Immunity

HideShow resource information
  • Created by: Sophie
  • Created on: 01-12-13 11:30
View mindmap
  • Immunity
    • Disease
      • A pathogen is an organism that causes disease.
      • Gas exchange system- mucus lining in lung epithelium and cilia protect against pathogens.
        • Cilia waft and move pathogens up trachea
        • Pathogens can reach alveoli, invade call and cause damage
      • Skin
        • Pathogens can enter bloodstream
        • Blood clotting prevents this
      • Digestive System
        • Stomach acid
        • The bacteria that survives passes into intestines and invade cells in the gut wall to causes disease
      • Producing toxins and cell damage
        • Lysis, breaking down nutrients inside the cell for their own use, replicating inside cells and causing lysis
      • Lifestyle
        • Smoking, alcohol, poor diet, exposure to sunlight, lack of exercise, saturated fat
    • The Immune System
      • Antigens are proteins, glycoproteins or polysaccharides that trigger an immune response
      • Antibodies can produce antitoxins, mark bacteria for a phagocyte to engulf it or bind to the antigen and cause lysis
        • A disulphide bridge on an antibody holds polypeptides together
        • The hinge region allows the antibody to change shape and bind to more than one antigen
        • Complementary to antigen, forms antibody-antigen complex.
        • Types of antibody
          • Opsonins- bind to antigen, act as marker to attract phagocytes
          • Lysins- bind to antigen, cause lysis
          • Agglutinins- stick pathogens together so they can't enter a host cell
      • Phagocytosis
        • Recognises antigens
          • Cytoplasm surround pathogen, engulfing it
            • Pathogen now contained in a phagocytic vacuole
              • Lysosome fuses with the phagocytic vacuole, hydrolyses pathogen
      • T-Lymphocytes
        • Activated by phagocytes
        • MR T SOLDIER
        • HUMORAL RESPONSE
        • Bind to antigens on a pathogen and kill the cell
          • By making holes in CSM
        • Some activate B cells
          • Produce T Memory Cells
        • Only respond to an infected, antigen presented cell
          • Attaches to antigen presenting cell
      • B-Lymphocytes
        • NURSE
        • CELLULAR RESPONSE
        • If a B cell meets an antigen with a complementary shape
          • Rapid mitotic division
            • Produces plasma cells
              • Antibodies
                • Osponins, Lysins, Agglutins
              • Clones of B cells
        • Memory B cells- long term immunity
    • Monoclonal Antibodies
      • Technique used to produce a large amount of a single antibody outside the body
        • Problem- B cells are short lived and only divide inside an organism
        • separating a chemical from a mixture
          • Immunoassay
            • Calculating amounts of a substance from a mixture, pregnancy tests
          • Cancer treatment
            • Antibodies bind with antigens on cancer cells due to complementary shape, enzyme activates drug, minimal damage to other cells
          • Transplant surgery
    • Vaccines
      • Use dead or attenuated pathogens so the antigens are still intact
        • Or remove antigens and use them
      • Success due to; medical infrastructure, cost effective, herd immunity, few side effects
      • Disadvantage of oral vaccines- could be broken down by enzymes in the gut or the molecules may be too large to be absorbed into the blood
      • Booster vaccines ensure memory cells are produced
      • Side affects e.g allergies, process of killing microbes may not be 100% effective, changed antigens due to mutations, organisms are non virulent

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »