Cell Injury, Degeneration and Death Flashcards
1
Q
What are the causes of cell injury?
A
- Physical agents
- Chemicals/drugs
- Infections
- Hypoxia/ischaemia
- Immunological reactions
- Nutritional imbalance
- Genetic disease
2
Q
What damage occurs in mitochondria?
A
- Disrupted aerobic respiration/ATP synthesis
3
Q
What damage occurs in the cell membrane?
A
- Disrupted ion concentrations (especially Ca2+ ions)
4
Q
What damage occurs in the cytoplasm?
A
- Disrupted enzyme and structural protein synthesis
5
Q
What damage occurs in the nucleus?
A
- Disrupted DNA maintenance and DNA damage
6
Q
What is reversible cell injury?
A
- Caused by changes due to stress in environment but return to normal once stimulus removed
- Changes include cloudy swelling (osmotic disturbance: loss of energy dependant Na pump leads to Na influx and build-up of metabolites), cytoplasmic blebs, disrupted microvilli, swollen mitochondria and fatty change
7
Q
What is irreversible cell injury?
A
- Permanent injury and cell death
- Changes are the same as reversible but more severe
8
Q
Define necrosis
A
- Pathological cell death
- Main histological changes include swelling, vacuolation, distuption of membranes/organelles, release of cell contents, DNA disruption and hydrolysis
9
Q
Describe coagulative necrosis
A
- Firm, tissue outline retained
- Caused by ischaemia/infarction
10
Q
Describe haemorrhagic necrosis
A
- Blockage of venous drainage
11
Q
Describe gangrenous necorsis
A
- Larger area (especially lower leg)
12
Q
Describe colliquative necrosis
A
- Tissue becomes liquid and its structure is lost
13
Q
Define caseous necrosis
A
- Combination of coagulative, colliquative and fat
14
Q
Define apoptosis
A
- Programmed/activated cell death
- Physiological apoptosis occurs in embryogenesis, hormone dependant involution, deletion of inflammatory cells, deletion of self-reactice lymphocytes in the thymus and cell deletion in proliferating cell populations to maintain a constant number
- Pathological can be involved in viral infection, DNA damage and hypoxia/ischaemia
15
Q
What is amyloid?
A
- Accumulation of abnormal substances outside cells
- Resembles fibrosis but without prior inflammation
- Can be stained by Congo Reed
- Occurs through excessive production/accumulation of normal protein/abnormal protein or a tendency of proteins to misfold
