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Flashcards in MoD Session 3 Deck (108):
0

What is chronic inflammation?

Chronic response to injury w/associated fibrosis

1

How long can chronic inflammation last?

From hours to days

2

What does chronic inflammation overlap with?

Host immunity

3

Is chronic inflammation homogenous or heterogenous?

Very heterogenous

4

How does acute insult lead to chronic inflammation?

Acute insult --> acute inflammation --> more than slight damage --> chronic inflammation

5

What is the result of chronic insult and more than slight damage from acute insult?

Repair and scarring

6

How does chronic inflammation arise?

Take over form acute inflammation of damage cannot be resolved in a few days
De novo
Develop alongside acute inflammation in severe, persistent or repeated irritation

7

When does de novo chronic inflammation arise?

Some autoimmune conditions - RA
Some chronic infections - viral hepatitis
Chronic low level irritation (physical/microbiological)

8

What disease may cause chronic inflammation due to repeated irritation?

Chronic cholysytisis

9

What is the most important characteristic of chronic inflammation?

Type of cell present

10

Describe the microscopic appearances in chronic inflammation.

V. variable

11

Is chronic inflammation stereotyped?

Nope

12

Where are macrophages derived from?

Blood monocytes

13

What allows macrophages to be present in blood but not activated?

Various levels of activation

14

Which type of inflammation are macrophages important in?

Acute and chronic

15

What are the functions of macrophages?

Phagocytosis
Antigen presentation
Synthesis of cytokines, complement components, blood clotting factors and proteases
Control cells by cytokines release

16

Why do macrophages have a foamy appearance?

Abundant ER

17

What type of pathogen is macrophage phagocytosis particularly useful for?

Difficult to kill bacteria e.g. mycobacteria

18

How does the lifespan and replication of macrophages compare to that of neutrophils?

Live for moths and can replicate unlike neutrophils

19

What effects do macrophages have in chronic inflammation?

Stimulate angiogenesis
Induce fibrosis
Fever
Acute phase reaction
Cachexia

20

Hen are lymphocytes seen?

Normal component of many tissues but always present in chronic inflammation

21

What is needed in addition to lymphocyte presence to indicate chronic inflammation?

Tissue damage

22

What is the function of B lymphocytes?

Mature in bone marrow to form plasma cells to release antibodies

23

What are the functions of T lymphocytes?

Process antigens
Secrete cytokines to influence inflammatory cells
Differentiate into NK cells which attack virus infected and some tumour cells

24

Where do T lymphocytes mature?

In the bone marrow

25

What do B lymphocytes and T lymphocytes provide together?

Coordinated immune response

26

How does the chromatin in a plasma cell appear after it has been phenotypically changed from a B lymphocyte?

'Clock face' - clear background w/blobs

27

Why do plasma cells have abundant cytoplasm?

For antibody production and secretion

28

What do the presence of plasma cells imply?

Chronicity as they take a longer time to develop

29

Describe the distribution of eosinophils.

Normally present but scattered, accumulate in certain circumstances

30

What circumstances cause accumulation of eosinophils?

Parasite infestations
Some tumours
Immune response
Allergic reactions

31

What circumstance are eosinophils predominant in?

Parasite infestations

32

What do demotactic stimuli do?

Secreted by macrophages and other inflammatory cells to recruit fibroblasts and myofibroblasts

33

What do fibroblasts and myofibroblasts secrete?

Collagen
Elastin
Glucosaminglycans (fibroblasts only)

34

Why do myofibroblasts differentiate?

So they can contract

35

What are the three types of giant cells?

Foreign body type
Langhans
Touton

36

How are small and large foreign bodies dealt with?

Small foreign bodies are engulfed
Giant cells stick to the surface of large foreign bodies

37

How are the nuclei arranged in foreign body type giant cells?

Randomly

38

How are giant cells formed?

Fusion of macrophages

39

What appearance do Langhans giant cells have?

Foamy centre w/peripheral horseshoe shared nuclei

40

What disease are Langhans cells associated with?

TB

41

What are Touton cells associated with?

Fat necrosis

42

What do Touton cells form in high lipid content?

Lesions

43

What cells are seen with Touton cells?

Foam cells

44

Which type of cells form xanthomas?

Touton

45

How are the nuclei arranged in Touton cells?

Ring towards centre

46

What is 'frustrated phagocytosis'?

Formation of giant cells

47

How is the morphology of most chronic inflammatory reactions described?

Non-specific

48

Give the main cell types present in RA, chronic gastritis and Leishmaniasis.

RA = plasma cells
Chronic gastritis = lymphocytes
Leishmaniasis = macrophages

49

What cell type can be used in chronic inflammation to help diagnosis?

Giant

50

What is Leishmaniasis?

Protozoal infection

51

What are the effects of chronic inflammation?

Fibrosis
Impaired function
Atrophy
Stimulation of immune response

52

How is fibrosis caused?

Cytokines stimulate fibroblasts to produce excess fibrous tissue

53

How is fibrosis initially helpful?

Walls off infected area
Scar needed for wound healing

54

How can fibrosis be problematic?

Can replace parenchymal tissue and impair organ function

55

What determines the consequences of fibrosis?

Position

56

How does chronic cholecystitis causes fibrosis?

Repeated obstruction by gall stones --> repeat acute inflammation causing chronic inflammation --> fibrosis of gall bladder wall as the muscle thickens to try and push stone out

57

How do peptic ulcers appear?

