Download The Immune System

The Immune System
Pathogens-disease-causing agents like
bacteria, protozoans, fungi, viruses, and
other parasites
How is Bacteria in Your Body Good?
History
 Robert Koch-1876, German Physician
 He cultured the rod-shaped bacteria that
caused anthrax in cattle and sheep
 He injected the anthrax into healthy animalsthey died.
Transmission
 From human to human
 Transmission during incubation periods
 Carriers
 Animals to humans (rabies, Lyme disease)
 Soil and Water
What causes symptoms?
 Viruses take over the host cells, and
eventually kill them
 Bacteria produce toxins that are transported
by blood

These toxins can inhibit protein synthesis,
destroy blood cells and blood vessels,
produce fever, or disrupt the nervous system
Patterns of Diseases
 Endemic disease-constantly present (the
common cold)
 Epidemic disease-people get the same
disease at the same time (polio)
Treating Diseases
 Antibiotics-substance produced by a
microorganism that, in small amounts, will kill
or inhibit growth and reproduction of bacteria
Innate Immunity
 Your body’s first line of defense!
skin, mucus, oil, sweat, tears, and
saliva
Inflammation
 redness, swelling, pain, and heat
Phagocytes
 White blood cells that engulf pathogens
Macrophages
 Also engulf and destroy pathogens
Interferons
 Used for the invasion of viruses
 They go to healthy cells and produce antiviral
proteins that prevent the virus from
multiplying
Acquired Immunity
 Building a resistance to pathogens
 The lymphatic system
Antibody Immunity
 Your body builds up this immunity by
producing antibodies to it
 T-Cells-interact with B-cells
 B-Cells-produce antibodies (memory)
Cellular Immunity
 Killer T-cells
 Stored in lymph nodes, spleen, and tonsils
 Release enzymes that kill pathogens
Passive Immunity
 Develops as a result of acquiring antibodies
that are generated in another host
 Ex.-mother-to-child, during nursing
 Artificial passive immunity-injecting antibodies
into body from an animal or human that is
already immune (snake bites)
Active Immunity
 Obtained naturally when a person is exposed
to antigens
 Will be immune if exposed again
 vaccines