Slide 1
Immunity
Slide 2
Updating knowledge
1. What components make up internal environment body? 2. What is homeostasis?
3. What are the main functions of blood?
4. What does blood contain? 5. What is plasma, what is its composition and significance? 6. Characterize blood cells. 7. What is phagocytosis?
Slide 3
4. What does blood contain? 5. What is plasma, what is its composition and significance? 6. Characterize blood cells. 7. What is phagocytosis?
"Protective properties of blood": Slide 4 Germs await people at every step. How can we explain that when infected with microbes a person does not always get sick, and if he does get sick, then the disease does not develop in the same way for everyone? Infection and disease -
different processes
. A person can become infected, that is, be a carrier of a wide variety of microbes, including very dangerous ones, but not always get sick. For some diseases, for every 8-10 cases of infection carriers, one case of the disease occurs. People are especially often carriers of the tuberculosis bacillus. The body actively fights the infection, delays its development, and the person does not get sick. Infection turns into a disease if the body is weakened (immunity is reduced from malnutrition, overwork, nervous shock, etc.) The development of colds (flu, sore throat, pneumonia) is facilitated by cooling the body. Alcohol has a detrimental effect on the course of diseases - it suppresses the immune system.
Slide 5
Immunity is the body’s ability to find foreign substances (antigens) and get rid of them. Antigens (microbes and the poisons they secrete) cause an immune response in the body. In progress
historical development
The immune system has developed in the human and animal bodies.
Slide 6 Organs of the immune system. Bone marrow - blood cells are formed. Thymus (
thymus
Lymphoid tissue in the digestive system. Lymphocyte maturation. Palatine tonsils. (Lymphoid tissue in respiratory system.) Maturation of lymphocytes.
Slide 8
Immunity is distinguished:
cellular
The destruction of foreign bodies is carried out by cells, for example phagocytes. Cellular immunity was discovered by I.I. Mechnikov
humoral
Foreign bodies are removed using antibodies, chemicals carried by the blood. Humoral immunity was discovered by Paul Ehrlich.
Slide 9
Mechnikov Ilya Ilyich 1845 – 1916
Cellular immunity was discovered by I.I. Mechnikov
Slide 10
Phagocytes can destroy any antigens, antibodies - only those against which they were developed.
Slide 11
Message. Opening protective function leukocytes belongs to the remarkable Russian scientist Ilya Ilyich Mechnikov. Here's how it happened. There is a transparent starfish larva on the microscope stage. Small dark lumps are introduced into it - carcass grains. I. I. Mechnikov observes how amoeboid cells capture them. He goes into the garden and plucks thorns from the rose bush. Sticks them into the body of the larva. The next morning he sees many such cells around the thorn. So I. I. Mechnikov discovered the devouring function of cells - phagocytosis. Phagocyte cells are capable of devouring, or better yet, absorbing microbes. I. I. Mechnikov also proved the ability of phagocytes to process useless and harmful substances. He noticed that amoeboid cells can perceive and, if possible, digest substances foreign to the body. As a result of his many years of work, Mechnikov came to the conclusion that phagocytosis is a common phenomenon. It has its own evolution. In lower animals, phagocytes perform a digestive function, in higher animals they perform a protective function. Remember, for example, how the hydra digests food. Based on these studies, I. I. Mechnikov explained the essence of inflammation.
Slide 12
Slide 13
Slide 14
Types of immunity.
Species Hereditary Acquired
The causative agent of canine distemper does not infect humans. Congenital. Appears after the antigen has been identified and identified, and then neutralized.
Slide 15
The cause of many diseases is pathogenic bacteria. These diseases are usually contagious and can take over entire countries. Epidemics - outbreaks infectious diseases.
Slide 16
An excerpt from A. S. Pushkin’s work “A Feast during the Plague”:
Now the church is empty; The school is tightly locked; The cornfield is idly overripe; The dark grove is empty; And the village, like a burnt dwelling, stands - Everything is quiet. (One cemetery) Doesn’t empty, doesn’t remain silent. Every minute they carry the dead, And the groans of the living fearfully ask God to calm their souls! Every minute there is a need for space, And the graves, like a frightened herd, huddle together in a close line.
Slide 17
Message. The plague has been known since ancient times. In the 6th century, the plague in the Byzantine Empire lasted 50 years and killed 100 million people. The chronicles of the Middle Ages describe terrible pictures of the plague: “Cities and villages were devastated. There was the smell of corpses everywhere, life stood still, only gravediggers could be seen in the squares and streets.” In the 6th century, the plague in Europe killed 1/4 of the population - 10 million people. The plague was called the Black Death. Smallpox was no less dangerous. In the 18th century in Western Europe, 400 thousand people died annually from smallpox. It affected 2/3 of those born and out of 8 people, three died. A special sign of that time was considered to be “No sign of smallpox.” IN early XIX century, with the development of world trade, cholera began to spread. Six cholera epidemics have been recorded. It was brought to Russia with caravans from Iraq and Afghanistan, and later from Western Europe. In Russia before 1917, during the 59 years of cholera, 5.6 million people fell ill and almost half of them died. Six cholera epidemics have been recorded. The last global epidemic lasted from 1902 to 1926. According to the World Health Organization, there was a seventh cholera epidemic in 1961-1962. In 1965-1966, from Asia and the Middle East, the disease approached the southern borders of Europe.
