Podcast
Questions and Answers
What is the primary distinction between necrosis and apoptosis?
What is the primary distinction between necrosis and apoptosis?
- Necrosis is always physiological, while apoptosis is always pathological.
- Necrosis requires gene activation, while apoptosis does not.
- Necrosis affects individual cells, whereas apoptosis affects groups of cells.
- Necrosis involves cellular swelling and rupture, while apoptosis involves controlled shrinkage and fragmentation. (correct)
Which of the following best describes the defining characteristic of necrosis?
Which of the following best describes the defining characteristic of necrosis?
- Programmed cell death affecting single cells
- Cell death mediated by specific gene activation
- Death of a group of cells within a living body (correct)
- Cellular self-destruction for the benefit of the organism
What is the primary initiator of cell swelling during the pathogenesis of necrosis?
What is the primary initiator of cell swelling during the pathogenesis of necrosis?
- Dysfunction of the sodium-potassium (Na K) pump (correct)
- Activation of caspases
- Decreased intracellular calcium
- Increased ATP production
How do reactive oxygen species (ROS) contribute to the pathogenesis of necrosis?
How do reactive oxygen species (ROS) contribute to the pathogenesis of necrosis?
Why do necrotic cells often lead to an inflammatory reaction in the surrounding tissue?
Why do necrotic cells often lead to an inflammatory reaction in the surrounding tissue?
Which of the following nuclear changes is associated with necrosis?
Which of the following nuclear changes is associated with necrosis?
What cellular change is observed in the cytoplasm of necrotic cells?
What cellular change is observed in the cytoplasm of necrotic cells?
What is the key characteristic of coagulative necrosis?
What is the key characteristic of coagulative necrosis?
In which type of necrosis is the affected tissue transformed into a liquid viscous mass?
In which type of necrosis is the affected tissue transformed into a liquid viscous mass?
What is the typical gross appearance of caseation necrosis?
What is the typical gross appearance of caseation necrosis?
What is the underlying mechanism in fat necrosis?
What is the underlying mechanism in fat necrosis?
Which type of necrosis is characterized by the deposition of glassy, eosinophilic, fibrin-like material in vessel walls?
Which type of necrosis is characterized by the deposition of glassy, eosinophilic, fibrin-like material in vessel walls?
What determines the fate of necrotic tissue?
What determines the fate of necrotic tissue?
Which of the following distinguishes apoptosis from necrosis?
Which of the following distinguishes apoptosis from necrosis?
What is a key feature of apoptotic bodies?
What is a key feature of apoptotic bodies?
Which of the following is a physiological cause of apoptosis?
Which of the following is a physiological cause of apoptosis?
What is the role of pro-apoptotic genes like PAX in the pathogenesis of apoptosis?
What is the role of pro-apoptotic genes like PAX in the pathogenesis of apoptosis?
How does apoptosis impact the surrounding tissue?
How does apoptosis impact the surrounding tissue?
Which of the following is an example of coagulative necrosis?
Which of the following is an example of coagulative necrosis?
Which of the following is considered pathologic apoptosis?
Which of the following is considered pathologic apoptosis?
What is the underlying cause of the tissue damage observed in fibrinoid necrosis?
What is the underlying cause of the tissue damage observed in fibrinoid necrosis?
Which of the following microscopic features is characteristic of apoptosis?
Which of the following microscopic features is characteristic of apoptosis?
What happens to blood vessels and stroma in coagulative necrosis?
What happens to blood vessels and stroma in coagulative necrosis?
What occurs as a result of increased calcium ions during necrosis?
What occurs as a result of increased calcium ions during necrosis?
Which of the following cellular processes is LEAST likely to be associated with apoptosis?
Which of the following cellular processes is LEAST likely to be associated with apoptosis?
Which process primarily defines liquefactive necrosis?
Which process primarily defines liquefactive necrosis?
What is the MOST likely outcome for a large area of necrotic tissue?
What is the MOST likely outcome for a large area of necrotic tissue?
Which of the following is the most accurate description of the role of mitochondria in the context of necrosis?
Which of the following is the most accurate description of the role of mitochondria in the context of necrosis?
Which of the following is an accurate comparison of the genetic activity in necrosis versus apoptosis?
Which of the following is an accurate comparison of the genetic activity in necrosis versus apoptosis?
In the context of cellular injury, what point signifies the transition from reversible to irreversible damage culminating in cell death?
