B8 Treating disease

• Specific systems the body uses to stop germs getting into it

  • Nose and mucus
  • Stomach acid
  • Skin
  • Bronchi
• Three functions of white blood cells

  • Phagocytosis
  • Producing antibodies
  • Producing antitoxins
• Phagocytosis

  1. Phagocyte is attracted to the area of infection

  2. Engulfs a pathogen

  3. Releases enzymes to digest the pathogen
• Antigens


  Proteins on the surface of a pathogen
• Antibodies


  Have to be the right shape for a pathogen's unique antigens, so they target a specific pathogen
• Antitoxin


  Neutralise toxins produced by pathogens by binding to them
• Vaccine

  Contains small quantities of a dead or inactive form of a pathogen
• How vaccination protects against a specific pathogen

  1. Vaccination stimulates the body to produce antibodies against a specific pathogen

  2. If the same pathogen re-enters the body, white blood cells rapidly produce the correct antibodies
• Herd immunity


  When most of a population is vaccinated against a disease, meaning it is less likely to spread
• Antibiotic

  A drug that kills bacteria but not viruses
• Painkillers

  Treat some symptoms of diseases and relieve pain
• Tested in clinical trials

  • Test toxicity, efficacy, and optimum dose of new drugs
• Pre-clinical stage of a drug trial

  Drug is tested on cells, tissues, and live animals
• Placebo


  A medicine with no effect that is given to patients instead of the real drug in a trial
• Double-blind trial

  A trial where neither patients nor doctors know what receives the real drug and who receives the placebo