Exam 1 Material Flashcards
Pathology definition
“Study of suffering” or “study of disease”
Etiology
Origin of disease, “why”
- genetics
- environmental exposures
- risk factors
Pathogenesis
Steps in development, “how”
Homeostasis
Tendency to maintain internal stability
Disease definition
Structural or functional change in the body that is harmful to the organism
Deviation from optimal homeostasis
Sign
Objective and observable indication that a disease is present
Symptom
Subjective evidence of disease or physical disturbance
Cells that are stressed will attempt to undergo..
Adaptation
Two factors that influence a cell’s ability to adapt
- Cell type
2. Nature of the cellular stress
Happens when a cell is no longer to adapt to a cellular stressor
Cellular injury
Physiologic adaptations
Responses that would be expected to occur with normal physiological changes
Pathologic adaptations
Responses to excessive cellular stress and indicate a loss of optimal structure and function
Cellular adaptation definition
Reversible changes in cell populations
- Ex: number of cells, cell size, cell type
Four main adaptations to stress
- Hypertrophy
- Hyperplasia
- Metaplasia
- Atrophy
Hypertrophy
Increase in the size of a cell
Hypertrophy is achieved by
Increase in synthesis of intracellular proteins and organelles
Example of pathologic hypertrophy
“Ventricular hypertrophy”
Pathology results from
Disruption in homeostasis
Irreversible cellular injury results in
Death
Two types of cell death
Necrosis (inflammatory) and apoptosis (controlled)
Cardiac myocytes adapt to chronic hypertension via
Hypertrophy
Which cellular adaptation is most likely to cause pre-cancerous cellular changes
Metaplasia
Some cases hyperplasia
An HPV infection is most likely to cause which pathologic adaptation at the area of the infection?
Hyperplasia
Stenosis definition
Narrowing
Steatosis definition
Fat accumulation
Hyperplasia
Increase in the number of cells
Hyperplasia can result from
Compensatory factors, gene activation or hormonal factors
Atrophy
Decrease in cell size, or reduced size and function
Decrease in cell size
Decrease protein synthesis or increase protein breakdown
Reduced size and function can be due to
- Disuse
- Denervation
- Ischemia
- Endocrine disruption
- Aging
Metaplasia
Change of one cell type into another
Possible consequences of metaplasia
Decreased function, and malignant transformation
Three types of trauma
Physical
Thermal
Radiation
Injury occurs if stressors
- Exceed ability to adapt
- Direct damage
- Intrinsic abnormalities
Type of stressor in a reversible injury
Transient or mild stressor
Examples of reversible injuries
Cellular swelling and fatty accumulation
Irreversible injuries due to what type of stressor
Prolonged or severe stressor
Examples of what prolonged or severe stressors cause
- Irreparable mitochondrial damage
2. Damaged cellular membranes
Two types of cell death
- Necrosis
2. Apoptosis
Inflammatory cell death
Necrosis
Type of cell death caused by trauma, toxins and ischemia
Necrosis
Type of cell death that is non-inflammatory
Apoptosis
Type of cell death due to decrease in growth factor or damage to DNA/proteins
Apoptosis
Pyknosis necrosis
Nucleus becomes a Solid, shrunken mass
Karyorrhexis necrosis
Nucleus becomes fragmented
Karyolysis necrosis
Nucleus fades and dissolutes
What happens to the Plasma membrane during necrosis?
Becomes disrupted
What happens to plasma membrane in apoptosis?
Stays intact, but structure is altered
Which type of cell death is considered pathologic?
Necrosis
Which type of cell death is often considered physiologic?
Apoptosis
5 patterns of necrosis
- Coagulative
- Liquefactive
- Caseous
- Fat
- Fibrinoid
Coagulative necrosis
Severe ischemia, death of solid organ tissue
Infarction
Process of killing cells due to ischemia
Infarct
Area of dead tissue
Gangrene
Coagulative necrosis in an extremity
Major causes of gangrenous necrosis
Peripheral vascular disease
Frost bite
Trauma that obstructs blood supply
3 types of gangrene
Dry
Wet
Gas
Which pathology is most likely to cause gangrene in the U.S.?
