Immunology (1)

• Immune system


  To protect from pathogens
• Immune system


  • Has 2 systems: recognition and response
• Innate immune responses


  • Physical barriers
  • Anti-microbial surfaces found in secretions (saliva, tears)
  • Stomach acid
  • Defecation and vomiting can remove microbes from the body
  • Inflammation
  • Interferons
  • NK cells and macrophages
• NK cells


  Natural Killer cells
• NK cells are 5-10% of circulating lymphocytes
• NK cells


  • Attack infected cells and some tumors and release perforin and/or granzymes (for apoptosis)
• Phagocytes


  Attracted to areas of damage or infection by chemotaxis
• Types of phagocytes

  • Neutrophils
  • Monocyte-derived macrophages
• Cell Adhesion Molecules (CAMS)

  Hold together the tissue
• Interferons


  1. Bind to their receptors

  2. Form a cascade

  3. Eventually stops protein synthesis
• Chemokines


  A family of small polypeptides that control adhesion, chemotaxis, leukocyte activation
• Defensins


  Soluble components
• Complement

  A system of soluble proteins which help the body fight off infections
• Neutrophils are the first to migrate from blood
• Neutrophils are essential against bacteria and fungi