defense against disease

• What is a pathogen?

  A disease-causing organism
• Which organisms are typically classified as pathogens?

  Viruses, bacteria, fungi, and protists
• What type of organisms are not known to cause diseases in humans?

  Archaea
• How does the skin function as a defense against pathogens?

  It acts as a physical and chemical barrier
• What is the role of clotting factors in blood clotting?

  They control bleeding
• What is the cascade pathway in blood clotting?

  It converts fibrinogen to fibrin

  
• What is the difference between the innate and adaptive immune systems?

  Innate responds broadly; adaptive is specific
• What is the role of phagocytes in the immune system?

  They engulf and digest pathogens

  
• Where do lymphocytes circulate?

  In the blood and lymph nodes
• What triggers antibody production in lymphocytes?

  Recognition of specific antigens
• What are antigens?

  Recognition molecules on pathogens
• How do helper T-lymphocytes activate B-lymphocytes?

  Through direct interaction with major histocompatibility complexes (MHCs)

  
• What happens to activated B-lymphocytes?

  They multiply to form plasma cells

  
• What is the role of memory cells in immunity?

  They provide long-term immunity
• What is the timeline for the innate immune response?

  0 to 12 hours
• What is the timeline for the adaptive immune response?

  1 to 7 days

  
• What are the main components of the innate immune system?

  • Skin and secretions
  • Mucous membranes
  • Phagocytes
• What are the main components of the adaptive immune system?

  • T-Lymphocytes
  • B-Lymphocytes
  • Antibodies

  
• What is the role of macrophages in the immune system?

  They engulf foreign bodies

  
• How do antibodies function in the immune response?

  They bind to specific antigens

  
• What is the structure of an antibody?

  Globular protein with binding sites
• What is the function of MHC proteins?

  They help identify self and non-self cells
• How do T-lymphocytes assist in the immune response?

  They signal B-lymphocytes and killer T-cells
• What is the role of cytokines in the immune response?

  They trigger influx of defensive cells

  
• What is the function of lysozymes in mucus?

  They destroy pathogens
• How do cilia in mucous membranes help defend against pathogens?

  They trap and expel harmful particles
• What is the role of sebum in skin defense?

  It maintains moisture and lowers pH
• What happens when the skin is cut?

  Blood vessels bleed and clotting occurs
• How do activated B-lymphocytes contribute to the immune response?

  They produce large quantities of antibodies

  
• What is the significance of the antigen presentation process?

  It activates B-lymphocytes and T-lymphocytes

  
• What is the role of neutrophils in the immune system?

  They circulate in the blood to kill microbes
• How do pathogens spread?

  Through various transmission methods
• What diseases can bacteria cause?

  Food poisoning, strep throat, cholera
• What diseases can fungi cause?

  Athlete's foot, ringworm, skin rashes

  
• What diseases can protozoan parasites cause?

  Malaria, sleeping sickness, Giardia
• What diseases can helminthic parasites cause?

  Elephantiasis, schistosomiasis, pinworm
• How do the innate and adaptive immune systems differ in their response time?

  Innate is immediate; adaptive takes longer
• What is the role of the thymus gland in T-cell development?

  It processes T-cells before they enter circulation
• What is the function of plasma B-cells?

  They secrete antibodies

  
• What is the role of helper T-cells in the immune response?

  They activate B-cells and killer T-cells