Interactive Physiology Innate Defense
Question to answer after watching the Interactive Physiology - The Immune System: Innate Host Defenses
1. Name the two major categories of innate (nonspecific) defenses:
• Surface Barriers
• Innate Internal Defenses
2. Surface barriers include the Intact skin and mucous membranes of the respiratory, gastrointestinal and genitourinary tracts.
3. List the three properties of skin that help it resist invasion:
• Keratin: tough protein in skin cells, forms an abrasion- and water-resistant outermost layer
•Intercellular Junctions hold skin cells tightly together
• Skin secretions are acidic and contain chemicals that make skin inhospitable for pathogens. Ex: lysozyme, can digest cell walls of certain bacteria.
4. The mucus membranes not only provide a barrier, but they also produce a variety of protective chemicals. For example, the stomach secretes digestive enzymes and has a very low pH. The respiratory and digestive tracts are lined with sticky mucous that traps pathogens.
5. Once the surface barrier has been broken, the second line of defense, the innate internal defense system (nonspecific defense system), attempts to limit the spread of pathogens. Name the 5 components of the innate internal defense system:
• Phagocytic cells- neutrophils and macrophages
• Natural Killer cells- kill body cells that have become virus infected or cancerous
• Antimicrobial Proteins- complement and interferons
• Inflammation
• Fever
6. Neutrophils and monocytes/macrophages (monocytes develop into macrophages in the tissue) are the two types of phagocytes discussed. Answer the following questions by circling the correct answer. Which phagocyte is most abundant? Neutrophil or Monocyte Which phagocytizes more pathogens? Neutrophil or Macrophage Which cell is not found in healthy tissue? Neutrophil or Macrophage 7. A phagocyte recognizes and binds to molecules found on pathogens using special membrane receptors, such as the mannose receptor and the Toll-like (TLR)
1. Name the two major categories of innate (nonspecific) defenses:
• Surface Barriers
• Innate Internal Defenses
2. Surface barriers include the Intact skin and mucous membranes of the respiratory, gastrointestinal and genitourinary tracts.
3. List the three properties of skin that help it resist invasion:
• Keratin: tough protein in skin cells, forms an abrasion- and water-resistant outermost layer
•Intercellular Junctions hold skin cells tightly together
• Skin secretions are acidic and contain chemicals that make skin inhospitable for pathogens. Ex: lysozyme, can digest cell walls of certain bacteria.
4. The mucus membranes not only provide a barrier, but they also produce a variety of protective chemicals. For example, the stomach secretes digestive enzymes and has a very low pH. The respiratory and digestive tracts are lined with sticky mucous that traps pathogens.
5. Once the surface barrier has been broken, the second line of defense, the innate internal defense system (nonspecific defense system), attempts to limit the spread of pathogens. Name the 5 components of the innate internal defense system:
• Phagocytic cells- neutrophils and macrophages
• Natural Killer cells- kill body cells that have become virus infected or cancerous
• Antimicrobial Proteins- complement and interferons
• Inflammation
• Fever
6. Neutrophils and monocytes/macrophages (monocytes develop into macrophages in the tissue) are the two types of phagocytes discussed. Answer the following questions by circling the correct answer. Which phagocyte is most abundant? Neutrophil or Monocyte Which phagocytizes more pathogens? Neutrophil or Macrophage Which cell is not found in healthy tissue? Neutrophil or Macrophage 7. A phagocyte recognizes and binds to molecules found on pathogens using special membrane receptors, such as the mannose receptor and the Toll-like (TLR)