Ch 2 - 5/4 Dobson Flashcards
What kind of cellular adaptation is a result of increased demand and stimulation?
Hyperplasia or hypertrophy
What kind of cellular adaptation is a result of chronic irritation (physical or chemical)?
Metaplasia
What cellular adaptation is most common in the uterus during pregnancy?
Endometrium from estrogen?
Hypertrophy
Hyperplasia
What cellular adaptation is most common in muscle disuse?
Barrett esophagus?
Atrophy
Goblet cell Metaplasia
Metabolic alterations to a cell that are due to chronic injury result in what?
Intracellular accumulations, calcification
Cumulative sub lethal injury over long life span induce what cellular response?
Cellular aging
What type of necrosis is associated with tuberculous infection?
What type specifically?
Caseous
Myobacterium tuberculosis
Caseous necrosis is described as what?
How does it look on microscopic examination?
Yellow-white and “cheese-like”
Appears as a structure less collection of fragmented or lysed cells and amorphous granular debris enclosed within a distinctive inflammatory border (Granuloma)
If there is ischemia to a cell, what happens in the mitochondria?
DEC ox-phosph and DEC ATP production
What are the 3 consequences of DEC ATP production in the mitochondria?
DEC Na pump
INC anaerobic glycolysis
Detachment of ribosomes (dec protein synthesis)
What are the major sequellae of increased anaerobic synthesis in the cell?
What happens structurally in the cell?
DEC glycogen
INC lactic acid and Dec pH
Clumping of nuclear chromatin
What are the consequences of DEC activity in the Na+ pump?
What structural changes seen in the cell?
INC influx of Ca, H2O, and Na
INC effluent of K+
ER swelling, cellular swelling, loss of Microvilli and Blebbing
What are the major causes of ATP depletion?
Reduced supply of oxygen and nutrients, mitochondrial damage, and actions of toxins (Cyanide)
What are the consequences of membrane damage?
Loss of cellular components
Enzymatic digestion of cellular components
What are the microscopic features of coagulative necrosis in the heart?
Wavy fibers
Widened spaces bw dead fibers containing edema fluid and scattered neutrophils
What pathological conditions lead to apoptosis?
DNA damage
Accumulation of misfolded proteins
Cell death in infection
Pathological atrophy in parenchymal organs after duct obstruction
Li-Fraumeni syndrome is a result of DNA damage to what gene?
TP53
What kind of cellular adaptation is a result of decreased nutrients and and decreased stimulation?
Atrophy
What are the 3 basic steps in the molecular pathogenesis of cardiac hypertrophy?
Actions of mechanical sensors
Signals that activate a signal transduction pathways
Signaling pathways activating TFs
What are the the GFs of mechanical sensors in hypertrophy?
Vasoactive agents?
TGF-B, IGF-1, FGF
A-adrenergic agonists, Endothelin-1, Angiontensin II
What are the TFs which increases the synthesis of muscle proteins responsible for muscle hypertrophy?
GATA4
NFAT
MEF2
Cardiac hypertrophy is associated with INC/DEC gene expression of ANF?
What does this do?
Increased
Decreases blood volume and pressure
What is an example of hormonal hyperplasia?
Compensatory hyperplasia?
Pathologic hyperplasia?
Enlargement of breast tissue during puberty
Liver regeneration
Endometrial, BPH
What are the 6 different causes of atrophy?
Dec workload Loss of innervation Diminished blood supply Inadequate nutrition / malnutrition Loss of endocrine stimulation Pressure (tissue compression)
How does the degradation of cellular protein mainly occur?
Ubiquitin-proteasome pathway
Some of the cell debris within autophagic vacuoles may resist digestion and persist in the cytoplasm as what?
Example of one?
Residual bodies
Lipofuscin granule (brown color)
What is the order of change in a cell during irreversible cell injury? (Fig. 2-7)
Biomechanical alterations leading to cell death
Ultrastructural
Light microscopic
Gross morphologic
BULGe
How does the cell size change in necrosis?
