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Questions and Answers
Which type of necrosis is characterized by the outlines of cells being discernible while fine structural details are lost?
Which type of necrosis is characterized by the outlines of cells being discernible while fine structural details are lost?
What type of necrosis is typical in cases where tissue undergoes anoxic injury, resulting in pale and ghost-like cells?
What type of necrosis is typical in cases where tissue undergoes anoxic injury, resulting in pale and ghost-like cells?
Which pattern of necrosis is commonly associated with an infectious process, resulting in cheese-like tissue appearance?
Which pattern of necrosis is commonly associated with an infectious process, resulting in cheese-like tissue appearance?
Which type of necrosis results in the transformation of tissue into a liquid mass due to the action of enzymes?
Which type of necrosis results in the transformation of tissue into a liquid mass due to the action of enzymes?
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In necrosis, what is the term for the process where the nucleus condenses and shrinks?
In necrosis, what is the term for the process where the nucleus condenses and shrinks?
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Which type of necrosis is characterized by the presence of fat cell necrosis, often associated with pancreatitis?
Which type of necrosis is characterized by the presence of fat cell necrosis, often associated with pancreatitis?
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What is the term for nuclear dissolution that occurs due to the enzymatic degradation during necrosis?
What is the term for nuclear dissolution that occurs due to the enzymatic degradation during necrosis?
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In the context of necrosis, what type involves the death of tissue accompanied by the presence of clostridia or other bacterial infections?
In the context of necrosis, what type involves the death of tissue accompanied by the presence of clostridia or other bacterial infections?
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Which of the following types of necrosis is primarily due to a lack of blood supply that affects both oxygen delivery and substrate supply for glycolysis?
Which of the following types of necrosis is primarily due to a lack of blood supply that affects both oxygen delivery and substrate supply for glycolysis?
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What type of necrosis commonly results from tuberculosis and is characterized by cheese-like (caseous) appearance?
What type of necrosis commonly results from tuberculosis and is characterized by cheese-like (caseous) appearance?
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Which type of necrosis results from the effects of pancreatic enzymes and leads to the destruction of fat tissue?
Which type of necrosis results from the effects of pancreatic enzymes and leads to the destruction of fat tissue?
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In which type of necrosis does the tissue transform into a liquid mass due to enzymatic breakdown?
In which type of necrosis does the tissue transform into a liquid mass due to enzymatic breakdown?
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Which mechanism primarily leads to coagulative necrosis, typically observed in myocardial infarction?
Which mechanism primarily leads to coagulative necrosis, typically observed in myocardial infarction?
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What type of necrosis is characterized by the presence of preserved outlines of necrotic cells with loss of nuclei and an inflammatory infiltrate?
What type of necrosis is characterized by the presence of preserved outlines of necrotic cells with loss of nuclei and an inflammatory infiltrate?
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Which type of necrosis is most commonly associated with brain tissue ischemia?
Which type of necrosis is most commonly associated with brain tissue ischemia?
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Which of the following conditions typically results in both coagulative and liquefactive necrosis occurring together?
Which of the following conditions typically results in both coagulative and liquefactive necrosis occurring together?
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What histological feature primarily characterizes caseous necrosis?
What histological feature primarily characterizes caseous necrosis?
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Which type of necrosis is most likely following a pulmonary abscess due to bacterial infection?
Which type of necrosis is most likely following a pulmonary abscess due to bacterial infection?
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In which form of gangrene is tissue typically dry and shriveled, often found in limbs?
In which form of gangrene is tissue typically dry and shriveled, often found in limbs?
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Which of the following best describes liquefactive necrosis?
Which of the following best describes liquefactive necrosis?
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Which subtype of necrosis is present in a tuberculous lung showing evidence of cheese-like debris?
Which subtype of necrosis is present in a tuberculous lung showing evidence of cheese-like debris?
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Which necrotic process is indicated by intense eosinophilia and loss of cross striations in myocytes?
Which necrotic process is indicated by intense eosinophilia and loss of cross striations in myocytes?
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What condition is characterized by a combination of coagulative necrosis and bacterial infection, leading to tissue destruction?
What condition is characterized by a combination of coagulative necrosis and bacterial infection, leading to tissue destruction?
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Which type of necrosis is characterized by an amorphous, granular appearance and is commonly associated with tuberculosis?
Which type of necrosis is characterized by an amorphous, granular appearance and is commonly associated with tuberculosis?
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What cellular process occurs in fat necrosis leading to the characteristic chalky white deposits?
What cellular process occurs in fat necrosis leading to the characteristic chalky white deposits?
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In the context of acute pancreatitis, what pathologic change is observed in the fat necrosis?
In the context of acute pancreatitis, what pathologic change is observed in the fat necrosis?
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Which type of necrosis is most likely to occur in ischemic injury, and is characterized by the preservation of cellular outlines?
