Immune System

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Immune System

• Defense Against Infectious Diseases

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The Lymphatic System

• Three basic functions
• Maintains body fluids at a constant level
• Absorbs fats from the digestive tract
• Helps body defend itself against disease

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Immune System

• Innate Immune System defense mechanisms that
  your body uses to protect you from MANY different
  types of pathogens
• Skin the first line of defense also home to
  lots microorganisms that inhibit the
  multiplication of pathogens

• Secretions mucus, sweat, tears, saliva
• Secretions trap or kill off pathogens

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If a pathogen gets by the skin and secretions.

• Phagocytes a white blood cell (WBC) that
  ingests and destroys pathogens by surrounding and
  engulfing them
• When a pathogen is present, phagocytes migrate
  out of your blood capillaries to the infected
  areas

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• Macrophage one type of phagocyte
• After a macrophage engulfs large numbers of
  microbes and damaged tissue, they eventually die
• The infected area will contain a collection of
  dead WBCs and various body fluids pus
  (eeeeewwwww!! But now you know what it is!)

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Inflammation of body tissues

• Inflammation (redness, swelling, pain and heat)
  occurs when body tissues are damaged by pathogens
  (can also be a reaction to ANY type of injury)
• Injured cells release histamine which is a
  chemical alarm system, causes blood vessels to
  dilate and inflammation to happen

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Adaptive Immune System

• Immunity defense against a specific pathogen by
  building up a resistance to it
• Antigen foreign substances (proteins, bacteria,
  viruses, etc.) that stimulate the production of
  antibodies in the blood
• Antibody proteins produced in reaction to
  foreign substances (antigens) antibodies are
  specific to an antigen

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Vaccinations

• Vaccine a mixture of a harmless component of a
  disease-causing microbe, a dead or weakened
  pathogen or part of a microbe
• Pathogen microbe
• A vaccine stimulates the immune system to
  increase defenses against the antigen
• Body builds up antibodies and can react quickly
  if exposed to the pathogen (antigen) again

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