Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Chapter 1 Cell Pathology Part 2

2 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Outline of Cell Pathology   Cell adaptations   Atrophy, hypertrophy, metaplasia, intracellular, accumulation, aging   Cell death   Necrosis, apoptosis

3 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Cell Adaptations   Occur as result of prolonged exposure to adverse or exaggerated normal stimuli   Main forms of adaptation:   Atrophy means cells wasting away from lack of use. Atrophy   Hypertrophy means swelling of cells. Hypertrophy  means increase in number of cells.  Hyperplasia means increase in number of cells. Hyperplasia   Metaplasia means replacing one cell type with another. Metaplasia  Under some circumstances cells may accumulate abnormal amounts of various substances like lipids or proteins.  Intracellular accumulation: Under some circumstances cells may accumulate abnormal amounts of various substances like lipids or proteins. Intracellular accumulation

4 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Cellular Adaptations

5 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Atrophy   Decrease in size of cell, tissue, organ, or entire body:   Physiologic & predictable: atrophy caused by aging   Pathologic: lack of nutrition, chronic ischemia, denervation, inactivity. This happens when you break an arm and it stays in a cast for 6 – 8 weeks. The muscle atrophies and weakens. Recurrent physical therapy is required to regain the lost muscle mass and tone.

6 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Atrophy of Brain G = gyri, S = sulci

7 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.ISCHEMIA  In medicine, ischemia, is a restriction in blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism (to keep tissue alive) medicinetissuesoxygenglucosecellular metabolismmedicinetissuesoxygenglucosecellular metabolism  Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue. blood vessels blood vessels

8 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Hypertrophy   Hypertrophy: enlarged cells   Hypertrophy of heart in hypertension   Hypertrophy of skeletal muscles in bodybuilders   Hypertrophy often combined with hyperplasia

9 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Hypertrophy of Left Ventricle

10 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Hyperplasia   Increased number of cells in tissue or organ   Endometrial hyperplasia caused by estrogen   Benign prostatic hyperplasia (BPH) in elderly men   Callus (corn) on hand (in some occupations) or on heels (high-heeled shoes, tight shoes)   Hyperplastic polyps of intestine

11 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Hyperplasia

12 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Intracellular Accumulations   Exogenous materials   Coal particles (anthracosis)   Endogenous metabolites   Hemosiderin   Lipids

13 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Alcohol-Induced Fatty Liver

14 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Death of a Cell   Cell death occurs in two forms: Necrosis: localized death of cells or tissues in living organisms due to disease Apoptosis: programmed death of single cells within living organisms

15 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Types of Necrosis   Coagulative necrosis: most common form   Liquefactive necrosis: in brain   Caseous necrosis: tuberculosis   Enzymatic fat necrosis: acute pancreatitis

16 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Necrosis

17 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Coagulative Necrosis

18 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Liquefactive Necrosis Often it is associated with focal bacterial or fungal infections. In liquefactive necrosis, the affected cell is completely digested by hydrolytic enzymes, resulting in a soft, circumscribed lesion consisting of pus and the fluid remains of necrotic tissue. Dead leukocytes will remain as a creamy yellow pus. [1] After the removal of cell debris by white blood cells, a fluid filled space is left. It is generally associated with abscess formation and is commonly found in the central nervous system.bacterialfungalhydrolytic [1]white blood cellsabscesscentral nervous system

19 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Caseous necrosis is a form of cell death in which the tissue maintains a cheese-like appearance. The dead tissue appears as a soft and white proteinaceous dead cell mass. Tuberculosis

20 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Dry Gangrene

21 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Calcified Aortic Valve

22 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Necrosis/Apoptosis Apoptosis is the process of programmed cell death (PCD), whereas Necrosis is the premature death of cells and living tissue

23 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Necrosis vs Apoptosis Apoptosis Necrosis NaturalYes caused by infection, toxins, or trauma EffectsBeneficialDetrimental Introduction Apoptosis programmed cell death (PCD) Naturally Necrosis is the premature death of cells and living tissue. result Can prevent tumor formation (homeostasis between cell death rate and mitosis rate) Necrosis results in inflammation, which could become chronic.

24 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Apoptosis

25 Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Apoptosis