Which type of necrosis is most likely to occur in ischemic injury, and is characterized by the preservation of cellular outlines?
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What is the primary cause of fat necrosis in acute pancreatitis?
What is the primary cause of fat necrosis in acute pancreatitis?
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Which type of necrosis is characterized by liquefaction of tissue, often seen in brain injury?
Which type of necrosis is characterized by liquefaction of tissue, often seen in brain injury?
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Which pathological process is least likely to result in a granulomatous inflammatory response?
Which pathological process is least likely to result in a granulomatous inflammatory response?
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In traumatic fat necrosis, which of the following is a key histological feature?
In traumatic fat necrosis, which of the following is a key histological feature?
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What type of necrosis is commonly associated with the death of a portion of the limb due to insufficient blood supply?
What type of necrosis is commonly associated with the death of a portion of the limb due to insufficient blood supply?
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What is the primary pathological feature of necrosis that occurs due to blunt trauma to the breast tissue?
What is the primary pathological feature of necrosis that occurs due to blunt trauma to the breast tissue?
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What characterizes fat necrosis in acute pancreatitis?
What characterizes fat necrosis in acute pancreatitis?
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Which form of necrosis is likely to occur as a response to hypoxic injury in tissues?
Which form of necrosis is likely to occur as a response to hypoxic injury in tissues?
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Which characteristics define apoptosis?
Which characteristics define apoptosis?
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What type of necrosis is particularly characterized by the presence of tuberculosis?
What type of necrosis is particularly characterized by the presence of tuberculosis?
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What is a likely outcome of heterophagocytosis?
What is a likely outcome of heterophagocytosis?
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In coal worker’s pneumoconiosis, excessive fibrosis is primarily due to which mechanism?
In coal worker’s pneumoconiosis, excessive fibrosis is primarily due to which mechanism?
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Which of the following processes is least likely to occur during the menstrual cycle just before bleeding?
Which of the following processes is least likely to occur during the menstrual cycle just before bleeding?
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What cellular change is primarily involved in liquefactive necrosis?
What cellular change is primarily involved in liquefactive necrosis?
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Which statement accurately reflects autophagy?
Which statement accurately reflects autophagy?
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Which type of necrosis is most likely to be observed in cases of brain infarction?
Which type of necrosis is most likely to be observed in cases of brain infarction?
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Study Notes
Cellular Adaptations and Injury - Lecture 1
- Each cell has a specific function dictated by its genetic makeup and associated machinery/metabolic pathways.
- Homeostasis is the concept of equilibrium within the external environment, maintaining a dynamically stable internal environment. Input is orchestrated with output.
- External disturbances (physiological or pathological) lead to changes in cell machinery, enabling adaptation to a new steady state.
- Adaptation responses aim to maintain cell viability and prevent injury.
Cellular Adaptations
- Adaptive responses are triggered by physiological or pathological stimuli.
- These responses aim to prevent cell injury.
- Adaptative responses include atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia.
Hypertrophy
- Hypertrophy is an increase in the size of cells, leading to an increase in the size of the organ.
- It's caused by increased functional demand or specific hormonal stimulation.
- Hypertrophy can be physiological (e.g., in athletes) or pathological (e.g., left ventricular hypertrophy in systemic hypertension).
Hyperplasia
- Hyperplasia is an increase in the number of cells in an organ or tissue leading to an increase in its size..
- Hyperplasia and hypertrophy are closely related and often occur together.
- Physiological hyperplasia can be driven by hormones or to compensate for tissue loss (e.g., the uterus during pregnancy, or following partial liver resection).
- Pathological hyperplasia can result from excessive hormonal stimulation (e.g., estrogen-induced endometrial hyperplasia) or growth factors (e.g., viral warts).
Atrophy
- Atrophy refers to a decrease in the size of cells, organs or tissue.
- It is an adaptive response.
- Causes of atrophy include: decreased workload (e.g., immobilization), denervation (e.g., in poliomyelitis), ischemia, undernutrition (e.g., starvation), or loss of endocrine stimulation (e.g., post-menopausal endometrial atrophy).
Metaplasia
- Metaplasia refers to the replacement of one mature cell type by another mature cell type.
- It's a reversible adaptive response.
- Examples include:
- Squamous metaplasia of laryngeal & bronchial respiratory epithelium in heavy smokers.
- Squamous metaplasia in urothelium of urinary bladder in bilharziasis
- Columnar metaplasia can affect lower esophageal squamous epithelium in gastro-esophageal reflux disease.
Cellular Adaptations and Injury - Lecture 2
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Cell injury occurs when the limits of adaptive capacity are exceeded or no adaptive response is possible.
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Cell injury is classified as reversible or irreversible.
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Irreversible injury leads to cell death.
