Lecture 5 Immunity and disease Flashcards Preview

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

What is immunity?

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

2

What does immune system do? (3)

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

3

Define innate immunity?

Defence mechanisms present before infection.

4

Examples of innate immunity?

Skin, mucus membranes, phagocytic cells, inflam, fever

5

What phagocytic cells are in the innate immunity?

Neutrophils and macrophages.

6

What is the time frame for the innate immunity?

0-12 hours

7

Complement and NK cells are in which immunity?

Innate

8

What does the adaptive immune response entail?

Cell-mediated immunity and humoral immunity

9

What cells are involved in the adaptive immunity?

B lymphocytes and T tymphocytes

10

What do B lymphocytes become?

Antibodies

11

What do T lymphocytes become?

Effector T cells

12

Name 4 examples of non-specific deferences?

Intact skin, mucus, cilla and chemical barriers

13

How does skin defend?

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

14

What does sweat and oils contain?

Anti-microbial chemicals

15

How do mucous membranes defend?

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

16

How do chemical barriers protect?

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

17

What do cellular defences involve?

Phagocytosis

18

What are granulocytes?

Neutrophils, Eosinophils and Basophils

19

How do granulocytes work?

Remove dead cells and micro-organisms

20

What attracts granulocytes?

Inflam response or damaged cells

21

What are monocytes?

Macrophages

22

Monocytes/macrophages location?

in tissues which act as filters for trapping microbes

23

Monocytes/macrophages life span?

Live longer than granulocytes

24

Do monocytes or granulocytes arrive at site first?

Granulocytes

25

What do monocytes/macrophages do?

Stimulate specific immune response (antigen presenting).

26

What are the non-specific responses to infection?

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

27

Why does a fever work?

Most bacteria grow optimally at temp below body temp

28

Why does pain, swelling and redness work?

^ capillary permeability, ^blood flow, ^ phagocytic.

29

Why does acute-phase proteins release from liver work?

Bind to bacteria and activate complement proteins

30

What is the specific immunity?

Adaptive. Needs antigens and lymphocytes

31

What are antigens?

Toxin/foreign substance which induces immune response.

32

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

1%. Rest in lymphatic system.

33

How many lymphocytes in human body?

2x10^12

34

What is a lymphocyte?

small leucocyte (white blood cell)

35

Where do B-cells mature?

Mature in bone marrow then conc in lymph nodes and spleen

36

Where do T-cells mature?

Mature in thymus

37

Both B-cell and T-cells

Circulate in blood ensuring they come in contact with pathogens

38

What do T-cells recognise?

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

39

What do T-cells do?

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

40

What can sometimes recognise and destroy cancer cells?

Cytotoxic T-cells

41

What to T helper cells do?

Stimulate B-cells and activate cytotoxic cells/macrophages.

42

How do T-cells recognise an invader?

Detect an antigen - protein marker on cell surface.

43

Define epitope?

Fragment of antigen

44

What happens when an antigen is encountered by macrophage?

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

45

How are B-cells stimulated to divide?

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

46

How does HIV affect immune response?

Destroys helper T-cells so immune response diminished

47

What do B-cells do?

Secrete antibodies, humoral immunity and recognise pathogens outside cells.

48

What antibodies do B-cells produce?

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

49

Antibodies are on

B-cells

50

B-cell antibodies can be

Glycoproteins, specific hypervariable region, or different subtypes

51

What different subtypes of antibodies is there?

IgG, IgM, IgA, IgD.

52

Define opsonisation

identifying the invading particle to the phagocyte

53

B-Cells also stimulate

Complement

54

What do memory cells do?

remain ready to divide rapidly if an invasion occurs again

55

Explain pathway of B-cells

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

56

Examples of when immune system is deficient?

Chemo, HIV, Splenectomy, bone marrow dysfunction

57

What is HIV?

Human immunodeficiency virus. Retro virus.

58

How does HIV effect?

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

59

What is AIDs?

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

60

Causes of 2nd immunodeficiency?

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

61

Type 1 hypersensitivity examples?

Anaphylaxis/allergy. Rhinitis (hayfever)

62

Self reactive lymphocytes are

deleted centrally and suppressed in periphery

63

4 examples of autoimmune diseases

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

64

Example of live (attenuated) vaccine?

MMR

65

Example of inactivated vaccine

Hep B

66

Example of toxoid (bacterial toxin) vaccine?

Diptheria

67

Example of conjugated (antigen linked to protein) vaccine

pneumococcal