cavities contain a yellow brain. In children's bones, there is only red. This type contains stem cells.
2. Thymus (thymus). Located behind the chest. Represents 2 shares: with right side and from the left. Both lobes are divided into smaller lobules containing along the edges cortex and in the center of the brain. The basis of the thymus gland are epithelioreticulocytes. They are responsible for the formation of a network of T-lymphocytes, the production of thymosin and thymopoietin (bioactive components). Lymphocytes are produced by the cortical substance, then they enter the brain, and from there into the blood.

The immune system contains peripheral organs. Their total weight (both those and others) is about 1 kilogram.

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What organs are peripheral?

The immune system has 6 tonsils:

1. Palatine steam room. Located on both sides of the pharynx. It is an organ covered with several layers of squamous epithelium.
2. Tubal tonsil (also steam room). Its base is lymphoid tissue. Located in the region of the auditory tube. Surrounds the opening of the pharynx.
3. Pharyngeal tonsil (unpaired organ). Its location is the wall of the pharynx from above.
4. Lingual tonsil (also unpaired). The place of its localization is the region of the language root.

The following organs also belong to the peripheral part of the immune system:

1. lymph nodes. They are located in the following systems: digestion, respiration, urination. They form a ball shape, consisting of a large number of lymphocytes. Protect the body from the ingress of foreign harmful substances. If an antigenic danger arises, then the process of formation of lymphocytes starts, since the centers of their reproduction are located in the nodules.
2. Lymphoid plaques. Their location is the small intestine. Consist of several nodules of the same name. These plaques do not allow foreign substances to enter the bloodstream or lymph. It is in the small intestine that there are especially many strangers, since the process of digestion of food takes place here.
3. appendix (which is appendix). It contains a lot of lymphoid nodules. They lie close to each other. The process itself is located in the border zone between small intestine and thick. It is one of the main functions of the immune system.
4. The lymph nodes. They are located in places where lymph flows. In the lymph nodes, foreign substances and dead cells of the body are retained. There they are destroyed. Lymph nodes in the body are not located one at a time. Usually there are two or more.
5. Spleen. Its location is abdomen. The task of this important body— control over blood and its composition. The spleen consists of a capsule with trabeculae extending from it. It also contains pulp, white and red pulp. The basis of the white is the lymphatic tissue, the red is the reticular stroma. 78% of the entire organ is given by nature to the red pulp, which contains many lymphocytes and leukocytes, as well as other cells.

All of them are located so that they surround the place where the mouth and nose cavities enter the pharynx. If foreign substances (from food or from inhaled air) try to enter the body, then it is in this place that lymphocytes await them.

The interaction of all organs presents a complex picture. Their coordinated work, as well as the structure and functions of the immune system, provide reliable protection organism.

Long before the baby is born, even in the womb, the formation of the child's immune system begins. In order for it to develop in the future, the child needs mother's milk. For the same purpose, an antigenic load is needed - the contact of the child's body with various microorganisms.

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What is the immune system responsible for?

The functions of the human immune system can be represented as the following algorithm:

• recognize a foreign element;
• destroy the alien;
• provide maximum protection to your body.

In the body, nothing passes without a trace, including the immune response. The immune system at the first encounter with any foreign substance (infection, microbe, etc.) will definitely remember its properties. The next meeting with him affects him more effectively.

Bacteria appear in the life of the baby almost immediately after his birth. Many parents believe that the child should be as sterile as possible. But this opinion is wrong. Basic hygiene rules are necessary, but you should not go to extremes. Excessive sterility can prevent the infant's immune system from developing its properties. If the mother's milk contains a certain amount of bacteria, then you can not refuse it. Children's body must learn to deal with harmful substances. The function of the immune system is to fight against different viruses and bacteria.

In most cases, she copes with them before they have time to show their negative impact on the human body, that is, the person does not even notice that not everything is in order in the body.

But if there are too many pathogenic substances, then not every immune system will be able to cope. There are also pathogens that, even in small quantities, are not subject to the best immunity. For example, cholera or chicken pox. A decrease in the functions of the immune system is manifested frequent colds, chronic infections, constant temperature at 37-38°C. There are such diseases, the peculiarities of which are that a person suffers from them only once in a lifetime. For example, measles. This is due to the immune system, which forms a stable immunity to the transferred disease.

