Cellular Injury Lec. one

1. Cellular Injury Lec. one Lecturer Dr. Zainab Sajid Al-Shimmari

2. 1-Cellular injury can occur in a number of different ways. The extent of injury that cells experience is often related to the intensity and duration of exposure to the injurious event or substance. • 2- Cellular injury may be a reversible process, in which case the cells can recover their normal function, or it may be irreversible and lead to cell death. The causes of cellular injury are many , • Physical injury,Mechanicaltrauma,Temperature extremes (burn injury), Electrical current, Chemical injury,Chemicals, toxins, heavy metals, solvents, smoke, pollutants, drugs, gases,Radiation injury • Ionizing radiation — gamma rays, X rays,Non-ionizing radiation — microwaves, infrared, laser, Biologic agents Bacteria, viruses, parasites. • .

4. Cells of liver are swollen and have homogenous granules. with Cytoplasm take a deep stain. Cloudy swelling.

5. Lumen of renal tubules or glandular acini has star shapeappearance. Cloudy swelling.

6. Structural &Functional alteration • 1-Cell injury decreased oxidation phosphorylation. • 2-Changes in the cell membrane increased • permeability of membrane to enter H2O and ions • (Na,K,Ca) changes in intra osmotic pressure • more H2O gets in side the cells cellular edema. • 3- Permeability of the cell membrane Leakage of • protein and synthesis

7. Hydropic degeneration • Synonyms: Vascular degeneration = hydrops. • Definition: Its accumulation of H2O in the cell cytoplasm especially in the epithelial cells. • Examples:1-Epidermis in viral infection pox • 2-Epithelium of a minion at birth. • 3-Epithelium of neoplasm.

10. Clear spaces usually around the nucleus.Its boundaries are hazy and undefined(Fat,glycogen).Skin with Hydropic degeneration

11. Fatty degeneration • Definition: Its accumulation ofintracellular • lipids(liver, kidney, heart).

14. Heart: • 1-Fine droplets in the muscle cell. • 2-effected cells grouped to gathers as patches.

15. Heart withOsmic acid stain,the fat droplets are black.Fine droplets in the muscle cell and effected cells grouped to gathers as patches.

16. Causes of fatty change: • 1-Excessive release of fatty acid from adipose tissue (starvation) • 2-Decreased oxidation of fatty acid ex. bacterial toxins • (diphtheria toxin). • There is no co-factors needed for the oxidation (ex. carnitine) • 3-Lipotrope deficiency: ex. deficiency of methionine and • choline lead to decreased phospholipids synthesis . • 4-Fatty acids are esterified to triglyceride. • ex.acute ethanol poisoning. • 5-Failuar of protein synthesis lead to decreased lipoprotein • synthesis . • ex.ethionine ,carbon tetrachloride phosphorus. • Obesity : to much fat.

17. Calcification:it is the deposition of calcium salts in tissues other than those with preformed matrix ( bone & teeth). It is usually deposited in excess & has a multiple-focal distribution. Also called Mineralization. Ossification:is the deposition of Ca salts in a preformed matrix & it is done by osteoblast, & the deposition is not distributed through the matrix in a regular manner.

18. Types of Calcification: 1- Dystrophic Calcification: deposition of calcium salts in dead or degenerated tissues. It is not related to Ca level in the blood. 2-Metastatic.Calcification: Precipitation of Ca salts as a result of high concentration of calcium in blood.

25. Significance: 1-Ca deposits are permanent & harmless. 2-May interfere with the function of the organ. 3-Ca deposition is one way of disposal of deed tissue, since it is inert. 4-May cause ossification.

26. Significance: 1-the articular form is recurrent. 2- recovery is possible with change in the diet. GOUT It is the deposition of crystals of uric acid & urates in tissues. Mostly seen in articular & periarticular tissues.

28. Pigmentation Exogenous Pigmentation ANTHRACOSIS It is the deposition of carbon, usually in the form of coal dust in tissues as a result of inhalation of carbon particles. It colors the lungs or regional lymph nodes. Carbon may be introduced through cutaneous abrasions & when this occurs, local tattooing in the form of a bluish-black pigment is observed under the skin.

29. Anthracotic pigment is not fibrogenic, but in massive amounts (as in "black lung disease" in coal miners) a fibrogenic response can be elicited to produce the "coal worker's pneumoconiosis" seen here. ANTHRACOSIS.

31. ANTHRACOSIS: It is the deposition of carbon, usually in the form of coal dust in tissues as a result of inhalation of carbon particles. It colors the lungs with black.

