Pathology sheet (3) LECTURER : CORRECTED BY :yara saleh Heba abu khalaf Abdallah riyalat

Transcription

1 Pathology sheet (3) LECTURER : CORRECTED BY :yara saleh Heba abu khalaf Abdallah riyalat

2 Slide 23 ** " االنحالل النووي " karyolysis The First pattern is the basophilia of chromatin ** مبدئ ا تالشى اللون القاعدي )الصباغ القاعدي )... **The second pattern is pyknosis,,we can see it in both cases necrosis and apoptosis **نالحظ انكماش النواة وبالتال تنكمش محتو اتها وتصبخ الصباغ اوضح ( ز ادة كم ة ) chromatin و صبح chromatin متجمع على بعضه ( إحدى المواصفات الهامة ) Slide 24 "تمزق و تشظ النواة" ** The third pattern is karyorrhexis - pyknotic nucleus which shrank in the second pattern will disappear during a day or - So if we don't see the two.. nucleus under the microscope this means cell death over a day or two.. Slide 25 (4:00) ** Are all kinds of necrosis identical? No ** Cell death leads to tissue death.

3 ** When large numbers of cells die the tissue or organ is said to be necrotic. ** Necrosis of tissues has several morphologically distinct patterns, which are important to recognize because they may provide clues about the underlying cause. ** There are types of morphology necrosis should know because they take us to etiology.. ** من الممكن ان نرى ف بعض الحاالت المرض ة تموت خلوي لبعض الخال ا و كون له داللة تشخ ص ة ما و لكن ال كون على المستوى النس ج أي ال عتبر necrosis )عدد قل ل( ولكن عندما صبح عدد كب ر تكون حالة مرض ة أخرى و تحول إلى necrosis على المستوى النس ج. Slide 26 (5:45) ** Coagulative necrosis is a form of necrosis in which the architecture of dead tissues is preserved for a span of at least some days, caused by ischemia (occlusion of blood vessels).. **عمل ا س ظهر فقط خ ال للنس ج. Cell death Degradation Phagocytosis ض اع المادة )جزء من المكون(

4 **For example the heart,if we lose part of the heart tissue it will lose his job which leads to death texture) (The effected tissues exhibit a firm "تحافظ على الصفة البن و ة للعنصر " The mechanism of necrosis : ** denaturation of proteins and lysis of cell but in this type of necrosis causes denaturation وقف عمله of proteins and lysis of enzyme Slide 27 احتشاء بالكل ة ** اعلى ال سار نرى النس ج الطب ع للكل ة ( tubules )glomerulus, ** ف الجهة االخرى نرى خ ال ( cell )necrotic مع عدم وجود أنو ة فقط عبارة عن amorphous eosinophilic material. ** النقاط الكحل ة ه inflammation ** Any necrosis elsewhere in the body will attracts inflammatory cell and will induce inflammatory response.. Slide 28

5 ** We can see coagulative necrosis in all tissues except the brain,, mostly we can see liquefaction necrosis in brain. ** coagulative necrosis is called infarct تعن احتشاء طب ا,, جلطة بالعام ة Clot or fibri clot Occlusion of atrial supply Ischemia Coagulation necrosis (infarct) Slide 29 ( 12:25) شبه سائل, مائع, لزج * Liquefactive necrosis ** جب ان كون هذا المكان الذي حدث فه هذا التنخر غن باإلنز مات الت تقوم بال hydrolysis اكثر من غ ره أو العضو الذي لد ه إماهة أكثر من باق األعضاء. ** It Is characterized by digestion of the dead cells, resulting in transformation of the tissue into a liquid viscous mass. ** It is seen in focal bacterial or, occasionally, fungal infections, because microbes stimulate the accumulation of leukocytes and the liberation of enzymes from these cells.

6 **Any microbes and viruses or any foreign body enters our bodies it carries its own antigen which works to attack the immune system so there is abundant number of leukocytes that work on libration of enzymes from these cells. Slide 30 Liquefactive necrosis. An infarct in the brain, showing dissolution of the tissue. The necrotic material is frequently creamy yellow because of the presence of dead leukocytes and is called pus. For unknown reasons, hypoxic death of cells within the central nervous system often manifests as liquefactive necrosis... ق ح او صد د مخلفات الدفاع المناع واألشالء الخلو ة Pus Slide 31 (15:30) Gangrenous necrosis الغرغر نة its not a specific pattern of cell death but it is a clinical ** terminology, used to describe the large area of necrosis especially if we are talking about limbs,, this does not mean we can't see the gangrene in other organs e.g in the intestine

7 ** Causes of gangrene: -blood vessels occlusion - Ischemia - Abstraction -large area of necrosis ** ه باالصل coagulative necrosis لكن بما انها على مساحة واسعة سم ت gangrenous necrosis When bacterial infection is superimposed there is more liquefactive necrosis because of the actions of degradative enzymes in the bacteria and the attracted leukocytes (giving rise to so-called wet gangrene). Wet gangrene often produces fluid or pus ** Slide 32 Caseous necrosis: is encountered most often in foci of tuberculous (TB) infection. The term caseous (cheese like) is derived from the friable white appearance of the area of necrosis. النخر المتجبن )من الجبنة الفاسدة( On microscopic examination, the necrotic area appears as a collection of fragmented or lysed cells and amorphous granular debris enclosed within a distinctive inflammatory border; this appearance is characteristic of a focus of inflammation known as a granuloma. Notice that the gangrenous small intestine is longer than normal small intestine -

8 Twisting in about 180 of loops of small intestine ( blood vessels and nerves ) leads to ischemia then gangrene. - Slide 33 (20:50 ) "tuberculosis" The term TB means مرض السل This type of necrosis contain two types: - cellular debris and lysed cell ** White areas are the areas of tuberculosis Slide 34 (25:10) - Fat necrosis النخرة الشحمية It 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 very serious severe abdominal emergency known as acute pancreatitis. **In this disorder pancreatic enzymes leak out of acinar cells and liquefy the membranes of fat cells in the peritoneum. **The released lipases split the triglyceride esters contained within fat cells. **The fatty acids, so derived, combine with calcium to produce grossly visible chalky-white areas (fat saponification). **On histologic examination the necrosis takes the form of foci of shadowy outlines of necrotic fat cells, with basophilic calcium deposits, surrounded by an inflammatory reaction.

9 Slide 36 Fibrinoid necrosis **Is a special form of necrosis usually seen in immune reactions involving blood vessels. ** This pattern of necrosis typically occurs when complexes of antigens and antibodies are deposited in the walls of arteries. **Deposits of these immune complexes, together with fibrin that has leaked out of vessels, result in a bright pink and amorphous appearance in H&E stains, called fibrinoid (fibrin-like) by pathologists. Slide 37 (27:30) Fibrinoid necrosis e.g in glomerulus ( kidney) it causes acute glomerulonephritis which can progress to rapidly progressing glomerulonephritis or even chronic glomerulonephritis (auto immune disease )..

10 Dystrophic calcification التكلس الضموري Ultimately, in the living patient most necrotic cells and their contents disappear by phagocytosis of the debris and enzymatic digestion by leukocytes. If necrotic cells and cellular debris are not promptly destroyed and reabsorbed, they tend to attract calcium salts and other minerals and to become calcified.

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