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− | ==Introduction==
| + | #REDIRECT[[:Category:Degenerations and Infiltrations]] |
− | * Degenerations and infiltrations are the morphological manifestation of an altered metabolism within the cell.
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− | ** A particular kind of change within a cell or tissue may suggest that a specific type of alteration has occurred.
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− | * Degenerations and infiltrations are types of structural changes.
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− | ** These are best considered at a cellular level.
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− | ** These structural changes are deviations from the cell's normal structure and function.
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− | *** Parameters are outside the normal physiological range for the cell.
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− | * '''Degeneration'''
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− | ** The tissue cell shows some change in itself.
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− | * '''Infiltration'''
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− | ** Something accumulates in the cell or tissue.
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− | ==[[Cellular Swelling]]==
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− | ==[[Hydropic Degeneration]]==
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− | ==[[Cellular Fatty Change]]==
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− | ==[[Mucoid Degeneration]]==
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− | ==[[Hyaline Degeneration]]==
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− | ==Glycogen Infiltration==
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− | * Glycogen is normally present in substantial amounts in the [[Liver - Anatomy & Physiology|liver]] and muscle.
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− | ** Is a readily utilisable source of energy.
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− | * Moderate glycogen infiltration in the [[Liver - Anatomy & Physiology|liver]]:
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− | ** Grossly - doesn't have much effect.
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− | ** Histologically - shows up as foamy cytoplasmic vacuoles, similar to that of fat.
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− | * Some conditions may result in an increase in glycogen deposits.
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− | ** [[DM|'''Diabetes mellitus''']]
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− | *** Gives an increase in hepatic glycogen stores.
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− | *** May be overshadowed by the increased fat in the hepatocytes, and therefore difficult to see.
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− | **** Renal tubular deposits are more easily observed.
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− | ** '''Excessive glucocorticoids'''
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− | *** Could be due to:
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− | **** Hyperadrenocortism
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− | **** Animals being maintained on glucocorticoid therapy over a long period of time.
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− | ***** Has more dramatic effect.
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− | *** Huge amounts of glycogen infiltration.
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− | **** [[Liver - Anatomy & Physiology|Liver]] appears larger and paler.
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− | **** Vacuoles may be so extensive that the rest of the cytoplasm appear as pink strands passing from the nucleus to the plasma membrane.
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− | ***** A "feathery appearance" or "web-like effect".
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− | ** '''Glycogen storage diseases'''
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− | *** Due to an inherited deficiency of an enzyme required for the breakdown of glycogen to glucose.
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− | **** Cells continuously accumulate glycogen.
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− | *** Seen in all tissues of the body but exerts its major effect in the CNS.
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− | * Selective staining must be employed to distinguish glycogen vacuoles from fatty vacuoles in the [[Liver - Anatomy & Physiology|liver]].
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− | ** Alcohol fixation is preferred.
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− | ** Best's Carmine is the commonly used stain.
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− | *** Stains the intracellular glycogen red.
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− | [[Category:Degenerations and Infiltrations]]
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− | ==Cellular Inclusions==
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− | ===[[Viruses|Viruses]]===
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− | * Either in the nucleus or cytoplasm.
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− | ===Storage Products===
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− | * Due to '''hereditary storage diseases''' in which there is a missing or defective cellular enzyme. There are many types known in domestic animals.
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− | ** Break down/ build up of intracellular substances is halted.
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− | *** The intermediate substance accumulates in the lysosomes.
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− | ** Affects all tissues
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− | *** The central nervous system is particularly vulnerable.
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− | * Due to '''age'''
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− | ** Lysosomes will accumulate non-degradable products
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− | *** E.g. lipofuscin - the 'ageing' or 'wear and tear pigment'.
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− | **** Commonly seen in middle-aged cats in the hepatocytes nearest the centrilobular veins.
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− | ===Intracellular Bacteria===
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− | * For example, [[:Category:Mycobacterium species|''Mycobacterium tuberculosis'']] in macrophages.
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− | ===Protein Accumulation===
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− | * In the renal tubular epithelium.
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− | * Occurs when there is leakage of protein out through a damaged glomerulus.
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− | [[Category:Degenerations and Infiltrations]]
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