FINAL EXAM Pathology D2 Fall Flashcards
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)
Anti-Apoptotic Proteins
BCL2
prevents apoptosis
BLC2 antagonists inhibit the apoptosis prevention… so pro-apoptotic proteins can destroy the cell
Pro-Apoptotic Proteins
BAX and BAK
promote outer mitochondrial membrane proteins
Types of Intracellular Accumulations (4 general… not specific substances)
- normal endogenous substance produced at a higher rate, but the metabolism isn’t high enough to remove it
- abnormal endogenous (usually because of mutated gene) accumulates because the body has no enzymes to degrade it)
- normal endogenous when there is an enzyme defect, so body can’t degrade it
- abnormal exogenous because the cell doesn’t know how to deal with it
Steatosis
Lipid accumulation (fatty change)
Abnormal triglyceride accumulation in parenchymal cells (normal endogenous substance at normal or increased rate, but rate of metabolism is not enough)– increased lipid synthesis and reduced breakdown
liver, heart, muscle, and kidney
Cholesterol Intracellular Accumulation
can see accumulations by intracellular vacuoles
Atherosclerosis– smooth muscle and macrophages of large arteries filled with lipid vacuoles (can see cholesterol under microscope)
Xanthomas– collection of lipid-laden macrophages (foamy cells)
Cholesterolosis– cholesterol-laden macrophages in the gallbladder
Neumann-Pick Disease– lysosomal storage disease because there is an enzyme deficit in processing lipids
Hyaline Change
only a descriptive term
alteration in cells or extracellular space that gives a homogenous, glassy, pink appearance
Glycogen Accumulation
glycogen masses appear as clear vacuoles within the cytoplasm
enzymatic defects cause glycogen storage diseases (problems with glycogen or glucose metabolism)
Pigment Accumulation
can be endogenous or exogenous (coal dust and amalgam tattoo would be exogenous)
LIPOFUSCIN– wear and tear pigment, polymer of lipids and phospholipids in complex with proteins (NORMAL CONSEQUENCE OF AGING)
- resists autophagy
- associated with free radical injury
Melanin– protective mechanism
Hemosiderin– hemoglobin derived pigment, major storage forms of iron (breakdown product of blood, plays a role in bruising)
Pathologic Calcification
Abnormal deposition of calcium salts with other small amounts of mineral salts
Dystrophic calcification– deposition occurs locally in diseased or dying tissues
Metastatic calcification– occurs in otherwise normal tissues, caused by HYPERCALCEMIA
Does apoptosis have inflammation?
NO– apoptosis does not have inflammation (no inflammatory infiltrates with apoptosis)
Necrosis, however, DOES have inflammation
Foreign bodies cause which type of inflammation?
Foreign body granulomatous inflammation/foreign body granuloma
TLRs are a “sensor for microbes”, and are located where?
TLRs are located in…
- plasma membrane
- endosomes
- cytoplasm
Inflammasomes
sense CELL DAMAGE
multiprotein cytoplasmic complex for recognition of products of dead cells
Edema vs. warmth/erythema
Edema is caused by leakage of exudate/plasma protein
Warmth/erythema (redness) is caused by increased blood flow due to dilation of microcirculation of the injured area
Vascular changes with Inflammation
increased blood flow and vasodilation (after transient vasoconstriction)
increased vascular permeability
Herpes infection is an example of ________ inflammation
Serous
Dental abcesses are an example of ___________ inflammation
Purulent
Which cell is recruited first during cell injury?
Neutrophils
Which proteins help mediate with leukocyte rolling and adhesion?
rolling– mediated by selectin family of adhesion molecules
adhesion– mediated by integrins (responsible for cytoskeletal protein interactions with ECM)
Diapedesis
extravasation of leukocytes
driven by PECAM-1 (CD31)
PECAM-1
cell adhesion molecule that drives DIAPEDESIS
What inflammatory mediators are involved in chemotaxis?
- leukotriene B4
- TNF
- C5a
(cytokines, bacterial products)
Chemotaxis is NOT mediated by kinins
Process of microcirculation events mediated by resident inflammatory cells?
- transient constriction
- dilation
- increased permeability
- leaving of exudate
- increase in blood viscosity and decrease in blood flow (blood viscosity increases because exudate is gone)
What molecule activates macrophages?
INF-𝛾
(secreted by helper T cells)
Papillon-Lefevre Syndrome
genetic disorder
Mutation in the cathepsin C gene, involved in skin development and inflammatory response
depressed blood neutrophil chemotaxis
gingivitis, loss of attachment and alveolar bone resorption
What cell contributes to the major production of histamine?
