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Flashcards in 3 - Cell injury Deck (11):
1

Aetiology of cell injury

O2 availability
Physical trauma
Chemical agents
Infectious organisms
Irradiation
Others: immunological, lack of nutrients/vitamins, genetic disorders, ageing

2

Difference between hypoxia, anoxia and ischaemia

Hypoxia an anoxia = reduction/loss of O2 to cells
Caused by ischaemia which = lack of blood flow

3

Necrosis vs apoptosis

Necrosis = passive, unprogrammed
Apoptosis = active, programmed

4

Types of necrosis

Coagulative
Caseous
Colliquative
Gangrene
Fat, fibrinoid

5

Coagulative necrosis

Denaturation of intracytoplasmic protein
Dead tissue becomes firm and swollen
Tissue retains microscopic architecture
Ischaemic injury (except brain)
Cellular proteins may leak into blood

6

Colliquative necrosis

Necrotic neural tissue is liable to total liquefaction and site is eventually marked by a cyst.

7

Caseous necrosis

Characteristic of TB
Cheese like
Cellular detail destroyed in this area, surrounded by granulomatous inflammation
Dead tissue lacks any structure

8

Gangrenous necrosis

Wet or dry
E.g. wet bowel infarct
E.g. dry gangrene in diabetes

9

Physiological apoptosis e.gs

Embryogenesis
Involution
Elimination of self-reacting lymphocytes

10

Pathological apoptosis

DNA/protein damage
Viral infections
Cell killing by cytotoxic T-cells
Chemo/radiotherapy

11

Necrosis vs apoptosis:
No of cells
Cell size
Nucleus
Plasma membrane
Cellular contents
Adjacent inflammation
Physiological/pathologic role

Necro first, apoptosis 2nd
Multiple vs single
Enlarged vs reduced
(pyknosis -> karyorrhexis -> karyolysis) vs (fragmentation -> apoptotic bodies)
Disrupted vs intact
Enzymatic digestion vs intact
Frequent vs no
Invariably pathologic vs physiologic