Degeneration, or dystrophy, is a pathological process caused by disturbances in cellular or tissue metabolism that results in structural changes to cells and tissues. There are two main mechanisms of degeneration - cellular mechanisms involving enzymes and extracellular mechanisms involving transport and endocrine systems. Degenerations are classified based on location (intracellular vs extracellular accumulation), type of disturbed metabolism (protein, fat, carbohydrate, mineral), origin (acquired vs inherited), propagation (general vs local), and appearance microscopically. Common types of degeneration include hyalin-drop, hydropic, fatty, and carbohydrate degenerations which result from issues with protein, fluid regulation, fat, and carbohydrate metabolism, respectively.

1. DEGENERATIONS
(dystrophy)

2. 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.

3. Trophism mechanisms are cellular and
extracellular:
cellular: autoregulation (enzymes)
extracellular: transportation systems
(blood, lymph); endocrine regulation;

4. 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.

5. 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 propagation
a) general,
b) local.

6. Parenchymatous degenerations
Parenchymatous albuminous
degenerations (dysproteinoses)

7. The modern classification of
parenchymatous albuminous
degenerations:
1) hyalin-drop
2) hydropic (edematous, balloon)

8. 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

10. 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

11. 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)

13. Parenchymatous degenerations
Parenchymatous fatty
degenerations

14. 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).

15. 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).

19. Parenchymatous degenerations
Parenchymatous carbohydrate
degenerations

20. 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

21. Storage diseases
(enzymopathy)
proteinoses
lipidosis
glucogenoses

22. Thank you for your attention