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Flashcards in Responses to Cell and Tissue Injury Deck (103)
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1
Q

What are the major causes of disease on a cellular level?

A

Change in homeostasis caused by;

Retaining more water within the cell- oncosis

Accumulating of fat- steatosis

Autophagy

Atrophy

2
Q

What is autophagy?

A

Cells eating itself up

3
Q

What is atrophy?

A

Decrease in cell size through autophagy

4
Q

What are examples of sublethal injury?

A

Energy failure

Mechanical disruption

Damage to cell membrane caused by free radicals

Blockage of metabolic pathways

Failure of membrane integrity

5
Q

What are the different types of nature of the injury?

A

Acute vs chronic

Mild versus severe

Cell type affected

6
Q

What is necrosis?

A

The death of tissues following bioenergetic failure and loss of plasma membrane integrity.

7
Q

What does necrosis induce?

A

Inflammation and repair.

8
Q

What can cause necrosis?

A

Ischaemia, metabolic and trauma.

9
Q

What are the different categories of necrosis?

A

Coagulative, colliquative, caseous, gangrene, fibrinoid and fat.

10
Q

What is coagulative necrosis?

A

Can happen in most tissues. Appears as a firm pale area.

11
Q

Where is colliquative necrosis seen?

A

Seen in the brain.

12
Q

What is observable in colliquative necrosis?

A

The dead area is liquified.

13
Q

Which disease is associated with caseous necrosis?

A

Tuberculosis

14
Q

What is observable with caseous necrosis?

A

There is a pale yellow semi-solid material.

15
Q

What is putrefaction?

A

The process of decay or rotting in a body.

16
Q

Which necrosis involves putrefaction?

A

Gangrene necrosis.

17
Q

What does gangrene necrosis follow?

A

Vascular occlusion or certain infections.

18
Q

What colour is observable with gangrene necrosis?

A

Black

19
Q

What is fibrinoid necrosis?

A

A microscopic feature in arterioles in malignant hypertension.

20
Q

What may fat necrosis follow?

A

Trauma or pancreatitis.

21
Q

What may be seen with fat necrosis after pancreatitis?

A

Multiple white spots.

22
Q

What may be seen with fat necrosis after trauma?

A

A mass.

23
Q

Define apoptosis.

A

The death of cells which occurs as a normal and controlled part of an organism’s development.

24
Q

What causes reduced apoptosis?

A

Neoplasia, autoimmune disease and virus infection

25
Q

What causes increased apoptosis?

A

Neurodegenerative disorders and HIV infection of T lymphocytes.

26
Q

What does apoptosis effect?

A

Single cells

27
Q

What does necrosis effect?

A

Cell groups

28
Q

What are the biochemical events of apoptosis?

A

Energy-dependent fragmentation of DNA

29
Q

What are the biochemical events of necrosis?

A

Abnormal ion homeostasis

30
Q

Is the cell membrane integrity maintained in apoptosis?

A

Yes

31
Q

Is the cell membrane integrity maintained in necrosis?

A

No

32
Q

What is the morphology in apoptosis?

A

Cell shrinkage and fragmentation

33
Q

What is the morphology in necrosis?

A

Cell swelling and lysis

34
Q

What is the fate of dead cells with apoptosis?

A

Phagocytosed by neighbouring cells

35
Q

What is the fate of dead cells in necrosis?

A

Phagocytosed by inflammatory response

36
Q

What is the commonest type of necrosis?

A

Coagulative necrosis

37
Q

What is involved in coagulative necrosis?

A

Involves coagulation of cellular proteins

38
Q

What is involved in colliquative necrosis

A

Liquefaction with formation of cystic spaces

39
Q

What dominates over coagulation?

A

Proteolysis

40
Q

Define proteolysis

A

The breakdown of proteins or peptides into amino acids by the action of enzymes

41
Q

What is gas gangrene due to?

A

C perfringens

42
Q

What is fibrinoid necrosis most commonly associated with?

A

Malignant hypertension

43
Q

What is pyroptosis?

A

A highly inflammatory form of programmed cell death

44
Q

When does pyroptosis occur most?

A

Infection with intracellular pathogens

45
Q

What stages of response does pyroptosis fall into?

A

Part of apoptosis but then necrosis

46
Q

What infection is pyroptosis associated with?

A

Salmonella infection

47
Q

Define healing.

A

Restitution with no, or minimal, residual defect.

48
Q

What is repair?

A

Is necessary when there is tissue loss: healing by second intention.

49
Q

Which tissues can heal?

A

Blood, skin and gut.

50
Q

Which tissues can repair?

A

Liver and kidney.

51
Q

What is the function of granulation tissue?

A

Actively contracts to reduce wound size which may result in a stricture later.

52
Q

What needs to be rapid in order to favour resolution?

