Immunity and immune system presentation. Presentation on the topic: Organs of the immune system. Barrier functions of the skin

Lecture plan PURPOSE: to teach students an understanding of the structural and functional organization of the immune system,
features of innate and adaptive
immunity.
1. The concept of immunology as a subject, basic
stages of its development.
2. .
3 Types of immunity: features of innate and
adaptive immunity.
4. Characteristics of cells involved in reactions
innate and adaptive immunity.
5. Structure of central and peripheral organs
immune system functions.
6. Lymphoid tissue: structure, function.
7. GSK.
8. Lymphocyte – structural and functional unit
immune system.

A clone is a group of genetically identical cells.
Cell population – cell types with the most
general properties
Subpopulation of cells - more specialized
homogeneous cells
Cytokines – soluble peptide mediators
immune system, necessary for its development,
functioning and interaction with others
systems of the body.
Immunocompetent cells (ICC) - cells
ensuring the performance of immune functions
systems

Immunology

- the science of immunity, which
studies structure and function
body immune system
person as under normal conditions,
as well as in pathological
states.

Immunology studies:

The structure of the immune system and mechanisms
development of immune reactions
Diseases of the immune system and its dysfunction
Conditions and patterns of development
immunopathological reactions and methods for them
corrections
Possibility of using reserves and
mechanisms of the immune system in the fight against
infectious, oncological, etc.
diseases
Immunological problems of transplantation
organs and tissues, reproduction

Main stages in the development of immunology

Pasteur L. (1886) - vaccines (prevention of infectious diseases
diseases)
Bering E., Ehrlich P. (1890) - laid the foundation for humoral
immunity (discovery of antibodies)
Mechnikov I.I. (1901-1908) - theory of phagocytosis
Bordet J. (1899) – discovery of the complement system
Richet S., Portier P. (1902) - discovery of anaphylaxis
Pirke K. (1906) – the doctrine of allergies
Landsteiner K. (1926) – discovery of blood groups AB0 and Rh factor
Medovar (1940-1945) - the doctrine of immunological tolerance
Dosse J., Snell D. (1948) - laid the foundations of immunogenetics
Miller D., Klaman G., Davis, Royt (1960) - the doctrine of T- and B
immune systems
Dumond (1968-1969) – discovery of lymphokines
Koehler, Milstein (1975) - method for obtaining monoclonal
antibodies (hybridomas)
1980-2010 – development of diagnostic and treatment methods
immunopathology

Immunity

- a way to protect the body from living bodies and
substances that carry genetic characteristics
foreign information (including
microorganisms, foreign cells,
tissue or genetically altered
own cells, including tumor cells)

Types of immunity

Innate immunity is hereditary
fixed defense system of multicellular organisms
organisms from pathogenic and non-pathogenic
microorganisms, as well as endogenous products
tissue destruction.
Acquired (adaptive) immunity is formed throughout life under the influence of
antigenic stimulation.
Innate and acquired immunity are
two interacting parts of the immune system
systems that ensure the development of the immune system
response to genetically foreign substances.

Systemic immunity – at the level
the whole body
Local immunity -
additional level of protection
barrier fabrics ( skin And
mucous membranes)

Functional organization of the immune system

Innate immunity:
- stereotyping
- non-specificity
(regulated by the pituitary-adrenal system)
Mechanisms:
anatomical and physiological barriers (skin,
mucous membranes)
humoral components (lysozyme, complement, INFα
and β, proteins acute phase, cytokines)
cellular factors (phagocytes, NK cells, platelets,
red blood cells, mast cells, endothelial cells)

Functional organization of the immune system

Acquired immunity:
specificity
formation of immunological
memory during the immune response
Mechanisms:
humoral factors- immunoglobulins
(antibodies)
cellular factors – mature T-, B-lymphocytes

The immune system

- a set of specialized bodies,
tissues and cells located in
different parts of the body, but
functioning as a single whole.
Peculiarities:
generalized throughout the body
constant recycling of lymphocytes
specificity

Physiological significance of the immune system

security
immunological
individuality throughout life
immune recognition account with
involving components of congenital and
acquired immunity.

antigenic
nature
endogenously arising
(cells,
changed
viruses,
xenobiotics,
tumor cells and
etc.)
or
exogenously
penetrating
V
organism