The immune system provides specific protection of the body from genetically alien molecules and cells.

Cells have a unique ability to recognize foreign antigens.

The immune system emphasizes the unity of cells by a common origin, functional action and adjustment mechanisms

Central or primary organs of the immune system- red bone marrow and thymus.

red bone marrow- the birthplace of all cells of the immune system and the maturation of B-lymphocytes. In it, from pluripotent stem cells, erythrocytes, granulocytes, monocytes, dendritic cells, B-lymphocytes, precursors of T-lymphocytes and NK cells.

Red bone marrow in children under 4 years of age is located in the cavities of all flat and tubular bones.

And At the age of 18, it remains only in flat bones and epiphyses of tubular bones.

With age, the number of red bone marrow cells decreases and it is replaced by yellow bone marrow.

thymus- is responsible for the development of T-lymphocytes, which come there from the red bone marrow from pre-T-lymphocytes.

In the thymus, T-lymphocytes with clusters (receptors that determine the functional abilities) of CD4+ CD8+ differentiation are selected and those variants that are highly sensitive to the antigens of their own cells, i.e., are destroyed. it prevents an autoimmune reaction.

Thymus hormones accompany the functional maturation of T-lymphocytes and increase their secretion of cytokines.

The thymus is surrounded by a thin connective tissue capsule, consists of 2 asymmetric lobes, divided into lobules. Under the capsule is a basal membrane, on which epithelioreticulocytes are located in one layer. The periphery of the lobules is the cortical substance, central part- cerebral, all lobules are populated by lymphocytes. With age, Timu undergoes involution.

T-lymphocytes differentiate into mature immune cells in the thymus, responsible for cellular lymphocytes, B-lymphocytes - Bursa Fabricius

The secondary organs of the immune system are peripheral organs.

Group 1 - structured organs of the immune system - the spleen and lymph nodes.

Group 2 - unstructured.

lymph nodes- filter the lymph, extract antigens and foreign substances from it. In the lymph nodes, antigen-dependent proliferation and differentiation of T and B lymphocytes occurs. Mature non-immune lymphocytes formed in the bone marrow, with the lymph / bloodstream, enter the lymph nodes, meet the antigen in the bloodstream, receive an antigenic and cytokine stimulus and turn into mature immune lymphocytes capable of recognizing and destroying the antigen.

The lymph node is covered with a connective tissue capsule, trabeculae depart from it, have a cortical zone, a paracortical zone, cerebral cords and a cerebral sinus.

The cortex contains lymphoid follicles, which contain dendritic cells and B-lymphocytes. A primordial follicle is a small follicle with non-immune B lymphocytes.

After interacting with the antigen, dendritic cells and t-lymphocytes, the B-lymphocyte is activated and forms a clone of proliferating B-lymphocytes, as a result, a germinal center is formed that contains proliferating B-lymphocytes, and after the completion of immunogenesis, the primary follicle becomes secondary.

In the paracortical zone there are T-lymphocytes and postcapillary venules with high epithelium, through their walls lymphocytes migrate from the blood to the lymph nodes and back. It also contains interdigitating cells that migrated to the lymph node through the lymphatic vessels from the integumentary tissues from the skin and from the mucous membranes together with the already processed (antigen processing) antigen. The medullary cords lie beneath the paracortical zone and contain macrophages activated by B lymphocytes that differentiate into antibody-producing plasma cells. The cerebral sinus accumulates lymph with antibodies and lymphocytes and it is discharged into lymphatic bed and it is taken away by the efferent lymphatic vessel.

Spleen

It has a connective tissue capsule, trabeculae depart from it, making up the frame of the organ. It has a pulp that forms the basis of the organ. The pulp contains lymphoid reticular tissue, blood vessels, and shaped elements blood. In the white pulp, there is an accumulation of lymphoid cells in the form of periarterial lymphoid muffs. They are located around the arterioles. The white pulp also contains germinal centers and B cell follicles.

The red pulp contains capillary loops, erythrocytes, macrophages.

The functions of the spleen - in the white pulp, the cells of the immune system come into contact with the antigen that has penetrated into the blood, the processing and presentation of this antigen. And also the implementation various types immune response, predominantly humoral.