A

Rapid destruction of casual agent and rapid removal of fluid/debris by good local vascular drainage.

53
Q

Where should injury happen to favour resolution?

A

In an organ or tissue with regenerative capacity e.g. liver.

54
Q

What is a factor that favours resolution of an injury?

A

Minimal cell death and tissue damage.

55
Q

Define organisation.

A

Repair of specialised tissue by formation of a scar.

56
Q

What is formed during organisation?

A

Granulation tissue.

57
Q

What is removed during organisation?

A

Dead tissue by phagocytosis.

58
Q

What happens to the wound during organisation?

A

Wound contraction and scarring

59
Q

What substance favours organisation?

A

Large amounts of fibrin

60
Q

What is fibrin?

A

An insoluble protein formed from fibrinogen during the clotting of blood

61
Q

What event favours organisation?

A

Substantial necrosis.

62
Q

What is granulation tissue formed of?

A

Loops of capillaries, myofibroblasts, collagen and inflammatory cells.

63
Q

What organises granulation tissue?

A

Deposition of collagen and contraction?

64
Q

What moves towards a clot in healing by first intention?

A

Neutrophils.

65
Q

How much cell death is there in healing by first intention?

A

Limited cell death

66
Q

What happens to the epidermis in healing by first intention?

A

It thickens at its cut edges

67
Q

What do epidermal cells do in healing by first intention?

A

They migrate along cut margins of dermis.

68
Q

What do epithelial cells do in healing by first intention?

A

They fuse in the midline beneath the surface of the scab.

69
Q

By day 3 what has happened in healing by first intention?

A

Neutrophils largely replaced by macrophages.

70
Q

What has happened by day 5 in healing by first intention?

A

Granulation tissue invades incision space

71
Q

What happens before the epidermis has recovered normal thickness in healing by first intention?

A

The collagen fibres bridge the incision.

72
Q

What is there an accumulation and proliferation of during the second week of healing by first intention?

A

Accumulation of collagen and proliferation of fibroblasts

73
Q

What has happened by the end of the 1st month in healing by first intention?

A

Scar consists of cellular connective tissue. (Tensile strength now increases).

74
Q

What is healing by first intention?

A

Wound with opposed edges.

75
Q

What is healing by second intention?

A

Wounds with separated intention

76
Q

Is there extensive cell loss in healing by second intention?

A

Yes

77
Q

What is the common denominator in healing by second intention?

A

A large tissue defect that must be filled

78
Q

What plays an important role in reducing the size of defect in healing by second intention?

A

Wound contraction

79
Q

What is there more of in healing by second intention?

A

More fibrin and more necrotic tissue

80
Q

What differentiates between first and secondary healing?

A

Wound contraction

81
Q

What has been contraction been ascribed to?

A

The presence of myofibroblasts.

82
Q

What are the stages of bone healing?

A

Repair, remodelling and resolution.

83
Q

What happens when the liver is damaged?

A

Necrosis, regeneration, fibrous scarring and architectural disruption.

84
Q

What are the systemic factors that influence wound healing?

A

Age, nutrition, metabolic status, circulatory status and hormones.

85
Q

Why does nutrition affect wound healing?

A

Affects protein and collagen synthesis

86
Q

How can hormones affect wound healing?

A

Glucocorticoids anti-inflammatory but impair collagen synthesis

87
Q

What local factors may influence wound healing?

A

Infection, mechanical factors, foreign bodies, size, location and type of wound

88
Q

What are the two forms of deficient scar formation?

A

Dehiscence and ulceration

89
Q

What is a keloid scar?

A

A tough heaped-up scar that rises above the rest of the skin.

90
Q

Define oncosis.

A

Cellular swelling

91
Q

Define steatosis.

A

Abnormal condition of fat, any change to pH or other conditions causes a different way of producing fat

92
Q

What is autophagy?

A

A process in which lysosomes decompose damaged organelles to reuse their organic monomers.

93
Q

Define atrophy.

A

To waste away

94
Q

What is an acute injury?

A

An injury with sudden onset and short duration.

95
Q

What is a chronic injury?

A

An injury that develops over a long period of time.

96
Q

What is an hydropic change?

A

Damage leads to water entering cells to be sequestered into vacuoles.

97
Q

What defines a mild injury?

A

Regeneration and no scarring.

98
Q

What defines a lethal injury?

A

Irreversible injury that causes cell death

99
Q

What is a severe injury?

A

Fibrinous exudate

100
Q

What is ischaemia?

A

Lack of blood to a part of the body

101
Q

What are some examples of apoptosis?

A

Embryology, lumen of tubes. HIV AIDS-activated T cell death

102
Q

What cells can be replaced if lost?

A

Labile and stable

103
Q

What are the types of permanent tissues?

A

Neurones and skeletal muscle