In the context of cellular injury, what point signifies the transition from reversible to irreversible damage culminating in cell death?
Which feature is exclusively associated with apoptosis, distinguishing it from other forms of cell death and cellular processes?
Which feature is exclusively associated with apoptosis, distinguishing it from other forms of cell death and cellular processes?
Which of the following is a critical early event in the pathogenesis of necrosis?
Which of the following is a critical early event in the pathogenesis of necrosis?
If a pathologist observes a tissue sample under a microscope and notes that cells have undergone pyknosis, karyorrhexis and karyolysis, which of the following types of cell death is the MOST likely diagnosis?
If a pathologist observes a tissue sample under a microscope and notes that cells have undergone pyknosis, karyorrhexis and karyolysis, which of the following types of cell death is the MOST likely diagnosis?
Which of the following enzymes are LEAST likely to be activated by increased intracellular calcium levels during necrosis?
Which of the following enzymes are LEAST likely to be activated by increased intracellular calcium levels during necrosis?
Given that fibrinoid necrosis is often observed in cases of vasculitis, what specific histological changes would be MOST indicative of this type of necrosis?
Given that fibrinoid necrosis is often observed in cases of vasculitis, what specific histological changes would be MOST indicative of this type of necrosis?
A researcher is studying cellular response to injury and observes a cell undergoing enzymatic digestion, resulting in a soft and turbid fluid-filled area. Which type of necrosis is MOST likely occurring?
A researcher is studying cellular response to injury and observes a cell undergoing enzymatic digestion, resulting in a soft and turbid fluid-filled area. Which type of necrosis is MOST likely occurring?
A pathologist examines a liver biopsy from a patient with chronic alcohol abuse. Microscopic examination reveals cellular swelling, protein denaturation, and eventual cell death with inflammation. Which of the following best describes the type of cell death observed?
A pathologist examines a liver biopsy from a patient with chronic alcohol abuse. Microscopic examination reveals cellular swelling, protein denaturation, and eventual cell death with inflammation. Which of the following best describes the type of cell death observed?
What is the molecular mechanism by which caspases execute apoptosis?
What is the molecular mechanism by which caspases execute apoptosis?
A researcher induces cell death in vitro and observes that the cells shrink and form membrane-bound vesicles that are subsequently phagocytosed, without causing an inflammatory response. Which signaling pathway is most likely activated in this process?
A researcher induces cell death in vitro and observes that the cells shrink and form membrane-bound vesicles that are subsequently phagocytosed, without causing an inflammatory response. Which signaling pathway is most likely activated in this process?
Dystrophic calcification can occasionally be observed in some areas. Which of the following types of necrosis is least likely to exhibit dystrophic calcification.?
Dystrophic calcification can occasionally be observed in some areas. Which of the following types of necrosis is least likely to exhibit dystrophic calcification.?
Flashcards
Necrosis
Necrosis
Death of a group of cells within the living body due to severe injury or long-duration damage.
Necrosis Pathogenesis: Mitochondrial Damage
Necrosis Pathogenesis: Mitochondrial Damage
Mitochondria damage leading to decreased ATP and failure of the Na/K pump, resulting in cell swelling.
Necrosis and Inflammation
Necrosis and Inflammation
Necrotic cells release chemicals that irritate adjacent living tissue.
Pyknosis
Pyknosis
Signup and view all the flashcards
Karyorrhexis
Karyorrhexis
Signup and view all the flashcards
Karyolysis
Karyolysis
Signup and view all the flashcards
Coagulative Necrosis
Coagulative Necrosis
Signup and view all the flashcards
Liquefactive Necrosis
Liquefactive Necrosis
Signup and view all the flashcards
Caseation Necrosis
Caseation Necrosis
Signup and view all the flashcards
Traumatic Fat Necrosis
Traumatic Fat Necrosis
Signup and view all the flashcards
Enzymatic Fat Necrosis
Enzymatic Fat Necrosis
Signup and view all the flashcards
Fibrinoid Necrosis
Fibrinoid Necrosis
Signup and view all the flashcards
Apoptosis
Apoptosis
Signup and view all the flashcards
Physiologic Apoptosis
Physiologic Apoptosis
Signup and view all the flashcards
Pathologic Apoptosis
Pathologic Apoptosis
Signup and view all the flashcards
Apoptotic Body Morphology
Apoptotic Body Morphology
Signup and view all the flashcards
How does necrosis differ from apoptosis?
