Degenerations and Infiltrations - Pathology
Introduction
- Degenerations and infiltrations are the morphological manifestation of an altered metabolism within the cell.
- A particular kind of change within a cell or tissue may suggest that a specific type of alteration has occurred.
- Degenerations and infiltrations are types of structural changes.
- These are best considered at a cellular level.
- These structural changes are deviations from the cell's normal structure and function.
- Parameters are outside the normal physiological range for the cell.
- Degeneration
- The tissue cell shows some change in itself.
- Infiltration
- Something accumulates in the cell or tissue.
Cellular Swelling
Hydropic Degeneration
Cellular Fatty Change
Mucoid Degeneration
Hyaline Degeneration
Glycogen Infiltration
Cellular Inclusions
Viruses
- Either in the nucleus or cytoplasm.
Storage Products
- Due to hereditary storage diseases in which there is a missing or defective cellular enzyme. There are many types known in domestic animals.
- Break down/ build up of intracellular substances is halted.
- The intermediate substance accumulates in the lysosomes.
- Affects all tissues
- The central nervous system is particularly vulnerable.
- Break down/ build up of intracellular substances is halted.
- Due to age
- Lysosomes will accumulate non-degradable products
- E.g. lipofuscin - the 'ageing' or 'wear and tear pigment'.
- Commonly seen in middle-aged cats in the hepatocytes nearest the centrilobular veins.
- E.g. lipofuscin - the 'ageing' or 'wear and tear pigment'.
- Lysosomes will accumulate non-degradable products
Intracellular Bacteria
- For example, Mycobacterium tuberculosis in macrophages.
Protein Accumulation
- In the renal tubular epithelium.
- Occurs when there is leakage of protein out through a damaged glomerulus.