Innate Immmunity

Question 1

define the immune system

Answer 1

cells and organs that contribute to immune defences against infectious and non-infectious conditions

Question 2

true or false: cancer is a type of non-infectious condtion

Answer 2

true

Question 3

define infectious disease

Answer 3

when a pathogen succeeds in evading and overwhelming the hosts immune defences

Question 4

what physical barriers are involved in the innate immune system

Answer 4

• skin
• musocus membranes
• bronchial cilia

Question 5

what are the differences in the innate and adaptive immunity

Answer 5

Innate:

• fast
• lacks specificity
• lacks memory
• no change in intensity
• first line of defence

Question 6

what type of innate immune cells activate the adaptive immunity

Answer 6

dendritic

Question 7

what type of barriers are involved in the innate response

Answer 7

physical, physiochemical, chemical and biological

Question 8

what do the barriers of the innate immunity aim to do

Answer 8

prevent pathogen entry and limit growth

Question 9

what are the physiological barriers in the innate immunity

Answer 9

• diarrhoea: expels miscorbes
• vomiting
• coughing
• sneezing

Question 10

what are the chemical barriers in the innate immunity

Answer 10

• low pH (skin, stomach and vagina)

- antimicrobial molecules

Question 11

what are the biological barriers in the innate immunity

Answer 11

• normal flora

Question 12

what is the normal flora

Answer 12

non pathogenic molecules (as long as they don’t change location) found in the body

Question 13

where is normal flora found

Answer 13

• skin
• mouth/throat
• nasopharynx
• GI tract
• vagina

Question 14

what are the advantages of the normal flora

Answer 14

competes with pathogens for attachment sites and resources
produce antimicrobial chemicals
synthesise vitamins

Question 15

give examples of antimicrobial molecules

Answer 15

IgA, lysozymes, mucus and gastric acid

Question 16

give examples of normal flora that inhabit the skin

Answer 16

• staphylococcus aureus

- staphylococcus epidermidis

Question 17

give examples of normal flora what inhabit the nasopharynx

Answer 17

• streptococcus pneumonia

- Neisseria meningitidis

Question 18

when are there problems with the normal flora

Answer 18

• when its displaced from its normal location to a sterile location
• when it overgrows and becomes pathogenic when the host is immunosuppressed
• when it is depleted by antibiotics

Question 19

what causes the displacement of normal flora

Answer 19

• breaching the skin
• the fecal oral route
• fecal-perineal-urethral route
• poor dental hygiene

Question 20

how can the skin be breached

Answer 20

IV lines, burns, surgery and injection drug users

Question 21

what is involved in the second line of defence in the innate immunity

Answer 21

factors that will contain and clear the infection:

• phagocytes
• chemicals
• inflammation

Question 22

what are the 3 main phagocytes

Answer 22

macrophages
monocytes
neutrophils

Question 23

what do macrophages do

Answer 23

• phagocytosis
• antigen presenting to T cells
• produces cytokines

Question 24

what do monocytes do

Answer 24

recruited to site of infection and differentiate into macrophages

Question 25

what do neutrophils do

Answer 25

recruited by cytokines and ingest bacteria | increase during infection

Question 26

what happens to neutrophils after phagocytosis

Answer 26

they die

Question 27

what do basophils and mast cells do

Answer 27

activators of inflammation | important in allergic repsonse

Question 28

what do eosinophils do

Answer 28

kill parasites

Question 29

what do natural killer cells do

Answer 29

kill all abnormal host cells

Question 30

what do dendritic cells do

Answer 30

present antigens to T cells

Question 31

what is on the surface of microbes which is recognised by immune cells

Answer 31

Pathogen associated molecular patterns (PAMPs)

Question 32

what are the receptors on pathogens that bind to PAMPs

Answer 32

Pathogen recognition receptors (PRRs)

Question 33

what is opsonisation

Answer 33

coating proteins called opsonins to the surface of microbes leading to enhanced attachment of phagocytes and clearance of microbes

Question 34

give an example of a complement protein used in opsonisation

Answer 34

C3b

Question 35

give an example of a antibody which is used as an opsonin

Answer 35

IgG

Question 36

give an example a of acute phase protein which are used as opsonins

Answer 36

c-reactive protein

Question 37

what 2 things allows the recognition of microbes by phagocytes

Answer 37

opsonins and PAMPs

Question 38

outline phagocytosis

Answer 38

- chemotaxis and adherence of pathogen - ingestion - phagosome formation - phagolysosome formation - digestion with enzymes - formation of residual body containing indigestible material - discharge of waste

Question 39

what is oxygen dependant pathway

Answer 39

where toxic oxygen products e.g. hydrogen peroxide and nitric acid kill pathogens directly

Question 40

what is oxygen independent phagocytosis

Answer 40

were lysozymes and hydrolytic enzymes digest the microbe

Question 41

what 3 actions does the complement system produce

Answer 41

- opsonisation - inflammation - attacking membranes

Question 42

what 2 pathways activate the complement system

Answer 42

- - alternative pathway: initiated by cell surface constituents e.g. endotoxins - MBL pathways: when mannose binding lectin binds to mannose containing residues of proteins found on microbes

Question 43

which complement proteins are used in membrane attacking

Answer 43

C5-C9

Question 44

what are the antimicrobial actions of TNF and interleukin 1 and 6

Answer 44

- cause the hypothalamus to increase body temp - cause inflammatory actions such as vasodilation, vascular permeability - cause neutrophil mobilisation in bone marrow - liver produces acute phase response proteins e.g. CRP which are also opsonins so activates complement cascade

Question 45

what is chronic granulomatous disease

Answer 45

neutrophils don't function properly so theres no respiratory burst

Question 46

what can cause a decrease in neutrophil number

Answer 46

chemotherapy drugs leukaemia

Question 47

what bacteria causes thrush when it goes into the vagina

Answer 47

candida albicans

Question 48

what bacteria causes colitis when it goes into the intestine

Answer 48

clostridium difficile

Question 49

what is Antibiotic prophylaxis

Answer 49

Antibiotic prophylaxis refers to the prevention of infection complications using antimicrobial therapy

Question 50

which high risk patients can serious infections be caused by displacement of normal flora

Answer 50

- asplenic patients - damage valves - previous infective endocarditis