Platelets are deposited in the red pulp, up to 1/3 of all platelets are contained in the spleen, erythrocytes and granulocytes, and this is the destruction of damaged erythrocytes and platelets.

Lymphoid tissue associated with the skin.

These are white outgrowth interdigitating Langengars cells. They fix the antigen coming from the skin, process it and migrate to the regional lymph nodes ("these are the border guards who catch the saboteur and take him to the commandant's office")

Lymphoid cells of the epidermis, mainly T-lymphocytes and keratinocytes, as a mechanical barrier.

Lymphoid tissue associated with mucous membranes (the area of ​​which is 400 m 2)

It is presented structured - solitary follicles, appendix and tonsils, single lymphoid cells. The antigen penetrates into the lymphoid tissue from the surface of the mucous membranes through special epithelial M-cells. Macrophages and dendritic cells located under the pithelium process the antigen and deliver its specific part to T and B lymphocytes.

It is characteristic that each tissue has populations of limophycetes capable of recognizing their place of residence. They have homing "Home" receptors on their membranes. CLA - skin lymphocytic antigen.

Peyrorva plaques - Lymphoid formations located in their own mucosal membrane have three main components - the epithelial dome consists of an epithelium devoid of intestinal villi and containing many M - cells. A lymphoid follicle with a germinal center filled with B-lymphocytes.

Interfollicular zone - N lymphocytes and interdigitating cells.

The main function of the specific immune response is the specific recognition of an antigen.

Forms of the immune response.

1. Cellular immunity is the accumulation of antigen-specific active T-lymphocytes that perform effector functions, either directly by the lymphocytes themselves, or through the cellular mediators of lymphokines secreted by them.
2. Humoral immunity is based on the production of specific antibodies - immunoglobulins that perform the main effector functions.
3. Immunological memory is the body's ability to respond more intensely to a second encounter with an antigen than to the first. This ability is acquired as a result of immunization with the same antigen.
4. Immunological tolerance is a state of specific immunological a-reactivity of the organism to certain antigens. It is characterized -

A) lack of response to an antigen

B) the absence of antigen elimination upon its repeated administration

C) Absence of antibodies to a given antigen. The antigens that cause immunological tolerance called tolerogenic

Forms of immunological tolerance

Natural- formed on antigens in the prenatal period

Artificial- when introducing very high or very low doses of the antigen into the body.

Immunoglobulins- contained in the blood and tissue fluid. The molecule is composed of a protein and an oligosaccharide. According to electrophoretic properties, gamma globulins are mainly, but alpha and beta are found.

Immunoglobulin monomers consist of 2 pairs of chains - 2 short or L chains and 2 long or heavy H chains. The chains have constant C and variable - V regions.

light chains There are 2 types - lambda or kappa, they are the same for all immunoglobulins, contain 200 amino acid residues.

heavy chains divided into 5 isotypes - gamma, mu, alpha, delta and upsilon.

They have 450 to 600 amino acid residues. According to the type of heavy chain, there are 5 classes of immunoglobulins - IgI, IgM, IgA, IgD, IgE.

The papain enzyme cleaves the immunoglobulin molecule into 2 identical antigen-binding Fab fragments and one Fc fragment.

Immunoglobulins classes A, M, G- major immunoglobulins, D, E-minor. G, D, E, as well as serum fractions A are monomers, i.e. have 1 pair of heavy and 1 pair of light chains and 2 antigen binding sites.

Immunoglobulin M- is a pentamer.

The secretory fraction of immunoglobulin A is a dimer connected to each other by a j - chain (join - connect). The antigen binding site is called the active site of the antibody and is formed by the hypervariable regions of the H and L chains.

These sites - there are specific molecules that are complementary to certain antigenic epitopes.

The FC fragment is capable of binding compliment and is involved in the transfer of some immunoglobulins across the placenta.

Immunoglobulins have compact structures held together by a disulfide bond. They are called domains. Available variable domains and constant domains. Light L chains have 1 variable and one constant domain, and heavy H chains have 1 variable and 3 constant domains. The CH2 domain contains a complement-binding site. Between the CH1 and CH2 domains there is a hinged area ("antibody waist"), it contains a lot of proline, makes the molecule more flexible and, as a result, F ab and F ac can rotate in space.

