3. Patterns of liquefactive type necrosis. Organ examples.

What are the two main types of liquefactive necrosis?

- Encephalomalacia - Abcess formation

Where is abcess formation common? (3)

- Lungs - Brain - Liver

Abcess definition:

Accumulation if pus wihin tissue

Why must wet gangrene and abscesses always be removed?

Can lead to sepsis

Desribe the abcess: (morphology)

Center fluid: - liquefactive necrotic cell debris - Pus (neutrophils and edema fluid) Pyogenic membrane (sourrounds center) - Surrounds purulent inflammation - If it fails → sepsis

Describe Encephalomalacia:

Cerebral infarct: -occurs when parts of the brain are ischemic → Tissues in CNS dying from hypoxia always results in liquefactive necrosis → over time a cyst will form

Describe liquefactive necrosis in general:

In liquefactive necrosis cells are completely digested by enzymes → Soft lesion consisting of the fluid remains of the necrotic tissue (Tissue turns into a liquid mass)

What causes Abcess formation?

Pyogenic pathogens

What are the three types of Encephalomalacia/cerebral infarct?

White type: → Occurs in white matter due to a thrombus Red/haemorrhagic type: → Occurs in grey matter due to an embolus Yellow type: → Is a weeks old infarct