Cell death Flashcards
types of cell death
oncosis
necrosis
apoptosis
oncosis
cell death with swelling, the spectrum of changes that occur in injured cells prior to death
necrosis
in a living organism, the morphological changes that occur after a cell has been dead for some time e.g. 12-24h
apoptosis
Cell death with shrinkage, induced by a regulated intracellular program where a cell activates enzymes that degrade it’s own nuclear DNA and proteins
types of necrosis
coagulative (main)
liquefactive (main)
caseous
fat necrosis
coagulative necrosis occurs in
ischaemia in solid organs
liquefactive necrosis occurs in
ischaemia in loose tissue
*presence of many neutrophils*
coagualtive necorsis due to
protein denaturation dominates over release of active proteases

liquefactive necrosis due to
enzyme release dominated over protein denaturation

what do cells that have undergone coagulative necrosis look like
cellular architecture is somewhat preserved-ghost outline

liquefactive necrosis lead to
liquefaction of tissue
- cell architecture lost

caseous necrosis is a distinctive form of
coagulative necrosis
- amphorous (structureless debris)
- tissue maintains a cheese-like appearance.
where does caseous necrosis occur
mainly in the lungs
- particularly associated with infection e.g. TB

fat necrosis
- Destruction in the adipose tissue
- Present in people with pancreatitis and in breast tissue after trauma

infarction
necrosis caused by reduction in arterial blood flow
• Can result in gangrene
gangrene
necrosis visible to the naked eye
• An appearance of necrosis
dry gangrene
necrosis modified by exposure to air (coagulative)

wet gangrene
necrosis modified by infection (liquefactive)

gas gangrene
Wet gangrene where the infection is with anaerobic bacteria that produce gas

what is an infarct
an area of necrotic tissue which is the result of loss of arterial blood supply
• An area ischaemic necrosis
apoptosis is
Cell death with shrinkage, induced by a regulated intracellular program where a cell activates enzymes that degrade it’s own nuclear DNA and proteins
Characteristic microscopic appearance
what does apoptosis look like
- Characteristic microscopic appearance
- Characteristic DNA breakdown
- Non-random, internucleosomal cleavage of DNA (in oncosis, DNA is chopped into pieces of random length)




