Nonspecific Defenses

1
Nonspecific Defenses

• Adriana Perta
• Marisa Pawlowski
• Paige Simko
• Rachel Ragone
• Jill Ross

2
Nonspecific Defenses

• Occur automatically because they are innate
• No memory is involved- no recognition that this
  same intruder has been attacked before
• Barriers to entry, the inflammatory response,
  phagocytes and natural killer cells, and
  protective proteins are types of nonspecific
  defenses

3
Immunity

• The bodys capability to remove foreign
  substances and to kill pathogens and cancer cells
• Involves both nonspecific defenses and specific
  defenses

4
Barriers to Entry

• Include nonchemical barriers such as the skin and
  the mucous membranes lining the respiratory,
  digestive, and urinary tracts serve as
  mechanical barriers to entry by pathogens
• Also include antimicrobial molecules (ex oil
  gland secretions contain chemicals that weaken or
  kill certain bacteria on the skin)
• The stomach has an acidic pH, which inhibits the
  growth of or kills many types of bacteria

5
Inflammatory Response(refer to page 637 figure
35.3)

• When tissue is damaged by physical or chemical
  agents or by pathogens, a series of events occur
• An inflamed area has four outward signs redness,
  heat, swelling, and pain
• These signs are due to capillary changes in the
  damaged area
• Histamine a chemical signal, released by damaged
  tissue cells and mast cells
• Mast cells a type of white blood cell in
  tissues, cause capillaries to dilate and become
  more permeable
• Some inflammatory responses trigger fever, the
  onset being controlled by the brain
• The fever serves to inhibit the growth of some
  microorganisms, promotes accelerated tissue
  repair, stimulates immune cells to divide and
  increases the production of viral-fighting
  interferon

6
Chronic Inflammation

• One that persists for weeks or longer
• Often treated by administering anti-inflammatory
  agents, such as aspirin, ibuprofen, or cortisone
• These medications act against the chemical
  signals, such as histamines, that bring about an
  inflammation
• Chronic inflammation is thought to play a role in
  many human illnesses
• May lead to heart attacks, may destroy nerve
  cells in the brains of Alzheimer patients, can
  also be involved in the development of diabetes
  in obese individuals
• Autoimmune diseases involve inflammation, but in
  these cases specific immunity seems to be the
  leading cause
• A healthy diet, exercise, and good dental hygiene
  can reduce the occurrence of inflammation and
  help keep us well by reducing the occurrence of
  chronic inflammation

7
Macrophages and Cytokines

• Macrophages in tissues, that devour many
  pathogens and survive
• Have receptors that allow them to recognize the
  presence of pathogens
• Release cytokines
• Cytokines chemical signals that stimulate other
  white cells such as neutrophils and monocytes,
  that then mature into macrophages

8
Natural Killer Cells

• Large, granular lymphocytes that kill
  virus-infected cells and cancer cells by
  cell-to-cell contact
• Produce cytokines that stimulate these cells
• Congregate in the tonsils, lymph nodes, and
  spleen
• Look for a self protein on the bodys cell
• Not specific have no memory and their numbers
  do not increase after stimulation occurs

9
Protective Proteins(refer to page 638 figure
35.4)

• Complement composed of a number of blood plasma
  proteins
• complement certain immune responses
• Involved in the inflammatory response because
  certain complement proteins can bind to mast
  cells and trigger histamine release
• Some combine to form a membrane attack complex
  that produces holes in the surface of bacteria
  and viruses
• Interferons proteins produced by virus-infected
  cells as a warning to noninfected cells in the
  area
• Binds to receptors of noninfected cells, causing
  them to prepare for a possible attack
• Used as treatment in certain viral infections
  like hepatitis C