FINAL EXAM Pathology D2 Fall Flashcards
(201 cards)
The etiology of most diseases is ____________
multifactorial
Hypertrophy
Increase in cell SIZE (we want a BIG “trophy”)
physiologic or pathologic
caused by increased workload (functional demand) or by stimulation of trophic hormones
increased production of cellular proteins
Nondividing cell increased tissue mass
Hyperplasia
increase in cell NUMBER
physiologic or pathologic
happens in labile cells (cells that are capable of division)
Physiologic hyperplasia can be hormonal (increase in order to gain function) or compensatory (in order to fix damage)
Pathologic hyperplasia is caused by excess hormones or growth factors– may be at higher risk of malignant transformation (ex. enlargement of the prostate)
Metaplasia
Change in cell PHENOTYPE
One differentiated cell type (epithelial or mesenchymal) is replaced by another cell type
Necrosis is always __________, whereas apoptosis can be _________ OR _____________
Necrosis is always PATHOLOGIC, whereas apoptosis can be pathologic OR physiologic
Necrosis
different types described in other cards
If damage to membranes is severe, lysosomal enzymes enter the cytoplasm and digest the cell, resulting in necrosis
- LYSOSOMAL ENZYME RELEASE IS IRREVERSIBLE
Apoptosis
caspases and endonucleases degrade DNA and proteins… cells break into fragments (apoptotic bodies)…
phagocytosis of cell fragments
DNA damage is characteristic of APOPTOSIS but NOT necrosis
apoptosis is NOT a cell adaptation to stress (cell adaptations are reversible.. like hyperplasia)
Characterized by:
- nuclear dissolution
- fragmentation of the cell without complete loss of membrane integrity
- rapid removal of cellular disease
Reversible injury is characterized as cellular ___________ or ________ change
Reversible injury: cellular swelling or fatty change
Cellular swelling due to failure of energy-dependent ion pumps, loss of fluid homeostasis
Fatty change– occurs in hypoxic injury or toxic and metabolic injury. Seen in cells dependent on fat metabolism (hepatocytes and myocardial cells)
First manifestation of all forms of injury?
cellular swelling
Depletion of ATP
ATP depletion caused by reduced oxygen and nutrient supply, mitochondrial damage, and the actions of some toxins.
Decreased ATP causes:
- failure of energy dependent sodium pump– there is influx of calcium and osmotic gain of water– cell swells
- increased glycolysis
- failure of calcium pump
- ribosomes detach from rEr… decreased protein synthesis
Mitochondrial Damage
results in apoptosis OR necrosis
apoptosis occurs through the release of pro-apoptotic proteins (like Cytochrome C)
mitochondrial damage causes:
- decreased ATP
- increased ROS
- apoptosis or necrosis
Necrosis occurs with the formation of the mitochondrial permeability transition pore (depletes ATP)
Influx of Ca and loss of Ca2+ homeostasis
usually Ca inside cell is LOW
Ischemia and certain toxins cause Ca inside cell to be released, and later calcium influxes through plasma membrane
Calcium activates enzymes, including phospholipase, proteases, endonucleases, and ATPases
Induces apoptosis by activating cascades or increasing mitochondrial permeability
Accumulation of Oxygen-derived Free Radicals
Reactive oxygen species (ROS)– single unpaired electron in outer orbit
- lipid peroxidation in membranes– attach double bond of unsaturated fatty acids of cell membrane
- oxidative modification of proteins– alters activity
- lesions in DNA– free radicals can cause single and double strand breaks in DNA
failure of sodium and calcium pumps does NOT HAPPEN with ROS
ROS inactivated by antioxidants
- intracellular: superoxide dismutase, catalase, glutathione peroxidase
- extracellular: vitamins A, C, and E
Hypoxia
Reduced oxygen
Energy production may continue by anaerobic means (hypoxia can continue glycolysis)
Ischemia
secondary to reduced blood flow
reversible if oxygen is restored, but irreversible injury and necrosis can occur if ischemia continues
Delivery of substrates for glycolysis is compromised– ATP production STOPPED
Loss of ox phos– sodium pump fails, potassium is lost and water enters cell– cell swelling
loss of surface microvilli and blebs develop on the surface
mitochondria are swollen and ER are dilated
Irreversible Cell Damage… “Which would cause the most damage?”
- irreversible mitochondrial dysfunction
- disturbances in membrane function
leakage of intracellular enzymes and other proteins into the blood may provide an indication of cell death (like in myocardial infarction)
Cellular changes in necrosis
- cell swelling
- cytoplasm is glass, homogenous, and pink and may have vacuoles
- nuclear changes (karyolysis, pyknosis, karyorrhexis)
- cells die and release cytoplasm contents– induce inflammation and repair
Name the 6 types of necrosis
- coagulative
- liquefactive
- caseous
- fat
- fibroid
- gangrene (only a description word)
Coagulative necrosis
intact cellular membrane with NO NUCLEUS
most commonly associated with ischemic injury (irreversible ischemia)
localized area of coagulative necrosis is called an infarct
Liquefactive necrosis
enzymatic digestion until tissue is gone and only pus remains
due to release of lysosomal enzymes
major causes are bacterial infections and cerebral infarcts
- cerebral infarcts present similar to wet gangrene
Caseous necrosis
associated with M. tuberculosis (mycobacterial infection)
tissue appears white and “cheesy”
morphologically defined by caseating granulomatous inflammation
Fat necrosis
common in trauma to breast or pancreatitis
Adipose has chalky white-yellow appearance
dead adipocytes look like “soap bubbles”
Fibroid necrosis
associated with autoimmune disease affecting blood vessels
- ex. Lupus erythematosis
neither fibrous or fibrinous
like fibrin but is NOT fibrin– associated with immunoglobulin deposition and necrotic material within blood vessles
Gangrene
CLINICAL TERM (description word, not a technical necrosis type)
black necrotic tissue
Wet gangrene: liquefactive necrosis and bacterial infection
Dry gangrene: ischemia and coagulative necrosis (diabetics)