immune system and resistance to disease Flashcards
what are the types of resistance
- innate - prevents entry of microbes into body or remove foreign material
- adaptive (immunity) - production of specific lymphocyte or antibody against antigen
what does innate involve
- physical barrier
- mechanical barriers
- chemical barriers
- normal microbiome
- phagocytes
- inflammation
- fever
- natural killer cells
physical barriers
skin, mucous membrane
mechanical barriers
flow of tears, sweat, mucus; cilia beating; coughing sneezing
chemical barriers
e.g. 1 gastric acid, lysozyme
e.g. interferons
mechanisms in nearby uninfected cells that prevent infection
normal microbiome
outcompete newcomers
phagocytes
macrophages + neutrophils
inflammation
local tissue damage - release of chemicals. e.g. histamine from mast cells
- results: swelling, heat, redness
fever
immune cells + microbe chemicals trigger release of prostaglandins in hypothalamus which increases temperature
antigen
(Ag) - protein/polysaccharide - recognized as foreign by immune system e.g. parts of bacteria
antibody
- (Ab) plasma protein (y globulin) - matches a specific Ag
- produced by plasma cells
immunes response to adaptive resistance
phagocytes “eats” invader and displays parts of it (Ag) on its surface
- Th binds and is activated - proliferates and releases chemicals which may activate cytotoxic T lymphocytes and B cells
cytotoxic T lymphocytes
proliferate + directly destroy
- cells containing virus
- cells altered by cancer or transplated organs
what are transplanted organs called
- cell-mediated immunity
B cells
- proliferate and convert to plasma cells - antibody
- called humoral (antibody-mediated) immunity
types of humoral immunity
- active - lasts years
- body makes Ab, memory B cells - passive - lasts weeks
- natural: mother to baby across placenta in milk
- artificially produced Ab injected for tetanus, rabies, snake bite
