40 - Cell Injury Flashcards
do you know
review
What are some common causes of cell injury?
What is important in identifying cell injury?
How can cell injury be determined morphologically stage-by-stage?
How can reversible cell injury be identified morphologically?
What is ultrastructural morphology and how can it be identified? What are the functional consequences of the cell injury that results in ultrastructural morphology?
Ultrastructural morphology refers to the detailed examination of cellular structures at the electron microscope level. When cells are injured, either by physical, chemical, or biological factors, these alterations in ultrastructural morphology can provide important insights into the nature and extent of the injury.
* Cell membrane (blebs, loss of microvilli)
* Myelin figures (membrane-derived)
* Swelling of mitochondria and endoplasmic reticulum
* Detachment of ribosomes
* Nuclear chromatin clumping
What are the differences between necrosis and apoptosis?
What is the morphology of necrosis?
- Increased eosinophilia (decreased RNA, protein
denaturation) - Homogenization (glycogen depletion)
- Dystrophic calcification
- Nuclear changes (pyknosis, karyorrhexis, karyolysis)
What are the types of necrosis? aka patterns of necrosis
What are the features of coagulative necrosis?
- Individual cell architecture preserved
- Firm consistency (no significant tissue digestion)
- Most commonly due to ischemia
- Infarction
- Gangrene
What are the feature of liquefactive necrosis?
- Individual cell architecture not preserved
- Soft consistency (more extensive tissue digestion,
many neutrophils) - May be purulent (abscess)
- Bacterial infections
- Brain involvement
What are the features of caseous necrosis? (think casein)
- Individual cell architecture not preserved
- White, friable (cheese-like) appearance
- Central amorphous eosinophilic material with
peripheral chronic inflammation (macrophages) - Granuloma
- Most commonly due to tuberculosis
What are the features of fat necrosis?
- Occurs in adipose tissue (peripancreatic, soft tissues)
- Activation of lipases (breakdown of fat)
- Secondary calcification
- Common causes include pancreatitis and trauma
What are the features of fibrinoid necrosis?
- Occurs in blood vessel walls
- Leakage of plasma proteins (fibrinogen) due to
vascular injury - Zone of eosinophilic necrosis in vessel wall with
surrounding inflammation - Commonly seen with vasculitis
What are free radicals (ROS)? What are the most common ones? How do they cause cell injury?
- Highly reactive oxygen-containing molecules (unpaired electrons)
Most common: Superoxide, Hydrogen peroxide, Hydroxyl radicals, Peroxynitrite - Normal products of cell metabolism
- Normal systems to neutralize free radicals
- Injury causes increased ROS (oxidative stress)
What does cell injury result in generally depending on the type of injury?
What are some common ROS? How are they made? How are they inactivated? What are their effects?
How are free radicals neutralized?
- Superoxide dismutase (superoxide)
- Glutathione peroxidase (hydroxyl radicals)
- Catalase (hydrogen peroxide)
- Other anti-oxidants (vitamins)
What is reperfusion injury?
