Immune response
- Created by: Miranda Balfe
- Created on: 05-05-13 19:01
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- Immune response
- Phagocytes
- two types
- Neutrophils : multilobed nucleus and made in bone marrow. short lived but released when an infection occurs
- Macrophages: large cells made in the bone marrow. found in body organs specially in lymph nodes.
- engulf pathogens (non specific)
- 1)Recognises antigens on pathogen
- 2) By endocytosis, pathogen enters phagocyte
- 3) Pathogen is now a in a phagosome
- 4) Lysosomes fues to phagosome and digest the bacteria
- 5) End products are hrmless and are realeased or absorbed in the cytoplasm.
- two types
- Antibodies: proteins that can identify and neutralise antigens
- antigens: molecules that stimulate immune response
- Have a specific shape complementary to the particular antigen
- Structure
- Four polypeptide chains held together by disulfide bridges (2 light chains, 2 heavy chains)
- Constant region which enables antibodies to attach to phagocytes
- Variable region which is specific to each antigen (result of amino acid sequence)
- Hinge region which allows for movement and allow for antibody to attach to more than one antigen
- How they work
- Attach to antigens on a pathogen
- Then neutralise or agglutinate.
- Neutralise: antibodies cover the binding sites to prevent pathogen binding to host cell
- Agglutinate: large antibodies bind many pathogens together preventing the pathogens entering host cell
- Response
- Primary
- Takes longer as immune system has to build up the number of antibodies
- Secondary
- Antibodies must be made again but immune system quicker and so reach a higher concentrationmore rapidly
- Primary
- primary response
- skin- acts as a barrier.
- mucous membranes such as the nose,throat and ears)
- vagina has high acidity(low pH)
- tears have antibacterial qualities
- Communicated response
- Pathogen is engulfed from cells in immune system and antigens are presented on surface of cell (macrophage)
- Selection of correct T killer cells and T helper cells (CLONAL SELECTION)
- Reproduction by mitosis of T helper cell (CLONAL EXPANSION)
- 1)Release of interleukins 2) Activation of B cells 3) Reproduction of B cells (CLONAL EXPANSION AND DIFFERENTIATION)
- B memory cells ( circulate in body providing immunological memory)
- Plasma cells (manafacture antibodies)
- 1)Release of interleukins 2) Activation of B cells 3) Reproduction of B cells (CLONAL EXPANSION AND DIFFERENTIATION)
- Reproduction of T killer cells (CLONAL EXPANSION)
- Search for infected cells, when found attach to infected cells
- Secrete toxic substances to kill the cell and pathogens it contains
- Search for infected cells, when found attach to infected cells
- Reproduction by mitosis of T helper cell (CLONAL EXPANSION)
- Selection of correct T killer cells and T helper cells (CLONAL SELECTION)
- Pathogen is engulfed from cells in immune system and antigens are presented on surface of cell (macrophage)
- Phagocytes
- 1)Release of interleukins 2) Activation of B cells 3) Reproduction of B cells (CLONAL EXPANSION AND DIFFERENTIATION)
- B memory cells ( circulate in body providing immunological memory)
- Plasma cells (manafacture antibodies)
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