What is morphologic hallmark of cell death?

[Medicoman]

Cell death

1. What is morphologic hallmark of cell death?

• Loss of nucleus

2. What are the steps by which nucleus is lost?
   • Pyknosis - shrinking of nucleus
   • Karyorrhexis - breaking of nucleus to big pieces
   • Karyolysis - big nuclear pieces broken down to molecular building blocks
3. Explain necrosis
   • Necrosis occurs as a result of acute inflammation to a large group of cells and is always pathologic
4. Coagulative necrosis
5. Liquefactive necrosis
6. Gangrenous necrosis - dry and wet
7. Caseous necrosis
8. Fat necrosis
9. Fibrinoid necrosis
   • Types
10. Describe coagulative necrosis

• Cell and organ structure is preserved by coagulation of cellular proteins
• Characteristic of ischemic infarction of any organ except brain .

5. When does red infraction (hemorrhagic infraction) occur?
   Red infraction occurs when blood reenters a loosely organized tissue. Ex - ischemia of testis, lungs.
   (is red infraction a type of coagulative necrosis?)
   •
6. Describe liquefactive necrosis

• Necrosis in which enzymatic lysis of cells and proteins result in liquefaction
  Characteristic of brain (microglial cells destroy the tissue), abscess (neutrophils contain hydrolytic
  enzyme that destroy the tissue), and pancreatitis (pancreatic enzyme digest the pancreas and
  liquify; however surrounding fat will have fat necrosis)

7. Describe gangrenous necrosis
   It is coagulative necrosis that resembles mummified tissue (dry gangrene). If infection occurs on
   dry gangrene, liquifactive necrosis occurs and is called wet gangrene.

• Characterstic of ischemia of lower limb and GI tract

8. Describe caseous necrosis

• It is soft, friable necrosis with ‘cottage cheese’ like appearance
• It’s liquefactive necrosis with debris that thickens the soup to make it cheese like
  Characteristic of granulomatous inflammation of TB or fungal infection (fungal cell wall and
  micobacterium thickens the soup).