bsci202 exam 1 - immune system

• what is nonspecific resistance?

  barriers, cells, proteins, processes
• what is immunity?

  actual response from your immune system using cells, antibodies, etc
• why is skin a good barrier?

  salty, relatively dry, has acidic pH
• why are mucous membranes good barriers?

  has hair and cilia to trap foreign particles
• why are phagocytic cells good barriers?

  engulf foreign particles
• why are NK cells good barriers?

  eliminate cells that lack "self" cell-surface proteins called MHC

  • release perforins (poke holes in cell) and granzyme B (stimulates apoptosis)
• why are interferons good barriers?

  activate macrophages, NK cells, and there are antiviral effects
• why is complement a good barrier?

  amplify inflammatory response, enhance immune adhesion, and pathogen lysis
• why is inflammation a good barrier?

  promotes healing, stimulate/enhance immune response, destroy injurious agents and remove them from inflammatory site, wall off area to confine agents to protect healthy tissues
• why is a fever a good barrier?

  increases metabolic rate which increases rate of repair
• what are the characteristics of an immune response?

  1. antigen specific
  2. systemic in scope
  3. has memory
• what is humoral immunity?

  b cells bind to free floating antigens outside the cell that are viruses, bacteria, worms, etc., and creates an army to fight them
• what is cell mediated immunity?

  t cells attack viruses within the cell that is displaying the foreign fragment of the particle on its MHC I and MHC II, stimulating apoptosis
• where do b lymphocytes originate and mature?

  originate and mature in red bone marrow
• what do b lymphocytes do?

  when they encounter the right antigen, they are activated and proliferate and differentiate into effector/memory cells
• where do t lymphocytes originate and mature?

  originate in the red bone marrow and mature in the thymus
• what do helper t cells do?

  needed to activate cytotoxic t cells and super activate b cells
• what do cytotoxic t cells do?

  attack your own infected cells
• what do macrophages originate from?

  monocytes
• what do macrophages do?

  surrounds and kills foreign microorganisms
• what do plasma cells originate from?

  b cells
• what do plasma cells do?

  secrete antibodies (humoral immunity)
• what is an antigen (immunogen)?

  substances which evoke immune responses
• what is a complete antigen?

  has immunogenicity and reactivity
• what is immunogenicity?

  can activate b/t cells
• what is a hapten (incomplete antigen)?

  too small to be immunogenic; must attach to larger carrier protein
• what are epitopes?

  portions of the antigen actually immunogenic
• what is the mechanism used in humoral response?

  1. plasma cells secrete antibodies into body fluids
  2. antibody is transported in the body fluids to the site of infection
  3. antibodies form complexes w/ antigens and will a. activate complement, b. neutralize/immobilize antigen, c. precipitation or agglutination
• what is naturally acquired immunity?

  acquired as a result of natural processes

  • active: infection
  • passive: antibodies passed down from mother to fetus
• what is artificially acquired immunity?

  acquired when antigen is introduced from clinical process

  • active: vaccine
  • passive: injection of immune serum
• what is active immunity?

  b cell encounters antigen to make the antibodies
• what is passive immunity?

  person received antibodies that were produced by another organism (no memory generated)
• what are antibodies (immunoglobulins)?

  glycoproteins secreted by plasma cells
• what is the structure of antibodies?

  4 polypeptide chains (2 heavy and 2 light); each chain has 2 functional areas
• what are the 2 functional areas of the antibody chains?

  variable region: highly variable amino acid sequence, base of antigen specificity (Ab binds antigens here)

  constant region: more conserved amino acid sequence (Defines five classes each with different function)
• what is the mechanism used in cell mediated immunity?

  t lymphocytes travel directly to site of infection and lyse invaded body cell, causing apoptosis
• what is MHC I?

  • hold "self-antigen" unless infected
  • on all nucleated body cells and recognized by CD8 cells
• what proteins are typed and matched prior to transplantion?

  MHC I proteins
• what are the 4 types of transplantions?

  autograft, isograft, allograft, zenograft
• what is an autograft?

  tissues grafted from individual back to themselves