Slide 18
Slide 19
The involvement of microbes in infectious diseases was proven by the French scientist Louis Pasteur.
Slide 20
He expressed the idea that if you infect a person with weakened microbes that cause a mild illness, then in the future the person will not get sick with this disease. He will develop immunity. He was prompted to this idea by the work of the English physician Edward Jenner.
Slide 21
What is the merit of E. Jenner.
The English country doctor E. Jenner made the world's first vaccination - a smallpox vaccination. To do this, he rubbed liquid from an abscess on a cow's udder into the wound of an eight-year-old boy. A month and a half later, he infected the child with pus smallpox and the boy did not get sick: he developed immunity to smallpox.
Slide 22
Monument to Edward Jenner.
The sculptor depicted the first smallpox vaccination of a child. This is how the noble feat of a scientist who has won the recognition of all mankind is immortalized.
Slide 23
Slide 24
Slide 25
Slide 26
A vaccine is a liquid containing a culture of weakened microbes or their poisons. If a person has become infected with any infectious disease, then he is injected with a healing serum. Therapeutic serum is a preparation of antibodies formed in the blood of an animal that was previously specifically infected with this pathogen.
Slide 27
Heroism of scientists. The successes of science in the fight against infectious diseases are enormous. Many diseases are a thing of the past and are only of historical interest. Scientists who have made their names famous in the fight against microbes have earned the gratitude of all mankind. The names of E. Jenner, L. Pasteur, I. I. Mechnikov, N. F. Gamaleya, E. Roux, R. Koch and many others are written in golden letters in the history of science. Our domestic scientists have written many bright pages in microbiology. There was so much courage and nobility in their service for the benefit of people’s health! Many heroes of science courageously died for the sake of its interests. An example of selfless heroism can be the act of the doctor I. A. Deminsky, who infected himself with the plague in 1927 for scientific purposes. He gave the following telegram: “...infected with pneumonic plague from gophers... Take the harvested crops. Open my corpse as a case of experimental human infection from gophers..."1. Deminsky's discovery, which cost him his life, confirmed his earlier assumption that gophers are carriers of plague in the steppes.
Slide 28
Thanks to the heroic efforts of Russian doctors in 1910-1911, an outbreak of plague in Harbin was extinguished and its advance to the East and Siberia was stopped. One of the members of this anti-plague expedition, medical student I.V. Mamontov, wrote in the last hour of his life: “Life now is a struggle for the future... We must believe that all this is not in vain and people will achieve it, even through many suffering, real human existence on Earth, so beautiful that for one idea of it you can give everything that is personal, and life itself.”2 Doctor N.K. Zavyalova herself became infected with the pneumonic form of plague in 1951, deciding to test for herself how long immunity lasted after recovery. She sets up a heroic experiment - she again exposes herself to contact with a patient with pneumonic plague. The disease passed in a mild form. So it was found out that immunity exists. Doctor N.I. Latyshev repeatedly infected himself with relapsing fever in order to study the course of the disease. His research was of great scientific importance. He established the latent period of infection, discovered one of the causative agents of the disease, named after him.
Slide 29
Classification of immunity.
Slide 30
Immunity classification:
Natural Natural Artificial Artificial
Active Passive Active Passive
Species Hereditary Acquired during the course of an illness. Antibodies are passed through mother's milk. Vaccination is the introduction of weakened antigens that cause the formation of one’s own antibodies. Introduction of therapeutic serum containing antibodies produced in the donor’s body.
Slide 31
Vaccination against rabies.
Rabies is caused by a virus that affects dogs, wolves, foxes and other animals. It is also dangerous for humans. The virus infects cells nervous system. In a sick animal or person, water causes convulsions of the pharynx and larynx. It is impossible to drink, although I am thirsty. From paralysis respiratory muscles or death may occur from cessation of cardiac activity. If you are bitten by a dog, you should immediately consult a doctor. He will carry out a course of vaccinations against rabies, which were proposed by Louis Pasteur. Remember! Immunity against rabies only lasts for a year, and therefore in case of repeated bites it is necessary to vaccinate again if this period has passed.
Slide 32
Tetanus.
Particular vigilance must be exercised with injuries sustained in rural areas, as you can become infected with tetanus. The causative agents of tetanus develop in the intestines of domestic animals and enter the soil with manure. If the wound is contaminated with soil, anti-tetanus medicinal serum must be administered. Tetanus is a dangerous incurable disease. It begins like a sore throat - a sore throat. Then convulsions occur, which lead to painful death. The introduction of therapeutic serum, which contains ready-made antibodies, destroys tetanus poison.
Slide 33
AIDS and allergic reactions.
Slide 34
AIDS and allergic reactions.
Currently, a fairly common incurable disease is AIDS (acquired immunodeficiency syndrome). The causative agent of this disease, the human immunodeficiency virus (HIV), makes the immune system inoperable, and people die from those microbes, bacteria, fungi that are absolutely safe for a healthy person, that is, with a healthy immune system. Prevention of AIDS is compliance with the following rules: - exclusion of casual sexual relations; - use of disposable syringes for injections. Another ailment of the century is allergic reactions to various factors external environment, i.e. allergy is an increased reaction of the body to certain environmental factors. In this case, a person experiences: - sneezing; - lacrimation; - swelling. In case of predisposition to allergic reactions For the purposes of prevention, the following rules should be observed: - diet; - timely examination and treatment of the disease; - refusal of self-medication.
