Lecture 5 Immunity and disease Flashcards Preview

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Flashcards in Lecture 5 Immunity and disease Deck (67)
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1
Q

What is immunity?

A

Protection/defence against infections. Bacteria, virus, fungi, toxins, cancer.

2
Q

What does immune system do? (3)

A

Distinguishes self from non-self molecules. Activates mechanisms to either eliminate or neutralise threat. Innate and adaptive.

3
Q

Define innate immunity?

A

Defence mechanisms present before infection.

4
Q

Examples of innate immunity?

A

Skin, mucus membranes, phagocytic cells, inflam, fever

5
Q

What phagocytic cells are in the innate immunity?

A

Neutrophils and macrophages.

6
Q

What is the time frame for the innate immunity?

A

0-12 hours

7
Q

Complement and NK cells are in which immunity?

A

Innate

8
Q

What does the adaptive immune response entail?

A

Cell-mediated immunity and humoral immunity

9
Q

What cells are involved in the adaptive immunity?

A

B lymphocytes and T tymphocytes

10
Q

What do B lymphocytes become?

A

Antibodies

11
Q

What do T lymphocytes become?

A

Effector T cells

12
Q

Name 4 examples of non-specific deferences?

A

Intact skin, mucus, cilla and chemical barriers

13
Q

How does skin defend?

A

Mechanical barrier. Keratin outer layer. Dead cells constantly lost -> X invading bacteria colonisation.

14
Q

What does sweat and oils contain?

A

Anti-microbial chemicals

15
Q

How do mucous membranes defend?

A

Normal flow of mucus washed bacteria and viruses off membranes. Cilia in resp tract, acid in stomach and vagina. Enzymes in saliva & eyes

16
Q

How do chemical barriers protect?

A

Proteins. Complement (work with other defence mechanisms). Interferons (X replication of viruses)

17
Q

What do cellular defences involve?

A

Phagocytosis

18
Q

What are granulocytes?

A

Neutrophils, Eosinophils and Basophils

19
Q

How do granulocytes work?

A

Remove dead cells and micro-organisms

20
Q

What attracts granulocytes?

A

Inflam response or damaged cells

21
Q

What are monocytes?

A

Macrophages

22
Q

Monocytes/macrophages location?

A

in tissues which act as filters for trapping microbes

23
Q

Monocytes/macrophages life span?

A

Live longer than granulocytes

24
Q

Do monocytes or granulocytes arrive at site first?

A

Granulocytes

25
Q

What do monocytes/macrophages do?

A

Stimulate specific immune response (antigen presenting).

26
Q

What are the non-specific responses to infection?

A

Macrophages releasing IL-1 & IL-6, fever, pain, swelling, redness, acute-phase proteins.

27
Q

Why does a fever work?

A

Most bacteria grow optimally at temp below body temp

28
Q

Why does pain, swelling and redness work?

A

^ capillary permeability, ^blood flow, ^ phagocytic.

29
Q

Why does acute-phase proteins release from liver work?

A

Bind to bacteria and activate complement proteins

30
Q

What is the specific immunity?

A

Adaptive. Needs antigens and lymphocytes

31
Q

What are antigens?

A

Toxin/foreign substance which induces immune response.

32
Q

How much of lymphocytes are carried in blood? Where are the rest?

A

1%. Rest in lymphatic system.

33
Q

How many lymphocytes in human body?

A

2x10^12

34
Q

What is a lymphocyte?

A

small leucocyte (white blood cell)

35
Q

Where do B-cells mature?

A

Mature in bone marrow then conc in lymph nodes and spleen

36
Q

Where do T-cells mature?

A

Mature in thymus

37
Q

Both B-cell and T-cells

A

Circulate in blood ensuring they come in contact with pathogens

38
Q

What do T-cells recognise?

A

X free antigens. Only recognised antigens presented by major histocompatibility complex - Class I (all cells) class II (APC)

39
Q

What do T-cells do?

A

Directly attack invaders (cytotoxic, CD8+, MHCI) and recognise pathogens inside cells.

40
Q

What can sometimes recognise and destroy cancer cells?

A

Cytotoxic T-cells

41
Q

What to T helper cells do?

A

Stimulate B-cells and activate cytotoxic cells/macrophages.

42
Q

How do T-cells recognise an invader?

A

Detect an antigen - protein marker on cell surface.

43
Q

Define epitope?

A

Fragment of antigen

44
Q

What happens when an antigen is encountered by macrophage?

A

It will bring the protein to a helper T-cell -> if T-cell recognises it as “not-self” -> Launch immune response.

45
Q

How are B-cells stimulated to divide?

A

Helper T-cells (CD4+) that has been stimulated by antigen -> releases cytokines to stimulate B-cell division.

46
Q

How does HIV affect immune response?

A

Destroys helper T-cells so immune response diminished

47
Q

What do B-cells do?

A

Secrete antibodies, humoral immunity and recognise pathogens outside cells.

48
Q

What antibodies do B-cells produce?

A

Glycoproteins, specific, hypervariable region, different subtypes (IgM, IgA and IgD)

49
Q

Antibodies are on

A

B-cells

50
Q

B-cell antibodies can be

A

Glycoproteins, specific hypervariable region, or different subtypes

51
Q

What different subtypes of antibodies is there?

A

IgG, IgM, IgA, IgD.

52
Q

Define opsonisation

A

identifying the invading particle to the phagocyte

53
Q

B-Cells also stimulate

A

Complement

54
Q

What do memory cells do?

A

remain ready to divide rapidly if an invasion occurs again

55
Q

Explain pathway of B-cells

A

Antigen binds to antibodies-> B-cell multiples-> differentiate into 1) memory cells 2) plasma cells - more antibodies

56
Q

Examples of when immune system is deficient?

A

Chemo, HIV, Splenectomy, bone marrow dysfunction

57
Q

What is HIV?

A

Human immunodeficiency virus. Retro virus.

58
Q

How does HIV effect?

A

Infects CD4 + T-cells. Infection -> latency -> AIDS (acquired immunodeficiency syndrome).

59
Q

What is AIDs?

A

Acquired immunodeficiency syndrome. Decline in CD4 and T cells -> opportunist infections.

60
Q

Causes of 2nd immunodeficiency?

A

Malnutrition, burns, uremia, diabetes m, recreational drugs and alcohol. AIDs!

61
Q

Type 1 hypersensitivity examples?

A

Anaphylaxis/allergy. Rhinitis (hayfever)

62
Q

Self reactive lymphocytes are

A

deleted centrally and suppressed in periphery

63
Q

4 examples of autoimmune diseases

A

Hashimoto’s thyroiditis, type 1 diabetes M, coeliac disease, multiple sclerosis,

64
Q

Example of live (attenuated) vaccine?

A

MMR

65
Q

Example of inactivated vaccine

A

Hep B

66
Q

Example of toxoid (bacterial toxin) vaccine?

A

Diptheria

67
Q

Example of conjugated (antigen linked to protein) vaccine

A

pneumococcal