unit 4 AOS 1

Question 1

what are antigens

Answer 1

-
- 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)

Question 2

non self antigen

Answer 2

• recognized by leukocyte in the immune system as foreign
• MHC proteins differ between individuals

Question 3

pathogen

Answer 3

microorganism which is either cellular or non cellular that MAY cause disease

Question 4

cellular vs non cellular pathogen

Question 5

1st line of defense

Question 6

what are and the types of cellular pathogens

Answer 6

have cellular structure and are living organism
- bacteria
-fungi
- parasites
-arthripods
-protists

Question 7

what are non cellular pathogens

Answer 7

• dont have cellular structure and are non- living
• virus (HIV- AIDS)
• prions (misfolded protein)

Question 8

virus

Question 9

prions

Question 10

what are types of human barriers

Answer 10

• physical (skin, eyelashes)
• chemical (low ph)
• microbiota

Question 11

what is the innate immune system

Answer 11

-non specific- respons the same way regardless of type of pathogen or antigen
- composed of 1st and second lod

Question 12

what is the first line of defense

Answer 12

• barrier to infection
  in animals- barriers that block or hinder pathogens from entering the organism

Question 13

mast cell

Answer 13

-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

Question 14

mhc i and ii markers

Answer 14

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

Question 15

phagocyte

Answer 15

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.

Question 16

lysosome

Question 17

Natural killer cell

Answer 17

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

Question 18

eosinophils

Answer 18

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

Question 19

interferons

Answer 19

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

Question 20

the compliment system

Answer 20

-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

Question 21

what cells are apc’s and what are they

Answer 21

have mhcii markers,
-macrophage and dendritic cells
-present foreign antigens of mhc2 markers, initiating adaptive immune response

Question 22

what is apoptosis

Answer 22

programmed cell death

Question 23

types of vaccinees

Answer 23

• live attenuated- weakened virus made in lab
• inactivated vaccienes- dead pathogen killed with heat
• subunit- genetically modified pathogen

Question 24

chain of infection

Answer 24

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

Question 25

emerging disease vs re emerging

Answer 25

not occurred in humans before
-once an issue and has returned

Question 26

how do emerging diseases occur

Answer 26

• globalisation and travel
  lack of san
  increase exposure of humans to animals

Question 27

classes of pathogens

Answer 27

epidemic- infectious disease in a specific place at a specific time e.g highvale
pandemic- epidemics that spread across country

Question 28

zoonosis

Question 29

how is the adaptive immune response activated

Answer 29

• antigen presentation, apc’s present antigens on mhc 2 markers, find matching t helper cells with t receptor that fits

Question 30

passive vs active

Answer 30

-a- longterm
p- short term

Question 31

artificial vs natural

Answer 31

a- medical tech