Mast cells
histamine is stored in mast cell granules
histamine dilates arterioles and increases venule permeability
What is the most important coagulation factor?
Thrombin
What do opsonins do?
They enhance recognition and attachment of PMNs
Which mediators are in charge of fever?
IL-1
TNF
Prostaglandins
What are the principal mediators for increased vascular permeability?
Histamine and serotonin
C3a and C5a (mast cells)
Leukotrienes C4, D4, E4
Chronic inflammation is associated with what process/pathway?
Fibrosis
Macrophage Types (M1 and M2)
M1: classically activated macrophages
- phagocytosis and killing of bacteria and fungi
- inflammation
M2: alternatively activated macrophages
- tissue repair and fibrosis
- anti-inflammatory effects
Examples of diseases demonstrating granulomatous inflammation
Tuberculosis
Leprosy
Syphilis
Cat scratch disease
sarcoidosis
Crohn’s disease
Systemic Effects of Inflammation
- increased pulse and BP
- decreased sweating
- rigors (shivering)
- chills (search for warmth)
- anorexia
- somnolence
- malaise
Tissue Regeneration
100% recovery of lost or damaged tissue
proliferation of new cells to replace lost structures
ex. hematopoietic system and epithelia of the skin and GI tract renew themselves 24/7
Tissue Repair
combination of regeneration and scar formation (fibrosis)
Fibrosis
extensive deposition of collagen that occurs during repair (replacing parenchymal tissue with scar tissue)
Labile Tissue Differentiation
continuous division throughout life, replacing those that are destroyed
epithelial tissue, hematopoietic cells
Stable Tissue Differentiation
quiescent, which a low level of replication
liver, pancreas, kidney, bone, cartilage
2 examples of permanent tissues
cardiac muscle and neurons
(these are non-dividing cells)
Which stem cells have the easiest and hardest time differentiating?
embryonic stem cells have the greatest capacity to form the 3 tissue layers (easiest)
Adult stem cells have the hardest time differentiating
Integrins role in the cell cycle
integrins: interaction between cytoskeletal proteins and the ECM
the ECM then signals the division to happen and cytoskeletal proteins actually carry out the division
integrins from ECM activate transcription factors
integrins are “receptors for proliferation”
Cyclins and CDKs
progression through the cell cycle is regulated by cyclins and cyclin dependent kinases (CDK)
CDKs form interactions with cyclins in order to drive the cell cycle… CDK INHIBITORS block these interactions and therefore block the cell cycle
Epidermal growth factor (EGF) and transforming growth factor alpha (TGF⍺)
both share common EGFR receptor
mitogenic for epithelium, hepatocytes, and fibroblasts
Transforming growth factor beta (TGF-β)
considered FIBROGENIC
growth inhibitor for epithelial cells, strong anti-inflammatory effect
ECM structural proteins (3)
- proteoglycans (like GAGs)– provide lubrication and resilience
- fibrous structural proteins (collagen)
- adhesive glycoproteins that connect matrix elements
Collagen development from procollagen is dependent on __________
Vitamin C
(so collagen development is affected with a Vit. C deficiency)
Remember tensile strength comes from collagen
What things give tissues expansion and recoil capabilities?
Elastin
Fibrillin
Elastic Fibers
Name the four families of cell adhesion molecules (CAMs)
immunoglobulin family
cadherins
integrins
selectins
Name some glycosaminoglycans and proteoglycans
heparin sulfate, chondroitin/dermatan sulfate, keratin sulfate and hyaluronan
Angiogenesis
VEGF is the most important growth factor in adult tissues undergoing angiogenesis
vasodilation is response to NITRIC OXIDE produced by macrophages, endothelial cells, etc.
Proteinases are important in tissue remodeling during endothelial invasion, and they cleave extracellular proteins, releasing growth factors like VEGF and FGF-2
2 types of “intention” for cutaneous wound healing
primary intention: cell basement membrane injury are limited and wound edges are approximated by surgical sutures
secondary intention: larger tissue defects such as an abscess or ulceration (results in greater scarring)
Proliferative phase of cutaneous wound healing
formation of granulation tissue, proliferation and migration of connective tissue cells
Granulation tissue
presence of new small blood vessels and proliferation of fibroblasts
Wound contraction occurs through which type of cell
Myofibroblasts
happens during maturation stage of cutaneous wound healing
Dehiscence
rupture of a wound
can be caused by inadequate formation of granulation tissue or assembly of a scar