Notes: Chapter 39 (page 1022-1047)

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Notes Chapter 39 (page 1022-1047) Immunity
from Disease
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Pathogens

• Disease causing agents
• Can be bacteria, protists, fungi, viruses, or
  parasites like tape worms
• Infectious diseases are any diseases caused by a
  pathogen

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Symbiosis with microorganisms

• Bacteria on our skin and intestines help us
  digest our food and keep harmful bacteria from
  growing and causing illness.
• Helps maintain homeostasis within our digestive
  tract

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Host cells

• Viruses need be inside of host cells in order to
  reproduce

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Antibiotics

• A substance that kills or inhibits the growth or
  reproduction of other microorganisms.
• Effective against bacteria and some fungi but NOT
  VIRUSES.

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Antibiotic resistance

• Continued use of antibiotics selects for
  resistant bacteria. Soon the antibiotics do not
  work.
• In the case of penicillin, over-prescribing and
  failure to use the entire dose led to resistant
  bacteria surviving and reproducing.

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Our Immune system
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Innate Immunity

• Bodys first defense
• NON-Specific defense (attacks everything)
• Skin, saliva, sweat, tears, inflammation
• Main cells are macrophages
• Macrophages engulf and kill foreign invaders

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Acquired Immunity

• Second defense
• Goes after specific pathogens (targeted)
• Main cells are lymphocytes
• T-cells and B-cells

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Acquired Antibody Immunity

• Macrophages recognize and engulf a foreign
  invader which activates helper T-cells
• Helper T-cells then activate B-cells
• B-cells mature into plasma cells and make
  antibodies against the specific pathogen
• Memory B-cells and T-cells hang around in case
  the pathogen shows up again later
• Quick response next time

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Acquired Cellular Immunity

• Cytotoxic T-cells are killer T-cells that destroy
  cancer and virus infected cells but punching them
  full of holes

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Autoimmune responses

• Allergic reactions are immune responses to
  harmless substances
• Autoimmune diseases happens when the immune
  system turns on own body and attacks (example is
  lupus)

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Passive Immunity

• When you are given antibodies made by someone
  else. Not lasting protection
• Antibodies from mother to infant through the
  placenta and breast feeding
• anti-venom

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Active Immunity

• Body produces its own antibodies after being
  exposed to antigens
• Antigens are proteins from pathogens
• Vaccines are weakened or dead pathogen that
  induces a person to make antibodies
• Gives lasting protection against the disease
  through memory cells

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AIDS, HIV and the Immune System

• HIV stands for Human Immunodeficiency Virus
• HIV is a retrovirus (RNA) that attacks helper
  T-cells which prevents the immune system from
  working properly
• The causes AIDS (acquired immune deficiency
  syndrome)
• Person with AIDS cannot fight off infections and
  they may die
• Passed through bodily fluids