The immune system is a collection of special tissues, organs and cells. This is a rather complex structure. Next, let's figure out what elements are included in its composition, as well as what are the functions of the immune system.
General information
The main functions of the immune system are the destruction of foreign compounds that have entered the body and protection from various pathologies. The structure is a barrier to infections of a fungal, viral, bacterial nature. When a person's immunity is weak or there is a malfunction in his work, the likelihood of penetration of foreign agents into the body increases. As a result, various diseases can occur.
Historical background
The concept of "immunity" was introduced into science by the Russian scientist Mechnikov and the German figure Erlich. They studied the existing defense mechanisms that are activated in the process of the body's struggle with various pathologies. First of all, scientists were interested in the reaction to infections. In 1908, their work in the field of studying the immune responsewere awarded the Nobel Prize. In addition, the works of the Frenchman Louis Pasteur also made a significant contribution to the research. He developed a method of vaccination against a number of infections that were dangerous to humans. Initially, there was an opinion that the protective structures of the body direct their activity only to eliminate infections. However, subsequent studies by the Englishman Medawar proved that immune mechanisms are triggered by the invasion of any foreign agent, and indeed respond to any harmful intervention. Today, the protective structure is mainly understood as the body's resistance to various kinds of antigens. In addition, immunity is a response of the body, aimed not only at destruction, but also at the elimination of "enemies". If there were no protective forces in the body, then people would not be able to exist normally in the environment. The presence of immunity allows, coping with pathologies, to live to old age.
Organs of the immune system
They are divided into two large groups. The central immune system is involved in the formation of protective elements. In humans, this part of the structure includes the thymus and bone marrow. The peripheral organs of the immune system are an environment where mature protective elements neutralize antigens. This part of the structure includes lymph nodes, spleen, lymphoid tissue in the digestive tract. It was also found that the skin and neuroglia of the central nervous system have protective properties. In addition to those listed above, there are also intra-barrier andbarrier tissues and organs of the immune system. The first category includes the skin. Barrier tissues and organs of the immune system: CNS, eyes, testicles, fetus (during pregnancy), thymus parenchyma.
Structure Tasks
Immunocompetent cells in lymphoid structures are represented mainly by lymphocytes. They are recycled between the constituent components of the protection. It is believed that they do not return to the bone marrow and thymus. The functions of the immune system of the organs are as follows:
- Formation of conditions for the maturation of lymphocytes.
- Connecting populations of protective elements scattered throughout the body into an organ system.
- Regulation of the interaction of representatives of different classes of macrophages and lymphocytes in the process of implementing protection.
- Ensuring timely transportation of elements to the lesions.
Next, let's take a closer look at the organs of the immune system.
Lymph node
This element is formed by soft tissues. The lymph node is oval in shape. Its size is 0.2-1.0 cm. It contains a large number of immunocompetent cells. Education has a special structure, which allows you to form a large surface for the exchange of lymph and blood flowing through the capillaries. The latter enters from the arteriole and exits through the venule. In the lymph node, cells are immunized and antibodies are formed. In addition, the formation filters foreign agents and small particles. Lymph nodes in every part of the body have their own set of antibodies.
Spleen
Outwardly, it resembles a large lymph node. The above are the main functions of the immune system of organs. The spleen also performs several other tasks. So, for example, in addition to producing lymphocytes, blood is filtered in it, its elements are stored. It is here that the destruction of old and defective cells occurs. The mass of the spleen is about 140-200 grams. Its lymphoid tissue is presented in the form of a network of reticular cells. They are located around the sinusoids (blood capillaries). Basically, the spleen is filled with erythrocytes or leukocytes. These cells do not contact each other, they change in composition and quantity. With the contraction of smooth muscle capsular strands, a certain number of moving elements are pushed out. As a result, the spleen is reduced in volume. This whole process is stimulated under the influence of norepinephrine and adrenaline. These compounds are secreted by postganglionic sympathetic fibers or the adrenal medulla.
Bone marrow
This item is a soft spongy fabric. It is located inside flat and tubular bones. The central organs of the immune system produce the necessary elements, which are then distributed to the zones of the body. The bone marrow produces platelets, red blood cells, and white blood cells. Like other blood cells, they become mature after they have acquired immune competence. In other words, receptors will form on their membranes, characterizing the similarity of the element withothers like him. In addition to the bone marrow, such organs of the immune system as tonsils, Peyer's patches of the intestine, and thymus create conditions for the acquisition of protective properties. In the latter, the maturation of B-lymphocytes occurs, which have a huge number (one hundred to two hundred times more than that of T-lymphocytes) microvilli. The blood flow is carried out through the vessels, which include sinusoids. Through them, not only hormones, proteins and other compounds penetrate into the bone marrow. Sinusoids are channels for the movement of blood cells. Under stress, the current is almost halved. When calmed, circulation is increased up to eight times.
Peyer's patches
These elements are concentrated in the intestinal wall. They are presented in the form of accumulations of lymphoid tissue. The main role belongs to the circulation system. It consists of lymphatic ducts connecting the nodes. Fluid is transported through these channels. She has no color. The fluid contains a large number of lymphocytes. These elements protect the body from diseases.
Thymus
It is also called the thymus gland. In the thymus, the reproduction and maturation of lymphoid elements occurs. The thymus gland performs endocrine functions. Thymosin is secreted from its epithelium into the blood. In addition, the thymus is an immunoproducing organ. It is the formation of T-lymphocytes. This process occurs due to the division of elements that have receptors for foreign antigens that penetrated the body in childhood. Formation of T-lymphocytescarried out regardless of their amount in the blood. Does not affect the process and content of antigens. In young people and children, the thymus is more active than in older people. Over the years, the thymus decreases in size, and its work becomes less fast. Suppression of T-lymphocytes occurs under stressful conditions. It can be, for example, cold, heat, psycho-emotional stress, blood loss, starvation, excessive physical exertion. People exposed to stress have weak immunity.
