B8 - Treating and Preventing Disease

• Origins of Drugs:

  • Digitalis (heart drug) - foxglove plants
  • Aspirin (painkiller) - willow trees
  • Penicillin - Penicillum mould
• Explain how vaccines work (4 marks):

  1. Inactive pathogen is injected into the bloodstream
  2. White Blood Cells produce antibodies
  3. Information stored in memory cells
  4. When exposed to the real pathogen, white blood cell produces specific antibodies quickly
  5. Antibodies destroy the virus
• Types of White Blood Cell: (1. Phagocyte)

  • Attracted to infection
  • Cell engulfs pathogen
  • Pathogen is destroyed by enzymes
• Types of White Blood Cell: (2. Lymphocyte)

  • Detect a harmful virus or toxin
  • Lymphocyte produces complementary (specific) antibody or antitoxin
• Placebo - a drug with 0 effect (usually a sugar pill)

  Double Blind Trial - When neither the patient or doctor knows the placebo which reduces bias