intracellular accumulations
DESCRIPTION
Intracellular accumulationsTRANSCRIPT
DEGENERATIONS (dystrophy)
Degeneration (dystrophy) is a pathological process due to disturbance of either cellular or tissue metabolism which causes changes in the structure of cells, tissues, etc.
Trophism mechanisms are cellular and extracellular:
cellular: autoregulation (enzymes)
extracellular: transportation systems (blood, lymph); endocrine regulation;
Morphogenetic mechanisms of degenerations: infiltration: abundant invasion of metabolite
products from the transportation system to the cell followed by their accumulation;
decomposition: destruction of cellular ultrastructure (lipoprotein complex from cellular membranes) with accumulation within a cell;
abnormal synthesis: intracellular synthesis of the substances which are not produced normally (e.g. amyloid);
transformation: formation of products of one type of metabolism from the common primary products, e.g. increased polymerization of glycogen from glucose.
Classification of degenerations
According to the localization:a) parenchymatous (intracellular accumulation),b) mesenchymatous (extracellular accumulation), c) mixed type.
According to the type of metabolism disturbance: a) albuminous (protein), b) fatty (adipose), (lipidosis),c) carbohydrate, d) mineral
According to the origin: a) acquired,b) heriteted.
According to propagationa) general, b) local.
Parenchymatous degenerations
Parenchymatous albuminous degenerations (dysproteinoses)
The modern classification of parenchymatous albuminous
degenerations:
1) hyalin-drop
2) hydropic (edematous, balloon)
Hyalin-drop degeneration
Microscopically: rounded, eosinophilic droplets, vacuoles, or aggregates in the cytoplasm
Macroscopically: organs enlarged, flabby, grey colour on section
Localizations: kidney, liver, myocardium
Hydropic degeneration
Microscopically: large vacuoles of cytoplasm fluid in the cytoplasm, the nucleus which displaced to the peripheral areas
Macroscopically: organs enlarged, flabby, grey colour on section
Localizations: kidneys, skin, liver, muscles, nerves
Horny degeneration
abundant formation of horny substance in keratinized epithelium (hyperkeratosis and ichtyosis)
appearance of horny substance in the places where is not found under normal conditions (leukoplakias)
Parenchymatous degenerations
Parenchymatous fatty degenerations
Manifestation
of disturbance of fat metabolism: appearance of fat in the place where it
does not appear under normal conditions (e.g. in the myocardium),
appearance of fat of unusual composition;
increase of fat amount in the places where it is present under normal conditions (e.g. in the fat depots).
Hypoxia - the main cause of fatty degeneration
disturbances in transportation systems (e.g. in patient with chronic cardiovascular and chronic pulmonary insufficiency);
chronic intoxications (e.g. alcoholism);cachexia, avitaminosis; infections (e.g. diphtheria, tuberculosis).
Parenchymatous degenerations
Parenchymatous carbohydrate degenerations
Glycogen metabolism disturbance
increase or reduction in the amount in the tissues where it is present under normal conditions,
its appearance in the areas where it is not present under normal conditions
Storage diseases(enzymopathy)
proteinoses lipidosis
glucogenoses
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