Properties of the immune system

Specificity - “one AG – one AT – one clone
lymphocytes"
High degree sensitivity - recognition
AG by immunocompetent cells (ICC) at the level
individual molecules
Immunological individuality “specificity of the immune response” - for everyone
the organism has its own characteristic, genetically
controlled type of immune response
Clonal principle of organization - ability
all cells within a single clone respond
only for one antigen
Immunological memory is the ability of the immune system
systems (memory cells) respond quickly and
intensively for re-entry of antigen

Properties of the immune system

Tolerance is a specific unresponsiveness to
body's own antigens
The ability to regenerate is a property of the immune system
systems to maintain lymphocyte homeostasis due to
replenishment of the pool and control of the population of memory cells
The phenomenon of “double recognition” of antigen by T lymphocytes - the ability to recognize foreign
antigens only in association with MHC molecules
Regulatory effect on other body systems

Structural and functional organization of the immune system

Structure of the immune system

Organs:
central (thymus, red Bone marrow)
peripheral (spleen, lymph nodes, liver,
lymphoid accumulations in different organs)
Cells:
lymphocytes, leukocytes (mon/mf, nf, ef, bf, dk),
mast cells, vascular endothelium, epithelium
Humoral factors:
antibodies, cytokines
ICC circulation pathways:
peripheral blood, lymph

Immune system organs

Features of the central organs of the immune system

Located in areas of the body
protected from external influences
(bone marrow - in the bone marrow cavities,
thymus in the chest cavity)
The bone marrow and thymus are the site
lymphocyte differentiation
In the central organs of the immune system
lymphoid tissue is in a peculiar
microenvironment (in the bone marrow -
myeloid tissue, in the thymus - epithelial)

Features of peripheral organs of the immune system

Located on the paths of the possible
introduction of foreign substances into the body
antigens
Consistently increasing their complexity
buildings depending on size and
duration of antigenic
impact.

Bone marrow

Functions:
hematopoiesis of all types of blood cells
antigen-independent
differentiation and maturation B
- lymphocytes

Hematopoiesis scheme

Types of stem cells

1. Hematopoietic stem cells (HSCs) –
located in the bone marrow
2. Mesenchymal (stromal) stems
cells (MSCs) – a population of pluripotent
bone marrow cells capable of
differentiation into osteogenic, chondrogenic,
adipogenic, myogenic and other cell lines.
3. Tissue-specific progenitor cells
(progenitor cells) –
poorly differentiated cells
located in various fabrics and organs
are responsible for updating the cell population.

Hematopoietic stem cell (HSC)

Stages of development of GSK
Multipotent stem cell– proliferates and
differentiates into parent stems
cells for myelo- and lymphopoiesis
Progenitor stem cell - limited in
self-maintenance, intensively proliferates and
differentiates in 2 directions (lymphoid
and myeloid)
Progenitor cell - differentiates
into only one type of cell (lymphocytes,
neutrophils, monocytes, etc.)
Mature cells - T-, B-lymphocytes, monocytes, etc.

Features of GSK

(the main marker of HSC is CD 34)
Poor differentiation
Self-sustaining ability
Moving through the bloodstream
Repopulation of hemo- and immunopoiesis after
radiation exposure or
chemotherapy

Thymus

Consists of lobules
medulla.
each has a cortical
And
The parenchyma is represented by epithelial cells,
containing a secretory granule that secretes
“thymic hormonal factors.”
The medulla contains mature thymocytes, which
turn on
V
recycling
And
populate
peripheral organs of the immune system.
Functions:
maturation of thymocytes into mature T cells
secretion of thymic hormones
regulation of T cell function in others
lymphoid organs through
thymic hormones

Lymphoid tissue

- specialized fabric that provides
concentration of antigens, contact of cells with
antigens, transport of humoral substances.
Encapsulated – lymphoid organs
(thymus, spleen, lymph nodes, liver)
Unencapsulated – lymphoid tissue
mucous membranes, associated with the gastrointestinal tract,
respiratory and genitourinary system
Lymphoid subsystem of the skin -
disseminated intraepithelial
lymphocytes, regional lymph nodes, vessels
lymphatic drainage

Lymphocytes are the structural and functional unit of the immune system

specific
continuously generate
diversity of clones (1018 variants in T-
lymphocytes and 1016 variants in B-lymphocytes)
recirculation (between blood and lymph in
on average about 21 hours)
renewal of lymphocytes (at a speed of 106
cells per minute); among peripheral lymphocytes
blood 80% long-lived memory lymphocytes, 20%
naive lymphocytes formed in the bone marrow
and have not had contact with the antigen)

