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Flashcards in Immune System Deck (55):
0

What does the immune system do?

Defence against disease-producing agents (pathogens)

1

What are the different types of pathogens?

Viruses
Bacteria
Parasites
Fungus & yeasts
Prions

2

What are the properties of a virus?

Infectious particles, rather than living cells.
Cannot replicate on their own but must hijack the hosts genetic machinery.

3

What can a virus not do?

Replicate on its own.

4

What are the properties of a bacteria?

Multiply quickly
True living cells,
larger and more highly organised than viruses.
Can multiply outside the host cell. (Binary fission)
They grow rapidly, dividing roughly once every 20 minutes in ideal conditions.

5

What is the process of the bacteria multiplying outside the cell called?

Binary fission

6

In ideal conditions how rapidly does bacteria grow?

Divide roughly once every 20 minutes

7

Parasites can be be put into 2 categories. What are they?

Single-celled (protozoa)
Multicellular (helminths)

8

Where are single-celled (protozoa) parasites found?

Live freely in soil or water.

9

Can u name any parasitic single celled diseases?

Malaria
Amoebic dysentery
Giardia (affects small intestine)

10

Where are multicellular (helminths) parasites found?

Inhabit the guts of animals

11

How are multicellular parasites transmitted?

Faeces or ingestion

12

Can you name any multicellular (helminth) parasites?

Roundworm
Tapeworm
Threadworm
Liver fluke

13

What are the properties of yeast & fungi?

Cause diseases known collectively as mycoses.

14

Why are mycoses important in people with compromised immune systems?

Cause "opportunistic infections"

15

Give an example of an opportunistic infection?

Oral thrush (candida)

16

What are prions?

Abnormal proteins

17

What conditions can prions cause?

CJD (creutzfeld-Jacob disease)
CJDv (new variant CJD)
Kuru

18

What is the immune systems second line of defence?

Blood & lymph

19

When would the immune systems second line of defence be recruited?

If pathogens breach the physical & chemical defences.

20

What is involved in the second line of defence in its simplest form?

Huge array of blood cells & circulating proteins

21

What 2 components is the human immune system divided into?

Natural (innate) immune system
Adaptive immune system

22

What is the immune systems first line of defence?

Physical & chemical defence mechanisms.
Skin
Natural orifices in the skin posses additional protective strategies

23

Name some additional protective strategies of some of the orifices of the skin?

Mucociliary epithelium of upper airway
Acid pH of vaginal secretions
Tear fluid of the eyes

24

What makes up the natural (innate) immune system?

Variety of white blood cells & many proteins.

25

What white blood cells are included in the natural (innate) immune system?

Natural killer cells
Basophils
Mast cells
Neutrophils
Macrophages
Eosinophils

26

Describe the innate immune system?

It is evolutionary "old", is non-specific and has no memory.

27

What makes up the adaptive immune system?

Lymphocytes (T-cells & B-cells)

28

Describe the adaptive immune system?

Evolutionary "new", recognises specific foreign proteins (antigens or pathogens), and has a memory to a disease once we have fought it off

29

Why does the immune system carry unique protein markets?

Act as a personal signature (self)

30

What happens to cells possessing the signature self?

Ignored by the immune system

31

What happens to anything without the self signature (not-self)?

Viewed as foreign & will be attacked by the immune system

32

What are some of the proteins of the natural immune system measured for?

Inflammatory diseases (e.g rheumatoid arthritis)

33

What do mast cells & basophils secrete in response to injury or infection?

Histamine

34

What do natural killer cells secrete?

Non-specific cytotoxins

35

What are neutrophils, monocytes & macrophages & what do they do?

Phagocytes
Clean up debris

36

What do macrophages also secrete?

Pyrogens

37

What do pyrogens do?

Raise temperature

38

What is the purpose of a dendritic cells?

Present antigens (pathogen proteins) to the lymphocytes

39

Where do T & B lymphocytes originate?

Bone marrow

40

Where do B- lymphocytes mature?

Bone marrow

41

Where do T-lymphocytes mature?

Thymus gland

42

What releases lymphocytes into the blood?

Lymphatic system

43

Where do lymphocytes particularly accumulate?

Lymph nodes & other lymphatic tissue

44

What do B & T-lymphocytes recognise?

Foreign antigens (pathogens)

45

How many B& T- cells are capable of recognising each pathogens?

Only a few

46

What happens after B & T cells recognise an antigen (pathogen)

Form B-cell & T-cell clones (clonal proliferation)

47

What is the name of the B & T cell cloning process?

Clonal proliferation

48

What do B & T- lymphocytes do after clonal proliferation?

Differentiate into cells specialised to perform particular roles

49

What is the function of a T-cell?

Some T-cells are cytotoxic t-cells & go to the site of infection & destroy pathogens using specific toxins.
Others act as helper cells

50

What is the function of B-cells?

Act at a distance from site of infection.
Secrete specific antibodies that can stick to the pathogen & destroy it.

51

What happens to the lymphocytes once the disease is wiped out?

Mist of the lymphocytes die.
A few B & T-cells remain as memory cells

52

What do memory cells give us?

Immunity

53

How do vaccines work?

Designed to convince the body's adaptive immune system to mount an immune response without the person becoming seriously ill.
Body will generate memory cells.

54

What does creating a vaccination involve?

Manufacturing an attenuated form of the pathogen.
Modified so that it is still recognised by the immune system but is not longer highly pathogenic.
The body generates memory cells in the usual way.