6.10 Intro to Pathology Necrosis, Apoptosis Flashcards
What is Necrosis?
The death of cells or groups of cells within a living organism.
What is the difference between Necrosis and Autolysis?
Necrosis is seen in the living (with inflammation) and autolysis is seen in tissues after death.
Define coagulative necrosis
- The most common form of necrosis.
- Occurs when cell proteins are altered or denatured, similar to coagulation that occurs when cooking eggs. histologically, the cell outline are preserved ad the cytoplasm appears finely granular.
What type of organ does coagulative necrosis normally occur in?
Solid internal organs.
What is the best example of coagulative necrosis?
Heart tissue undergoing myocardial infarction.
What is the hallmark cell of inflammation?
The neutrophils are always involved in necrosis, no neutrophil it is autolysis.
What is liquefactive necrosis?
Referes to a process by which dead cells liquefy under the influence of certain cell enzymes. The tissue becomes soft and gel-like.
What is the best and second best example of liquefactive necrosis?
1) brain infarcts
2) Abscesses in the lung/
What is caseous necrosis?
A form of coagulative necrosis which a thick, yellowish, cheesy substance forms.
What is the best example of caseous necrosis?
TB forms lung granulomas, which inside can be found caseous necrosis, this is called a Ghon Complex.
What is the second best example of caseous necrosis?
Valley fever fungus.
What is Fat necrosis?
A specialized form of liquefaction necrosis caused by the action of lipolytic enzymes.
What is the best example of Fat necrosis?
Is limited to fat tissue, usually around the pancreas, where enzymes are released into the adjacent fat tissue, usually after rupture of the pancreas, causing degradation of fat into glycerol and free fatty acids. The free fatty acids rapidly bind with calcium form in saps, and causing whit calcified specks.
What is the difference between Coagulative and liquefactive Necrosis?
Liquefactive turns to liquid, where as coagulative turns more solid jelly like.
What is the difference between Liquefactive and fat necrosis?
Fat necrosis is a type of liquefaction necrosis, but can only occur in fat tissue.
What is the difference between Wet and Dry Gangrene?
Necrotic tissue can provide a good medium for infection by bacteria. The bacterial infection of coagulated tissue leads to inflammation and secondary liquefaction clinically known as wet gangrene. If the necrotic tissue dries out, it becomes black and mummified or dry gangrene. Such infections frequently occur after an infarction of the intestine or in a limb and are usually caused by atherosclerosis or diabetes.
What is a Dystrophic Calcification?
Necrotic tissue attracts calcium salts and frequently undergoes calcification. Refers ti the macroscopic deposition of calcium in injured or dead tissues. Represents an extracellular deposition of calcium from the circulation into dead or ting necrotic tissue often visible to the naked eye, and range from gritty, sand-like grains to firm, rock hard material.
What is metastatic calcification?
Reflects deranged calcium metabolism (not cell injury), usually associated with increased serum calcium levels, leading to deposition of calcium in other locations.
Examples of Dystrophic Calcifications
1) Calcifications in Atherosclerotic Cornary arteries
2) Calcifications of the Mitral or Aortic valves
3) Calcifications seen around breast cancer
4) Infant periventricular calcifications seen in congenital Toxoplasmosis
Example of Metastatic calcifications
Seen in various disorder including Hyperparathryroidism, Vitamin D toxicity, and Chronic Renal Failure, can also be seen in formations of Calcium Carbonate stones in sties such as the gallbladder, kidney, and bladder are due to precipitation of the salts from solution into tissues.
Define Apoptosis
Is a form of programed cell death (no inflammation) that is an energy dependent process designed to switch cells off and eliminate them. It is usually a physiological process occurring normally during development, but can be caused by radiation, chemotherapeutic drugs, or tumors causing the death of normal cells.
Where is the most common place for apoptosis to occur?
The brain
How are apoptotic cells identified?
- Apoptotic cells are recognized by nuclear fragmentation and pyknosis of individual cells or small groups of cells.
- Inflammation and necrosis are generally not present.
- Appear shrunken with round or oval masses of bright pink or orang in the cytoplasm (apoptotic bodies), cytoplasmic blebs, and nuclear fragments.