32. Significance: 1-In small amounts; it is harmless. 2-In large amounts; may cause Pulmonary fibrosis & may predispose the lung to infections. Melanosis: deposition of melanin in various tissue, especially (Lung & Aorta). Pigment is seen in macrophage and causes no change to form, consistency or structure of the tissue. Albinism: complete absence of melanin. Causes: unability of melanocytes to synthesize of tyrosinas.

33. Albinism & vitiligo

34. Hemosiderin = Hemosiderosis: Is a shiny golden – yellow or golden– brown pigment its origins is HB. Absorbed iron in the form of ferrous  convert ferric form and combined with transferring (plasma protein) and this store in the form of ferritin (protein apoferritin –iron complex) in the liver and bone marrow and the ferritin in small amount not see but when called hemosiderin in soluble ferritin in the large amount.

35. Pulmonary congestion with dilated capillaries and leakage of blood into alveolar spaces leads to an increase in hemosiderin-laden macrophages, as seen here. Brown granules of hemosiderin from break down of RBC's appear in the macrophage cytoplasm. These macrophages are sometimes called "heart failure cells" because of their association with pulmonary congestion with congestive heart failure.

36. Prussian blue iron stain demonstrates the blue granules of hemosiderin in hepatocytes and Kupffer cells. Hemochromatosis can be primary (the cause is probably an autosomal recessive genetic disease) or secondary (excess iron intake or absorption, liver disease, or numerous transfusions). Hemochromatosis leads to bronze pigmentation of skin, diabetes mellitus (from pancreatic involvement), and cardiac arrhythmias (from myocardial involvement).

37. The yellowish-green accumulations of pigment seen here are bile. Most often this is due to extrahepatic biliary tract obstruction. However, bile may also accumulate in liver (called cholestasis) when there is hepatocyte injury.

38. Atrophy Ashrinkage of a tissue or organ to less than its normal and former size. Types: 1-Numerical A: there is decrease in the number of constituent cell, due to necrosis. 2-Quantitative A. there is decrease in size of each component cells. Occurence: in a single cell or whole organ.

39. There is a relatively normal kidney at the left with only a few scattered, shallow cortical scars and one fairly large pale tan-yellow scar in the upper pole. The right kidney is atrophic because of renal arterial occlusion. Such a situation can lead to hypertension (Goldblatt kidney).

40. Hypertrophy It is an increase in the size of a tissue or organ with out an increase in the number of cells. Gross and Microscopic app: large cells or organ. Causes: increase need for function.

41. Heart with hypertrophy:It is an increase in the size of a tissue or organ with out an increase in the number of cells. large cells or organ. The left ventricle is markedly thickened in this patient with severe hypertension that was untreated for many years. The myocardial fibers have undergone hypertrophy.

42. Hyperplasia It is an increase in the size of a tissue or organ as the result of an abnormal increase in the number of cells with out regard to maintenance of normal histological picture and usually it causes impaired function at the organ, and this one of the most important characteristic of tumors.

44. normal prostate gland is about 3 to 4 cm in diameter. This prostate is enlarged due to prostatic hyperplasia, which appears nodular. Thus, this condition is termed either BPH (benign prostatic hyperplasia) or nodular prostatic hyperplasia.

45. The enlarged prostate has glandular hyperplasia. The glands are well-differentiated and still have some intervening stroma. The small laminated pink concretions within the glandular lumens are known as corpora amylacea.

46. Significance: 1- response to the irritant. 2- No clear cut between it and neoplasia. Metaplasia It is the transformation of one type of tissue in to another of the same original primary tissue, it seen in epithelial tissue. In metaplasia the cell it self does not undergo transformation, but rather the new cells in the area appear as a replacement of a different cell type.

48. Dysplasia Abnormality of development, it is most commonly used in reference to developmental defects in the skin, brain and skeleton system. The dysplasia applies to cells which are malformed during maturation. Ex. spermatozoa are dysplastic when the head and tail pieces are structurally abnormal.

49. Epithelial dysplasia is characterised by cellular proliferation and cytologic changes. These changes include: 1. Increased number of layers of epithelial cells 2. Disorderly arrangement of cells from basal layer to the surface layer 3. Loss of basal polarity i.e. nuclei lying away from basement membrane 4. Cellular and nuclear pleomorphism 5. Increased nucleocytoplasmic ratio

50. This is cervical squamous dysplasia at high magnification extending from the center to the right. The epithelium is normal at the left. Note how the dysplastic cell nuclei are larger and darker, and the dysplastic cells have a disorderly arrangement.