Literature:

1. Khaitov R.M. Immunology: textbook. For
students of medical universities. - M.: GEOTAR-Media,
2011.- 311 p.
2. Khaitov R.M. Immunology. Norm and
pathology: textbook. for students of medical universities and
Univ.- M.: Medicine, 2010.- 750 p.
3. Immunology: textbook / A.A. Yarilin.- M.:
GEOTAR-Media, 2010.- 752 p.
4. Kovalchuk L.V. Clinical immunology
and allergology with the basics of general
Immunology: textbook. – M.: GEOTARMEDIA, 2011.- 640 p.

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Text content of presentation slides: Central and peripheral hematopoietic organs and immune defense Author Ananyev N.V. GBPOU DZM "MK No. 1" 20016 The central organ of hematopoiesis is the red bone marrow The central organ of immune defense is the thymus Peripheral organs Spleen tonsils Lymph nodes Lymphoid follicles Red bone marrow In the embryo, it fills most bones, including tubular ones. In adults it is located: in flat bones, in vertebral bodies, in the epiphyses tubular bones. Red bone marrow Reticular tissue Hematopoietic elements Reticular tissue consists of: Cells Intercellular substance Reticular fibers Cells: 1. Reticular cells (fibroblast-like) 2. Macrophages 3. A small number of fat cells Hematopoietic elements – 1. All types of hematopoietic cells located on different levels differentiation 2. blood stem cells 3. mature blood cells Hematopoietic islets are groups of cells in the bone marrow. Red bone marrow I. ERYTHROPOIETIC ISLANDS: 1 - proerythroblast, 2-4 - erythroblasts: basophilic (2); polychromatophilic (3); oxyphilic (4); 5 - red blood cells. II. GRANULOCYTOPOIETIC ISLANDS (eosinophilic, basophilic, neutrophilic): 6 - promyelocyte, 7A-7B - myelocytes: eosinophilic (7A), basophilic (7B), neutrophilic (7B); 8A-8B - metamyelocytes: eosinophilic (8A) and basophilic (8B); 9 - band granulocyte (neutrophil); 10A-10B - segmented granulocytes: eosinophilic (10A) and neutrophilic (10B). III. Other hematopoietic cells: 11 - megakaryocyte; 12 - cells similar to small lymphocytes (cells of classes I - III and more mature cells of the monocyte and B-lymphocyte series). IV. Other components of red bone marrow: 13 - reticular cells (form stroma); 14 - adipocytes, 15 - macrophages; 16 - perforated sinusoidal capillaries. Features of blood supply - The bone marrow contains sinusoidal capillaries that do not allow immature blood cells to pass from the bone marrow into the blood. Mature cells enter the capillaries and the bloodstream. Functions Hematopoiesis is the formation of all blood cells. Differentiation of B lymphocytes, which then populate peripheral organs Thymus consists of stroma and parenchyma Stroma is loose fibrous connective tissue, which forms the outer shell. Partitions extend from it into the gland and divide the gland into lobules. Parenchyma - consists of epithelial and lymphocytic structures. The thymus lobule has 3 parts: Subcapsular zone Cortical substance Medullary substance The thymic lobule has 3 parts Subcapsular zone Consists of branched epithelial cells that are connected to each other using processes. Functions: participation in the differentiation and maturation of T-lymphocytes under the control of thymic hormones: thymosin, thymopoietin Cortical substance Formed by precursor cells of T-lymphocytes and T-lymphocytes located at different levels of differentiation and macrophages. The cortex is darker than the medulla. Functions: differentiation of T-lymphocytes. The medulla is formed by T-lymphocytes and macrophages and thymic bodies - a layer of epithelial cells that have lost their oval-shaped processes. But there are significantly