Characterization of classes of immunoglobulins.

IgG(80%) - concentration in the blood 12 g per liter. Mol. Weight 160 daltons, formed during the primary and secondary administration of antigens. It is a monomer. There are 2 epitope-binding sites. It has a high activity in binding to bacterial antigens. Participates in the activation of the compliment along the classical pathway and in lysis reactions. Penetrates through the placenta of the mother into the body of the fetus. The Fc fragment can bind to macrophages, neutrophils and NK cells. The half-life is from 7 to 23 days.

IgM- 13% of all immunoglobulins. Its serum concentration is 1 g per liter. It is a pentamer. This is the first immunoglobulin produced in the body of the fetus. Formed during the primary immune response. Normal antibodies, as well as isohemagglutinin, belong to this class. It does not pass through the placenta, it has the most high speed binding to antigens. When interacting with an antigen in vitro causes reactions of agglutination, pretepetation, compliment binding. Its Fc fragments are also involved. Immunoglobulin monomers in the form of membranes are present on the surface of B lymphocytes.

IgA - 2 subclasses - serum and secretory. 2.5 g per liter synthesized plasma cells spleen and lymph nodes, do not give the phenomenon of agglutination and pretepetation, do not lyse the antigen. The half-life is 5 days. The secretory subclass has a secretory component that binds 2 or rarely 3 IgA monomers. The secretory component has a j chain (beta globulin with a molecular weight of 71 kilodaltons, is synthesized by epithelial cells of the mucous membranes and can join serum immunoglobulin, when it passes through the cells of the mucous membrane - transcytosis). SIgA Participates in local immunity, dimer, 4 epiope binding sites. Interferes with adhesion of microbes on cells of mucous and absorption of viruses. IgA controls compliment through an alternative pathway.

40% - serum, 60% - secretory

IgD- 0.03 g per liter. The monomer, 2 epitope-binding sites, does not pass through the placenta, does not bind the compliment. It is located on the surface of B lymphocytes and activates their activation or suppression.

properties of antibodies.

1. Specificity - each antigen has its own antibody
2. Affinity - the strength of binding to an antigen
3. Avidity - the rate of binding to an antigen and the amount of bound antigen
4. Valence - the number of working active centers or antideterminant groups. There are 2 valent and 1 valent antibodies (1 active center is blocked)

Antigenic property of antibodies

Allotypes are intraspecific antigenic differences. There are 20 types in humans.

Idiotypes are antigenic differences in antibodies. Characterize the active differences in the active centers of antibodies.

Isotypes - classes and subclasses of immunoglobulins, isotypes are defined by cezdamides and heavy chains.

Functions of immunoglobulins.

The main one is antigen binding. This ensures the neutralization of toxins and the prevention of the penetration of pathogens into the cell.

Effector function - binding to cells or tissues with the participation of specific receptors, binding to cells of the immune system, phagocytes, to complement components and binding to staphylococcal and staphylococcal antigens.

Types of antibodies

According to their properties, they are distinguished - complete divalent (agglutinin, lysines, pretepicins), incomplete monovalent blocking

By location - circulating and supracellular

In relation to temperature - thermal, cold and 2-phase

Dynamics of antibody formation

1. Lag phase - antibodies are not formed in the blood
2. Log phase - logarithmic increase in antibody concentration
3. Plateau phase - stable high concentration of antibodies
4. Attenuation, recession - termination of the action of antibodies.

With a secondary immune response

The lag phase accelerates, antibody titers are higher, with the primary immune response, immunoglobulin M is formed, and then G, with the secondary, IgG is immediately formed, and IgA is formed even later

The characteristic of incomplete antibodies is monovalent, blocking, one active center. They are formed during infection, allergies, Rhesus conflict, are thermostable, appear the earliest and disappear late, pass through the placenta. Their detection is carried out by the Coombs method, enzyme methods.

The level of antibodies in the blood or other fluids is estimated by titer, i.e. the maximum dilution of the biological fluid, at which a visible reaction phenomenon is observed during the interaction of the antigen with the antibody. Analytical methods are used and the concentration is determined in grams per litre.