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Stages in the cellular response to stress and injurious stimuli include stress or increased demand, reversible responses from adaptation, and injury/inability to adapt leading to necrosis or apoptosis.
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Types of injurious agents include hypoxia / ischemia, physical agents (trauma), chemical agents (poisons), infectious agents, immunological reactions, genetic derangements, nutritional imbalances, and aging.
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Factors influencing severity of injury include type and severity of the injurious agent; duration of exposure; and type of affected cells.
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Examples of cell injury and necrosis include Ischemic injuries and hypoxic injuries
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In ischemia, the delivery of substrates for glycolysis is cut off due to impaired blood supply.
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The consequence of ischemia is typically more rapid and severe compared to hypoxia.
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Examples of cellular responses to hypoxia and ischemia involve: loss/decrease of ATP leading to paralysis in ion pumps; anaerobic glycolysis exhausting glycogen stores and producing lactic acid accumulation; and reduction to protein synthesis.
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Reversible cell injury occurs when injurious agents are mild or short-lived, leading to functional/morphological changes that are reversible.
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Irreversible cell injury occurs when an injury has progressed to severe damage of cellular membranes/nucleus, meaning the cell cannot recover and dies.
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Types of irreversible cell injury, which is cell death, include necrosis and apoptosis.
Necrosis
- Necrosis is a form of cell death characterized by morphological changes in a living tissue or organ.
- It results from a degraded action of enzymes within the irreversibly damaged cells with denaturation of proteins.
- Morphologic changes within necrosis include cytoplasmic changes (increased eosinophilia, loss of cytoplasmic RNA), more homogenous appearance (lost of glycogen particles), and vacuolated cytoplasm (from digested organelles).
Types of necrosis
- Coagulative necrosis: outlines of cells are still visible but structural details are lost (Sudden ischemia in organs leads to denaturation of structural proteins and enzymes, stopping proteolysis).
- Liquefactive necrosis: complete digestion of cells by enzymes (Common in ischemic destruction of brain tissue and bacterial infections like abscesses).
- Fat necrosis: involves adipose tissue and is mediated through lipases, which leads to calcium deposits and chalky white areas. (Common in acute pancreatitis).
- Caseous necrosis: a combination of coagulative and liquefactive necrosis, with a cheesy/yellow-white appearance (Common in tuberculosis).
- Gangrenous necrosis: a combination of coagulative necrosis (ischemia) and liquefactive necrosis (bacterial infection) (Common in lower limbs).
Cellular Adaptations and Injury - Lecture 3
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Subcellular responses to injury include autophagy, which is lysosomal digestion of cellular components as a survival mechanism during nutrient deprivation.
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Autophagy involves the cell "eating its own contents" in order to survive.
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Several pigment accumulations occur, including carbon (coal dust), that can lead to pneumoconiosis.
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Endogenous pigments include melanin and hemosiderin(caused by iron overload).
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Exogenous pigments (caused external exposure) include carbon, tattoos, etc.
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Apoptosis is a regulated cell death mechanism in which cells activate enzymes (caspases) to degrade their own nuclear DNA and other nuclear/cytoplasmic proteins. Apoptotic cells are typically round/oval, with intensely eosinophilic cytoplasm, chromatin condensation, fragmentation. Apoptotic bodies are quickly phagocytosed, avoiding inflammation.
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Several mechanisms cause DNA damage that triggers apoptosis and cellular function decline.
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Accumulation of misfolded proteins can occur due to problems with protein synthesis or folding control within the ER.
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Effects of misfolded proteins are generally adverse, including potential pathways for apoptosis, cellular damage, and neurodegenerative diseases like Parkinson’s.
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Accumulations may happen due to abnormal metabolism, mutations, or an inability to degrade phagocytosed particles.
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Lipid accumulations (fatty change): abnormal accumulation of TG within cells, in the liver (from toxins like alcohol, diabetes mellitus, obesity), or in the heart.
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Protein accumulations: Can be due to a variety of causes, in various tissues and cells, including plasma cells with excessive immunoglobulin accumulation (Russel bodies), neurofibrillary tangles in the brain (in Alzheimer's).
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Glycogen accumulations: in poorly regulated diabetes mellitus in various tissues, or in glycogen storage diseases.
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Pigments (colored substances): Normal constituents (melanin etc.) versus abnormal endogenous (like iron overload) or exogenous (like carbon) accumulations
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Calcification: can involve abnormal calcium deposition in tissues (dystrophic; like in necrosis) and also widespread systemic calcification (e.g., due to hypercalcemia), in various tissues.
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Description
Test your knowledge on the different types of necrosis and their characteristics. This quiz covers various forms of necrosis, including caseous, liquefactive, and fat necrosis, along with important terms related to cellular death. Challenge yourself with questions about patterns and descriptive terms associated with necrosis.