fewer of them than in the cortex, so it looks lighter when stained. Functions: unknown, perhaps some stages of differentiation of T-lymphocytes Features of blood supply: 1. The cortex and medulla are supplied with blood separately2. Blood from the cortex, without entering the medulla, immediately flows out of the thymus3. In the cortex there is a hematothymic barrier - a barrier between the parenchyma of the thymus and the blood of the capillaries of the cortex. The hematothymic barrier delays the flow of high-molecular substances from the capillaries into the thymus and allows thymocytes to differentiate in the absence of contact with foreign antigens. Involution of the thymus The thymus reaches its maximum development in childhood when the body’s immune system is intensively formed. IN old age its age-related involution occurs - a decrease in size and a decrease in functions. Under the influence of stress due to the effects of glucocorticoids (adrenal hormones), rapid involution occurs. Thymus cells die by apoptosis, the thymus shrinks, and its parenchyma is replaced by adipose tissue. Spleen The spleen consists of stroma and parenchyma. Stroma is loose fibrous connective tissue that forms the outer shell. Partitions - trabeculae - extend from it into the gland. Parenchyma - consists of pulp: red and white. White pulp consists of lymphoid nodules. Lymphoid nodules of the spleen have a diameter of 0.3-0.5 mm. In the center of the nodule is an arteriole. The basis of the nodule is formed by reticular tissue, in the loops of which lymphocytes lie. There are 2 zones in the nodule: B-zone - the largest part, responsible for the differentiation of B-lymphocytes. T-zone - the smaller part - reproduction and differentiation of T-lymphocytes. Nodules have 3 stages of development: 1. Initial 2. Without a light center 3. With a light center - an indicator of high functional activity. Formed during antigenic stimulation. Lymph node with a light center It has 3 zones: 1. Reproduction center 2. Periarterial zone 3. Mantle or marginal layer Reproduction center Here are B-lymphocytes and their antigen-dependent differentiation occurs Periarterial zone Here are T-lymphocytes and their antigen-dependent differentiation occurs Mantle layer Here the interaction between T and B lymphocytes occurs, which is necessary for their differentiation. Red pulp Occupies most of the spleen. Comprises sinusoidal capillaries containing blood and reticular tissue. Functions of the spleen White pulp - antigen dependent differentiation of T and B lymphocytes. Red pulp – Death of old red blood cells. Death of old platelets. Blood depot – up to 1 liter. The final stages of lymphocyte differentiation. Blood supply to the spleen Splenic artery – trabecular arteries – pulp arteries – central arteries (inside the nodule) – brush arteries (have sphincters) – ellipsoid arterioles – hemocapillaries. Blood supply to the spleen A minority of the hemocapillaries opens into the red pulp, the majority passes into the venous sinuses. A sinus is a cavity filled with blood. From the sinuses, blood can flow into the red pulp or into the venous capillaries. Blood supply to the spleen The venous sphincters contract - blood accumulates in the sinuses, they stretch. Arterial sphincters contract - shaped elements blood exits through pores in the walls of the sinuses into the red pulp. All sphincters are relaxed - blood from the sinuses flows into the veins, they empty. Blood supply to the spleen From the sinus, blood enters the pulp veins - trabecular veins - splenic vein - hepatic portal vein (portal). The lymph nodes

