drugs and diseases

• What is the definition of disease?

  A disorder of the body or mind that negatively affects an individual’s health
• What are the two types of disease?

  Communicable and non-communicable
• What is a communicable disease?

  A disease that is passed directly between individuals and caused by a pathogen
• What is a pathogen?

  A disease-causing organism such as a virus, fungi, bacteria, or protists
• What is a non-communicable disease?

  A disease that cannot be transmitted between individuals and is generally long-lasting with a slow onset
• What causes non-communicable diseases?

  They are caused by lifestyle, environmental conditions, genetic mutations, etc.
• How do viruses cause disease?

  They enter host cells, replicate inside them, and cause the host cells to rupture, releasing new viruses
• What are examples of pathogens?

  • Virus
  • Fungi
  • Bacteria
  • Protists
• What are the characteristics of non-communicable diseases?

  • Cannot be transmitted between individuals
  • Generally long-lasting
  • Slow onset
  • Caused by lifestyle, environmental conditions, genetic mutations, etc.
• What is the immune system?

  The body’s defence against pathogens once they have entered the body
• What is the primary aim of the immune system?

  To prevent or minimise disease caused by pathogens
• How do white blood cells detect pathogens in the body?

  Pathogens have unique antigens on their surface
• What role do specialised receptors on white blood cells play?

  They detect unique antigens on pathogens
• How do B-lymphocytes contribute to the immune response?

  They produce antibodies in response to a particular antigen
• What do antibodies do to pathogens?

  They ‘tag’ pathogens or clump them together, disabling them
• How are disabled pathogens handled by the immune system?

  They can be killed by other white blood cells
• How does the secondary immune response differ from the primary immune response?

  The secondary response produces antibodies more rapidly and in higher concentrations
• What happens to the pathogen during the secondary immune response?

  The pathogen is destroyed before it can cause symptoms
• What is a vaccination?

  Deliberate exposure of an individual to foreign antigens
• What is the purpose of a vaccination?

  It triggers an immune response and provides immunity
• What is a key characteristic of the individual receiving a vaccination?

  The individual does not contract the disease they are being immunised against
• What are the components of a vaccine?

  Dead, weakened or inactivated pathogens with their surface antigens still present
• What are the benefits of vaccinations?

  • Herd immunity protects non-immune individuals
  • Helps to prevent epidemics and pandemics
• What are the drawbacks of vaccinations?

  • High mutation rate of viruses can make vaccines ineffective
  • Not guaranteed to work
  • Inactivated pathogens may mutate and become pathogenic
  • May cause an adverse reaction
  • Vaccination programmes are costly
• What is an antibiotic?

  A substance that kills or inhibits the growth of bacteria
• How do antibiotics affect viruses?

  They have no effect on viruses
• What is the effect of antibiotics on host organism cells?

  They have no effect on cells in the host organism
• What are antibiotics produced by?

  Living organisms, e.g., fungi
• Why are antibiotics ineffective against viruses?

  Because they specifically target bacterial processes
• If a patient has a viral infection, what would be the appropriate treatment?

  Antiviral medication, not antibiotics