Cell Injury - Reversible and Irreversible Flashcards
What are the two options an injured cell has?
- Reverse the Injury
2. Die!
Reversible cell injury results in…
A decrease in cell function.
Acute cell swelling is AKA…(4)
Hydropic degeneration Hydropic changes Cytotoxic edema (in the CNS) Ballooning Degeneration (in the epidermis)
What cells are highly prone to hypoxia and cell swelling? (7)
- cardiomyocytes
- Proximal renal tubule epithelium
- Hepatocytes
- Endothelium
- CNS neurons
- Oligodendrocytes
- Astrocytes
What is acute cell swelling?
early, sub-lethal manifestation of cell damage, characterized by increased cell size and vol. due to water overload
-most common and fundamental expression of cell injury**
What is the Etiology of Acute Cell Swelling?
A. loss of ionic and fluid homeostasis
- failure of ATP production
- damage to cell membrane (inner and outer)
- enzyme injury regulating ion channels of membranes
Examples of causes of Acute Cell Swelling…
Physical, mechanical injury HYPOXIA** TOXIC AGENTS** free radicals viral organisms bacterial organisms
What is the PATHOGENESIS of acute cell swelling? (9 steps!)
Injury, hypoxia, decreased ATP production, Na and H20 move into cell, K moves out of cell, increase in osmotic pressure, increase of H20 moving into cell, cistern of ER distend, rupture, and forms a vacuole, extensive vacuolation, HYDROPIC DEGENERATION
Describe the GROSS APPEARANCE of acute cell swelling?
slightly swollen organ with rounded edges
pallor when compared to normal
cut surface: tissue will budge and cannot be easily put in correct position
What is Vesicular Exanthema of Swine Virus, a Calicivirus (vesivirus)?
ballooning degeneration resulting in formation of a vesicle (bullae/blister)
What is the HISTOLOGICAL APPEARANCE of cellular swelling?
H20 uptake dilutes cytoplasm cells enlarge with pale cytoplasm increased cytoplasmic eosinophilia normal nucleus positioning with no morphological changes **see hepatocyte slide from lecture**
What are the ULTRASTRUCTURAL CHANGES of cellular swelling? (4)
- PLASMA MEMBRANE alterations, such as BLEBBING, BLUNTING, and
loss of microvilli - MITOCHONDRIAL changes, including SWELLING and the appearance
of small amorphous densities - DILATION OF ER, with detachment of polysomes; intracytoplasmic myelin figures may be present (see later)
- NUCLEAR ALTERATIONS, with disaggregation of granular and fibrillar elements
Fatty Changes - Hydropic Change = Cell Swelling…what is this due to and what does it do to the organelles and cytoplasmic proteins?
due to ↑uptake of H2O & then to diffuse disintegration of organelles and cytoplasmic proteins
What is the PROGNOSIS of cellular swelling? Briefly explain.
GOOD - if oxygen is restored before the “point of no return”
BAD/POOR - if progression to irreversible cell injury occurs
What does the presence of Lipofuscin in a cell imply?
Evidence of Previous Injury
What is the definition of “Fatty Change”?
SUB_LETHAL cell damage characterized by intracytoplasmic fatty vacuolation
**may be preceded or accompanied by cell swelling
What classes of lipids can accumulate in cells?
ALL LIPIDS!
- Triglycerides
- Cholesterol/cholesterol esters
- Phospholipids
- Abnormal complexes of lipids and carbohydrates (lysosomal storage diseases)
What is Lipidosis? Where does it tend to occur? (4)
accumulation of triglycerides and other lipid metabolites (neutral fats and cholesterol) within parenchymal cells
ex: heart muscle, skeletal muscle, kidney and liver