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 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.

CENTRAL ORGANS OF THE IMMUNE SYSTEM Bone marrow. All the formed elements of blood are formed here. 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 account for 60-65% of 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 bone marrow man is walking intensive maturation of all cell types except 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.

T IMUS. C SPECIALIZES EXCLUSIVELY ON THE DEVELOPMENT OF T-LYMPHOCYTES. AND HAS AN EPITHELIAL FRAMEWORK IN WHICH T-LYMPHOCYTES DEVELOP. IMATURE 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 (PR-T-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. DIFFERENTATION OF T-CELLS INTO SUB-POPULATIONS (CD4 AND CD8). 3. ABOUT 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 TIMUS CONSISTS OF TWO LOBES. EACH OF THEM IS LIMITED BY A CAPSULE, FROM WHICH CONNECTIVE FABRIC SEPARATIONS GO INSIDE. THE SEPTIA DIVIDE THE PERIPHERAL PART OF THE ORGAN CORTEX INTO LOBES. THE INTERNAL PART OF THE ORGAN IS CALLED THE BRAIN.

P ROTYMOCYTES ENTER THE CORTICAL LAYER AND AS THEY MATURATE, THEY MOVE TO THE MEDIUM LAYER. FROM THE DEVELOPMENT 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 HISTO COMPATIBILITY COMPLEX WITH THE HELP OF THE 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). THE SURVIVED THYMOCYTES LOSE ONE OF THE FOUR T-CELL MARKERS OR THE CD4 OR CD8 MOLECULE. AS A RESULT, THE SO-CALLED “DOUBLE POSITIVE” (CD4 CD8) THYMOCYTES BECOME SINGLE POSITIVE. ON THEIR MEMBRANE EITHER THE CD4 OR THE CD8 MOLECULE IS EXPRESSED. THEREFORE, 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. THE SURVIVED THYMOCYTES MIGRATE TO THE MEDUAL LAYER AND THEN LEAVE INTO THE BLOOD, TURNING INTO “NAIVE” T-LYMPHOCYTES.

P 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.

L LYMPHATIC NODES CONSTITUTE THE MAIN MASS OF ORGANIZED LYMPHOID TISSUE. THEY ARE REGIONALLY LOCATED AND ARE NAMED ACCORDING TO THE LOCATION (AXILLARY, INGUINAL, PAROTICAL, ETC.). L LYMPHATIC NODES PROTECT THE BODY FROM ANTIGENS THAT PENETRATE THROUGH THE SKIN AND MUCOUS MEMBRANES. H CARRONS 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. L 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 ORCAL AND PARACORTICAL AREAS ARE DIVIDED BY CONNECTIVE TISSUE TRABECULES INTO RADIAL SECTORS.

L LYMPH ENTERS THE NODE THROUGH SEVERAL AFFERENT LYMPHATIC VESSELS THROUGH THE SUBCAPSULAR ZONE COVERING THE CORTICAL AREA. AND FROM THE LYMPH NODE, LYMPH EXITS THROUGH A SINGLE OUTFERING (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 MULTIPLICATION CENTERS, OR “GERMINAL CENTERS,” IN WHICH THE MATURATION OF B CELLS THAT ENCOUNTER THE ANTIGEN OCCURS.

THE PROCESS OF MATURATION IS CALLED AFFINE MATURATION. O N IS ACCOMPANIED BY SOMATIC HYPERMUTATIONS OF VARIABLE IMMUNOGLOBULIN GENES, OCCURING WITH A FREQUENCY 10 TIMES EXCEEDING THE FREQUENCY OF SPONTANEOUS MUTATIONS. C OMATIC HYPERMUTATIONS RESULT IN AN INCREASE IN THE AFFINITY OF ANTIBODIES WITH THE SUBSEQUENT REPRODUCTION AND CONVERSION OF B CELLS INTO PLASMA ANTIBODY PRODUCING CELLS. P PLASMIC CELLS ARE THE FINAL STAGE OF B-LYMPHOCYTE MATURATION. T-LYMPHOCYTES ARE LOCALIZED IN THE PARACORTICAL AREA. E E IS 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 ARRIVED INTO THE LYMPH NODE THROUGH THE AFFERENT LYMPHATIC VESSELS AFTER MEETING WITH A FOREIGN ANTIGEN AT THE PERIPHERY. NIVE T-LYMPHOCYTES, IN THEIR TURN, ENTER THE LYMPH NODES WITH THE LYMPH CURRENT 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. AND ACTIVATION RESULTS IN PROLIFERATION AND FORMATION OF CLONES OF EFFECTOR T-LYMPHOCYTES, WHICH ARE ALSO CALLED REINFORCED 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 WERE PROGRAMMED BY ALL PREVIOUS DEVELOPMENT.

THE LENE 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 CONSISTS OF LYMPHOID TISSUE, WHICH FORMES PERIARTERIOLARY LYMPHOID COUPLINGS AROUND THE ARTERIOLES. THE CLUTCHES HAVE T- AND B-CELL AREAS. A T-DEPENDENT AREA OF THE CLUTCH, SIMILAR TO THE T-DEPENDENT AREA OF LYMPH NODES, DIRECTLY 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 LINKERS INTO THE RED PULP. THE RED PULP IS A cellular 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 APPILLARIES WITH WHICH END THE CENTRAL ARTERIOLES OF THE WHITE PULP OPEN FREELY IN BOTH THE WHITE PULP AND IN THE RED PULP TRADS. WHEN THE BLOOD LEAKS REACH THE HEAVY RED PULP, THEY ARE RESTAINED IN THEM. HERE MACROPHAGES RECOGNIZE AND PHAGOCYTE SURVIVED erythrocytes and platelets. PLASMIC 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.