How does necrosis differ from apoptosis?
Signup and view all the flashcards
Study Notes
- Cell injury becomes irreversible with continuous damage, leading to cell death
- There are two types of cell death: necrosis and apoptosis
Necrosis
- Necrosis is the death of a group of cells within a living body
- It's caused by severe injury or long-duration injury, which damages the nucleus and results in cell death
Pathogenesis of Necrosis
- Mitochondrial damage decreases ATP, disrupting energy-dependent functions like the Na/K pump, leading to cell swelling
- Anaerobic glycolysis occurs with the increase of pH
- Increased calcium ions activate enzymes (phospholipases, proteases, endonucleases, ATPases), damaging protein, membranes, and DNA
- Reactive oxygen metabolites (ROS) increase, damaging membranes and various cell components
Cellular Changes (Post Necrotic)
- Cell membrane disappears
- Cytoplasm swells, coagulates, becomes homogenous (due to loss of glycogen), and deeply eosinophilic (loss of basophilia of RNA)
- Nuclear changes include:
- Pyknosis: Nucleus shrinks, becomes dense and basophilic
- Karyorrhexis: Nucleus becomes fragmented
- Karyolysis: Nuclear fragments fade and disappear due to chromatin hydrolysis
Types of Necrosis
- Coagulative
- Liquefactive
- Caseation
- Fat
- Fibrinoid
Tissue Changes
- Denaturation of proteins causes cells to retain outlines but lose cellular details, area becomes firm, swollen, and pale
- Enzymatic digestion of the cell by lysosomal enzymes causes a loss of architectural and structural details, area becomes soft and filled with fluid
Coagulative Necrosis
- Protein denaturation predominates, preserving cell outlines but losing details
- Necrotic area is dry, firm, opaque, and pale yellow
- General architecture is preserved, dead cells retain their outline, and blood vessels/stroma persist longer
- Examples include acute ischemia of the heart, kidney, and spleen
Liquefactive Necrosis
- Enzymatic digestion predominates, liquefying necrotic tissue
- The necrotic area is soft and filled with fluid
- Characterized by the complete loss of architectural and cellular details
- Pyogenic abscesses, due to proteolytic enzymes from neutrophils (pus cells), are an example of liquefactive necrosis
- Brain infarction, due to high lipid and fluid content in nervous tissue, is another example
Caseation Necrosis
- Necrosis appears as friable, soft, grayish-yellow material resembling cheese
- Granuloma forms with homogenous granular eosinophilic material
- Seen in tuberculosis (TB), syphilis, or fungal infections in any organ
Fat Necrosis
- Traumatic fat necrosis occurs due to trauma to adipose tissue, causing fat cell rupture, releasing fatty acids that combine with calcium
- Enzymatic fat necrosis occurs in acute pancreatitis when lipase escapes, digesting surrounding fat
Fibrinoid Necrosis
- Histological changes in arteries during vasculitis and hypertension
- Glassy, eosinophilic fibrin-like material is deposited within the damaged vessel wall
Fate of Necrosis
- In small areas, healing occurs by regeneration or by granulation tissue and fibrosis (repair)
- Large areas become surrounded by a fibrous capsule, unabsorbed contents may dry and dystrophic calcification may occur
Apoptosis
- Programmed cell death where cells activate enzymes to degrade their own DNA, nuclear, and cytoplasmic proteins
Causes of Apoptosis
- Physiologic apoptosis includes embryogenesis and hormone-dependent processes in the menstrual cycle
- Pathologic apoptosis includes DNA damage and pathologic atrophy
Pathogenesis of Apoptosis
- The apoptotic process is stimulated by physiological or pathological stimuli
- Controlled by apoptosis genes: pro-apoptotic genes, like the PAX gene, are stimulated, and anti-apoptotic genes, like bcl-2, are inhibited
- Proteases (caspase family) are then activated
- Morphological changes occur
Morphology (E/M)
- Cell shrinkage
- Condensation and fragmentation of chromatin
- Formation of cytoplasmic blebs and apoptotic bodies
- Phagocytosis of apoptotic bodies by macrophages
Morphology L/M
- Apoptosis involves single cells or small groups of cells
- Apoptotic bodies appear rounded or oval with dense eosinophilic cytoplasm and nuclear fragments
- There is a lack of inflammation in surrounding tissue as apoptotic bodies are rapidly phagocytosed
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
