Mrs. Wolodkowicz

Biology 1H

Infectious Disease & The Immune System

  1. Nonspecific Defenses (primary lines of defense).
  2. Body Defenses
  3. Inherited defense- species resistance to diseases.
  4. Surface membrane barriers (skin & mucus membranes).
  5. Sweat (pH of 3) inhibits bacterial growth on skin.
  6. Stomach mucosa secretes HCl (pH 2)
  7. Lacrimal fluid (tears).
  8. Mucus- traps invaders.
  9. Nonspecific Cellular & chemical defenses.
  10. Macrophages (monocyte) - white blood cells (leukocytes) that wonder the body engulfing invaders and then presenting the antigen (invaders protein) to the t-cells to prompt an immune response.
  11. Neutrophils (most common WBC) - engulf invader and release defensins (antibiotic chemicals) & bleach. They destroy the invader & themselves.
  12. Natural Killers- lyse cancer & viral infected cells (inject perforin- creates pores in the invaders cell membrane that floods the cell with calcium & kills it (found in large numbers in Cancer & AIDs patients.
  13. Inflammatory response- chemical response to infection that leads to redness, heat, swelling, pain, runny nose, etc. (brings WBC’s, to location via increase blood flow).
  14. Fever- body temperature is regulated by the hypothalamus. Normal temp (37oC/98.6oF. Pyrogens (WBC’s) stimulate the body to shiver, increase metabolism. Once top temperature is reached (crisis), individual sweats to reduce temperature. Death at 112oF or below 70of.
  15. Specific Body Defenses (Immune System) trained cells that act on specific pathogens only.
  16. B lymphocytes- Include Antibodies & memory cells
  17. Antibodies (immunoglobulin’s) - proteins that are specific to invaders and immobilize them until complement comes in and destroys it.
  18. Memory Cells- circulate the body ready to attack if it encounters the invader it is specific to later on.
  19. T lymphocytes- control cell mediated immunity. Include: Regulatory Cells-Helper T & Suppressor T & Effector Cells- Cytotoxic T Cells.
  20. Immune response:
  21. Macrophage (scout) engulfs invader and presents antigen to Helper T cell (general of the immune system).
  22. Helper T cell releases Interleukin 2 which tells the T cells which invader is present and for those T cells that are specific to it to proliferate.
  23. Cytotoxic T cells dock onto target cell, release perforin which kills your cell & the invader (2hrs for death).
  24. Suppressor cells release chemicals to suppress the battle.
  25. Treatment and Cures
  26. Antibiotics- used to treat and cure an illness (typically bacterial) once the person is already sick. Does not work on Viruses.
  27. Vaccine-living or dead organism given prior to an illness to stimulate the creation of memory B cells.
  28. Diseases
  29. Leukemia- cancer of the WBC
  30. Hypersensitivities (allergies)- abnormally vigorous immune response
  31. Autoimmune Disease- immune system believes that your cells are invaders and attacks them. Diabetes Mellitus & Multiple Sclerosis.