N ENCAPSULATED LYMPHOID TISSUE Most of unencapsulated lymphoid tissue 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. Main effector mechanism local immunity at the level of the mucous membrane, the production and transport of secretory antibodies of the IgA class directly to 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 number 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 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. THE BASIC MASS OF LYMPHOCYTES IN PEYER'S PATCH ARE IN THE B-CELL FOLLICLE WITH A GERMAL CENTER IN THE MIDDLE. T-CELL ZONES SURROUND THE FOLLICLE CLOSE TO THE LAYER OF EPITHELIAL CELLS. THE MAIN FUNCTIONAL LOAD OF PEYER'S PATCHES IS THE ACTIVATION OF B-LYMPHOCYTES AND THEIR DIFFERENTIATION INTO PLASMA CYTES PRODUCING ANTIBODIES OF CLASSES I G A AND I G E. IN ADDITION TO THE 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 MUCOSAL SURFACES, NON-ENCAPSULATED LYMPHOID TISSUE INCLUDES: SKIN-ASSOCIATED LYMPHOID TISSUE AND SKIN INTRAEPITHELIAL LYMPHOCYTES; LYMPH, TRANSPORTING FOREIGN 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. HOWEVER, ALMOST HALF OF THE TISSUE MACROPHAGES OF THE ORGANISM ARE LOCALIZED IN IT. THEY PHAGOCYTATE AND DISSOLVE IMMUNE COMPLEXES, WHICH BRING RED CELLS HERE ON THEIR SURFACE. IN ADDITION, IT IS ASSUMED THAT LYMPHOCYTES LOCALIZED IN THE LIVER AND IN THE INTESTINAL SUBMUCOSA HAVE SUPRESSOR FUNCTIONS AND PROVIDE CONSTANT MAINTENANCE OF IMMUNOLOGICAL TOLERANCE (UNRESPONDENCE) TO FOOD.

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What is the immune system?

The immune system is a collection of organs, tissues and cells, the work of which is aimed directly at protecting the body from various diseases and to destroy foreign substances that have already entered the body. This system is an obstacle to infections (bacterial, viral, fungal). When the immune system malfunctions, the likelihood of developing infections increases, which also leads to the development autoimmune diseases, including multiple sclerosis.

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Organs included in the human immune system: lymph glands (nodes), tonsils, thymus(thymus), bone marrow, spleen and intestinal lymphoid formations (Peyer's patches). Main role plays a complex system circulation, which consists of lymphatic ducts connecting the lymph nodes.

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The organs of the immune system produce immunocompetent cells (lymphocytes, plasma cells), biologically active substances(antibodies) that recognize and destroy, neutralize cells and other foreign substances (antigens) that have entered the body or formed in it. The immune system includes all organs that are built from reticular stroma and lymphoid tissue and carry out the body’s protective reactions, create immunity, and immunity to substances that have foreign antigenic properties.

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Peripheral organs of the immune system

They are located in places of possible penetration of foreign substances into the body or along the paths of their movement in the body itself. 1. lymph nodes; 2. spleen; 3. lymphoepithelial formations digestive tract(tonsils, single and group lymphatic follicles); 4. perivascular lymphatic follicles

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The lymph nodes

A peripheral organ of the lymphatic system that performs the function of a biological filter through which lymph flows, coming from organs and parts of the body. In the human body there are many groups of lymph nodes, called regional. They are located along the path of lymph through the lymphatic vessels from organs and tissues to the lymphatic ducts. They are located in well-protected places and in the joint area.

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Tonsils

Tonsils: lingual and pharyngeal (unpaired), palatine and tubal (paired), located in the area of the root of the tongue, nasal pharynx and pharynx. The tonsils form a kind of ring surrounding the entrance to the nasopharynx and oropharynx. The tonsils are built from diffuse lymphoid tissue, which contains numerous lymphoid nodules.

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Lingual tonsil (tonsillalingualis)

Unpaired, located under the epithelium of the mucous membrane of the root of the tongue. The surface of the tongue root above the tonsil is lumpy. These tubercles correspond to the underlying epithelium and lymphoid nodules. Between the tubercles, openings of large depressions open - crypts, into which the ducts of the mucous glands flow.

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Pharyngeal tonsil (tonsillapharyngealis)

Unpaired, located in the area of the arch and back wall pharynx, between the right and left pharyngeal pouches. In this place there are transversely and obliquely oriented thick folds of the mucous membrane, inside of which there is lymphoid tissue of the pharyngeal tonsil and lymphoid nodules. Most lymphoid nodules have a proliferation center.

