unit 4 AOS 1 Flashcards
(32 cards)
what are antigens
-
- UNIQUE surface protein found on pathogens that initiates an immune response (found on pathogen)
-immune system uses antigens to recognize if a cell or molecule is self or not
(mch i and ii markers are types of antigens)
non self antigen
- recognized by leukocyte in the immune system as foreign
- MHC proteins differ between individuals
pathogen
microorganism which is either cellular or non cellular that MAY cause disease
cellular vs non cellular pathogen
1st line of defense
what are and the types of cellular pathogens
have cellular structure and are living organism
- bacteria
-fungi
- parasites
-arthripods
-protists
what are non cellular pathogens
- dont have cellular structure and are non- living
- virus (HIV- AIDS)
- prions (misfolded protein)
virus
prions
what are types of human barriers
- physical (skin, eyelashes)
- chemical (low ph)
- microbiota
what is the innate immune system
-non specific- respons the same way regardless of type of pathogen or antigen
- composed of 1st and second lod
what is the first line of defense
- barrier to infection
in animals- barriers that block or hinder pathogens from entering the organism
mast cell
-leukocyte (wbc)
- embedded in connective tissue (skin, connective tissue around bv)
- contains vesicles with signaling molecules HISTAMINES degranulates(releases them)
histamines cause vasodilation, blood vessels to become leaky (increase permeability) (need wbc to get out), chemoattractant for phagocytes
mhc i and ii markers
mch2- found on macropahegs, dendritic cells and b lymphocytes
mhc- found on every cell with a nucleus
- Degraded proteins in lysosomes(whether from the cell or from a
pathogen) are loaded onto MHC markers in vesicles that fuse with the
lysosome. These vesicles then fuse with the plasma membrane so that
the MHC marker with its peptide is on
the outside of the membrane.
present degraded protein/peptide so if MHC1 marker has something foreign on it cell is destroyed
phagocyte
Phagocytes are leucocytes that engulf non-self cells
by endocytosis (phagocytosis), and digest them
using lysosomes.
-neutrophils and monocytes (which specialise into
macrophages and dendritic cells).
Neutrophils are the most common phagocytes.
Monocytes are the largest.
lysosome
Natural killer cell
large granular cell
they find a self cell, displaying non -self antigens on its surface, releasing a death ligand; a
signalling molecule that stimulates the cell to die by
apoptosis
-stops cell from making new virus particles, also kill cells that have changed eg become cancerous
eosinophils
granulocytes; leucocytes that have many vesicles containing various chemicals that are
involved in many aspects of the innate immune
response.
-especially effective in combating multicellular parasites, such as worms.
When activated, they release cytotoxic cationic
granule proteins, which are toxic to many tissues.
They also release an array of other chemicals which
have many and various functions. For example, they
release a protein that has antiviral activity, and can
induce degranulation of mast cells
interferons
signalling molecules (cytokines) released from virus-infected host cells.
They cause nearby cells to heighten their antivirus defences. Cells stimulated by INFs produce
various enzymes that inhibit protein synthesis. One such enzyme is RNAse L, which destroys
many RNA molecules in the cell. Another cellular response to interferons is to upregulate the
production of MHC I markers.- PRESNET FOREIGN PARTICLES FATER SO THEY R MORE LIKELY TO GET ATTENTION OF PHAGOCYTE
the compliment system
-suite of small proteins, synthesized by the liver, and circulate in the blood in an inactivated state.
When activated, they achieve three primary outcomes:
-act as chemoattractant for phagocytes - help engulf and destroy bacteria
-opsonize bacteria, marking them for destruction by phagocyte
- form a MAC membrane attack complex, punches holes in bacteria, letting cytoplasm out of bacteria
what cells are apc’s and what are they
have mhcii markers,
-macrophage and dendritic cells
-present foreign antigens of mhc2 markers, initiating adaptive immune response
what is apoptosis
programmed cell death
types of vaccinees
- live attenuated- weakened virus made in lab
- inactivated vaccienes- dead pathogen killed with heat
- subunit- genetically modified pathogen
chain of infection
interactions between host, patho and enviro
- replicates
- reservoir- where
pathogen lives
- portal of exit how it gets out of reservoir
- mode of transmission eg droplet spread
- portal of entry- place where pathogen enters body, bloodstream, respiratry tract
- infect a host- resivoir for pathogen
-isolation/quarantine
-vaccine
