Podcast
Questions and Answers
Which process primarily involves the action of enzymes on cells following injury?
Which process primarily involves the action of enzymes on cells following injury?
- Necrosis (correct)
- Tissue regeneration
- Cell division
- Apoptosis
What is a characteristic feature of cells undergoing apoptosis?
What is a characteristic feature of cells undergoing apoptosis?
- Increased cell size
- Cell swelling
- Nuclear fragmentation
- Formation of apoptotic bodies (correct)
What initiates the extrinsic pathway of apoptosis?
What initiates the extrinsic pathway of apoptosis?
- ER stress
- Cell shrinkage
- Death receptor activation (correct)
- Mitochondrial damage
Which of the following is NOT a known cause of apoptosis?
Which of the following is NOT a known cause of apoptosis?
What morphologic change is associated with necrosis?
What morphologic change is associated with necrosis?
Which of the following is NOT a category of injurious stimuli that can cause cell injury?
Which of the following is NOT a category of injurious stimuli that can cause cell injury?
Which mechanism of cell injury is primarily associated with damage to energy production?
Which mechanism of cell injury is primarily associated with damage to energy production?
What is the key characteristic of apoptosis?
What is the key characteristic of apoptosis?
Which of the following is an example of irreversible cell injury?
Which of the following is an example of irreversible cell injury?
Which factor is NOT mentioned as one of the most important targets of injurious stimuli?
Which factor is NOT mentioned as one of the most important targets of injurious stimuli?
What happens during necrosis?
What happens during necrosis?
Which cause of cell injury is a result of a single gene defect?
Which cause of cell injury is a result of a single gene defect?
Which of the following correctly describes reversible cell injury?
Which of the following correctly describes reversible cell injury?
What is one purpose of apoptosis in physiologic situations?
What is one purpose of apoptosis in physiologic situations?
Which mechanism is primarily responsible for executing apoptosis?
Which mechanism is primarily responsible for executing apoptosis?
In which situation does apoptosis occur to maintain tissue function?
In which situation does apoptosis occur to maintain tissue function?
What triggers apoptosis in pathologic conditions related to DNA damage?
What triggers apoptosis in pathologic conditions related to DNA damage?
What role does apoptosis play in the elimination of self-reactive lymphocytes?
What role does apoptosis play in the elimination of self-reactive lymphocytes?
Which of the following is a common pathologic condition that can stimulate apoptosis?
Which of the following is a common pathologic condition that can stimulate apoptosis?
What is a consequence of apoptosis during embryogenesis?
What is a consequence of apoptosis during embryogenesis?
How does apoptosis respond to accumulated misfolded proteins?
How does apoptosis respond to accumulated misfolded proteins?
What is the primary characteristic that differentiates necrosis from apoptosis in terms of cell size?
What is the primary characteristic that differentiates necrosis from apoptosis in terms of cell size?
Which of the following forms of necrosis maintains the underlying tissue architecture for several days?
Which of the following forms of necrosis maintains the underlying tissue architecture for several days?
What happens to the plasma membrane during necrosis compared to apoptosis?
What happens to the plasma membrane during necrosis compared to apoptosis?
Which type of necrosis is primarily associated with bacterial or fungal infections?
Which type of necrosis is primarily associated with bacterial or fungal infections?
What is a common physiological role of apoptosis?
What is a common physiological role of apoptosis?
Which type of necrosis is characterized by a firm texture in the affected tissues?
Which type of necrosis is characterized by a firm texture in the affected tissues?
In necrosis, what typically happens to the cellular contents?
In necrosis, what typically happens to the cellular contents?
Which form of necrosis is typically the end result of irreversible cell injury?
Which form of necrosis is typically the end result of irreversible cell injury?
What is the appearance of caseous necrosis on microscopic examination?
What is the appearance of caseous necrosis on microscopic examination?
Which type of necrosis is typically associated with acute pancreatitis?
Which type of necrosis is typically associated with acute pancreatitis?
What triggers the formation of fibrinoid necrosis?
What triggers the formation of fibrinoid necrosis?
What distinguishes gangrenous necrosis from other types of necrosis?
What distinguishes gangrenous necrosis from other types of necrosis?
What is the consequence of fat saponification in fat necrosis?
What is the consequence of fat saponification in fat necrosis?
Which statement describes autophagy?
Which statement describes autophagy?
