Cell death Flashcards
1
Q
Describe the adaptive cellular responses
A
- Failure to adapt- failure of cellular function leads to..
- > Sublethal cell injury- cell endures stimulus but doesn’t die
- > Cell death
2
Q
What is apoptosis?
A
Programmed cell death
3
Q
What is oncosis?
A
Cell death due to pathological reasons
4
Q
What is coagulative necrosis?
A
Severe ischaemia in solid organs
5
Q
What is liquefactive necrosis?
A
Hydrolytic enzyme release in the brain
6
Q
What is caseous necrosis?
A
Cheese-like, seen in TB
7
Q
What is fat necrosis?
A
Typical in breast and pancreas
8
Q
What is fibrinoid necrosis?
A
Damaged arteries (e.g. vasculitis)
9
Q
What is haemorrhagic necrosis?
A
Dead tissue packed with extravasted RBC, blocked benous drainage–> congestion and arterial perfusion failure
10
Q
What is a gangrene?
A
- Dead black tissue
- Dry: coagulative type necrosis
- Wet: tissue infected with gram negative bacteria
11
Q
Describe apoptosis
A
- Cytoplasmic contents not released
- Cell components may be recycled
- Controlled genetically and apoptotic blebs phagocytosed
- Embryonic development, homeostatic mechanism to maintain cell populations, defence mechanism, cell damage/ageing
12
Q
Describe the mechanisms of apoptosis
A
- Lack of growth factors/hormones
- Ligand-receptor interaction
- Injurious agents, DNA
- Tc and NK cells
13
Q
What are the stages of apoptosis?
A
- Initiation: stimulated by Bax protein and pores form in mitochondrial membrane
- Execution: activation of interior and executor capsases–> endonuclease activation, breakdown of cytoskeleton and apoptotic body formation
- Disposal: phagocytosis by macrophages/ adjacent endothelial cells
14
Q
Compare oncosis and apoptosis (oncosis)
A
- Contiguous and pasive
- Cells swell- water influx
- Enzymes destroy organelles
- Stimulates inflammation
- PATHOLOGICAL
15
Q
Compare oncosis and apoptosis (apoptosis)
A
- Single/few cells and active
- Disassembled cytoskeleton
- Vesicles- phagocytosed- ordered packaging
- Physiological or Pathological