Apoptosis?
Swell
Shrinks
Describe the plasma membrane in necrosis?
Apoptosis?
Disrupted
Intact with altered structure
What happens to the cellular contents in necrosis?
Apoptosis?
Enzymatic digestion, may leak out of cell
Intact, released into apoptotic bodies
What is it called on microscopic examination, small clear vacuoles may be seen within the cytoplasm, representing distended and pinched-off segments of the ER?
The may show what kind of staining?
Hydropic change or vacuolar degeneration
Increased eosinophilic staining
What are the Ultrastructural changes of reversible cell injury?
Blebbing, blunting, loss of Microvilli
Mitochondrial swelling and amorphous densities
Dilation of the ER with detachment of polysomes
Nuclear alterations -> disaggregate on of granular and fibrillar elements
What do necrotic cells show in a H&E stain?
Due to what?
Increased eosinophilia
Loss of cytoplasmic RNA and denatured cytoplasmic proteins
Dead cells may be replaced by whirled phospholipid masses called what?
Derived from where?
Myelin figures
Damaged cell membranes
In living patients, if necrotic cells and cellular debris are not promptly destroyed and reabsorbed, what happens to them?
Dystrophic calcification
What kind of necrosis is characteristic of malignant hypertension and vasculitis?
Fibroid necrosis
What are the major causes of depletion of ATP?
Reduced supply of oxygen and nutrients, mitochondrial damage, toxins
What are 3 consequences of mitochondrial damage?
Formation of the mitochondrial permeability pore
Formation of ROS
Increased permeability of the outer mitochondrial membrane
Increased intracellular calcium activates what enzymes?
What do they do?
Phospholipase and proteases do membrane damage
Endonucleases do nuclear damage
ATPases hasten ATP depletion
How does intracellular calcium affect mitochondrial membrane permeability?
Increases it, thus decreasing ATP production
What ROS is the most reactive and principally responsible for damaging lipids, proteins, and DNA?
OH radical
How is hydrogen peroxide converted to oxygen?
Catalase (in Peroxisomes) and Glutathione peroxidase (cytosol, mitochondria)
What agents act as antioxidants??
Vitamins A, C, E and glutathione
What are the pathological effects of ROS?
Lipid peroxidation in membranes
Protein modification (misfolding and breakdown)
DNA damage -> mutations
How is membrane permeability damaged and what is responsible?
Phospholipid loss due to decreased phospholipid synthesis (ROS)
Increase in phospholipid breakdown via INC in intracellular Ca2+
Cytoskeleton damage via activation of proteases
If there is duct obstruction that may occur in the pancreas, parotid, or kidney what may this lead to?
Pathologic apoptosis
What is the most characteristic feature of apoptosis?
Describe it
Chromatin condensation
Chromatin aggregates peripherally and becomes dense, may fragment
What are the anti-apoptotic proteins?
What domains do they contain?
What do they prevent?
BCL2, BCL-XL, MCL
BH1-4
Cytochrome c leakage
What are the pro-apoptotic proteins?
What domains do tha even have?
BAX and BAK
BH1-4
What are the major sensors of apoptosis?
Domains?
BAD, BIM, BID, Puma, Noxa
BH3 ONLY
What happens once cytochrome c is released into the cytosol?
Binds APAF-1 forming apoptosome
Binds caspase 9 which activates caspase 3
What is responsible for inhibiting anti-apoptotic proteins?
Smac and Diablo
What are the death receptors of the extrinsic pathway?
TNFR1 and Fas (CD95)
What is the adaptor protein that begins the pathway of apoptosis once Fas binds FasL?
FADD
Once the adaptor protein of the extrinsic pathway is activated what happens leading up to apoptosis?
Caspase 8 and 10 are activated, which will activate executioner caspases 3 and 6
What protein is capable of inhibiting the death receptor pathway of apoptosis?
How?
What contains this protein?
FLIP
Binds pro-caspase-8
Viruses and normal cells
What are the most prominent signals for cells indicating apoptosis?
