The Immune System Flashcards
What is a pathogen?
infectious agent
Name some types of pathogens.
viruses, parasites, bacteria, fungi
What are the 2 types of immunity?
innate and acquired immunity (specific, non-specific)
Name and describe the barrier defenses.
skin- outer layer of dead skin cells, acidic pH of 3-5 to kill off the bad bacteria, also has good bacteria to eat bad ones as well
mucus- lines all openings, catches and traps pathogens, has lysozymes to kill pathogens
Name and describe white blood cells (leukocytes).
neutrophils, macrophages, eosinophils, dendritic cells - these recognize, engulf, and eat pathogens using phagocytosis (sending out pseudopods that engulf the pathogens and take them to the lysozymes). Natural killer cells are also cells that do this; they travel in the blood and naturally kills pathogens.
Where do the white blood cells reside (besides in the blood)?
lymph nodes, tonsils, adenoids, spleen, appendix
What are the protein responses involved in innate immunity?
interferon- fight off viruses (sometimes cancer)
complement system- group of 30 proteins that travel in the blood plasma; when activated, proteins cause pathogens to be lysed
inflammatory response- cut/injury: histamenes are released which cause blood vessels to dilate so more WBC are near to the area where pathogens are getting into the body. This makes pathogens easier to get rid of/eaten because the bacteria-fighting cells are right there.
pus- accumulation of dead white blood cells, dead cells, and dead pathogens
fever- pyrogens released from macrophages that inhibit the reproduction of pathogens by increasing the body’s temperature
What is innate immunity? What is acquired immunity?
innate- eats everything, every organism has this
acquired- specific, builds immunity to detected pathogens, uses antibodies and lymphocytes
What are lymphocytes? What are antibodies?
lymph- B and T cells
- B: made in bone marrow, make antibodies
- T: made in thymis gland above heart, kills infected cells
antibodies- proteins that attach to specific pathogens, infinite number of shapes balances infinite number of pathogens
Describe specific immune respone.
Virus enters the macrophage. It’s eaten. The macrophage displays part of the leftover virus on its surface (MHC 2). Helper T cells bind to the surface at the dead virus. It takes the shape of the virus and activates it. It goeas to B and T cells. B cells form plasma cells and memory B cells. Plasma cells form antibodies which inactivate the virus and mark infected body cells and the viruses for Killer T cells and macrophages to eat. Helper T cells also activate Cytotoxic T cells which kill infected body cells.
What is the major histocompatability complex?
a way that cells recognize each other
- Class 1: protein display infected body cells to Killer T cells
- Class 2: helps display pathogen on macrophages for Helper T cells
What are the 5 classes of antibodies? Which are the most common?
IGG, IGM, IGA, IGE, IGD (IG = immunoglobin, G, M, A,E, D = shapes)
How are anitbodies an example of positive feeback?
When making antibodies, more are continuously produced. This means more macrophages are eating the virus and infected body cells.
What is active and passive immunity?
Passive- get antibodies from mom (breast milk and umbilical cord) so babies don’t get sick for the first few months of life
active- when you start to produce your own immunity/antibodies
What is a vaccination?
a dead/inactive virus that could have an inflammatory response. This will cause the antibodies to be made, but they will remain inactive.
