Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infection > Innate Immunity > Flashcards

Innate Immunity Flashcards

0
Q

Define infectious disease

A

When the pathogen succeeds in evading and/or overwhelming the host’s immune defences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What is the immune system?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Four roles of the immune system?

A

Pathogen recognition
Containing/eliminating the infection
Regulating itself
Remembering pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give features of innate immunity that make it different from adaptive

A

Fast
Recognises group pathogens by shared structures
Lack of memory
No change in intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the first lines of defence in the innate immune system?

A

Physical barriers eg skin, mucous membranes, bronchial cilia

Physiological barriers eg diarrhoea, vomiting, coughing, sneezing

Chemical barriers eg low pH, antimicrobials molecules

Biological barriers eg normal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In the first line of defence, where can antimicrobials molecules be found and give examples

A

Tears and saliva have IgA
Sebum, sweat and urine have lysozyme
Mucus
β-defensins in epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do normal flora prevent infection?

A

Compete with pathogens for attachment sites and resources
Produce antimicrobial chemicals
Synthesise vitamins K and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name some flora that inhabit the skin

A 
Staph aureus
Staph epidermis
Streptococcus pyogenes 
Candida albicans
Clostridium perfringens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name some flora that inhabit the nasopharynx

A

Streptococcus pneumoniae
Neisseria meningitidis
Haemophilus species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can normal flora be displaced from normal location?

A 
Breaching skin integrity
Fecal-oral route
Fecal-perineal-urethral route
Poor dental hygiene/dental work
Can over grow and become pathogenic in immunocompromised
Can be depleted by antibiotics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give examples of natural flora that can become depleted with antibiotic use

A

Intestine - get severe colitis caused by C. difficile

Vagina - get thrush when lactobacillus is depleted and Candida albicans can grow more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give the overall mechanisms of second lines of defence in innate immunity

A

Phagocytes
Complement system
Cytokines/chemokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give examples of phagocytes and where they are found

A 
Macrophages
Monocytes
Neutrophils
Basophils/mast cells
Eosinophils
Natural killer cells
Dendritic cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are macrophages found and what do they do?

A

Present in all organs
Phagocytosis
Present microbial agents to T cells
Produce cytokines/chemokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where are monocytes found and what do they do?

A

Present in blood
Recruited to infection site
Differentiate into macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are neutrophils found and what do they do?

A

Present in blood
Increased during infection
Recruited by chemokines to the site of infection
Phagocytose pyogenic bacteria eg staph aureus and strep pyogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When are basophils/mast cells seen?

A

Early actors in inflammation
Allergic response
Phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do eosinophils do?

A

Defence against multicellular parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do natural killer cells do?

A

Kill all abnormal host cells (virus infected or malignant)

19
Q

What do dendritic cells do?

A

Present microbial antigens to T cells

20
Q

How do phagocytes recognise pathogens?

A

Microbe have pathogen-associated molecular patterns (PAMPs)

Phagocytes recognise these using their pathogen recognition receptors (PRRs)

21
Q

What can PAMPs be made up of?

A

Carbohydrates
Lipids
Proteins
Nucleic acids

22
Q

What do opsonins do?

A

Bind to microbial surfaces

Cause enhanced attachment of phagocytes and clearance of microbes

23
Q

Give some examples of opsonins

A

Complement proteins - C3b, C4b
Antibodies - IgG, IgM
Acute phase proteins - CRP, mannose-binding lectin

24
Q

What type of bacteria are opsonins essential for clearing? Give examples

A

Encapsulated bacteria

Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae B

25
Q

What are the mechanisms for phagocyte intracellular killing?

A

Oxygen dependent

Oxygen independent

26
Q

What does the oxygen-dependent pathway involve?

A

A respiratory burst of hydrogen peroxide, hydroxyl radical, nitric oxide, singlet oxygen, hydrohalite

27
Q

What does oxygen independent pathway involve?

A

Lysozyme
Lactoferrine/transferring
Cationic proteins
Proteolytic and hydrolytic enzymes

28
Q

How can the complement system be activated?

A

Alternative pathway - initiated by cell surface microbial constituents on pathogens

MBL pathway - initiated when mannose-binding lectin binds to mannose containing residues of proteins found on Salmonella spp and Candida albicans

29
Q

How do the two pathways activate the complement system?

A

Cleave proteins which activates them

30
Q

What are the proteins involved in the complement system (overall)?

A

C1-C9

31
Q

What do C3a and C5a do?

A

Recruit phagocytes

32
Q

What do C3b and C4b do?

A

Opsonisation

33
Q

What do proteins C5-C9 do?

A

Kill pathogens - bind to membrane of the microbe to produce attack complex, puts holes in the membrane

34
Q

What do cytokines and chemokines do in innate immunity?

A

Cytokines - activate phagocytes

Chemokines - chemoattraction

35
Q

What cytokines/chemokines do macrophages release?

A

TNF-α
IL-1
IL-6

36
Q

When cytokines/chemokines are released, what effect to the have in the liver?

A

Cause release of CRP and MBL -> complement activation

37
Q

When cytokines/chemokines are released, what effect to the have in the bone marrow?

A

Cause neutrophil mobilisation

38
Q

When cytokines/chemokines are released, what effect to the have in the hypothalamus?

A

Increased body temperature

39
Q

What inflammatory actions do cytokines have?

A

Vasodilation
Increased vascular permeability
Release of adhesion molecules which attract neutrophils

40
Q

What can happen when microbial toxins cause overreaction of TLR4 receptor on neutrophils, endothelium and monocytes?

A

Get an excessive inflammatory response

Sepsis and multi-organ failure caused by cytokine shower, coagulopathy, vasodilation, capillary leak

41
Q

What can reduce phagocytosis?

A

Decreased spleen function (asplenic/hyposplenic)

Decreased neutrophils from chemo, dugs, leukaemia, lymphoma

Decreased neutrophil function

  • chronic granulomatous disease (no respiratory burst)
  • Chediak-Higashi syndrome (no phagolysosome formation)
42
Q

What does the PRR TLR5 recognise?

A

Flagellin on bacterial flagella

43
Q

What does the PRR TLR2 recognise?

A

Peptidoglycan on Gram positive bacteria
Lipoprotein and lipopeptides on Gram negative bacteria
Mycobacteria

44
Q

What does the PRR TLR4 recognise?

A

Lipopolysaccharide (LPS) on Gram negative

Lipoteichoic acids on Gram positive

Infection (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions