L58. Cell Injury Flashcards
Describe how cell injury can be reversible or irreversible.
Reversible - cells adapt when a stimulus is applied and revert when the stimulus is removed. It depends on type and severity of the injury.
Irreversible - permanent, can cause cell death.
What is aetiology?
Cause of the disease
What can cause hypoxia?
Anaemia. It disrupts respiratory processes.
What causes ischaemia?
Shortage of blood flow to a tissue caused by artery or vein blockages.
Describe agents which can lead to cell injury.
Physical agents - mechanical trauma, temperature
Infectious agents - bacteria, viruses
Chemicals - poisons, alcohol
Immunological - anaphylaxis
Give examples of specialised and generalised inadequate nutrition.
Rickets - specific
Anorexia - generalised
Give examples of specialised and generalised excessive intake.
Hypervitaminosis - specific
Obesity - generalised
Give an example of a genetic defect.
Sickle cell anaemia
What happens to DNA and plasma during reversible injury?
Their integrity is maintained.
Give examples of 2 changes which can be seen in cells during cell injury.
Cloudy swelling - cells cannot maintain fluid homeostasis
Fatty change - accumulation of lipid vacuoles in cytomplasm
Give the 4 point flow chart for irreversible injury.
Normal cell > reversible changes > point of no return > irreversible changes
What is necrosis?
Irreversible cell injury/death due to pathology
What is pyknosis?
Nucleus shrinkage
What is karyorrhexis?
Nucleus fragments
What is karyolysis?
the blue-stained nucleus DNA is digested by endonucleases
Give a sign of cell necrosis.
loss of blue-stained nucleus.
What are the 3 types of necrosis?
- Co-agulative necrosis - no protein breakdown in cells due to enzyme denaturation
- Liquefactive necrosis - digestion of dead tissue (now in a liquid state - pus)
- Caseous necrosis - tissue has a cheese-like appearance (like in TB).
What is fat necrosis?
Areas of fat destruction brought about by pancreatitis.
What is fibrinoid necrosis?
seen in immune reactions in blood vessels.
Name 2 effects of necrosis
- Loss of function
2. Inflammation
What do nuclei tell you?
Whether or not they have died (pyknosis, karyorrhexis, karyolysis)
What does the cytoplasm tell you?
How it died (co-agulation necrosis, liquefaction necrosis, caseous necrosis, fat necrosis)
What is apoptosis?
genetically programmed cell death which requires energy with no inflammation.
Give 2 causes of apoptosis.
DNA damage or cell deletion during embryogenesis.