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Palatine tonsil (tonsillapalatina)

The steam room is located in the tonsillar fossa, between the palatoglossus arch in front and the velopharyngeal arch in the back. Medial surface tonsils, covered with multilayer flat epithelium, facing the pharynx. The lateral side of the tonsil is adjacent to the wall of the pharynx. In the thickness of the tonsil, along its crypts, there are numerous round-shaped lymphoid nodules, mainly with reproduction centers. There is diffuse lymphoid tissue around the lymphoid nodules.

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Palatine tonsil on the frontal section. Palatine tonsil. Lymphoid nodules near the tonsil crypt.

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Tubal tonsil (tonsillatubaria)

Steam room, located in the area of the pharyngeal opening auditory tube, in the thickness of its mucous membrane. Consists of diffuse lymphoid tissue and a few lymphoid nodules.

Slide 13

Vermiform appendix (appendix vermiformis)

It is located near the ileo-cecal junction, at the lower part of the cecum. In its walls it has numerous lymphoid nodules and internodular lymphoid tissue between them. There are group lymphatic follicles (Peyer's patches) - accumulations of lymphoid tissue located in the walls small intestine in the terminal ileum.

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Lymphoid plaques look like flat oval or round formations. Slightly protruding into the intestinal lumen. The surface of lymphoid plaques is uneven and lumpy. They are located on the side opposite to the mesenteric edge of the intestine. Constructed from lymphoid nodules tightly adjacent to each other. The number of which in one plaque varies from 5-10 to 100-150 or more.

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Solitary lymphoid

Available in the mucous membrane and submucosa of all tubular organs of the digestive system, respiratory systems and genitourinary apparatus. Lymphoid nodules are located at different distances from each other and at different depths. Often the nodules lie so close to the epithelial cover that the mucous membrane above them rises in the form of small mounds. In the small intestine in childhood, the number of nodules varies from 1200 to 11000, in the large intestine - from 2000 to 9000, in the walls of the trachea - from 100 to 180, in Bladder- from 80 to 530. Diffuse lymphoid tissue is also present in the mucous membrane of all organs of the digestive, respiratory systems and genitourinary apparatus.

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Spleen (lien, splen)

Performs the functions of immune control of blood. It is located on the path of blood flow from the aorta to the portal vein system, branching in the liver. The spleen is located in abdominal cavity. The weight of the spleen in an adult is 153-192 g.

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The spleen has the shape of a flattened and elongated hemisphere. The spleen has diaphragmatic and visceral surfaces. The convex diaphragmatic surface faces the diaphragm. The visceral surface is not smooth; it contains the gate of the spleen, through which the artery and nerves enter the organ and the vein exits. The spleen is covered on all sides by peritoneum. Between the visceral surface of the spleen on one side, the stomach and the diaphragm on the other, the layers of the peritoneum and its ligaments are stretched - the gastrosplenic ligament, the phrenic-splenic ligament.

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From the fibrous membrane, located under the serous cover, the connective tissue trabeculae of the spleen extend into the organ. Between the trabeculae there is parenchyma, the pulp (pulp) of the spleen. The red pulp is isolated, located between the venous vessels - the sinuses of the spleen. The red pulp consists of loops of reticular tissue filled with red blood cells, leukocytes, lymphocytes, and macrophages. The white pulp is formed by periarterial lymphoid couplings, lymphoid nodules and macrophage-lymphoid couplings, consisting of lymphocytes and other cells of lymphoid tissue located in loops of the reticular stroma.

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Slide 20

Periarterial lymphoid couplings

In the form of 2-4 layers of cells of the lymphoid series, they surround the pulpal arteries, starting from the place where they exit the trabeculae and up to the ellipsoids. Lymphoid nodules form in the thickness of the periarterial lymphoid couplings. The muffs contain reticular cells and fibers, macrophages and lymphocytes. When leaving the macrophage-lymphoid couplings, the ellipsoidal arterioles divide into terminal capillaries, which flow into the venous splenic sinuses located in the red pulp. Areas of red pulp are called splenic cords. Pulp and then trabecular veins form from the splenic sinuses.

