biosci 201

• plasma

  blood protein (includes albumin, antibodies, CF, and fibrinogen)
• buffy coat

  contains WBC/leukocytes involved in immune reactions
• contents of blood

  plasma, erythrocytes/RBC, and buffy coat
• immunity

  the ability to defend against infection/pathogen
• antigen

  molecule that elicts an immune response
• features of the immune system are

  specificity, diversity, memory, tolerance
• specificity


  ability to distinguish between similar molecules
• diversity


  recognises different molecules
• memory


  remembers previous experience with a microbe and reacts faster
• tolerence


  ability to distinguish self from non-self
• key to good immune defence is having multiple layers
• types of immunity:

  mechanical & chemical, innate immune system, and adaptive immune system
• CD

  cluster differentiation

  CD are cell surface markers for immunophenotyping cells

  CD often function as receptors or ligands
• co-ordinated responses require...

  communication
• cytokines are...


  small proteins that induce a signalling response
• chemokines


  induce chemotaxis; homeostatic or inflammatory
• interleukins


  differentiation and function of T and B cells (lymphokines)
• interferons (IFN)


  antiviral molecules and modulate effector functions
• tumour necrosis factors (TNF)


  cell death or T cell stimulation
• Immune cells


  • Found in tissues, blood and lymph
  • Cells leave blood vessel, enter tissues (interstitial fluid) and drain back into system in lymph

  
• Primary lymphoid tissue


  • Where cells are generated (thymus – T cells; bone marrow – B cells)

  
• Secondary lymphoid tissues

  • Site where adaptive immune responses are generated (includes lymph nodes, spleen)

  
• Stromal cells


  • Provide both structural support and secrete soluble mediators which facilitate cell survival in the lymph node