Please enable JavaScript.

Coggle requires JavaScript to display documents.

“Lymph Immune System, David Arroyo, Period 5. - Coggle Diagram

- - - - Helper T cells interact directly with B cells displaying antigen fragments bound to MHC II receptors
      - Stimulate B cells to divide more rapidly and begin antibody formation
    - - CD8 cells require Th cell to become activated into destructive cytotoxic T cells
      - Cause dendritic cells to express co-stimulatory molecules required for CD8 cell activation
    - - Play central role in adaptive immune response
        
        Activate both humoral and cellular arms
        
        Once primed by APC presentation of antigen, helper T cells:
    - - Amplify responses of innate immune system
        
        Activate macrophages, leading to more potent killers
        
        Mobilize lymphocytes and macrophages and attract other types of WBCs
    - - Directly attack and kill other cells
        
        Activated TC cells circulate in blood and lymph and lymphoid organs in search of body cells displaying antigen they recognize
        
        Activated TC cells target:
        
        Cytotoxic T cells deliver lethal hit using two mechanisms
        
        Regulatory T (TReg) cells
        
        Important in preventing autoimmune reactions
- - - - CD4 cells usually become helper T cells (TH) that can activate B cells, other T cells, and macrophages; direct adaptive immune response
      - CD8 cells become cytotoxic T cells (TC) that are capable of destroying cells harboring foreign antigens
    - - T cells respond only to processed fragments of antigens displayed on surfaces of cells by major histocompatibility complex (MHC) proteins
      - Antigen presentation is vital for activation of naive T cells and normal functioning of effector T cells
  - - - Antigen binding
        
        T cell antigen receptors (TCRs) bind to antigen-MHC complex on APC surface
        
        TCR must recognize both MHC and foreign antigen it displays
        
        Binding of TCR to complex triggers multiple intracellular signaling pathways that start T cell activation
      - Co-stimulation
        
        Complete T cell activation requires T cell to also bind to one or more co-stimulatory signals on surface of APC
    - - T cells that are activated enlarge and proliferate in response to cytokines
      - Differentiate and perform functions according to their T cell class
      - Primary T cell response peaks within a week
      - T cell apoptosis occurs between days 7 and 30
- - - - Constitutes first and second lines of defense
      - First line of defense: external body membranes
      - Second line of defense: antimicrobial proteins, phagocytes, and other cells
    - - Skin and Mucous membranes produce proactive chemicals that inhibit or destroy microorganisms
        
        Enzymes
        
        lysozyme of saliva, respiratory mucus, and lacrimal fluid kills many microorganisms; enzymes in stomach kill many microorganisms
        
        Mucin
        
        sticky mucus that lines digestive and respiratory tract traps microorganisms
        
        Acid
        
        acidity of skin and some mucous secretions inhibits growth; called acid mantle
      - Surface barriers are skin and mucous membranes along with their secretions
      - Second line of defense: cells and Chemicals
        
        Phagocytes
        
        Natural killer cells
        
        Inflammatory response
        
        Antimicrobial Proteins
        
        Fever
- - - - Can be a complete antigen or hapten(incomplete)
      - Contain antigenic determinants
      - Can be a self-antigen
  - - - Lymphocyte development, maturation, and activation
    - - B lymphocytes (B cells)—humoral immunity
      - T lymphocytes (T cells)—cellular immunity
  - - - Five major classes: IgM, IgA, IgD, IgG, andIgE
- - - - congenital or acquired conditions that impair function or production of immune cells or molecules
- - - - Prevent pathogens from penetrating mucous membrane
      - Site for lymphocyte activation and profilliration
      - Diffuse lymphatic tissue in addiction to follicles
    - - Site for T cell Maturation
    - - Cleanses blood and removes aged or defective red blood cells
      - Site for Lymphocyte activation and proliferation and stores platelets, monocytes, and iron
      - Red and white pulp
    - - Cleanse Lymph
      - Site for lymphocyte activation and proliferation
      - Both afferent and efferent lymphatic vessels