Immunology

• Physical barrier


  • Specific to each pathogen
  • eg. skin
• Antitoxin production

  Process where antitoxins are produced to neutralize toxins from pathogens
• Antibody production

  Process where antibodies are produced to bind to and neutralize pathogens
• Non-Specific Defence

  Defences that are not targeted to a specific pathogen
• Eyes

  • Produce tears
  • Tears contain enzymes to kill bacteria
• Nose

  • Hairs trap particles
  • Nose produces mucus to trap particles
• Skin

  • Tough outer layer acts as a barrier
  • Oil on surface repels pathogens
• Platelets

  • Help form a scab to seal cuts and prevent pathogens entering
• Stomach

  • Contains hydrochloric acid which kills bacteria in food
  • Mucus lining separates acid from tissue
• Breathing System

  • Trachea and bronchi contain mucus-producing cells
  • Cilia sweep mucus with trapped pathogens out of the lungs
• Immune System

  Tries to destroy pathogens that enter the body
• Monoclonal Antibodies

  Antibodies produced by a single clone of cells, all of which produce the same antibody
• Pregnancy Test

  1. Urine contains the hormone HCG

  2. HCG binds to mobile monoclonal antibodies which have an enzyme attached

  3. The HCG antibody complex binds to immobilised monoclonal antibodies causing a colour change to occur as an enzyme-substrate complex forms

  4. The mobile antibody binds to monoclonal antibodies on the control site, causing a colour change to prove the test works
• Pregnancy Test

  • PREGNANT
  • NOT PREGNANT
• Women who are pregnant

  Produce high levels of hormone HCG
• Pregnancy Test

  • Monoclonal antibodies that are complementary to the HCG protein
• Control Site

  Proves the test works
• Test Site

  Determines if the person is pregnant
• Treating Cancer


  • Monoclonal antibody is attached to radioactive source/toxic drug
  • Monoclonal antibody will attach to a specific antigen on the cancer cell
  • The drug/chemical can stop the cancer cell from dividing
  • Or it (toxic drug) can destroy the cancer cell
  • Or it can signal the white blood cells to destroy the cancer cell
  • The radioactive source can be used like a marker to detect where the cancer is in the body
• Lymphocytes

  White blood cells that produce antibodies
• Antibodies


  Proteins produced by lymphocytes that bind to specific antigens
• Monoclonal antibodies

  Identical copies of one type of antibody
• Producing monoclonal antibodies

  1. Mouse is injected with a specific antigen

  2. Lymphocytes produce specific antibodies

  3. These lymphocytes are extracted and combined with a tumour cell

  4. This forms a hybridoma cell

  5. The Hybridoma cell is cloned to create many cells that produce many identical antibodies

  6. A large amount of antibody can be collected and purified
• Antibodies bind to specific antigens
• A tumour cell is used to bind with the lymphocyte to form the hybridoma cell
• Bacteria


  Reproduce rapidly inside the body and may produce poisons that damage tissues and make us feel ill
• Virus


  Genetic material inside a protein coat (capsid), enters a host cell to replicate its DNA, then destroys the cell when they are released into the blood
• Non-specific defence response


  Immediate and the same for all pathogens
• Specific defence response


  Slower and specific to each pathogen
• Non-specific defences


  • Eyes produce tears with antiseptic properties
  • Nose hairs trap particles
  • Skin acts as a physical barrier
  • Phagocytosis
  • Antitoxin production
  • Antibody production
• Stomach


  • Contains hydrochloric acid which kills bacteria in food
• Breathing system


  • Trachea and bronchi contain cells which produce mucus to trap bacteria, cilia sweep the mucus out of the lungs
• Immune system response


  Tries to destroy pathogens that enter the body
• Antibodies


  Bind to specific antigen on a pathogen and make them stick together
• White blood cells called phagocytes


  • Engulf the pathogen
  • Destroy the pathogen
• Some pathogens make us ill by producing toxins
• Antitoxins


  Neutralise the toxins released by the pathogens
• Diseases


  • Cholera
  • Influenza
  • Gonorrhea
  • Athlete's Foot
  • Salmonella
• How to prevent transmission of disease

  1. Isolating when ill

  2. Washing hands

  3. Covering face when sneezing

  4. Not sharing cutlery/utensils

  5. Vaccinations

  6. Clean drinking water
• Types of disease transmission

  • Air Borne
  • Water
  • Food
  • Body Fluids
  • Direct Contact