M4 L1

Question 1

innate immunity

Answer 1

• 1st line of defense
• broad protection
• hours/days
• activates acquired/adaptive immunity

Question 2

adaptive/acquired immunity

Answer 2

• specific response
• days/weeks
• provides memory

Question 3

the 2 immune defenses function

Answer 3

inter-dependently

Question 4

how does skin work as a physical barrier

Answer 4

keratin fills epithelial cells to make them impermeable so nothing can enter

Question 5

mucus

Answer 5

made by mucin, acts to trap everything in / make it diffcult for things to reach epithelial layer

Question 6

cilia function

Answer 6

move bacteria entrapped in mucus

Question 7

ideal body temp

Answer 7

37

Question 8

how does acne ruin skin layer

Answer 8

sebum secreted from sebacious gland is metabolized by acne causing bacteria

Question 9

skin pH & what regulates it

Answer 9

3-5, lactic & fatty acids

Question 10

defensins

Answer 10

animal specific immune responses that make holes in bacterial membrane so bacteria can flow out

Question 11

lysosome

Answer 11

kill bacteria, concentration is closer to cell layer where there is more risk of bacteria entering

Question 12

main difference between bacteria & virus

Answer 12

bacteria can replicate on their own, virus relies on host in order to replicate

Question 13

interferons

Answer 13

bind to receptors on a cell to prevent transcription & translation of a virus = stop infection
- induces non-viral state in neighbouring cells also so virus cannot replicate

Question 14

complement

Answer 14

produces a cascade where serum proteins are activated that leads to opininization, chemotaxis, and killing of bacteria

Question 15

T or F: complement is activated by both innate & acquired immunity

Answer 15

T

Question 16

what are the 3 different pathways of the complement cascade

Answer 16

1) classical
2) alternative
3) lectin pathway

Question 17

classical pathway

Answer 17

adaptive immune system, antibodies might bind to something on bacteria then get complement cascade

Question 18

alternative pathway

Answer 18

bacteria will be recognized by L3

Question 19

lectin pathway

Answer 19

mannose binds to lectin = starts cascade

Question 20

which of the 3 pathways are part of the adaptive vs innate immune systems?

Answer 20

innate- alternative & lectin
adaptive - classical (b/c activated by antibodies)

Question 21

which pathway was discovered first?

Answer 21

classical

Question 22

in terms of evolution, the ( ) pathway was first

Answer 22

alternative

Question 23

3 common components of all complement cascade pathways

Answer 23

1) C3- always in blood, spontaneously combusts into c3a & b
2) C3a- chemotaxic protein -> directs movement
3) C3b - for opsonization & macrocytosis

Question 24

phagocytosis definition

Answer 24

internalization & killing of pathogens

Question 25

opsinization

Answer 25

coating pathogens to promote phagocytosis

Question 26

2 main opsonins

Answer 26

1) C3b of complement system
2) antibodies

Question 27

how does phagocytosis work

Answer 27

1) phagocyte receptors bind to complement
2) receptors bind to bacteria
3) recognition of bacteria
4) englufs bacteria & kills it

Question 28

phagocytosis & opsinization are apart of which immune system

Answer 28

innate

Question 29

chemotaxis

Answer 29

leukocytes follow chemical gradient of chemotactic molecules to site of infection

Question 30

the 3 chemotactic agents

Answer 30

1) C3a
2) bacterial components
3) chemokines/ecosinoids

Question 31

how does chemotaxis work

Answer 31

1) neutrophils eat bacteria
2) C3b binds to bacteria = activates complement = produce more C3b = more C3a
3) C3a goes towards capillary & diffuses out
4) increase blood flow to site of infection to bring white blood cells
5) chemokines follow chemical gradient from low->high concentration to start eating the bacteria

Question 32

what can secrete cytokines

Answer 32

macrophages

Question 33

haptoglobin

Answer 33

bind iron -> some bacteria need iron to grow/replicate so if get rid of iron = bacteria cannot grow

Question 34

what does a high level of acute phase proteins indicate?

Answer 34

there is an infection going on, can use to differentiate between viral vs bacterial infection

Question 35

epithelial cell function

Answer 35

sense infection & signal secretion of chemokines

Question 36

mast cell function (2)

Answer 36

• induce vasodilation to increase blood flow
• signalling using histamine /eicosinoids

Question 37

anti-histamine function

Answer 37

binds histamine & prevents it from causing inflammation & diapedesis

Question 38

polynmorphonuclear neutrophils

Answer 38

eat bacteria to control infection, does not secrete anything

Question 39

what are the 4 acute phase proteins

Answer 39

1) C-reactive protein
2) serum amyloid A
3) haptoglobin
4) fibrinogen

Question 40

antigen presenting cells

Answer 40

direct acquired immunity

Question 41

natural killer cells

Answer 41

cytotoxic function-> kill infected cells
use for cancer

Question 42

how is danger detected

Answer 42

pattern recognition receptors bind MAMPs & initiate inflammation

Question 43

T or F: bacteria cannot methylate

Answer 43

T

Question 44

MAMPs

Answer 44

pathogens have structures that we do not have, these act as flags that immune system is constantly looking out for

Question 45

Toll-like receptors (TLR)

Answer 45

each recognize a diff molecule that is not present in the mammalian world = indicator of infection
- when binding = activate intracellular signalling pathways to activate immune response

Question 46

how might neutrophils sense bacteria? (2)

Answer 46

• sense pathogen recognition receptors
• if chemokines -> can sense without touching

Question 47

goblet/panel cells

Answer 47

in small intestine, secrete mucus & antimicrobial peptides

Question 48

what happens when pathogen recognition receptors bind to a pathogen component?

Answer 48

cytokines are formed