Biology topic 3

• Pathogens ?


  Microbes that can cause communicable diseases
• How is internal immune system formed ?

  white blood cells
• Types of white blood cells

  Phagocycte and Lymphocycle
• Antigens

  Molecules on the surface of pathogens activate immune system.
• what do Phagocycle white blood cells do ?

  Engulf microbes/pathogens
• What do Lymphocyte white blood cells do ?

  Produce antibodies
• Herd Immunity ?


  Resistance to the spread of an infections within a population.
• Drugs ?


  Chemical substance that affects the state of the body
• Double blind trial ?

  Groups of people that get real drugs and other groups get drugs that thinks works but doesnt
• Placebo ?


  Thinking something worked but actually hasn't.
• Micro-organisms

  Single celled living things that cannot be seen unless seen in a microscope.
• Types of disease cells

  1. Bacterial cell
  2. Viral cell
• Communicable disease

  disease transmitted from person to person
• Ways pathogens spread?

  Food, water, insect bites, direct contact, indirect contact
• Ways to reduce pathogens

  Disinfectants, wash hands, personal hygiene, cooked food
• Physical barriers to infections

  1. skin
  2. Blood clots
  3. tears
  4. eyelids
  5. eyelashes
  6. cilia + mucus
  7. stomach acid
• What do white blood cells do ?

  Fight infections and destroy microbes
• Antitoxin

  Produced by white blood cells that neutralise bacterial toxins
• Memory cells

  Cells that are activated by the antigen and are able to produce antibodies
• How to prevent diseases ?

  1. balanced diet
  2. Good hygiene
  3. Exercise
  4. relieving stress
• Vaccines

  Injections that activate an individuals immune system against pathogens
• Antibiotics

  Cure bacterial diseases by killing bacteria or stopping the growth.
• How are drugs developed ?

  1. Animal testing
  2. Healthy volunteers
  3. Groups of people