Slide 35
Consolidation
Solution to the “Immunity” puzzle (fig) 1. Substances that can cause an immune response in the body. 2. The scientist who discovered cellular immunity. 3. Immunity, in which foreign bodies are removed by chemicals delivered by the blood. 4. Immunity acquired after vaccination or after administration of medicinal serum. 5. Protective proteins of the body that neutralize antigens. 6. A preparation made from killed or weakened microorganisms or their waste products. 7. Immunity is congenital or acquired as a result of a previous disease. 8. The scientist who created the rabies vaccine. 9. A preparation of ready-made antibodies, obtained from the blood of a recovered person or animal specifically infected with one or another pathogen.
Slide 36
1 I
M
3M
4 U
5 N
6 I
7 T
8 E
9 T
The organs of the immune system include: Bone marrow, thymus gland (thymus), accumulations of lymphoid tissue located in the walls of hollow organs (respiratory system
BALT and digestive system- SALT) and genitourinary apparatus, The lymph nodes and spleen.
PERIPHERAL IMMUNITY ORGANS
SPLEEN
A place where the reserve of circulating lymphocytes, including memory cells, is preserved. Capture
processing and presentation of antigens that enter the bloodstream. Antigen recognition by T- and B-lymphocyte receptors, their activation, proliferation, differentiation, production of immunoglobulins - antibodies, production of cytokines
REGIONAL LYMPH NODES
The same as in the spleen, but for antigens, transported along the lymphatic tract
Diagram of the structure of the white and red pulp of the spleen
In white pulp
there are accumulations of pymphoid cells (periarterial lymphatic couplings, vaginas) located around arterioles and germinal centers.
The arteriole is closely surrounded by the T-dependent coupling zone.
Closer to the edge of the muff there are B-cell follicles and germinal centers.
Red pulp
contains capillary loops, erythrocytes and macrophages.
Lymph nodes filter lymph, removing foreign substances and antigens from it. Antigen-dependent proliferation and differentiation of T- and B lymphocytes.
The lymph node is covered with a connective tissue capsule, from which trabeculae extend. It consists of the cortical zone, paracortical zone, medullary cords and medullary sinus.
Peyer's patch has three components.
1. epithelial dome, consisting of epithelium devoid of intestinal villi and containing numerous M cells;
2. lymphoid follicle with a reproduction center (germinal center) filled with B lymphocytes;
3. interfollicular zone of cells containing mainly T lymphocytes and interdigital cells.
Active immunity is a type of immunity
based on the formation of long-term immunological memory (natural
or artificial)
Passive immunity occurs with the introduction of antibodies or sensitized T-lymphocytes, which were formed in
body of another person or animal ( natural or artificial)
Functions of immunoglobulins (antibodies)
IMMUNOGLOBULINS |
ACTIONS |
|||||
IMMUNOGLOBULIN G Transplacental |
Newborn immunity |
|||||
Bloodstream |
Neutralization of toxins |
|||||
viruses. Activation |
||||||
complement. |
||||||
IMMUNOGLOBULIN M BLOOD ONLY |
Educationimmune |
|||||
complexes, binding and |
||||||
complement activation |
||||||
Subcutaneous |
||||||
IMMUNOGLOBULIN E submucosal |
||||||
space |
||||||
IMMUNOGLOBULIN A Mucosal secretions, | ||||||
Immunity
Immunity is the body’s ability to protect its own integrity and biological individuality.
Immunity is the body's immunity to infectious diseases.
Every minute they carry the dead, And the groans of the living Fearfully ask God to calm their souls! Every minute there is a need for space, And the graves huddle together in a close line, like a frightened herd. A.S. Pushkin "Feast during the Plague"
Smallpox, plague, typhus, cholera and many other diseases deprived a huge number of people of their lives.
Terms
Antigens are bacteria, viruses or their toxins (poisons), as well as degenerated cells of the body.
Antibodies are protein molecules synthesized in response to the presence of an antigen. Each antibody recognizes its own antigen.
Lymphocytes (T and B) - have receptors on the surface of cells that recognize the “enemy”, form “antigen-antibody” complexes and neutralize antigens.
The immune system– unites organs and tissues that provide protection for the body from genetically foreign cells or substances coming from outside or formed in the body.
Central organs (red bone marrow, thymus)
Peripheral organs (lymph nodes, tonsils, spleen)
Layout of organs of the human immune system
The immune system
Central immune system
Lymphocytes are formed: in the red bone marrow - B-lymphocytes and precursors of T-lymphocytes, and in the thymus - the T-lymphocytes themselves. T and B lymphocytes are carried in the blood to peripheral organs, where they ripen and carry out their functions.
Peripheral immune system
The tonsils are located in a ring in the mucous membrane of the pharynx, surrounding the point of entry into the body of air and food.
Lymph nodes are located on the borders with external environment- in the mucous membranes of the respiratory, digestive, urinary and genital tracts, as well as in the skin.
Lymphocytes located in the spleen recognize foreign objects in the blood, which is “filtered” in this organ.
In the lymph nodes, the lymph flowing from all organs is “filtered”.
TYPES OF IMMUNITY
Natural
Artificial
Innate (passive)
Acquired (active)
Passive
Active
Inherited by the child from the mother.
