*Immunology 1 (lectures 1 and 2) Flashcards Preview

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Flashcards in *Immunology 1 (lectures 1 and 2) Deck (63):
1

SCID?
What is it?

Severe combined immunodeficiency
Severe abnormalities of the immune system

2

5 things caused by the immune system going wrong?

Cancer
recurrent infections
Transplant rejection
Allergies
Autoimmune disease

3

6 causes of emergence of new infections?

Global village
population growth
change in human behaviour
changes in dynamic of other infections
loss of natural habitat
Interactions of pathogens with humans e.g. resistance

4

What exists between pathogens and hosts

Evolutionary arms race

5

Where do pathogens infect the body through?

Mucosal surfaces (airway, GI tract, repro. tract)
External epithelia (wounds, insect bites, etc.)

6

5 components of the body that protect against infection?

Lymph nodes
Spleen
Lymphatics
Bone Marrow
Skin

7

How does the skin protect against infection?

Physical barrier (highly packed, highly keratinised, multilayered cells)
Physiological barrier (low pH (5.5), low O2 tension)
Sebaceous glands (secrete hydrophobic oil, lysozyme (destroys bacterial cell wall), ammonia (anti-bacf. properties), defensins (anti-microbial peptides))

8

What does mucous line

All cavities that come into contact with the environment e.g. resp, GI, urogenital

9

How does mucous prevent infection?

Physical barrier
contains IgA
contains enzymes (lysozyme, defensins)
Contains lactoferrin (starves invading bacteria of iron)

10

what do cilia do

Directly trap pathogens
aid in the removal of mucous

11

How does commensal bacteria help to prevent infection?

Competes with pathogenic microbes for scarce resources
Produces fatty acids and bactericidns
reduce pH in large bowel
Synthesise vitamin K and B12

12

What is bactericidin

An antibody that causes complement dependent lysis of bacteria

13

What does eradication of normal flora by board spectrum antibiotics often cause?

Opportunistic infection

14

Probiotics

Live bacteria and east that are good for your health

15

Immune system?

Network of specialised cells, tissues and soluble factors that co-operate to kill and eliminate disease-causing pathogens and cancer cells

16

4 classes of pathogen

Extracellular bacteria, parasites, fungi
Intracellular bacteria, parasites
Viruses (intracellular)
Parasitic worms (Extracellular)

17

See mind map study material for info about components of the immune system

-

18

Antigen

Any substance that can stimulate an immune response

19

Complement system

Family of approx. 30 different proteins

20

Where is complement produced?

In the liver

21

What do antibodies provide defence against?

Extracellular pathogens and toxins

22

Where do complement proteins become activated?

infected/ inflamed tissues

23

What do complement proteins have the ability to do?

enzymatically cleave and activate other downstream complement proteins in a biological cascade

24

Name for chemical messanger

cytokine

25

Summarised role of cytokines

co-ordinates the immune system

26

4 examples of cytokines?

Interferons, tumour necrosis factor, chemokines, interleukins

27

Interferons?

Anti-viral activity

28

Tumour necrosis factor

Pro-inflammatory cytokine

29

Chemokines?

Control and directs cell migration

30

Interleukins

Various functions e.g. inflammatory mediator, stimulate T lymphocytes to become NK cells

31

Phagocytic cells?

Monocytes, macrophages, neutrophils (ingest bacteria and fungi and clear debris from the body

32

What is an important source of cytokines which regulate acute inflammatory response?

Phagocytic cells

33

Where do monocytes differentiate into macrophages

in peripheral tissues

34

what are macrophages

Long lived tissues resident phagocytes

35

What are the functions of macrophages

to clear cellular debris and engulf and kill pathogens

36

Where are kupffer cells located and what is their function

Liver
RBC breakdown

37

Location of alveolar macrophages

lung alveoli

38

location of mesangial cells

kidneys

39

location of microgal cells

CNS

40

Additional functions of macrophages (3)

limit inflammation
involved in tissue repair and wound healing
involved in antigen presentation

41

Other name for neutrophils
Half life

Polymorphonuclear cells
Less than 6 hours (short)

42

Where are neutrophils found?

Circulate the blood and are rapidly recruited into inflamed, damaged and infected tissues

43

How do dendritic cells work?

Present in peripheral tissues where they are in an immature state
They phagocytose an antigen
Then mature and migrate into secondary lymphoid tissue where they play a key role in antigen presentation

44

Which carries out more killing and degradation compared to antigen presentation, neutrophils or macrophages?

Neutrophils

45

Where are mast cells found?
Purpose?

In tissues
protect mucosal surfaces

46

Where are basophils and eosinophils found

circulate in blood and are recruited to sites of infection inflammatory signals

47

What do basophils and eosinophils do (3)

Release chemicals such as histamine, heparin and cytokines producing acute inflammation
Defence system against large pathogens that cannot be phagocytosed e.g. parasitic worms
key role in mediating allergic responses

48

Are NK cells part of the innate or adaptive immune system

Innate

49

What are NK cells

Large granular lymphocytes

50

What can NK cells do?

Kill tumour cells and virally infected cells, can also kill antibody-bound cells and pathogens

51

Where are B and T cells found?

Constantly circulating through the blood, lymph and secondary lymphoid tissues

52

When are t and b cells activated

When they meet a pathogen/ antigen

53

What are B cells responsible for

The production and secretion of antibodies to defend against extracellular pathogens

54

What type of pathogens do T cells defend against?

Intracellular pathogens (viruses, mycobacterium)

55

Types of T cells and role

Helper T cells (key immune system regulators)
Cytotoxic T cells (kill virally infected body cells)

56

What is immunological memory

Once the adaptive immune system has recognised and responded to a specific antigen, it exhibits life-long immunity to this antigen (mediated by memory T cells and B cells)

57

Innate immune system?

Rapid (mins-hrs), general response to many different pathogens

58

Adaptive immune system

slow (days), unique response to each individual pathogen mediated by T and B lymphocytes and responsible for generating immunological memory

59

What is primary lymphoid tissues?

Sites of leukocyte development

60

What are secondary lymphoid tissues?

Sites where adaptive immune responses are initiated (contain T cells, B cells and dendritic cells

61

What is the lymphatic system?

System of vessels draining fluid from body tissues - lymph nodes are positioned regularly along lymph vessels (trap pathogens and antigens in lymph)

62

What is lymphoedema?

Condition of localised fluid retention and tissue swelling caused by a compromised lymphatic system, which normally returns interstitial fluid to the thoracic duct and then the bloodstrem

63

Causes of lymphoedema?

Inherited
Cancer treatments
Parasitic infections