Fatty degenerations / lipidosis Flashcards
In general, what is fatty degeneration?
A pathological change in cells and tissues due to disturbances in fatty/ lipid metabolism.
Two types of fats (in this context)?
Neutral fat
Cytoplasmic fat
What is neutral fat?
Fat that accumulates in connective tissue under the skin and around the kidneys (responds to changes in body condition)
What is cytoplasmic fat?
The normal fat that is inside of all cells (does not respond to changes in body condition)
What is steatosis?
The amount and composition of cytoplasmic fat changes
Into what two types are fatty degenerations divided?
Parenchymal and mesenchymal
Where does parenchymal fatty degeneration occur?
Accumulation of fat in the cytoplasm of cells in parenchymal organs.
Mostly in liver, kidneys and myocardium (these organs only have a small amount of fat normally).
What causes parenchymal fatty degenerations?
Contagious diseases (sepsis, tuberculosis), intoxications, deficiencies, hypoxia, anemia
How does parenchymal fatty degeneration develop?
-Lipoproteins in the cell membranes decompose
-Fat production from carbohydrates and proteins is increased (transformation)
-Increased infiltration of fat into the cell from blood or lymph
What happens to the cell in parenchymatous degeneration?
Cell nucleus is damaged and the whole cell becomes damaged and can die (fat is deposited in damaged cells)
What happens to the liver in liver fatty degeneration?
Liver becomes enlarged, friable, and yellow in colour.
In physiologic fat infiltration (rasvamaksa), the liver cells are not able to process the excess fat transported to the liver by blood and lymph. The fat will instead be deposited in the cytoplasm to be consumed later by the liver cells. In this case the liver cells remain undamaged unlike in fatty degeneration.
What happens to the heart in cardiac muscle fatty degeneration?
The degenerations are focal. Deposits are in the sarcoplasm of muscle fibres –> grey-yellow stripes in the muscle, “tiger heart”
What happens to the kidneys in kidney fatty degeneration?
Fat deposits in the epithelial cells of renal tubules. Kidneys expand and become greyish yellow.
Where do mesenchymal fatty degenerations occur?
Linked to disturbances in neutral fat metabolism. Affects stroma of organs.
What two conditions affect the mesenchymal fatty degenerations?
Cachexia = stroma of organs may reduce
Obesity = stroma of organs may increase