Appears after infection. diseases.
Appears after vaccination.
Appears under the influence of healing serum.
Types of immunity
Active immunity
Active immunity (natural, artificial) is formed by the body itself in response to the introduction of an antigen.
Natural active immunity occurs after an infectious disease.
Active immunity
Artificial active immunity occurs after the administration of vaccines.
Passive immunity
Passive immunity (natural, artificial) is created by ready-made antibodies obtained from another organism.
Natural passive immunity is created by antibodies passed from mother to child.
Passive immunity
Artificial passive immunity occurs after the administration of therapeutic serums or as a result of volumetric blood transfusion.
The work of the immune system
A feature of the immune system is the ability of its main cells - lymphocytes - to genetically recognize “self” and “foreign”.
Immunity is ensured by the activity of leukocytes - phagocytes and lymphocytes.
Mechanism of immunity
Cellular (phagocytic) immunity (discovered by I.I. Mechnikov in 1863)
Phagocytosis is the capture and digestion of bacteria.
T lymphocytes
T-lymphocytes (formed in the bone marrow, mature in the thymus).
T-killers (killers)
T-suppressors (oppressors)
T-helpers (helpers)
Cellular immunity
Blocks B-lymphocyte reactions
Help B lymphocytes transform into plasma cells
Mechanism of immunity
Humoral immunity
B lymphocytes
B lymphocytes (formed in the bone marrow, mature in lymphoid tissue).
Antigen exposure
Plasma cells
Memory cells
Humoral immunity
Acquired immunity
Types of immune responses
Vaccination
Vaccination (from the Latin “vassa” - cow) was introduced into practice in 1796 by the English doctor Edward Jenner, who made the first vaccination “ cowpox» to an 8-year-old boy, James Phipps.
Vaccination calendar
12 hours first vaccination hepatitis B 3-7th day tuberculosis vaccination 1st month second vaccination hepatitis B 3 months first vaccination diphtheria, whooping cough, tetanus, polio, hemophilus influenzae 4.5 months second vaccination diphtheria, whooping cough, tetanus, polio, hemophilus influenzae infection 6 months third vaccination diphtheria, whooping cough, tetanus, polio, hemophilus influenzae infection, third vaccination hepatitis B 12 months vaccination measles, mumps, rubella
Calendar preventive vaccinations Russia (came into force on January 1, 2002)
Slide 1
Slide 2
ORGANS OF THE IMMUNE SYSTEM ARE DIVIDED INTO CENTRAL AND PERIPHERAL. THE CENTRAL (PRIMARY) ORGANS OF THE IMMUNE SYSTEM INCLUDE THE BONE MARROW AND THE THYMUS. IN THE CENTRAL ORGANS OF THE IMMUNE SYSTEM THE MATURATION AND DIFFERENTIATION OF IMMUNE SYSTEM CELLS FROM STEM CELLS OCCUR. IN THE PERIPHERAL (SECONDARY) ORGANS THE MATURATION OF LYMPHOID CELLS OCCURS TO THE FINAL STAGE OF DIFFERENTIATION. THESE INCLUDE THE SLEEN, LYMPH NODES AND LYMPHOID TISSUE OF THE MUCOUS MEMBRANES.
Slide 3
Slide 4
CENTRAL ORGANS OF THE IMMUNE SYSTEM DURING PERIODS OF EMBRYONAL AND POSTEMBRYONAL DEVELOPMENT
Slide 5
CENTRAL ORGANS OF THE IMMUNE SYSTEM Bone marrow. Everything is formed here shaped elements blood. Hematopoietic tissue is represented by cylindrical accumulations around arterioles. Forms cords that are separated from each other by venous sinuses. The latter flow into the central sinusoid. The cells in the cords are arranged in islands. Stem cells are localized mainly in the peripheral part of the bone marrow canal. As they mature, they move toward the center, where they penetrate the sinusoids and then enter the blood. Myeloid cells in the bone marrow make up 60-65% of the cells. Lymphoid - 10-15%. 60% of cells are immature cells. The rest are mature or newly entered into the bone marrow. Every day, about 200 million cells migrate from the bone marrow to the periphery, which is 50% of their total number. In the human bone marrow, intensive maturation of all types of cells occurs, except for T cells. The latter pass only initial stages differentiation (pro-T cells, then migrating to the thymus). Plasma cells are also found here, constituting up to 2% of the total number of cells, and producing antibodies.