Other items
The vermiform process also belongs to the organs of the immune system. It is also called "intestinal tonsil". Under the influence of changes in the activity of the initial section of the colon, the volume of lymphatic tissue also changes. The organs of the immune system, the scheme of which is located below, also include the tonsils. They are on both sides of the throat. The tonsils are small collections of lymphoid tissue.
The main defenders of the body
The secondary and central organs of the immune system are described above. The scheme presented in the article shows that its structures are distributed throughout the body. The main defenders are lymphocytes. It is these cells that are responsible for the destruction of diseased elements (tumor, infected, pathologically dangerous) or foreign microorganisms. The most important are T- and B-lymphocytes. Their work is carried out in conjunction with other immune cells. All of them prevent the invasion of foreign substances intoorganism. At the initial stage, some kind of "training" of T-lymphocytes takes place to distinguish normal (own) proteins from foreign ones. This process occurs in the thymus during childhood, since it is during this period that the thymus gland is most active.
The work of protecting the body
It should be said that the immune system was formed during a long evolutionary process. In modern people, this structure acts as a well-oiled mechanism. It helps a person cope with the negative influence of environmental conditions. The tasks of the structure include not only recognition, but also the removal of foreign agents that have entered the body, as well as decay products, pathologically changed elements. The immune system has the ability to detect a large number of foreign substances and microorganisms. The main purpose of the structure is to preserve the integrity of the internal environment and its biological identity.
Recognition process
How does the immune system detect "enemies"? This process takes place at the genetic level. Here it should be said that each cell has its own genetic information, characteristic only for a given person. It is analyzed by the protective structure in the process of detecting penetration into the body or changes in it. If the genetic information of the hit agent matches his own, then this is not an enemy. If not, then, accordingly, it is an alien agent. In immunology, "enemies" are called antigens. After detection of malwareelements of the protective structure includes its mechanisms, the "struggle" begins. For each specific antigen, the immune system produces specific cells - antibodies. They bind to antigens and neutralize them.
Allergic reaction
She is one of the defense mechanisms. This condition is characterized by an increased response to allergens. These "enemies" include objects or compounds that adversely affect the body. Allergens are external and internal. The former should include, for example, foods taken for food, medicines, various chemicals (deodorants, perfumes, etc.). Internal allergens are the tissues of the body itself, as a rule, with altered properties. For example, during burns, the protective system perceives dead structures as foreign. In this regard, she begins to produce antibodies against them. Reactions to the bites of bumblebees, bees, wasps and other insects can be considered similar. The development of an allergic reaction can occur sequentially or violently.
Child's immune system
Its formation begins in the very first weeks of gestation. The baby's immune system continues to develop after birth. The laying of the main protective elements is carried out in the thymus and bone marrow of the fetus. While the baby is in the womb, his body meets with a small number of microorganisms. In this regard, its defense mechanisms are inactive. Before birth, the baby is protected from infections by the mother's immunoglobulins. If onit will be adversely affected by any factors, then the correct formation and development of the protection of the baby may be disturbed. After birth, in this case, the child may get sick more often than other children. But things can happen differently. For example, during pregnancy, the mother of a child can suffer an infectious disease. And the fetus can form a strong immunity to this pathology.
After birth, a huge number of microbes attack the body. The immune system must resist them. During the first years of life, the protective structures of the body undergo a kind of "learning" to recognize and destroy antigens. Along with this, contacts with microorganisms are remembered. As a result, "immunological memory" is formed. It is necessary for a faster reaction to already known antigens. It must be assumed that the immunity of the newborn is weak, he is not always able to cope with the danger. In this case, antibodies obtained in utero from the mother come to the rescue. They are present in the body for approximately the first four months of life. Over the next two months, the proteins received from the mother are gradually destroyed. In the period from four to six months, the baby is most susceptible to illness. Intensive formation of the child's immune system occurs up to seven years. In the process of development, the body gets acquainted with new antigens. The immune system throughout this period is learning and preparing for adulthood.
How to help a weak body?
Experts recommendtake care of the baby's immune system even before birth. This means that the expectant mother needs to strengthen her protective structure. In the prenatal period, a woman needs to eat right, take special trace elements and vitamins. Moderate exercise is also important for immunity. The child in the first year of life needs to receive mother's milk. It is recommended to continue breastfeeding for at least 4-5 months. With milk, protective elements penetrate the baby's body. During this period, they are very important for immunity. A child can even bury milk in the nose during a flu epidemic. It contains a lot of useful compounds and will help the baby cope with negative factors.
Additional methods
Immune system training can be done in a variety of ways. The most common are hardening, massage, gymnastics in a well-ventilated room, sun and air baths, and swimming. There are also various remedies for immunity. One of them is vaccinations. They have the ability to activate protective mechanisms, stimulate the production of immunoglobulins. Thanks to the introduction of special sera, the memory of the body structures to the input material is formed. Another remedy for immunity is special preparations. They stimulate the activity of the protective structure of the body. These drugs are called immunostimulants. These are interferon preparations ("Laferon", "Reaferon"), interferonogens ("Poludan", "Abrizol", "Prodigiosan"), leukopoiesis stimulants - "Methyluracil", "Pentoxyl", immunostimulantsmicrobial origin - "Prodignosan", "Pirogenal", "Bronchomunal", immunostimulants of plant origin - tincture of magnolia vine, eleutherococcus extract, vitamins and many others. others
Only an immunologist or a pediatrician can prescribe these funds. Self-administration of this group of drugs is highly discouraged.
