Immune System

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Immune System
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Disease

• A disease is any change other than injury, that
  disrupts the normal functions of the body. Some
  diseases are inherited, others are caused by
  materials in the environment.
• Still others are caused by agents such as
  bacteria, viruses, fungi, animals such as worms,
  etc..

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Pathogens

• Disease-causing agents such as bacteria are
  called pathogens. (sickness makers)
• Diseases caused by pathogens are called
  infectious diseases, because the agents that
  cause infect the body they enter.

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Toxins

• Toxins are poisons that produce illness by
  disrupting bodily functions.
• Some bacteria cause disease by producing toxins
  and injecting them into host cells.
• Animals that carry disease-causing organisms from
  person to person are called vectors.

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Antibiotics

• Antibiotics are compounds that kill bacteria
  without harming the cells of humans or animals.
• Antibiotics work by interfering with the cellular
  processes of microorganisms.
• They have no affect on viruses
• Penicillin was discovered in 1928 by Alexander
  Fleming.
• http//www.biography.com/people/alexander-fleming-
  9296894

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Vaccines

• Killed or weakened viruses.
• The injection of a weakened or mild form of a
  pathogen to produce immunity is known as a
  vaccination.
• Today more than 20 serious human diseases can be
  prevented by vaccinations.

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• https//www.youtube.com/watch?vy0opgc1WoS4
• https//www.youtube.com/watch?v3aNhzLUL2ys

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First Line of Defense

• The body has several physical barriers
• An outer layer of intact skin
• Hair in the nostrils
• Mucous membranes
• Cilia
• Mucus in your nose or throat traps viruses and
  bacteria
• Stomach acids and digestive enzymes destroy many
  pathogens.
• Mucus, saliva, sweat, tears contain an enzyme
  that breaks down the cell walls of many bacteria.

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Cilia
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Second Line of Defense

• The inflammatory response is a defense reaction
  to tissue damage caused by injury or infection.
• White blood cells leak from the vessels to enter
  the infected tissues. They engulf and destroy
  bacteria.
• The infected tissue may become swollen and
  painful.

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The Immune Response

• If a pathogen is able to get past the bodys
  first few lines of defense the immune system
  reacts with a series of specific defenses that
  attack disease-causing agents.
• A substance that triggers this response is called
  an antigen.

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White Blood Cells

• Leukocytes (White blood cells)
• Macrophages
• Lymphocyte (B cells, T cells, cytotoxic)
• Basophil (release of histamine and inflammatory
  response)

Video Clip
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Third Line of Defense

• Antibodies

• Antigens
• Are foreign substances that cause an immune
  response.
• Antibodies
• Are proteins found in blood plasma that attach to
  one particular kind of antigen and help counter
  its effects.

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Lock and Key what does that remind you of?
Video Clip
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Permanent Immunity

• Once the body has been exposed to a pathogen,
  millions of memory B and T cells remain capable
  of producing specific antibodies to that
  pathogen.

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Immune System Disorders

• Allergies result when antigens from allergens
  (pollen, dust ball, dust mites) bind to a type of
  immune cells. The immune cell becomes activated
  and produces a chemical called histamine.
• Histamines increase the flow of blood and fluids
  to the surrounding area. They produce the
  sneezing, runny eyes and nose.
• Antihistamines are drugs that are used to
  counteract the effects of histamines.

Video
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Autoimmune Disease

• When the immune system makes a mistake and
  attacks the bodys own cells, it produces an
  autoimmune disease.

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A.I.D.S.

• HIV, the AIDS virus
• Attacks helper T cells
• HIV has one of the fastest rates of mutation of
  any pathogen ever studied.
• Drug-resistant HIV strains are now being
  documented in newly infected patients.
• Exhibits how this virus readily adapts through
  natural selection.