Immunology

• What is immunology the study of?

  The immune system
• Why is the immune system important?

  It is part of the body's response to infection
• What are microorganisms often thought of as?

  Pathogens
• Why might microorganisms be viewed primarily as pathogens?

  Because they have a significant impact on our lives through disease
• What is the typical size range of bacteria?

  0.5-5μm
• What type of organisms are bacteria classified as?

  Prokaryotes
• What are fungi, including yeasts, classified as?

  Eukaryotes
• What is the size range of yeast cells compared to bacteria?

  Yeast cells are larger, typically 4-12μm
• What is the largest living organism on Earth?

  A honey fungus measuring 2.4 miles (3.8km) across
• What defines a protist?

  A eukaryotic organism that is not an animal, plant, or fungus
• What is an example of a photosynthetic protist?

  Algae
• What is the size range of viruses?

  20-350 nm
• What do viruses consist of?

  Genetic material surrounded by a protein coat
• Are viruses considered living organisms?

  No, they are acellular
• What is a pathogen?

  A microorganism that causes illness or disease
• What is an example of a disease caused by bacteria?

  Tuberculosis
• What is the role of antibiotics?

  To treat bacterial infections
• What is a common viral disease?

  The common cold
• What are prions?

  Non-living pathogenic proteins
• What is Toxoplasmosis caused by?

  A parasitic protist called Toxoplasma gondii
• What is the first line of defense against pathogens?

  Physical and chemical barriers
• What role does lysozyme play in the immune system?

  It hydrolyzes bonds in bacterial cell walls
• What is the function of mucous membranes?

  To trap bacteria and other pathogens
• What is inflammation a response to?

  Injury or infection
• What are the types of pathogens and examples of diseases they cause?

  • Bacteria: chlamydia, gonorrhoea, tuberculosis
  • Viruses: common cold, mumps, measles
  • Fungi: yeast infection (thrush)
  • Prions: Creutzfeldt-Jakob disease (CJD)
  • Protists: malaria
• What are the different ways pathogens may enter the body?

  1. Direct transmission: physical contact, sharing needles
  2. Airborne transmission: carried by dust or droplets
  3. Indirect transmission: vehicle transmission (infected food/water), vector transmission (insect bites)
• What factors contribute to the spread of infectious diseases among populations?

  • Inadequate sanitation (clean water access, sewage disposal)
  • Dense populations (overcrowding, lack of social distancing)
  • Ignorance (lack of health promotion information)
• What is the definition of an antigen and an antibody?

  • Antigen: substance recognized by the immune system as self or non-self, stimulating an immune response
  • Antibody: blood protein produced in response to a specific antigen, binding specifically to it
• What are the stages of the immune response to foreign substances?

  1. Recognition of non-self antigens
  2. Activation of immune cells
  3. Elimination of pathogens
  4. Memory formation for future responses
• What are the non-specific and specific defenses against pathogens?

  • Non-specific defenses: physical barriers (skin, mucous membranes), inflammation, phagocytosis
  • Specific defenses: action of T cells and B cells
• What was John Snow's contribution to understanding cholera transmission?

  • Mapped cholera outbreaks in London
  • Showed transmission was linked to contaminated water
  • Led to improvements in sanitation and clean water provision
• How does the immune system distinguish between self and non-self cells?

  • Through antigens on the surface of cells
  • Self antigens are recognized as the body's own cells
  • Non-self antigens are recognized as foreign and trigger an immune response
• What is the role of antimicrobial proteins and peptides in the immune system?

  • Destroy pathogens
  • Stimulate the immune system
• What is the significance of the first principle of cell theory in relation to viruses?

  • Viruses are acellular and do not fit the definition of living organisms
  • Raises questions about the classification of viruses as living or non-living
• What role do mucous membranes play in the body?

  They act as an important external barrier lining the gut, airways, and reproductive system.
• What is the function of goblet cells?

  Goblet cells produce thick, sticky mucous that helps to trap bacteria and other pathogens.
• How do antimicrobial proteins and peptides contribute to the immune system?

  They help to destroy pathogens and can stimulate the immune system.
• What is lysozyme and what is its function?

  Lysozyme is an enzyme that hydrolyses bonds in the cell wall components of some bacteria, weakening their walls.
• Where is lysozyme found in the body?

  Lysozyme is present in tears and breast milk.
• What is the difference between non-specific and specific immune responses?

  Non-specific responses are rapid and the same for all pathogens, while specific responses are slower and tailored to each antigen.