Slide 6
THYMUS. SPECIALIZED EXCLUSIVELY IN THE DEVELOPMENT OF T-LYMPHOCYTES. HAS AN EPITHELIAL FRAMEWORK IN WHICH T-LYMPHOCYTES DEVELOP. IMMATURE T-LYMPHOCYTES THAT DEVELOP IN THE THYMUS ARE CALLED THYMOCYTES. MATURATING T-LYMPHOCYTES ARE TRANSIT CELLS THAT ENTER THE THYMUS IN THE FORM OF EARLY PREcursors FROM THE BONE MARROW (PROT-CELLS) AND AFTER MATURATION, EMIGRATE TO THE PERIPHERAL DEPARTMENT OF THE IMMUNE SYSTEM. THREE MAIN EVENTS OCCURRING IN THE PROCESS OF T-CELL MATURATION IN THE THYMUS: 1. APPEARANCE OF ANTIGEN-RECOGNIZING T-CELL RECEPTORS IN MATURING THYMOCYTES. 2. DIFFERENTIATION OF T-CELLS INTO SUB-POPULATIONS (CD4 AND CD8). 3. SELECTION (SELECTION) OF T-LYMPHOCYTE CLONES CAPABLE OF RECOGNIZING ONLY ALIEN ANTIGENS PRESENTED TO T-CELLS BY MOLECULES OF THE MAIN HISTO COMPATIBILITY COMPLEX OF THEIR OWN ORGANISM. THE HUMAN THYMUS CONSISTS OF TWO LOBES. EACH OF THEM IS LIMITED BY A CAPSULE, FROM WHICH CONNECTIVE TISSUE SEPTIONS GO INSIDE. SEPTATIONS DIVIDE THE PERIPHERAL PART OF THE ORGAN - THE CORTICK - into lobes. THE INNER PART OF THE ORGAN IS CALLED THE BRAIN.
Slide 7
Slide 8
PROTIMOCYTES ENTER THE CORTICAL LAYER AND AS THEY MATURATE, THEY MOVE TO THE MEDIUM LAYER. THE DEVELOPMENT TIME OF THYMOCYTES INTO MATURE T-CELLS IS 20 DAYS. IMMATURE T-CELLS ENTER THE THYMUS WITHOUT HAVING T-CELL MARKERS ON THE MEMBRANE: CD3, CD4, CD8, T-CELL RECEPTOR. AT THE EARLY STAGES OF MATURATION, ALL OF THE ABOVE MARKERS APPEAR ON THEIR MEMBRANE, THEN THE CELLS MULTIPLY AND PASS TWO STAGES OF SELECTION. 1. POSITIVE SELECTION - SELECTION FOR THE ABILITY TO RECOGNIZE OWN MOLECULES OF THE MAIN HISTOSCOMPATIBILITY COMPLEX WITH THE HELP OF A T-CELL RECEPTOR. CELLS THAT ARE NOT ABLE TO RECOGNIZE THEIR OWN MOLECULES OF THE MAIN HISTO COMPATIBILITY COMPLEX DIE BY APOPTOSIS (PROGRAMMED CELL DEATH). SURVIVING THYMOCYTES LOSE ONE OF FOUR T-CELL MARKERS - EITHER CD4 OR CD8 MOLECULE. AS A RESULT, THE SO-CALLED “DOUBLE POSITIVE” (CD4 CD8) THYMOCYTES BECOME SINGLE POSITIVE. EITHER THE CD4 OR CD8 MOLECULE IS EXPRESSED ON THEIR MEMBRANE. THUS, THE DIFFERENCES ARE ESTABLISHED BETWEEN THE TWO MAIN POPULATIONS OF T-CELLS - CYTOTOXIC CD8 CELLS AND HELPER CD4 CELLS. 2. NEGATIVE SELECTION - SELECTION OF CELLS FOR THEIR ABILITY TO NOT RECOGNIZE THE ORGANISM’S OWN ANTIGENS. AT THIS STAGE, POTENTIAL AUTOREACTIVE CELLS ARE ELIMINATED, THAT IS, CELLS WHOSE RECEPTOR IS CAPABLE OF RECOGNIZING ANTIGENS OF THEIR OWN BODY. NEGATIVE SELECTION LAYS THE FOUNDATIONS FOR THE FORMATION OF TOLERANCE, THAT IS, THE IMMUNE SYSTEM’S IMMUNE RESPONSES TO ITS OWN ANTIGENS. AFTER TWO STAGES OF SELECTION, ONLY 2% OF THYMOCYTES SURVIVE. SURVIVING THYMOCYTES MIGRATE INTO THE MEDUAL LAYER AND THEN LEAVE INTO THE BLOOD, BECOMING “NAIVE” T-LYMPHOCYTES.
Slide 9
PERIPHERAL LYMPHOID ORGANS Scattered throughout the body. The main function of peripheral lymphoid organs is the activation of naive T and B lymphocytes with the subsequent formation of effector lymphocytes. There are encapsulated peripheral organs of the immune system (spleen and lymph nodes) and non-encapsulated lymphoid organs and tissues.
Slide 10
LYMPH NODES CONSTITUTE THE MAIN MASS OF ORGANIZED LYMPHOID TISSUE. THEY ARE LOCATED REGIONALLY AND ARE NAMED ACCORDING TO THE LOCATION (ARMILLARY, INGUINAL, PAROTICAL, ETC.). LYMPH NODES PROTECT THE BODY FROM ANTIGENS THAT PENETRATE THROUGH THE SKIN AND MUCOUS MEMBRANES. FOREIGN ANTIGENS ARE TRANSPORTED TO THE REGIONAL LYMPH NODES THROUGH LYMPHATIC VESSELS, OR WITH THE HELP OF SPECIALIZED ANTIGEN PRESENTING CELLS, OR WITH THE FLOW OF FLUID. IN THE LYMPH NODES, ANTIGENS ARE PRESENTED TO NAIVE T-LYMPHOCYTES BY PROFESSIONAL ANTIGEN-PRESENTING CELLS. THE RESULT OF THE INTERACTION OF T-CELLS AND ANTIGEN-PRESENTING CELLS IS THE CONVERSION OF NAIVE T-LYMPHOCYTES INTO MATURE EFFECTOR CELLS CAPABLE OF PERFORMING PROTECTIVE FUNCTIONS. LYMPH NODES HAVE A B-CELL CORTICAL AREA (CORTICAL ZONE), A T-CELL PARACORTICAL AREA (ZONE) AND A CENTRAL, MEDULLARY (BRAIN) ZONE FORMED BY CELL TRADES CONTAINING T- AND B- LYMPHOCYTES, PLASMA CELLS AND MACROPHAGES. THE CORTICAL AND PARACORTICAL AREAS ARE SEPARATED BY CONNECTIVE TISSUE TRABECULAS INTO RADIAL SECTORS.
