Necrosis. L39 Flashcards
(31 cards)
Def of Necrosis
local death of group of cells in the living tissue.
Gross picture in necrosis
Necrotic area appears opaque and surrounded by red zone of inflammation
Microscopic picture are one of those?
Cytoplasmic changes
Nuclear changes
Cytoplasmic changes in necrosis
a- The cells become swollen (cytomegaly)
b- Increased eosinophilia
c- The cytoplasm becomes vacuolated
d- Finally the cell membrane ruptures
Nuclear changes inn necrosis
a- Pyknosis
b- Karyorrhexis
c- Karyolysis
What happens in Karyolysis
Lysis and dissolution of the nuclear chromatin
nuclear shrinkage occurs in?
Pyknosis
Fragmentation of nuclear material occurs in?
Karyorrhexis
Fate of necrosis?
1- Small area of necrosis
2- Large area of necrosis
In Small area of necrosis?
Necrotic tissue is removal by macrophages
In Large area of necrosis?
Surrounded by fibrous capsule
Types of necrosis
1- Coagulative necrosis
2- Liquifactive necrosis
3- Caseating necrosis
4- Fat necrosis
5- Fibrinoid necrosis
Most common type of necrosis
Coagulative necrosis
Cause of necrosis
sudden cut of blood supply (ischemia)
Site of Coagulative necrosis?
all organs except the brain
Gross pic of Coagulative necrosis
firm and opaque white
Microscopic picture Coagulative necrosis
Dead tissues shows preserved architecture (ghosts of cells) for a span of at least some days with no cell details
Define Liquifactive necrosis
Type of necrosis characterized by softening and liquefaction of the necrotic tissue
Examples of Liquifactive necrosis ? They happen due to?
a-Brain infarctions: due to high lipid and fluid content
b- Pyogenic abscess due to liquefaction of necrotic tissue by proteolytic enzymes.
In Liquifactive necrosis ……… is dominant than …….
enzymatic digestion
denaturation
Liquifactive necrosis makes The necrotic area what?
becomes soft and liquefied in?
Caseation necrosis occurs in which disease?
Tb
Caseation necrosis looks like?
cheese like
local area of fat destruction
Fat necrosis