Immunity Flashcards
non specific defense (innate)
consists of first line of defense skin, mucous membranes, secretions
the second line of defense phagocytic white blood cells, antimicrobial proteins, the inflammatory response
specific defense (adaptive)
the third line of defense lymphocytes, antibodies
functions of the immune system
defending against pathogens, removing worn out damaged cells, preparing for wound healing, immune surveillance
immune surveillance
the identification and destroying of abnormal cells that have originated in the body
inflammation
innate defense, first line, non-specific response to pathogen or tissue damage comma mediated by phagocytes
how does inflammation work?
stimulated by bacterial Invasion or tissue damage, release of histamine by mast cells, vasodilation and increased local capillary permeability, increased blood delivery, increase in plasma proteins clotting factors and phagocytes, defense against pathogen and tissue repair
signs of inflammation
redness (rubor), heat(calor), swelling(edema), pain,(dolor), sometimes loss of function
interferon
if a cell is infected by a virus, the cell will release interferon as a warning to other cells, prevents virus from multiplying
natural killer cells
lyce and Destroy viral infected cells and cancer cells
complement system
lyces the membrane of the pathogen and enhances inflammation
membrane attack complex
attacks the membrane of pathogen and forms a hole, made from c5b, C6, C7, C8, and C9.
C3 convertase
splits C3 in two parts A and B
c3a
enhances inflammation
c3b
coats things with opsonin to mark them as trash and notify phagocytes to engulf
opsonin
used in opsonization, Marc’s things as trash for phagocytosis
c-5a
enhances inflammation
C5b
forms the MAC
adaptive immunity
specific, antibody mediated immunity
antibody mediated immunity
production of antibodies by B lymphocytes, B cells make plasma cells, plasma cells make antibodies, some B cells become memory cells
antibodies
antigen binding sites on the tip of each arm determine what kind of antigen the antibody can bind to. V arms of the antibody are variable, C arms of the antibody are constant
outcomes of antigen binding to antibody
neutralization, agglutination, intensifying innate immune response, notifying natural killer cells
IgG
eighty-two 85% of antibodies, most common comma crosses placenta and can give immunity to fetus comma will decrease over time so newborn has to make its own, in secondary immune response
IgA
mucosal areas, saliva, tears, breast milk
IgD
an antigen receptor on the B cells , activates basophils and mast cells
IgE
allergies, parasitic infections
IgM
eliminates infection in early stages before there is sufficient IgG, in primary immune response
primary immune response
occurs during the first-ever contact with a microbial antigen, antibody response is delayed for several days until plasma cells are formed comma reaches a peak in a couple of weeks, memory cells are produced
secondary response
when the same antigen appears again, memory cells produce rapid more potent and longer-lasting response, prevents or minimizes the infection
cell mediated immunity
activated T lymphocytes, directly attack unwanted cells, T cells bind directly with their target, activated by a foreign antigen
pre T cells
go through the thymus to mature and be educated as clones comma they learn self vs non-self. the ones that are good are positively selected, the ones that attack self cells are negatively selected and get destroyed
types of mature t cells
CD4 helper T Cells/ CD8 cytotoxic T-cells
MHC Markers
self antigen
Class 1 MHC
carries self antigen so that the T Cell receptor can recognize it comma used with CD8+ T cells
Class 2 MHC
used for CD4 + helper cells
antigen presenting cells
can be dendritic cells, or macrophages
epitope
specific part of the antigen that the cells can recognize
perforin
create perforations in the membrane
CD4 helper T cells
bind with other immune cells and release cytokines that enhance other cell activity
regulatory T cells
secrete cytokines that suppress other immune cells ensuring the immune system does not over react
immunodeficiency diseases
characterized by insufficient immune responses
inappropriate immune attacks
characterized by excessive or inappropriate immune responses
SCID
no b or t cells, bubble boy
allergies
inappropriate immune attacks against harmless environmental substances
immediate hypersensitivities
involving production of IgE antibodies by B cells
delayed hypersensitivities
involving more slowly responding T cell response against the allergen
macrophages
destroy the free virus by phagocytosis, process and present the viral antigen to helper T cells, activate B & T cell clones specific to the viral antigen
hypersensitivity
allergies enter the body for the first time, allergens bind to B cell receptors, clonal expansion, activated plasma cells secrete ige antibodies active against the allergen, histamine release
mast cells
release histamine
