immunology

• What are the primary lymphatic organs?

  Red bone marrow and thymus gland
• What is the role of primary lymphatic organs?

  Site of lymphocyte formation and maturation
• Where do T and B cells originate?

  Born in bone marrow
• Where do B cells and T cells mature?

  B cells mature in bone marrow, T cells in thymus
• What type of immunity do T cells provide?

  Cell-mediated immunity
• What is the function of B cells?

  Provide antibody-mediated immunity
• What is B cell sensitization?

  Binding of antigens to B cell receptors
• What happens during B cell sensitization?

  Antigens are processed and presented on MHC
• How is B cell activation achieved?

  Helper T cells bind to MHC complex
• What do helper T cells do?

  Stimulate B cell activation and division
• What do activated B cells divide into?

  Plasma cells and memory B cells
• What is the role of macrophages?

  Engulf invaders and debris by phagocytosis
• What do neutrophils do?

  Circulate in blood and engulf invaders
• What is the function of basophils?

  Release histamines and participate in inflammation
• What do eosinophils target?

  Parasitic invaders
• What is the role of NK cells?

  Extracellular killing of infected cells
• What do phagocytes do?

  Ingest and destroy microbes or debris
• How do macrophages develop?

  From enlarged monocytes
• What are wandering macrophages?

  Macrophages that migrate to infected tissues
• What are fixed macrophages?

  Macrophages that stay in specific tissues
• What do lymphocytes form?

  T and B cells
• What triggers inflammation in innate immunity?

  Localized tissue injury
• What are the cardinal signs of inflammation?

  Redness, swelling, heat, pain, loss of function
• What are the five stages of phagocytosis?

  1. Chemotaxis: Phagocytes attracted to infection
  2. Adherence: Phagocytes attach to foreign material
  3. Ingestion: Phagocytes engulf microbes
  4. Digestion: Phagosome mixes with lysosomes
  5. Killing: Lysosomes break down microbes
• What is the major histocompatibility complex (MHC)?

  T cells recognize antigens bound to MHC proteins
• Where are MHC proteins genetically coded?

  Chromosome 6
• What are the two classes of MHC proteins?

  Class I and Class II
• What is the function of Class I MHC proteins?

  Found in all nucleated cells, present peptides
• What is the function of Class II MHC proteins?

  Found in antigen presenting cells, stimulate T cells
• What are antigen presenting cells (APCs)?

  Specialist immune cells like dendritic cells
• What are the major types of T cells?

  Cytotoxic, memory, helper, suppressor, inflammatory
• What do cytotoxic T cells do?

  Attack infected or cancerous cells
• What do memory T cells do?

  Clone themselves in response to antigens
• What is the role of helper T cells?

  Stimulate function of T and B cells
• What do suppressor T cells do?

  Inhibit function of T and B cells
• What is the role of inflammatory T cells?

  Associated with strong inflammatory responses
• What happens during TH cell mediated immunity?

  TH cells enlarge and produce clones
• What do Tc cells do?

  Destroy infected or cancerous cells
• What is perforin's role?

  Makes holes in membranes causing cytolysis
• What does lymphotoxin do?

  Damages target cell DNA