WBC's Flashcards
3 types of white blood cell
monocytes
lymphocytes
granulocytes
3 types of granular leucocytes (white blood cell)
neutrophils
basophils
eosinophils
are monocytes granulated or non-granulated
non
role of phagocytosis (3)
- protection from pathogens
- disposal of damaged cells
- presentation of antigen
3 types of Phagocytes
macrophages
dendritic
neutrophils
why are neutrophils also called polymorphonuclear leukocytes
multiple lobes of their nucleus
which is the most abundant wbc
neutrophils
what enzymes are in granules of neutrophils
lysozyme
collagenase
elastase
where are dendritic cells found
skin
mucosa
tissues
what do dendritic cells do
capture microbes
phagocytosis
present microorganisms antigen to T cells
when in the blood what are macrophages called
monocytes
in tissue what are macrophages called
macrophages
what do macrophages secrete
inflammatory factors- cytokines
steps in phagocytosis (4)
- phagocyte mobilization(chemotaxis)
- recognition and attachment to microbe
- engulfment
- digestion
- chemotaxis- guided by?
chemoattractants
- chemotaxis- what are the chemoattractants released by
bacteria
inflammatory cells
damaged tissues
- recognition- how
Pathogen Associated Molecular Patterns (PAMP’s)
- recognition- what are PAMP’s
invariant structures- shared by entire class of pathogens
- recognition- are the PAMP’s essential for survival to pathogens
yes
- recognition- what do phagocytes have to recognise PAMP’s
Pattern recognition receptors(PRR’s)
- recognition- types of PRR;s
- toll like receptors (TLR’s)
- C-type lectin receptors (CTLR’s)
- RLR’s
- scavenger receptors
some PAMPs that TLR’s recognise
lipopolysaccharide (gram -ve) singe/double stranded viral RNA Lipoteichoic acid(gram +ve)
what do TLR’s also stimulate production of
inflammatory cytokines
what does opsonization do
facilitate phagocytosis by recognising microbes
what is opsonization
coating of microbes in opsonins
what are the different components of opsonins
antibodies
proteins of complement
- engulfment- what begins to get rearranged when the microbe is attached to the phagocyte
actin cytoskeleton
- engulfment- what forms around the side of the microbe
pseudopods(feet)
what enzymes are in the lysosomes of oxygen independant killing
proteolytic
lysozyme
lactoferrin
defensins
what does proteolytic enzymes do
degrade microbes
whatt do lysozyme enzyme do
breaks down bacterial walls
what does lactoferrin do
binds iron- so not enough for bacteria
what do defensins do
destroy bacterial cell walls
if killing is oxygen dependant what is the first step
assembly of NADPH oxidase on the phagolysosome
what does the NADPH oxidase do
generate superoxide ions
what do the superoxide ions do
break down bacteria in activated phagocyte
what is salmonella resistant to
ROS
what does mycobacterium block
fusion of phagosome and lysosome
example of an encapsulated bacteria
streptoccocus pneumoniae
what do apoptotic cells express
‘eat me’ signals on membrane
