Immune System

1
Immune System

• The bodys primary defense against disease
  causing pathogens that threaten our homeostasis.
• Can be identified by molecules on their outer
  surface (antigens)

2
Antigens

• Found on both viruses and bacteria
• Trigger an immune response.
• Recognized by body as invaders.
• White blood cells and antibodies attack.
• The body can usually take care of a virus but
  antibiotics are often needed to kill bacteria.

3
White Blood Cell

• Some are specialized to engulf invading
  pathogens.
• Others produce antibodies proteins that either
  attack or mark for killing.
• WBCs have large nuclei.

4

• Most antibodies and WBCs break down soon after
  having defended the body.
• But some specialized WBCs remain. These can
  produce antibodies to fight off later invasions
  of the same microbes.
• This gives us immunity to viruses such as chicken
  pox, mumps and measles years later.

5
Vaccinations

• Scientists have discovered that weakened microbes
  stimulate the immune system to produce antibodies
  without making the person sick.
• Vaccines are made from weakened killed or parts
  of pathogens and injected into the body.

6
Damage to the Immune System

• Stress and fatigue can lower resistance and open
  the door to infection by pathogens.
• AIDS weakens the immune system and may leave a
  person unable to deal with infections and cancer
  cells.
• People with AIDS often die from secondary
  infections.

7
Problems Associated With Immune Response

• Allergies Your bodies may react to things like
  foods, insect bites, dust or pollen and produce
  an immune response.
• The body reacts by releasing histamines which
  produce an inflammatory response.

8

• Transplanted organs body detects foreign
  proteins. Tries to rid body of invader. This is
  organ transplant rejection.
• Doctor gives immune system suppressing drugs.