Which of the following is a common feature of caseous necrosis?
Which of the following is a common feature of caseous necrosis?
What is NOT typical of fibrinoid necrosis?
What is NOT typical of fibrinoid necrosis?
Study Notes
Overview of Cell Injury and Cell Death
- Cell injury can be classified into reversible and irreversible types.
- Stages involved in the progression of cell injury and death are crucial for understanding cellular responses to damage.
Causes of Cell Injury
- Causes range from physical trauma to genetic defects leading to metabolic diseases.
- Major categories of injurious stimuli include:
- Oxygen deprivation
- Physical agents (e.g., trauma, temperature extremes)
- Chemical agents and drugs (toxic substances)
- Infectious agents (bacteria, viruses)
- Immunologic reactions (autoimmune diseases)
- Genetic derangements (mutations)
- Nutritional imbalances (deficiencies or excesses)
- Aging processes
Mechanisms of Cell Injury
- Key mechanisms contributing to cell injury:
- ATP depletion affecting energy production
- Mitochondrial damage impacting cell respiration
- Calcium influx disrupting cellular function
- Increased reactive oxygen species leading to oxidative stress
- Membrane permeability changes compromising cell integrity
- Accumulation of damaged DNA and misfolded proteins
- Important targets of injury include aerobic respiration, cell membrane integrity, protein synthesis, cytoskeleton, and genetic material.
Types of Cell Death
- Two primary forms of cell death:
- Apoptosis: programmed cell death involving self-degradation of nuclear DNA and proteins.
- Necrosis: unregulated cell death due to irreversible injury, typically involving tissue decay and inflammation.
Apoptosis
- Physiologic roles include:
- Programmed cell death during embryogenesis.
- Cell elimination following hormonal changes (e.g., menstrual cycle).
- Maintenance of cell population by removing excess cells in proliferating tissues.
- Removal of self-reactive lymphocytes to prevent autoimmune responses.
- Pathologic conditions leading to apoptosis include:
- DNA damage from radiation or toxins.
- Accumulation of misfolded proteins due to genetic mutations or free radical damage.
Mechanisms of Apoptosis
- Activation of caspases (proteolytic enzymes) drives the process.
- Two pathways:
- Mitochondrial (intrinsic) pathway influenced by mitochondrial permeability.
- Death receptor (extrinsic) pathway triggered by surface molecules on cells.
Morphological Features of Apoptosis
- Cell shrinkage, chromatin condensation, bleb formation, and phagocytosis of apoptotic bodies characterize apoptosis.
Necrosis
- A term describing the morphologic changes after cell death in living tissue due to irreversible injury.
- Features include:
- Pyknosis: nuclear shrinkage and increased basophilia.
- Karyorrhexis: fragmentation of nuclear material.
- Karyolysis: fading basophilia of chromatin.
Differences Between Apoptosis and Necrosis
- Cell Size: Necrosis causes enlarged, swollen cells; apoptosis leads to reduced, shrunken cells.
- Nucleus: In necrosis, nuclear degradation progresses through pyknotic to karyolytic stages; apoptosis results in fragmentation into small pieces.
- Plasma Membrane: Lost integrity in necrosis; remains intact in apoptosis but altered.
- Inflammation: Often present in necrosis, absent or minimal in apoptosis.
- Physiologic Role: Necrosis is pathologic; apoptosis can be physiologic or pathologic.
Patterns of Necrosis
- Different forms include:
- Coagulative: tissue architecture preserved; firm texture after death.
- Liquefactive: occurs in bacterial infections; tissues become liquid due to enzyme action.
- Caseous: usually seen in tuberculosis; necrotic tissue appears cheeselike.
- Fat necrosis: fat tissue destruction due to lipase action, often linked to pancreatitis.
- Fibrinoid: occurs during immune reactions; bright pink appearance due to immune complex deposition.
- Gangrenous: reflects tissue death due to loss of blood supply, may lead to coagulative or liquefactive necrosis.
Additional Concept: Autophagy
- A lysosomal process where cells digest their own components, serving as a survival mechanism under stress conditions.
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Description
Test your understanding of cell injury and cell death concepts in General Pathology for the 1st semester of the 2024-2025 academic year. This quiz covers reversible and irreversible cell injuries, along with stages in the evolution of cell injury. Perfect for students in Medical Laboratory Technology.