Diabetes
Liquefactive necrosis
An infection occurs and dead cells are completely digested by WBC into a liquid/viscous mass
Liquefactive necrosis examples
- CNS ischemia/hypoxia
2. Infections (bacterial and fungal)
Examples of stressors
Trauma, ischemia, hypoxia, poisons, infections, immune reactions, malnutrition, aging
Ischemia
Insufficient blood supply to a tissue
Hypoxia
When an organ is not receiving adequate oxygen within the arterial bloody supplying the organ
Cyanosis
Bluish discoloration of the skin which may develop following tissue ischemia or hypoxia
Cellular swelling develops because
Injured cells may not have enough ATP to power ATP-dependent pumps
Toxin definition
Poisonous substance secreted from a living organism
Poison definition
Substance that may kill, injure, or impair a living organism
Types of infectious microbes
Bacterial, viral, protozoan, or fungal
Ways an infection can arise
- Microbes directly induce tissue damage
2. Microbes stimulate an excessive immune response that causes tissue damage
Nutritional imbalance
Deficiency or excess of dietary nutrients may inhibit homeostasis
Cellular senescence
Reduced capacity for cells to react to stress, and maintain homeostasis (result of age)
Fatty change (steatosis)
Accumulation of fat vacuoles within a cell’s cytoplasm
Apoptosis eliminates cells experiencing:
- Severe DNA damage
- Severe protein damage
- A loss of cellular survival signals
- Cells that have been infected by viruses
Dry gangrene
Uncomplicated gangrene
Most common
Wet gangrene
If gangrenous tissue becomes infected w/ bacteria and the tissue liquefies
Gas gangrene
When bacteria (Clostridium perfringens) infects the tissue and gas byproducts become trapped within the tissues
Cytoplasmic changes during necrosis
Eosinophilia
Myelin figures
Eosinophilia
Necrotic cells manifest with an increased pink/red appearance with H&E stain
Myelin figures
Necrotic cells contain membrane damage and myelin figures are “rolled-up” or “scroll-like”
Caseous necrosis
“Cheese-like” appearance— friable, yellow/white
Major cause of caseous necrosis
Tuberculosis
Granuloma definition
Walled-off collection of macrophages
Caseous necrosis via tuberculosis AKA
Caseous granuloma
Fat necrosis AKA
Enzymatic necrosis
Fat necrosis definition
Fat destruction, fat “saponification”
Causes of fat necrosis
Acute pancreatitis
Pancreatic trauma
Trauma to breast
Causes of acute pancreatitis
Gallstones
Alcoholism
Enzyme defected in fat necrosis
Lipase enzyme
Fibrinoid necrosis
Due to an autoimmune reaction
Autoimmune reaction in fibrinoid necrosis induces the formation of
An immune complex + fibrin
Immune complex
Antibody + antigen
Apoptosis
Programmed/regulated cell death
Apoptotic bodies
Intact membranes, produce no inflammation
Apoptosis activates
caspases
Two apoptosis mechanisms
Mitochondrial pathway
Death receptor pathway
Mitochondrial pathway caused by
Decreased growth factor
DNA damage
Misfolded proteins
Mitochondrial pathway activates
Caspase-9
Death receptor pathway signalled by
“Death receptors” binding with signaling molecules (extrinsic)
Death receptor pathway activates
Caspase-8
Autophagy
“Self-eating”; lysosomal digestion of a cell’s insides
What happens during autophagy
Organelles are sequestered/digested into autophagic vacuoles
Conditions when autophagy occurs
- Survival during “lean times”
2. Rids misfolded proteins
Cellular injury frequently begins with
Reduced ATP
Vulnerable cellular structures for cellular injury
Mitochondria
Membranes
Protein synthesis
DNA
Ischemia/ Hypoxic Injury results in low oxygen, which results in
Low ATP
Low ROS
Conditions when hypoxia will occur without ischemia
CO poisoning
Pneumonia
Choking
Premature baby (immature alveoli)
Persistent ischemia can result in
Ruptured membranes (necrosis) Minimal apoptosis
Ischemia-Reperfusion Injury
Ischemia, followed by restoration of blood flow
Ischemia-Reperfusion injury results in cell injury by
Increase inflammatory cells (increase WBC)
Increase ROS
Oxidative stress
Accumulation of ROS
Oxidative stress can result in
Cellular aging
Inflammation (neutrophils and macrophages)
Ischemia-reperfusion injury
ROS
Reactive oxygen species
Molecules with unpaired electrons in outer orbitals
Redox reactions
