Topic 3 - Infection and response

• What is a microorganism?


  Protists, fungi, Virus, Bacteria
• What is a pathogen?

  A microorganism that causes disease
• How can pathogens spread?

  Water, air and direct contact
• What is an antigen?

  a toxin or other foreign substance that induces an immune response in the body, like the production of antibodies.
• What is an antibody?

  A protein produced by the immune system that binds onto antigens.
• What are the bodies natural barriers to reduce pathogens entering.

  skin, tears, nostril hairs, eyelashes, earwax.
• How does the skin help defend against disease

  It covers the body, physically preventing pathogens from entering

  It secretes oils and antimicrobial substances that kill pathogens
• how does nose hair prevent pathogens entering the body?

  there each coated in mucus which catch the pathogens.
• What are the tiny projections called inside the lungs

  cilia
• What's the role of the immune system?

  to locate and destroy pathogens that enter the body.
• What are the roles of white blood cells?

  Phagocytosis, antibody production, antitoxin production
• What is phagocytosis?


  the ingestion of bacteria or other material by phagocytes.
• What do vaccines contain?

  -dead pathogens

  -live but weakened pathogens

  -parts of the pathogen
• What is herd immunity?

  When a majority of a population are vaccinated against a disease. This means that even people who have not been vaccinated are less likely to get it because there are fewer people to catch it from.
• What is antibiotic resistance?

  when the medicine no longer affects the bacteria because they are immune to it.
• How can you avoid antibiotic resistance?

  - Patients taking antibiotics for the full prescribed course.

  - Doctors only prescribing antibiotics for serious bacterial infections
• What does efficacy mean?

  Whether the drug works and produces the effect you're looking for
• What does toxicity mean?


  The potential side effects that may harm people
• What does dosage mean?

  The concentration that should be given, and how often it should be given
• What is a placebo?

  an inactive substance that has no effect on the body
• What is a double blind trial


  A trial where neither the patients nor the doctor know which group is given the real drug and which is given the placebo
• why are double blind trials important?

  - avoid being bias

  - patients more likely to report side effects

  - doctor is more likely to pay more attention to the patient with the drug