Slide 11
Slide 12
LYMPH ENTERS THE NODE THROUGH SEVERAL AFFERENT LYMPHATIC VESSELS THROUGH THE SUBCAPSULAR ZONE COVERING THE CORTICAL AREA. FROM THE LYMPH NODE LYMPH EXITS THROUGH A SINGLE EFFERENT (EFFERENT) LYMPHATIC VESSEL IN THE AREA OF THE SO-CALLED GATE. THROUGH THE GATE THROUGH THE CORRESPONDING VESSELS, BLOOD ENTERS AND OUTSIDE THE LYMPH NODE. IN THE CORTICAL REGION ARE LOCATED LYMPHOID FOLLICLES, CONTAINING REPRODUCTION CENTERS, OR “GERMINAL CENTERS,” IN WHICH THE MATURATION OF B CELLS THAT ENCOUNTER THE ANTIGEN OCCURS.
Slide 13
Slide 14
THE MATURATION PROCESS IS CALLED AFFINE MATURATION. IT IS ACCOMPANIED BY SOMATIC HYPERMUTATIONS OF VARIABLE IMMUNOGLOBULIN GENES, OCCURING WITH A FREQUENCY 10 TIMES HIGHER THAN THE FREQUENCY OF SPONTANEOUS MUTATIONS. SOMATIC HYPERMUTATIONS LEAD TO INCREASED ANTIBODY AFFINITY WITH THE SUBSEQUENT REPRODUCTION AND CONVERSION OF B CELLS INTO PLASMA ANTIBODY PRODUCING CELLS. PLASMA CELLS ARE THE FINAL STAGE OF B-LYMPHOCYTE MATURATION. T-LYMPHOCYTES ARE LOCALIZED IN THE PARACORTICAL AREA. IT'S CALLED T-DEPENDENT. THE T-DEPENDENT AREA CONTAINS MANY T-CELLS AND CELLS WITH MULTIPLE PROGRESSES (DENDRITIC INTERDIGITAL CELLS). THESE CELLS ARE ANTIGEN-PRESENTING CELLS THAT ENTERED THE LYMPH NODE THROUGH AFFERENT LYMPHATIC VESSELS AFTER MEETING A FOREIGN ANTIGEN AT THE PERIPHERY. NAIVE T-LYMPHOCYTES, IN THEIR TURN, ENTER THE LYMPH NODES WITH THE LYMPH FLOW AND THROUGH POST-CAPILLARY VENULES, HAVING AREAS OF THE SO-CALLED HIGH ENDOTHELIUM. IN THE T-CELL AREA, NAIVE T-LYMPHOCYTES ARE ACTIVATED WITH THE HELP OF ANTI-GEN-PRESENTING DENDRITIC CELLS. ACTIVATION RESULTS IN PROLIFERATION AND FORMATION OF CLONES OF EFFECTOR T-LYMPHOCYTES, WHICH ARE ALSO CALLED ARMED T-CELLS. THE LATTER ARE THE FINAL STAGE OF MATURATION AND DIFFERENTIATION OF T-LYMPHOCYTES. THEY LEAVE THE LYMPH NODES TO PERFORM EFFECTIVE FUNCTIONS FOR WHICH THEY WERE PROGRAMMED BY ALL PREVIOUS DEVELOPMENT.
