Ch'6 Notes: Immune System

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Ch.6 Notes Immune System
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Definitions

• Pathogen A disease causing organism
• Antigen the marker protein that identifies the
  pathogen.

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Causes of Pathogens

• Soil
• Contaminated water
• Infected animals
• People

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Examples of Diseases

• Spinal meningitis- virus or bacteria that attacks
  central nervous system
• Hepatitis B-virus that attacks liver

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Methods of disease transmission

• Direct contact
• Objects
• Air- sneeze or cough
• Intermediate organisms like flies or mosquitoes

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Your Bodys defense The Immune System

• Lymph nodes/vessels
• Hold macrophages and Helper T Cells
• Thymus Gland
• Where T Cells mature
• Bone Marrow
• Where B cells mature

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What Triggers your immune response?

• Anything that gets through the first line of
  defense

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First line of Defense Physical Barriers

• Skin- physical barrier against microorganisms
• Body Secretions- mucous, sweat, tears, saliva
  contain enzymes that break down cells walls of
  bacteria
• Swelling/ Inflammation- Blood vessels swell,
  temp. increases, redness, pain

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2nd line of defense white blood cells

• Macrophage- engulf digest pathogens display
  antigens to Helper T cells
• B Cell- make antibodies
• Helper T cell- found in lymph nodes signals B
  cells and Killer T cells
• Killer T cell- destroys infected cells and
  pathogens

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2nd line of defense chemicals

• Antibodies- proteins produced by B cells that
  mark the pathogen
• Interferon- chemicals produced by infected cells
  that help protect nearby cells from being invaded
  by viruses.

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3rd line of defense

• Memory B cells- reserve of B cells that can make
  antibodies to a certain antigen if you are
  infected again.
• Memory T cells- reserve of Killer T cells that
  can kill infected cells pathogens if you are
  infected again.

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Acquired Immunity-occurs over your lifetime

• Antibody immunity- can be 2nd or 3rd line of
  defense
• Cellular immunity - can be 2nd or 3rd line of
  defense