Slide 21

The lymph nodes

Lymph nodes (nodilymphatici) are the most numerous organs of the immune system, lying on the paths of lymph flow from organs and tissues to the lymphatic ducts and lymphatic trunks, which flow into the bloodstream in the lower parts of the neck. Lymph nodes are biological filters for tissue fluid and metabolic products contained in it (particles of cells that died as a result of cellular renewal, and other possible foreign substances of endogenous and exogenous origin). Lymph flowing through the sinuses of the lymph nodes is filtered through loops of reticular tissue. The lymph receives lymphocytes formed in the lymphoid tissue of these lymph nodes.

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Lymph nodes are usually located in groups of two or more nodes. Sometimes the number of nodes in a group reaches several dozen. Groups of lymph nodes are named accordingly to the areas of their location: inguinal, lumbar, cervical, axillary. Lymph nodes adjacent to the walls of cavities are called parietal, parietal lymph nodes (nodilymphatici parietals). Nodes that are located near internal organs, are called visceral lymph nodes (nodilymphaticiviscerales). There are superficial lymph nodes, located under the skin, above the superficial fascia, and deep lymph nodes, lying deeper under the fascia, usually near large arteries and veins. The shape of the lymph nodes is very different.

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On the outside, each lymph node is covered with a connective tissue capsule, from which thin capsular trabeculae extend into the organ. At the exit point lymph node Lymphatic vessels have a slight depression - the gate, in the area of which the capsule thickens, forms a portal thickening inside the node, portal trabeculae extend. The longest of them are connected to capsular trabeculae. An artery and nerves enter the lymph node through the gate. Nerves and efferent nerves emerge from the node lymphatic vessels. Inside the lymph node, between its trabeculae, there are reticular fibers and reticular cells, forming a three-dimensional network with loops of different sizes and shapes. The loop contains the cellular elements of lymphoid tissue. The parenchyma of the lymph node is divided into cortex and medulla. The cortex is darker and occupies peripheral parts node. The lighter medulla lies closer to the gate of the lymph node.

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Around the lymphoid nodules there is diffuse lymphoid tissue, in which an internodular zone is distinguished - the cortical plateau. Inward from the lymphoid nodules, at the border with the medulla, there is a strip of lymphoid tissue called the pericortical substance. This zone contains T-lymphocytes, as well as post-capillary venules lined with cubic endothelium. Through the walls of these venules, lymphocytes migrate into the bloodstream from the parenchyma of the lymph node and in the opposite direction. The medulla is formed by cords of lymphoid tissue - pulpy cords, which extend from the internal parts of the cortex to the gate of the lymph node. Together with the lymphoid nodules, the pulp cords form the B-dependent zone. The parenchyma of the lymph node is penetrated by a dense network of narrow slits - lymphatic sinuses, through which the lymph entering the node flows from the subcapsular sinus to the portal sinus. Along the capsular trabeculae lie the sinuses of the cortex, along the pulpy cords there are the sinuses of the medulla, which reach the portal of the lymph node. Near the portal thickening, the sinuses of the medulla flow into the portal sinus located here. In the lumen of the sinuses there is a soft-cell network formed by reticular fibers and cells. As lymph passes through the sinus system, the loops of this network trap foreign particles that enter the lymphatic vessels from the tissues. Lymphocytes enter the lymph from the parenchyma of the lymph node.

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The structure of the lymph node

Network of reticular fibers, lymphocytes and macrophages in the sinus of the lymph node

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Immunology

Immunology studies:

Main stages in the development of immunology

Immunity

Types of immunity

Functional organization of the immune system

Functional organization of the immune system

The immune system

Physiological significance of the immune system

Properties of the immune system

Properties of the immune system

Structural and functional organization of the immune system

Structure of the immune system

Immune system organs

Features of the central organs of the immune system

Features of peripheral organs of the immune system

Bone marrow

Hematopoiesis scheme

Types of stem cells

Hematopoietic stem cell (HSC)

Features of GSK

Thymus

Lymphoid tissue

Lymphocytes are the structural and functional unit of the immune system

Literature:

What is the immune system?

Peripheral organs of the immune system

The lymph nodes

Tonsils

Lingual tonsil (tonsillalingualis)

Pharyngeal tonsil (tonsillapharyngealis)

Palatine tonsil (tonsillapalatina)

Tubal tonsil (tonsillatubaria)

Vermiform appendix (appendix vermiformis)

Solitary lymphoid

Spleen (lien, splen)

Periarterial lymphoid couplings

The lymph nodes

The structure of the lymph node

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