Phosphatidlyserine
Thrombospondin
C1q
What is triggered when abnormal proteins accumulate in the ER?
Unfolded protein response
What does the unfolded protein response trigger?
INC production of chaperones
INC proteasomal degradation of abnormal proteins
Slows protein translation (and DEC protein synthesis)
Tay-Sachs disease is due to what defective protein?
Hexoaminidase Beta subunit
Familial hypercholesterolemia disease is due to what defective protein?
LDL receptor
Creutzfeldt-Jacob disease is due to what defective protein?
Prions (abnormal folding of PrPsc)
Alzheimer’s disease is due to what defective protein?
AlphaBeta peptide
What is the distinguishing feature of necroptosis?
Triggered by mostly what? What else?
NO activation of Caspases
TNFR1 and by viruses
Ligation of TNFR1 recruits what in necroptosis?
RIP1 and RIP3
Necroptosis occurs where?
Associated with what diseases?
Formation of mammalian bone growth plate
Cell death in steatohepatitis, acute pancreatitis, reperfusion injury, neurodegenerative diseases
Caspase-1 is involved of what?
It activates what?
Pyroptosis
IL-1
What cell processes involves inward invagination of lysosomal membranes for delivery?
Microautpohagy
What marker is used to identify cells in which Autophagy is occurring?
LC3
Deletion of what gene leads to increased susceptibility to tuberculosis?
Atg5
Autophagy plays a role in what main diseases?
Cancer Alzheimer's Huntington's IBD and Crohn's Infections diseases
Intracellular accumulation of cholesterol within macrophages is also characteristic of acquired and hereditary hyperlipidemic states is called what?
Found where?
Xanthomas (clusters of foamy cells)
Us epithelial CT of the skin and tendons
The focal accumulations of cholesterol-laden macrophages in LP of the gallbladder is referred to what?
Cholesterolosis
What is the name of a lysosomal storage disease caused by mutations affecting enzyme involved in cholesterol trafficking, resulting in cholesterol accumulation in organs?
Niemann-Pick type C disease
Large, homogenous eosinophilic inclusions produced from a distended ER are called what?
Russell bodies
This subclass of intermediate filaments resists forces applied to it in epithelial cells?
Muscle cells?
CT cells?
Keratin filaments
Desmin
Vimentin
What is the most common exogenous pigment?
Accumulations of this tissue in the lung is called what?
Carbon (coal dust)
Anthracosis
What is an insoluble pigment produced from wear-and-tear?
Lipofuscin
What is the only endogenous brown-black pigment?
Melanin
What is of a yellow-brown color and is a tell-tale sign of free radical injury and lipid peroxidation?
Lipofuscin
What is of a golden yellow-to-brown, granular or crystalline pigment?
Major storage form of what?
Hemosiderin
Iron
When there is local or systemic excess of iron, what will form hemosiderin granules?
Ferritin
What are the major causes of hemosiderosis?
INC absorption of dietary iron (hemochromatosis)
Hemolytic anemia
Repeated blood transfusions
What is the abnormal deposition of calcium salts, together with iron and magnesium called?
Pathologic calcification
What kind of calcification occurs locally in dying tissues with normal serum levels of calcium?
Frequently occurs where?
Dystrophic
Aging or damaged heart valves
Deposition of calcium salts in normal tissues is what?
Results from what?
Metastatic calcification
Hypercalcemia secondary to disturbance in calcium metabolism
What may be formed in the focus of calcification?
Heterotopic bone
Papillary cancers (thyroid) are apt to develop what?
Describe them
Psammoma bodies
Grains of sand, lamellated configurations
Where does metastatic calcification most often occur?
Gastric mucosa, kidneys, lungs, systemic arteries, PV
patients with Werner syndrome show what?
Defective gene is what?
Premature aging
DNA helicase
What does the CDKN2A locus encode for?
Controls what phase progression of the cell cycle?
p16
G1 to S