Partially reduced intermediate molecules
Inflammation/phagocytosis
Burts of ROS created by WBC when digesting phagocytized material
Nitric oxide
Natural free radical produced by macrophages or endothelial cells
Ionizing radiation
Hydrolyzed water into OH and H
Two types of chemical injury
Direct injury (rare) Latent injury (MC)
Direct chemical injury
Toxins bind to cells
Inhibits use of ATP or damages membranes
Latent chemical injury
Require conversions into highly reactive or toxic metabolites
Cytochrome P-450 works in
Smooth ER of liver
Example of latent chemical injury
Acetaminophen (NAPQI created in liver via cytochrome P- 450)
Genetic Damage occurs via
Radiation or chemotherapy meds
Chemicals
Viral infections
Genetic damage can result in
ROS damage to DNA
Apoptosis
Future cancer risk
4 mechanisms of intracellular accumulations
Abnormal metabolism
Defective protein folding or transport
Defective or absent enzymes
Ingestion of indigestible materials
Abnormal metabolism example
Fatty liver disease (via alcoholism or diabetes)
Defective protein folding or transport example
Alpha 1- antitrypsin deficiency (results in emphysema in non-smokers)
Absent enzymes examples
Tay-Sachs Disease
Gaucher Disease
Accumulation of indigestible materials examples
Pneumoconioses (carbon and silica)
Fatty change (steatosis)
Excessive lipid accumulation
Macroscopic fatty change
Hepatomegaly
Microscopic fatty change
Fat vacuoles
2 things that can lead to fatty changed
Alcoholic liver disease
Nonalcoholic fatty liver disease
Alcoholic liver disease symptoms
Ascites
Caput Medusae
Mallory Bodies
Ascites
Edema in peritoneal cavity
Caput Medusae
Varicose veins of stomach
Mallory Bodies
Intracellular inclusion that accumulate in liver cells
observed in alcoholic hepatitis and alcoholic liver disease
Causes of chronic liver disease that can result in hepatocellular carcinoma
Chronic HBV infection
HCV infection
Aflatoxin exposure
Inflammation of liver
Hepatitis
Scarring of liver
Cirrhosis
Percentage of heavy drinkers that will develop hepatic steatosis
90-100%
Percentage of heavy drinkers that will develop hepatitis
25%
Percentage of heavy drinkers that will develop cirrhosis
15%
About ___ years are required to cause cirrhosis
20
Steatosis and hepatitis are
Reversible
Liver cirrhosis is
Permanent
Ascites occurs because
Liver cirrhosis reduces ability to produce normal blood protein
Protein deficient blood causes fluid to leave circulation and accumulate in tissues
Caput Medusae occurs because
Liver cirrhosis prevents blood from flowing through liver, shunting venous blood from liver and to epigastric veins
Conditions that stimulate nonalcoholic fatty liver disease
Obesity
Type 2 DM
Dyslipidemia
Chronic hypertension
Africa and Asia patient are more likely to have __ between ages __ due to spreading from mother to baby
HBV
20 -40 years old
US patients are more likely to have
HCV
Males are about __ times more likely than females to develop hepatocellular carcinoma
3X
Aflatoxin is a carcinogen produced by
Aspergillus (mold)
Aflatoxin is present in
Peanuts
Up to __ of individuals with alcohol-induced liver cirrhosis will develop hepatocellular carcinoma
20%
Intracellular Pigment examples
Carbon
Melanin
Lipofuscin
Wear and tear pigments
Found in elderly
Hemosiderin
Bleeding or hemosiderosis
Hemosiderosis
High iron levels = oxidative stress
Due to repetitive blood transfusions
Dystrophic Calcification
Calcification of damaged tissue
MC cause of pathological calcification
Fibrodysplasia Ossificans Progressiva
Dysfunctional soft tissue repair
Any trauma leads to heterotopic ossification
Ankylosis (fusion)
Fibrodysplasia ossificans progressiva is an ___ disorder and is ____
Autosomal dominant
RARE (1 in 2 million births)
Metastatic calcification
Calcification of normal tissues (may deposit in any tissue)
Abnormal Ca2+ homeostasis (hypercalcemia)
Causes of hypercalcemia
Bone cancer Multiple myeloma Paget disease Leukemia Hyperparathyroidism Hypervitaminosis D Renal failure
Cellular aging
Reduced functional capacity of cells
Theories of cellular aging
DNA damage
Replication Senescence
Defective protein homeostasis
Progeroid Syndromes
Extremely rapid aging
Cells can’t fix cellular damage
Bloom syndrome
Death in 20s
Werner syndrome
Death in 40s