Microbiology

• What is Immune Micorbiology?

  Study of how the immune system interacts with microorganisms.
• What are Neutrophil?

  A type of white blood cell. They arrive at the site of injury (are attracted to it by chemicals released). They are made in bone marrow and circulate in the blood system where they engulf the pathogen
• What is an Eosinophil?

  White blood cells that are responsible for neutralizing histamines in allergic reactions. They are made in the bone marrow and circulate in the blood system. They are also parasite destroying cells
• What is a Basophil?

  A type of white blood cell that helps to release heparin (for blood clotting) or histamine (in inflammatory response). They can be found with "mast cells" at the site of inflammation.

  Made in bone marrow and circulate in the blood system
• What is a Monocyte?

  Large phagocytosing cells (bigger than neutrophil). They can be found in the circulatory system but will also migrate to the inflamed tissue, where they become a macrophage.

  Neutrophils enter before monocytes do.
• What is a Macrophage?

  A type of white blood cell that engulfs and digests foreign particles, dead cells and debris (phagocyte)
• Describe the process of Phagocytosis

  1. Chemotaxis and adherence of microbe to phagocyte
  2. ingestion of microbe by phagocyte
  3. formation of a phagosome - microbe in a vesicle within the phagocyte
  4. fusion of the phagosome with a lysosome = phagolysosome
  5. enzymes from the lysosome digest the microbe
  6. formation of a "residual body" which contains only the indigestible material
  7. exocytosis = discharge of waste
• What is a Lymphocyte?

  A type of white blood cell, which can be further divided into: T cells, B cells, Natural killer cells
• What are Natural killer cells?

  A type of lymphocyte (and therefore WBC) which defend the body against viruses and cancer cells by secreting Perforin which attacks the cell membranes. They can also inject these cells with chemicals that trigger apoptosis - this causes self destruction of the cells
• What are B-cells?

  A lymphocyte type (therefore WBC) that circulate in the blood system and become activated by T cells. After activation they produce clones with the correct antibodies to bind with the antigen of the pathogen - disabling it from binding with other cells.

  B-cells also produce memory lymphocytes to reduce time during secondary infection
• What are T-cells?

  A type of lymphocyte (therefore WBC) that is made in the thymus, there are 3 different types:

  • Helper - stimulates B cells
  • Cytotoxic - monitors the body, recognizing and eliminating infected cells
  • Memory - helps to provide faster response time to secondary infection
• What are Antigens?

  Molecules that identify a cell
• What is an Antibody?

  A Y shaped protein that is produced by plasma cells. It is used to neutralize pathogens.

  There are different classes:

  • IgG - most abundant and for long-lasting immunity
  • IgM - first antibody produced during an infection
  • IgA - found in mucosal secretions (like saliva and tears) that helps to protect the mucous membrane
  • IgE - involved in allergic repones