What is Necrosis ( Complete Overview ) скачать в хорошем качестве

What is Necrosis ( Complete Overview )

Hello Viewers !!! My Name Is Kavindu Lakmal , Medical Laboratory Science Student From University Of Peradeniya. I designed this video from my Text books notes & internet resources. I hope this video will helpful for your studies ... Don't Forget to subscribe me ... You can update with more new videos .... Please Comment your ideas about Video .... ***************************** HELP ME !!! ********************** I Love to make this like videos Continuously …. But everything need some money , So your little donation I really appreciate . Your just 1$ donation help to design many more videos … Become a Patron - https://www.patreon.com/user?u=4259366 ******************************************************************** Not Only That , Need To Design this Like Video For You Or Any Video Editing Help ??? Contact me ... [email protected] Skype Name - kavindu.lakmal11 Thank You ****************************************************************** Video Script :- Necrosis Necrosis is Greek word it is mean “the stage of dying” . Necrosis is the type of cell death that is associated with loss of membrane integrity , and leakage of cellular contents culminating in dissolution of cells, largely resulting from the degradative action of enzymes on lethally injured cells. necrosis is almost always detrimental and can be fatal.[2] Morphology Cytoplasmic Changes in Necrotic cells are , • Necrotic cells show increased eosinophilia • cell may have a more glassy appearance • homogeneous appearance • Myelin figures are more prominent Nuclear Changes in Necrotic cells , Nuclear changes has main three patterns, all due to breakdown of DNA and chromatin. So 3 main patterns are – • Pyknosis , Karyorrhexis & Karyolysis • pyknosis, characterized by nuclear shrinkage and increased basophilia; the DNA condenses into a solid shrunken mass. • In karyorrhexis pattern , the pyknotic nucleus undergoes fragmentation. • basophilia of the chromatin may fade in karyolysis stage. There are several morphologically distinct patterns of tissue necrosis, which may provide clues about the underlying cause. Patterns of Tissue Necrosis Coagulative necrosis - is a form of necrosis in which the underlying tissue architecture is preserved for at least several days . The affected tissues take on a firm texture. Presumably the injury denatures not only structural proteins but also enzymes, thereby blocking the proteolysis of the dead cells; as a result, eosinophilic, anucleate cells may persist for days or weeks. Coagulative necrosis is characteristic of infarcts in all of the solid organs except the brain. Liquefactive necrosis - the dead cells are completely digested, transforming the tissue into a liquid viscous mass. Eventually, the digested tissue is removed by phagocytes. Liquefactive necrosis is seen in focal bacterial or, occasionally, fungal infections, because microbes stimulate the accumulation of inflammatory cells and the enzymes of leukocytes. gangrenous necrosis - is not a distinctive pattern of cell death, It usually refers to the condition of a limb, generally the lower leg, that has lost its blood supply and has undergone coagulative necrosis involving multiple tissue layers. When bacterial infection is superimposed, coagulative necrosis is modified by the liquefactive action of the bacteria and the attracted leukocytes. Caseous necrosis - is encountered most often in foci of tuberculous infection. Caseous means “cheese-like,” referring to the friable yellow-white appearance of the area of necrosis. Unlike with coagulative necrosis, the tissue architecture is completely obliterated and cellular outlines cannot be discerned. The area of caseous necrosis is often enclosed within a distinctive inflammatory border. Fat necrosis - refers to focal areas of fat destruction, typically resulting from release of activated pancreatic lipases into the substance of the pancreas and the peritoneal cavity. This occurs in the acute pancreatitis . In this disorder, pancreatic enzymes that have leaked out of acinar cells and ducts liquefy the membranes of fat cells in the peritoneum, and lipases split the triglyceride esters contained within fat cells. The released fatty acids combine with calcium to produce grossly visible chalky white areas, which enable the surgeon and the pathologist to identify the lesions. On histologic examination, the foci of necrosis contain shadowy outlines of necrotic fat cells with basophilic calcium deposits, surrounded by an inflammatory reaction. Fibrinoid necrosis - is a special form of necrosis, visible by light microscopy, usually in immune reactions in which complexes of antigens and antibodies are deposited in the walls of arteries. The deposited immune complexes, together with fibrin that has leaked out of vessels, produce a bright pink and amorphous appearance on H&E preparations called fibrinoid by pathologists.