Slide 15
THE SPLEN IS A LARGE LYMPHOID ORGAN, DIFFERENT FROM THE LYMPH NODES BY THE PRESENCE OF A LARGE NUMBER OF RED CYTES. THE MAIN IMMUNOLOGICAL FUNCTION IS THE ACCUMULATION OF ANTIGENS BROUGHT WITH THE BLOOD AND THE ACTIVATION OF T- AND B-LYMPHOCYTES REACTING TO THE ANTIGEN BROUGHT BY THE BLOOD. THE SPLEN HAS TWO MAIN TYPES OF TISSUE: THE WHITE PULP AND THE RED PULP. THE WHITE PULP IS CONSISTED OF LYMPHOID TISSUE, WHICH FORMES PERIARTERIOLARY LYMPHOID COUPLINGS AROUND THE ARTERIOLES. THE COUPLERS HAVE T- AND B-CELL AREAS. A T-DEPENDENT AREA OF THE CLUTCH, SIMILAR TO THE T-DEPENDENT AREA OF LYMPH NODES, IMMEDIATELY SURROUNDS THE ARTERIOLE. B-CELL FOLLICLES CONSTITUTE THE B-CELL REGION AND ARE LOCATED CLOSE TO THE EDGE OF THE MOUNT. THERE ARE REPRODUCTION CENTERS IN THE FOLLICLES, SIMILAR TO THE GERMINAL CENTERS OF LYMPH NODES. IN THE CENTERS OF REPRODUCTION, DENDRITIC CELLS AND MACROPHAGES ARE LOCALIZED, PRESENTING ANTIGEN TO B-CELLS WITH THE SUBSEQUENT CONVERSION OF THE LATTER INTO PLASMA CELLS. MATURATING PLASMA CELLS PASS THROUGH VASCULAR JINDERS INTO THE RED PULP. THE RED PULP IS A METHOUS NETWORK FORMED BY VENOUS SINUSOIDS, CELLULAR TRADS AND FILLED WITH ERYTHROCYTES, PLATELETS, MACROPHAGES, AND OTHER CELLS OF THE IMMUNE SYSTEM. THE RED PULP IS A SITE OF DEPOSITATION OF erythrocytes and platelets. THE CAPILLARIES WITH WHICH END THE CENTRAL ARTERIOLES OF THE WHITE PULP OPEN FREELY IN BOTH THE WHITE PULP AND IN THE RED PULP TRADS. BLOOD CELLS, HAVING REACHED THE HEAVY RED PULP, ARE RETAINED IN THEM. HERE MACROPHAGES RECOGNIZE AND PHAGOCYTE SURVIVED erythrocytes and platelets. PLASMA CELLS, MOVED INTO THE WHITE PULP, CARRY OUT THE SYNTHESIS OF IMMUNOGLOBULINS. BLOOD CELLS NOT ABSORBED AND NOT DESTROYED BY PHAGOCYTES PASS THROUGH THE EPITHELIAL LINING OF VENOUS SINUSOIDS AND RETURN TO THE BLOOD STREAM TOGETHER WITH PROTEINS AND OTHER PLASMA COMPONENTS.
Slide 16
NON-ENCAPSULATED LYMPHOID TISSUE Most of the non-encapsulated lymphoid tissue is located in the mucous membranes. In addition, non-encapsulated lymphoid tissue is localized in the skin and other tissues. Lymphoid tissue of the mucous membranes protects only the mucous surfaces. This distinguishes it from the lymph nodes, which protect against antigens that penetrate both the mucous membranes and the skin. The main effector mechanism of local immunity at the mucosal level is the production and transport of secretory antibodies IgA class directly onto the surface of the epithelium. Most often, foreign antigens enter the body through the mucous membranes. In this regard, antibodies of the IgA class are produced in the body in the greatest quantities relative to antibodies of other isotypes (up to 3 g per day). The lymphoid tissue of the mucous membranes includes: - Lymphoid organs and formations associated with the gastrointestinal tract (GALT - gut-associated lymphoid tissues). Includes lymphoid organs of the peripharyngeal ring (tonsils, adenoids), appendix, Peyer's patches, intraepithelial lymphocytes of the intestinal mucosa. - Lymphoid tissue associated with bronchi and bronchioles (BALT - bronchial-associated lymphoid tissue), as well as intraepithelial lymphocytes of the mucous membrane respiratory tract. - Lymphoid tissue of other mucous membranes (MALT - mucosal associated lymphoid tissue), including as the main component the lymphoid tissue of the mucous membrane of the urogenital tract. Lymphoid tissue of the mucosa is most often localized in the basal plate of the mucous membranes (lamina propria) and in the submucosa. An example of mucosal lymphoid tissue is Peyer's patches, which are usually found in the lower part ileum. Each plaque is adjacent to a portion of the intestinal epithelium called follicle-associated epithelium. This area contains so-called M cells. Bacteria and other foreign antigens enter the subepithelial layer from the intestinal lumen through M cells.
Slide 17
Slide 18
THE BASIC MASS OF LYMPHOCYTES IN PEYER'S PATCH ARE LOCATED IN A B-CELL FOLLICLE WITH A GERMINAL CENTER IN THE MIDDLE. T-CELL ZONES SURROUND THE FOLLICLE CLOSE TO THE EPITHELIAL CELL LAYER. THE MAIN FUNCTIONAL LOAD OF PEYER'S PATCHES IS THE ACTIVATION OF B-LYMPHOCYTES AND THEIR DIFFERENTIATION INTO PLASMA CYTES PRODUCING ANTIBODIES OF THE IGA AND IGE CLASSES. IN ADDITION TO ORGANIZED LYMPHOID TISSUE, IN THE EPITHELIAL LAYER OF THE MUCOUS AND IN LAMINA PROPRIA, THERE ARE ALSO SINGLE DISSEMINATED T-LYMPHOCYTES. THEY CONTAIN BOTH ΑΒ T CELL RECEPTOR AND ΓΔ T CELL RECEPTOR. IN ADDITION TO LYMPHOID TISSUE OF MUCOUS SURFACES, NON-ENCAPSULATED LYMPHOID TISSUE INCLUDES: - SKIN-ASSOCIATED LYMPHOID TISSUE AND INTRAEPITHELIAL LYMPHOCYTES OF THE SKIN; - LYMPH, TRANSPORTING ALIEN ANTIGENS AND CELLS OF THE IMMUNE SYSTEM; - PERIPHERAL BLOOD, UNITING ALL ORGANS AND TISSUE AND PERFORMING A TRANSPORT AND COMMUNICATION FUNCTION; - CLUMPS OF LYMPHOID CELLS AND SINGLE LYMPHOID CELLS OF OTHER ORGANS AND TISSUE. AN EXAMPLE COULD BE LIVER LYMPHOCYTES. THE LIVER PERFORMES QUITE IMPORTANT IMMUNOLOGICAL FUNCTIONS, ALTHOUGH IT IS NOT CONSIDERED AN ORGAN OF THE IMMUNE SYSTEM FOR AN ADULT BODY. NEVERTHELESS, ALMOST HALF OF THE ORGANISM'S TISSUE MACROPHAGES ARE LOCALIZED IN IT. THEY PHAGOCYTATE AND DISSOLVE IMMUNE COMPLEXES THAT BRING RED CELLS HERE ON THEIR SURFACE. IN ADDITION, IT IS ASSUMED THAT LYMPHOCYTES LOCALIZED IN THE LIVER AND IN THE INTESTINAL SUBMUCOSA HAVE SUPPRESSOR FUNCTIONS AND PROVIDE CONTINUOUS MAINTENANCE OF IMMUNOLOGICAL TOLERANCE (UNRESPONDENCE) TO FOOD.