Inflamed w/central acute inflammation causing the submucosa to be washed in acid causing pure acute inflammation

58

What can cause acute gastritis leading to peptic ulcers?

Alcohol
NSAIDs

59

What can cause chronic peptic ulcers?

Helicobacter pylori

60

What is ulceration due to in peptic ulcers?

Imbalance of acid production and mucosal defence

61

What protects the gastric mucosa?

Mucus
Prostaglandins

62

How can myofibroblasts cause further problems in chronic inflammation?

Can slowly contract

63

What disease is impaired function due to chronic inflammation seen in?

Chronic inflammatory bowel disease

64

Give three diseases in which fibrosis due to chronic inflammation is seen.

Chronic cholecystitis
Peptic ulcers
Cirrhosis

65

Give two examples of increased function caused by chronic inflammation.

Increased mucus secretion
Thyrotoxicosis in Grave's disease

66

Why is Crohn's said to have a 'cobblestone' appearance?

Characterised by islands of mucosa surrounded by inflammation

67

What do both Crohn's and Ulcerative Collitus result in?

Scarring

68

Give two examples of sites of atrophy caused by chronic inflammation.

Adrenal glands
Gastric mucosa

69

What happens in atrophy of gastric mucosa caused by chronic inflammation?

Thickness and density of gastric bands decrease due to lymphocyte degeneration

70

What interactions stimulate immune response in chronic inflammation?

Macrophage-lymphocyte

71

What does stimulation of the immune response in chronic inflammation attack?

Innocuous targets
Autoimmune

72

What leads to a disease process?

Stimulation of immune response by chronic inflammation

73

How do patients with idiopathic inflammatory disease affecting large and small bowel present?

Diarrhoea
Rectal bleeding

74

What are the characteristics of Ulcerative Colitis?

Superficial
More likely to cause acute problems than Crohn's
Causes diarrhoea and bleeding

75

What are the characteristics of Crohn's Disease?

Transmural
Stricture and fistulae formation
Can be considered as 'regional enteritis'

76

What two effects of chronic inflammation is cirrhosis and example of?

Fibrosis
Impaired function

77

What are common causes of cirrhosis?

Alcohol
Infection with HBV or HCV
Fatty liver disease
Immunological
Drugs and toxins

78

How does chronic inflammation lead to cirrhosis?

Fibrosis --> disorganisation of architecture --> attempt regeneration --> abnormal collagen deposits --> nodules formed disrupting bile path giving green colour

79

What causes rheumatoid arthritis?

Autoimmune localised and systemic immune response causing joint destruction

80

What effects can rheumatoid arthritis have in organs?

Beta-pleated sheet deposited causing amyloidosis

81

What produces rheumatoid factor in RA?

Lots of lymphoid tissue

82

What shows lymphoid aggregates in RA?

Fronds of synovium

83

How can the link between chronic inflammation, immune response and immune disease sometimes be described?

Overlapped and circular

84

What is granulomatous inflammation?

Chronic inflammation w/granulomas

85

What is a granuloma?

Aggregate of active macrophages

86

What is a hypersensitivity reaction?

Immunological reaction that damages self

87

What are the cells present in a foreign body granuloma?

Macrophages
Foreign body cells
Epitheloid (tightly packed)
Some peripheral fibroblasts

88

Are lymphocytes present in foreign body granulomas?

Probably not - few if any

89

What are foreign body granulomas found around?

Not antigenic material e.g. Surgical thread causing persistent, low-grade stimulation

90

How does breakdown of an artificial joint cause fluorescence in polarised light?

Foreign material from breakdown of artificial joint --> giant cells form holes that shouldn't be in the joint --> foreign material fluoresces

91

What cells are present in a hypersensitivity/immune reaction?

Macrophages
Langhans
Epitheloid
Peripheral fibroblasts
Lymphocytes

92

What does central caseating necrosis in an immune reaction indicate?

TB

93

How does caseating necrosis damage organs?

Forms around insoluble antigenic particles and occupy parenchymal space

94

What are two idiopathic causes of granulomatous inflammation via hypersensitivity reactions?

Xanthogranulomatous pyelonephritis
Malakoplakia

95

What can cause granulomatous inflammation via immune reaction?

Fungi
Sarcoids
Crohn's - seen in ~50% of cases
'Cat-scratch disease'
Leprosy
Syphilis
TB
Wegener's granulomatosis

96

How are BCG and TB differentiated?

Look similar but BCG has no caseous necrosis

97

What does Wegener's granulomatosis affect?

Lungs
Kidneys

98

How do sarcoids present?

Common in young adult women affecting lungs and lymph with non-caseating granulomas

99

How does TB spread from the lungs?

Arrest, fibrosis and scarring in lungs
Erosion --> bronchus causing bronchopneumonia and TB in GI tract
Infects pleura
Erodes into bloodstream

100

Why does it take 6 weeks to receive a +/-ve result for TB?

M.tuberculosis difficult and slow to culture

101

Why can M. tuberculosis survive inside macrophages?

Has mycoside wall lipids

102

Does M. tuberculosis have toxins or lyric enzymes?

Nope

103

How does TB cause scarring in lungs?

Persistence and induction of cell-mediated immunity

104

What causes miliary TB?

Many M. tuberculosis present therefore affects multiple organs

105

What causes single organ TB?

Few M. tuberculosis present

106

In miliary TB what percentage of lung tissue is taken over by granulomas?

50%

107

Which type of TB is often fatal?

Miliary