Ch. 16 Innate Immunity Part 1 Flashcards
what is innate immunity?
in born; always present; nonspecific
what is the first line of dense?
intact skin
mucous membrane & their secretions
normal microbiota
what is the second line of defense?
Phagocytes ( neutrophils, eosinophils, dendritic cells & macrophages)
Inflammation
Fever
Antimicrobial substances
what is the third line of defense?
specialized lymphocytes T cell and B cells
antibodies
stimulated by the presence of antigens
what do activated Toll-like receptors on host cells do?
recognize pathogen-associated molecular patterns
induces the release of cytokines
what do cytokines do?
regulate immune response
activate macrophages
chemotactic effects
inflammatory response/ fever
activate T, B cells
what is the skin comprised of?
(physical factor)
comprised of epidermis & dermis; protective keratin layer on epidermis
what is a subcutaneous infection?
when skin is penetrated
what do mucous membranes do?
line GI, GU & respiratory tracts; epithelial & connective tissue layers
what does mucus do?
traps microbes moistens surfaces
what do tears and salvia do?
prevent the colonization of microbes
what do hair nose and cilia do?
trap microbes
what do the epiglottis, ear wax, and digestion do?
eliminates microbes
what are the chemical factors of skin?
sebum (oily secretion) forms a film on the skin
contains fatty acids & low pH
perspiration
what do fatty acids & low pH prevent?
colonization of pathogens
what is perspiration?
high salt
contain lysozyme ( found in tears Slavia)
what does your saliva contain?
lysozyme
urea
uric acid
antibody
what does your gastric stomach juice contain?
pH 1-3 due to HCL
what do your vaginal secretions contain?
acidic pH
what does urine contain?
lysozyme
pH 6
what does your normal microbiota do as 1st line of defense?
microbial antagonism, alteration of physical & chemical conditions
prevents colonization by pathogens
describe neutrophils
phagocytic
active in the initial stages of infection
do the bulk of the work
can exit blood & enter infected tissue
describe basophils
release components promoting
inflammatory & allergic responses (histamine)
describe eosinophils
phagocytic
exit blood
release toxins
deal with the large multicellular pathogen
what do monocytes differentiate into?
macrophages & dendritic cells in lymphatic tissue
describe monocytes dendritic cells, & macrophages
phagocytic cell types
are also antigen-presenting cells ( work w/an adaptive immunity system)
what are agranulotic leukocytes?
lymphocytes
Natural Killer Cells
T cells
B cells
what are natural killer cells?
kill infected body cells & some tumor cells
recognize abnormalities in the plasma membrane
destroy host cells that are infected and cancerous those that lack MHC antigens
what are T cells?
intracellular pathogens
modulate the specific immune response
what are B cells?
extracellular pathogens
produce antibodies to bind antigens
what does the binding of NK cells target?
stimulates the secretion of perforins ( inserts in the membrane of target cell causing lysis)
what do natural killer cells release?
granzymes ( induce apoptosis in target cell)
MHC Class II
antigen-presenting cells
macrophages, dendritic cells, B cells
MHC Class I
nucleated mammalian cells
all other cells that are not class II are type I
what does the lymphatic system do?
protect against inhaled ingested microbes
contain T cells, B cells, dendritic cells, & macrophages
what is the process of phagocytosis?
chemotaxis - macrophages come to phagocytic cell
adherence - sticks to pathogen
ingestion- engulfing the pathogen
digestion-breaks it & lysis it
what do monocytes & granulocytes do?
migrate to the site of infection
monocytes differentiate into macrophages:
fixed; stay in one spot
Free; wandering or moving around
granulocytes dominate when?
in the early stage of infection
when do macrophages dominate?
predominate later
what are chemotactic chemicals?
microbial products
components of damaged tissue
cytokines
what is adherence?
adherence via PAMPS to toll-like receptors
release of cytokines
opsonization facilitates phagocytosis
target coated with serum proteins (opsonins), antibodies complement
what happens during ingestion?
phagosome formation
what happens during digestion?
fusion of phagosome with lysozyme
enzymatic digestion
production of oxygen radicals & peroxides
what is phagocytosis enhanced by?
opsonization
what is opsonization?
a combination of innate & immune responses
engulfment of capsulated bacteria via anti-capsular antibodies
phagocytic cells recognized & ingested bacteria