Immunity (lat . immunitas‘liberation, getting rid of something’) is the ability of the immune system to rid the body of genetically foreign objects.
Provides homeostasis of the body at the cellular and molecular level of organization.
Purpose of immunity:
- Protozoa defense mechanisms, aimed at recognizing and neutralizing pathogens,
resisting the invasion of genetically alien objects
- Ensuring the genetic integrity of individuals of a species throughout their individual lives
- The ability to distinguish “one’s own” from “someone else’s”;
- Memory formation after initial contact with foreign antigenic material;
- Clonal organization of immunocompetent cells, in which an individual cell clone is capable, as a rule, of responding to only one of many antigenic determinants.
Classifications Classification
Congenital (non-specific)
Adaptive (acquired, specific)
There are also several other classifications of immunity:
- Purchased active immunity occurs after an illness or after the administration of a vaccine.
- Acquired passive immunity develops when ready-made antibodies are introduced into the body in the form of serum or transferred to a newborn with mother’s colostrum or in utero.
- Natural immunity includes innate immunity and acquired active (after an illness), as well as passive immunity when antibodies are transferred to the child from the mother.
- Artificial immunity includes acquired active after vaccination (vaccine administration) and acquired passive (serum administration).
- Immunity is divided into species (inherited to us due to the characteristics of our – human – body) And acquired as a result of “training” of the immune system.
- Thus, it is precisely the innate properties that protect us from canine distemper, and “training by vaccination” – from tetanus.
Sterile and non-sterile immunity .
- After illness, in some cases, immunity remains for life. For example, measles, chicken pox. This is sterile immunity. And in some cases, immunity lasts only as long as there is a pathogen in the body (tuberculosis, syphilis) - non-sterile immunity.
The main organs responsible for immunity are: red bone marrow, thymus, lymph nodes and spleen . Each of them performs its own important work and complements each other.
Mechanisms of immune system defense
There are two main mechanisms through which immune reactions. These are humoral and cellular immunity. As the name suggests, humoral immunity is realized through the formation of certain substances, and cellular immunity is realized through the work of certain cells of the body.
- This mechanism of immunity manifests itself in the formation of antibodies to antigens - foreign chemicals, as well as microbial cells. Fundamental role in humoral immunity taken over by B lymphocytes. They are the ones who recognize foreign structures in the body, and then produce antibodies against them - specific protein substances, which are also called immunoglobulins.
- The antibodies that are produced are extremely specific, that is, they can only interact with those foreign particles that caused the formation of these antibodies.
- Immunoglobulins (Ig) are found in the blood (serum), on the surface of immunocompetent cells (surface), and also in secretions gastrointestinal tract, tear fluid, breast milk(secretory immunoglobulins).
- In addition to being highly specific, antigens also have other biological characteristics. They have one or more active centers that interact with antigens. More often there are two or more. The strength of the connection between the active center of an antibody and an antigen depends on the spatial structure of the substances involved in the connection (i.e., antibody and antigen), as well as the number of active centers in one immunoglobulin. Several antibodies can bind to one antigen at once.
- Immunoglobulins have their own classification using Latin letters. In accordance with it, immunoglobulins are divided into Ig G, Ig M, Ig A, Ig D and Ig E. They differ in structure and function. Some antibodies appear immediately after infection, while others appear later.
Ehrlich Paul discovered humoral immunity.
Cellular immunity
Ilya Ilyich Mechnikov discovered cellular immunity.
- Phagocytosis (Phago - devour and cytos - cell) is a process in which special cells of the blood and body tissues (phagocytes) capture and digest pathogens of infectious diseases and dead cells. It is carried out by two types of cells: granular leukocytes (granulocytes) circulating in the blood and tissue macrophages. The discovery of phagocytosis belongs to I. I. Mechnikov, who identified this process by conducting experiments with sea stars and daphnia, introducing into their bodies foreign bodies. For example, when Mechnikov placed a fungal spore into the body of daphnia, he noticed that it was attacked by special mobile cells. When he introduced too many spores, the cells did not have time to digest them all, and the animal died. Mechnikov called cells that protect the body from bacteria, viruses, fungal spores, etc. phagocytes.
- Immunity is the most important process of our body, helping to maintain its integrity, protecting it from harmful microorganisms and foreign agents.
