Immunity - a self-defense system of an organism against invading infectious and non-infectious foreign materials. This term comes from a Latin word ''IMMUNIS'' which means "EXEMPT''.
The process of immunity in any living organism involves different types of cellular and humoral components. Any response mediated by its component has two main activities -first recognition of that agent and second response against it. The immune system has remarkable capacity to distinguish between itself and a foreign agent.
Generally two types of immunity are found-Adaptive or specific and innate or non-specific immunity. The mechanism of non- specific innate immunity exists in the body and doesn't need any memory of earlier contacts, while adaptive one is highly specific for pathogen recognition and needs memory.
Innate immune mechanisms help us to protect from those factors which we face in our daily lives as dust, air particles, fluctuation in cold weathers etc.
Cellular components of immune system are Lymphocytes (T and B), Macrophages, granulocytes etc. and antibodies and cytokines represent the humoral components. The key primary lymphoid organs of the immune system are thymus and bone marrow, and secondary lymphatic tissues such as spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin.
In adaptive immune system when a pathogen releases its immunogenic molecules in the host lymphoid system which is recognizable also, the cell, in response activates its "Antibodies''. These are "Glycoprotein", having a "Y" shaped structure made up of four polypeptide chains, in which two chains are identical light (L) and two identical heavy (H) chains. Both are connected by a "Disulphide bonds”. Every molecule of antibody has a specific “Antigen-binding site" or PARATOPE. Antibodies are classified as IgG, IgA, IgM ,IgD and IgE.
The second most important biological entity is ANTIGEN, it is a material which induces an immune response and also activates the Antibodies response after binding with it. Immune cells recognize them by their discrete sites or EPITOPES on which antibodies or lymphocytes are attached. These are specific proteins released from a certain class of immune cells (B lymphocytes). Antigens are defined as anything that elicits generation of antibodies, hence they are Antibody Generators
The humoral (antibody) response is defined as the interaction between antibodies and antigens. Antigens interact to B-cells in two ways-with the help if macrophages and T cells (T-dependent antigens) and direct interaction with B-cells (T-independent antigens).
PATTERN OF PRODUCTION OF ANTIBODIES-
When antigens enter the body, the production of antibody follows a pattern which is measured by the level of antibody in the blood. First the antibodies get activated during LAG PHASE. After this the antibodies are released in the blood, it is called LOG PHASE, which is followed by STEADY PHASE here the production equals to the removal. And then the antibodies are declined during DECLINE PHASE .Thus the first time response against any pathogen takes time due to recognition and activation process but in the second time the organism responds in lesser time due to the memory cell formed during the first attack.
The diseases caused by disorders of the immune system fall in two types: Immunodeficiency - when parts of immune system fail to provide an adequate response. Autoimmunity- when immune system attacks its own host's body.
Another system disorders is Hypersensitivities – when the system responds inappropriately to harmless compounds (asthma and other allergies) or responds too intensely.
The most known disease affecting immune system is AIDS, caused by HIV. In this case the virus of the HIV destroys the host’s T-Cells and Macrophages, the two main component of immune system. Thus the affected human can’t be protected from different types of pathogens.
In the 21st century, immunology has widened its horizons with much research being performed in different areas of immunology, which includes the immunological function of cells, organs, tissues and systems associated with the immune system.
The process of immunity in any living organism involves different types of cellular and humoral components. Any response mediated by its component has two main activities -first recognition of that agent and second response against it. The immune system has remarkable capacity to distinguish between itself and a foreign agent.
Generally two types of immunity are found-Adaptive or specific and innate or non-specific immunity. The mechanism of non- specific innate immunity exists in the body and doesn't need any memory of earlier contacts, while adaptive one is highly specific for pathogen recognition and needs memory.
Innate immune mechanisms help us to protect from those factors which we face in our daily lives as dust, air particles, fluctuation in cold weathers etc.
Cellular components of immune system are Lymphocytes (T and B), Macrophages, granulocytes etc. and antibodies and cytokines represent the humoral components. The key primary lymphoid organs of the immune system are thymus and bone marrow, and secondary lymphatic tissues such as spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin.
In adaptive immune system when a pathogen releases its immunogenic molecules in the host lymphoid system which is recognizable also, the cell, in response activates its "Antibodies''. These are "Glycoprotein", having a "Y" shaped structure made up of four polypeptide chains, in which two chains are identical light (L) and two identical heavy (H) chains. Both are connected by a "Disulphide bonds”. Every molecule of antibody has a specific “Antigen-binding site" or PARATOPE. Antibodies are classified as IgG, IgA, IgM ,IgD and IgE.
The second most important biological entity is ANTIGEN, it is a material which induces an immune response and also activates the Antibodies response after binding with it. Immune cells recognize them by their discrete sites or EPITOPES on which antibodies or lymphocytes are attached. These are specific proteins released from a certain class of immune cells (B lymphocytes). Antigens are defined as anything that elicits generation of antibodies, hence they are Antibody Generators
The humoral (antibody) response is defined as the interaction between antibodies and antigens. Antigens interact to B-cells in two ways-with the help if macrophages and T cells (T-dependent antigens) and direct interaction with B-cells (T-independent antigens).
PATTERN OF PRODUCTION OF ANTIBODIES-
When antigens enter the body, the production of antibody follows a pattern which is measured by the level of antibody in the blood. First the antibodies get activated during LAG PHASE. After this the antibodies are released in the blood, it is called LOG PHASE, which is followed by STEADY PHASE here the production equals to the removal. And then the antibodies are declined during DECLINE PHASE .Thus the first time response against any pathogen takes time due to recognition and activation process but in the second time the organism responds in lesser time due to the memory cell formed during the first attack.
The diseases caused by disorders of the immune system fall in two types: Immunodeficiency - when parts of immune system fail to provide an adequate response. Autoimmunity- when immune system attacks its own host's body.
Another system disorders is Hypersensitivities – when the system responds inappropriately to harmless compounds (asthma and other allergies) or responds too intensely.
The most known disease affecting immune system is AIDS, caused by HIV. In this case the virus of the HIV destroys the host’s T-Cells and Macrophages, the two main component of immune system. Thus the affected human can’t be protected from different types of pathogens.
In the 21st century, immunology has widened its horizons with much research being performed in different areas of immunology, which includes the immunological function of cells, organs, tissues and systems associated with the immune system.
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