The immune system- a complex of organs and cells, the task of which is to identify the causative agents of any disease. The ultimate goal of immunity is to destroy a microorganism, atypical cell, or other pathogen causing an adverse health effect.

The immune system is one of the most important systems of the human body.

Immunity is the regulator of two main processes:

1) he must remove from the body all the cells that have exhausted their resources in any of the organs;

2) build a barrier to the penetration into the body of an infection of an organic or inorganic nature of origin.

As soon as the immune system recognizes the infection, it seems to switch to an enhanced mode of body defense. In such a situation, the immune system must not only ensure the integrity of all organs, but at the same time help them perform their functions, as in a state of absolute health. To understand what immunity is, you should find out what this protective system is. human body. A set of cells such as macrophages, phagocytes, lymphocytes, as well as a protein called immunoglobulin - these are the components of the immune system.

More concisely the concept of immunity can be described as:

Immunity of the body to infections;

Recognition of pathogens (viruses, fungi, bacteria) and their elimination when they enter the body.

Organs of the immune system

The immune system includes:

• Thymus (thymus gland)

The thymus is at the top chest. The thymus gland is responsible for the production of T-lymphocytes.

• Spleen

The location of this body left hypochondrium. All blood passes through the spleen, where it is filtered, old platelets and red blood cells are removed. To remove a man's spleen is to deprive him of his own blood purifier. After such an operation, the body's ability to resist infections is reduced.

• Bone marrow

It is located in the cavities of tubular bones, in the vertebrae and bones that form the pelvis. The bone marrow produces lymphocytes, erythrocytes, and macrophages.

• lymph nodes

Another type of filter through which the lymph flow passes with its purification. Lymph nodes are a barrier to bacteria, viruses, cancer cells. This is the first obstacle that the infection encounters on its way. The next to fight the pathogen are lymphocytes, macrophages produced by the thymus gland and antibodies.

Types of immunity

Every person has two immunities:

1. specific immunity- this is the protective ability of the body, which appeared after a person suffered and successfully recovered from an infection (flu, chickenpox, measles). Medicine has in its arsenal of fighting infections a technique that allows you to provide a person with this type of immunity, and at the same time insure him from the disease itself. This method is very well known to everyone - vaccination. The specific immune system, as it were, remembers the causative agent of the disease and, in the event of a repeated attack of the infection, provides a barrier that the pathogen cannot overcome. Distinctive feature this type of immunity in the duration of its action. In some people, a specific immune system works until the end of their life, in others such immunity lasts for several years or weeks;
2. Nonspecific (innate) immunity – protective function, which begins to work from the moment of birth. This system goes through the stage of formation simultaneously with intrauterine development of the fetus. Already at this stage, cells are synthesized in the unborn child that are able to recognize the forms of foreign organisms and develop antibodies.

During pregnancy, all cells of the fetus begin to develop in a certain way, depending on which organs will be formed from them. The cells seem to differentiate. At the same time, they acquire the ability to recognize microorganisms that are hostile in nature to human health.

Main characteristic innate immunity is the presence of receptors-identifiers in cells, due to which the child in the prenatal period of development perceives the mother's cells as friendly. And this, in turn, does not lead to rejection of the fetus.

Prevention of immunity

Conditionally the whole complex preventive measures aimed at maintaining the immune system can be divided into two main components.

Balanced diet

A glass of kefir, drunk every day, will provide normal microflora intestines and exclude the possibility of dysbacteriosis. Enhance the effect of taking fermented milk products probiotics will help.

Proper nutrition is key strong immunity

Vitaminization

Regular consumption of foods high content vitamins C, A, E will provide an opportunity to provide yourself good immunity. Citrus fruits, infusions and decoctions of wild rose, blackcurrant, viburnum - natural springs these vitamins.

Citrus fruits are rich in vitamin C, which, like many other vitamins, plays a huge role in maintaining immunity.

You can buy the corresponding vitamin complex in a pharmacy, but in this case it is better to choose the composition so that it includes a certain group of trace elements, such as zinc, iodine, selenium, iron.

overestimate role of the immune system impossible, so its prevention should be carried out regularly. Absolutely simple measures will help strengthen the immune system and, therefore, ensure your health for many years.

Sincerely,