Pathology 11/25/20151 SECTION 2 CELL INJURY

Pathology 11/25/20152  Reversible  Irreversible Cellular Swelling Fatty Change Hyaline Change Amyloid Change Mucoid Change Pathologic Pigmentation Pathologic Calcification Cell Death Degeneration

Pathology 11/25/20153 Reversible Cell Injury Intracellular &/or extracellular abnormal accumulation: Excess amounts of various normal substances (water,lipids,proteins,pigments) Abnormal substances (exogenous, endogenous) Degeneration

Pathology 11/25/20154 Cellular Swelling Intracellular accumulation Sodium Water (hydropic degeneration) (1)

Pathology 11/25/20155 Cellular Swelling (2) Morphology NE: LM: EM ： Cloudy swelling Increase in the weight the organs Large Small & fine granules in the cytoplasm the cells Ballooning change Swelling Endoplasmic reticulum Mitochondria

Pathology 11/25/20156 Injurious agents Mitochondria damage Mechanism Water & sodium within the cells Cellular swelling ATP

Pathology 11/25/20157 Fatty Change Intracellular abnormal accumulation: Triglycerides (1) Steatosis Often occurred in the liver and the heart

Pathology 11/25/20158 Morphology Fatty Change (2) NE: LM: EM ： Large Yellow Soft Greasy Round, clear vacuoles Orange-red color by staining with Sudan Ⅲ or Oil Red O (Frozen tissue sections!) Fat vacuoles Membrane-bound inclusions Liposomes

Pathology 11/25/20159 Fatty Change of the Liver  Mild fatty change: Not affect the gross appearance  With progressive accumulation: NE Large Yellow Soft Greasy Fatty Liver: Severe & diffuse fatty change (1)

Pathology 11/25/ LM Fatty Change of the Liver (2) Fat vacuoles Small, in the cytoplasm around the nucleus Displacing the nucleus to the cell periphery Fatty cysts

Pathology 11/25/ Fatty Change of the Liver (3) Mechanism

Pathology 11/25/ Fatty Change of the Myocardium  Mild fatty change: Not affect the gross appearance  With progressive accumulation: NE Tigered effect Apparent bands of yellowed myocardium alternating with bands of dark,red-brown,uninvolved myocardium

Pathology 11/25/ A homogeneous, translucent, pink appearance in HE staining Hyaline Change Intracellular or extracellular abnormal accumulation: Proteins A descriptive morphologic term (1)

Pathology 11/25/  Hyaline change in arteriolosclerosis e.g. Hypertension, Diabetes  Hyaline change in connective tissues e.g. Old scars  Hyaline change within the cytoplasm e.g. Nephrotic syndrome, Russell bodies, Mallory body Hyaline Change (2)

Pathology 11/25/ Amyloidosis Extracellular abnormal accumulation: Amyloid

Pathology 11/25/ Physicochemical characteristics of amyloid  +Iodine--- a brown color--- +H 2 SO blue  Staining: Congo red--- red, HE--- homogeneous pink  EM: nonbranching fibrils nm wide  X-ray: a pleated  –sheet structure (rendering protein very resistant to enzymatic degradation, contributing to its accumulation in tissues)

Pathology 11/25/ Mucoid Change Extracellular abnormal accumulation: Mucopolysaccharide (Glycosaminoglycans, Hyaluronic Acid)

Pathology 11/25/ Pathologic Pigmentation Intracellular & extracellular abnormal accumulation: Exogenous Endogenous Colored substances

Pathology 11/25/ Pathologic Pigmentation Exogenous Endogenous Hemosiderin Lipofuscin Melanin Carbon

Pathology 11/25/ Pathologic Calcification Intracellular & extracellular abnormal accumulation: Calcium salts 1.Except for the bones and teeth 2.Pathologic conditions (1)

Pathology 11/25/  Dystrophic Calcification In areas of necrosis No calcium metabolic derangements  Metastatic calcification In normal tissues Some calcium metabolic derangements Pathologic Calcification (2)

Pathology 11/25/ Apoptosis 1. Necrosis Cell Death Irreversible Cell Injury A sequence of morphologic changes that follow cell death in living tissue A distinctive and important mode of cell death regulated by genes

Pathology 11/25/ Necrosis Two essentially concurrent processes to produce the morphologic changes : 1. Enzymatic digestion of the cell 2. Denaturation of proteins (1) Autolysis Heterolysis

Pathology 11/25/ Necrosis Basic pathologic changes Types of necrosis Sequences of necrosis (2)

Pathology 11/25/ Necrosis Basic Pathologic Changes (3)  Nuclear changes Karyolysis Pyknosis Karyorrhexis  CytoplasmIncreased eosinophilia

Pathology 11/25/ Necrosis Types of Necrosis (4)  Liquefactive necrosis  Fat necrosis  Coagulative necrosis  Caseous necrosis  Gangrene  Fibrinoid necrosis

Pathology 11/25/ Coagulative Necrosis  A mass of coagulated, pink-staining, homogeneous cytoplasm  Preservation of the basic structure outline of the coagulated cell or tissue for several days  In solid organs (kidney, heart, spleen )

Pathology 11/25/ Liquefactive Necrosis  Liquefaction of necrotic cells  Condition: Presence of more abundant proteolytic enzymes  Most often in suppurative inflammation & in the brain

Pathology 11/25/ Caseous Necrosis  A distinctive form of coagulative necrosis  Cheese-like  An amorphous coarsely granular eosinophilic debris  Most often in foci of TB

Pathology 11/25/ Fat Necrosis  A special type of liquefactive necrosis  Focal areas of fat destruction  Calcium soaps  Enzymatic fat necrosis(acute pancreatitis)  Nonenzymatic fat necrosis (following direct trauma to adipose tissue & extracellular liberation of fat)

Pathology 11/25/ Gangrene  Extensive tissue necrosis  Secondary bacterial infection Dry gangrene Wet gangrene Gas gangrene

Pathology 11/25/ Fibrinoid Necrosis  A type of connective tissue necrosis  Loss of normal structure  A homogeneous,bright pink-staining necrotic material that resembles fibrin microscopically

Pathology 11/25/ Necrosis Consequences of Necrosis (5)  Dissolution & absorption  Organization & encapsulation  Autolysis & inflammation  Sloughing  Calcification Ulcer, Cavity, Sinus, Fistula