Intracellular Accumulations Flashcards
What are intracellular accumulations
These are substances which accumulate in the cell due to increased production or defective removal by the cell
These accumulations could be _________(source), _______ (effect), _________( residency) and may be found in the ___________ (location)
Endogenous or exogenous
Toxic / non toxic
Temporary or permanent
Cytoplasm or nucleus
Causes of intracellular accumulations
1) A normal endogenous substance produced at a normal or increased rate but the rate of metabolism is inadequate to remove it e.g fatty droplets in liver
2) A normal endogenous substance accumulates due to a defect in the enzyme required for its metabolism e.g lysosomal storage dx
3) An abnormal endogenous substance accumulates e.g product of a mutated gene or misfolded proteins which cannot be degraded accumulate in the cell e.g in neurodegenerative disorders
4) an abnormal exogenous substance accumulates in the cell because the cell lacks the ability to degrade it or transport it to other sites e.g carbon particles in alveolar macrophages
Fatty change is seen in what organs
Mostly seen in the liver because it is the major organ involved in fat metabolism. May also be present in the heart, muscle and kidney.
Causes of fatty changes
1) Alcohol abuse, diabetes and obesity. Alcohol alters mitochondrial and microsomal function leading to increased synthesis and reduced breakdown of lipids. In DM, elevated glucose provides more substrate for triglyceride synthesis
2) Carbon tetrachloride (CCl4) and protein malnutrition cause reduced apoprotein synthesis which results in defective lipid transport
3) Hypoxia impairs fatty acid oxidation
4) Starvation causes mobilization of fat from peripheral stores
5) drugs and toxins
6) anoxia
7) pregnancy
What special stains are used to identify fatty droplet’s microscopically
Special stains like Sudan black & Oil Red-O are used to identify fatty
Types of cholesterol accumulations
1) Atherosclerosis in blood vessels
2) Xanthomas in connective tissue and skin
3) Cholesterolosis in the gall bladder
4) Niemann-Pick disease type C (genetic mutation that causes accumulation of cholesterol and fat)
I’m cholesterolosis surface appearance of mucosa of _______ resembles ______
Gall bladder
Strawberry
Types of protein accumulation
1) proteinuria
2) Immunoglobulins may accumulate in plasma cells within the ER producing inclusions called Russell bodies
3. Alpha 1 antitrypsin deficiency (emphysema) the enzyme is deficient because its precursors are misfolded and have accumulated in the liver.
4) accumulation of cytoskeleton proteins
5) aggregation of abnormal proteins e.g in amyloidosis
Types of glycogen accumulations
Seen in disorders of glucose or glycogen metabolism e.g in DM seen in hepatocytes stained by PAS/PASD
Also seen in genetic disorders of enzymes involved in glucose/glycogen metabolism
Examples of pigment accumulations
Exogenous pigments
• Carbon (coal dust): most common, results in anthracosis, coal workers pneumoconiosis
• Tattoos Endogenous:
• Lipofuscin: wear and tear pigment
• Hemosiderin: Old haemorrhage, Fe overload (hemosiderosis). From ferritin micelles
. Melanin
Disease due to protein mutation is
Alpha 1 antitrypsin deficiency
Another name for fatty change
Steatosis or fatty metamorphosis
What is fatty change
Intracellular accumulation of neural fat( triglycerides) within the parenchyma cells
In hereditary hyperlipemia cholesterol accumulates In _______
Macrophages, usually under the skin forming tumor like structures known as xanthomas
