antigens: Antigens are molecules that stimulate an immune system response. Bacteria, viruses, and other microorganisms are types of antigens.
bacteria: Bacteria are a major group of living organisms. Most are microscopic single-cell organisms with a relatively simple cell structure, lacking a cell nucleus.
connective tissue: Connective tissue is a type of biological tissue that serves to support, bind together, and protect organs.
C3a: C3a is the immune system’s emergency signal flare. When these chemicals touch bacteria they explode, releasing chemical signals. Macrophages follow these chemical signals to find invading bacteria.
friend or foe: The cells of the immune system differentiate self (friend) from non-self (foe), attacking invasive cells and chemicals. An overactive immune system can attack self-cells, leading to diabetes, rheumatoid arthritis, and many other autoimmune diseases.
ICAMs: Intercellular Adhesion Molecules (ICAMs) are big molecules on the surface of cells that allow one cell to stick to another. Immune system cells use ICAMs to stick to where they are needed.
LPS: LPS is a macromolecule found on the surface of bacteria. LPS does not naturally occur in the human body, it is only found on bacteria. This makes it an excellent marker that the immune system can use to distinguish between friends (healthy body cells) and foes.
monocyte: Monocytes flow in the blood as one of the white blood cells. When they are activated, they morph into macrophages.
macrophage: Macrophages are versatile and powerful immune system cells. Constantly on patrol, they can find and kill many different kinds of bacteria without any help. They are usually the first responders to any invasion.
nanobot: A fictional robot of microscopic proportions, built by means of nanotechnology to help retrain inactive immune cells.
neutrophil: Neutrophils are a type of white blood cell. They destroy many kinds of invading bacteria. They attack very quickly and in large numbers.
pseudomonas: Pseudomonas is a bacteria that causes swimmer’s ear.
selectins: Selectins are big molecules that help immune system cells find where they need to go. For example, selectins mark the part of a blood vessel near an infection.
staphylococcus: Staphylococcusis is a bacteria that causes the staphylococcus (staph) bacterial infection.
transmigration: The transformation and migration of cells from one environment (blood vessels) to another (connective tissue).
white blood cell: White blood cells (leukocytes) are the cells of the immune system. Monocytes, macrophages, neutrophils, natural killer cells, T-cells and B-cells are all white blood cells.