accumulation Flashcards
Diabetes mellitus
Glycogen accumulates in renal tubular epithelium , cradiac myocytes and beta cells of the islets in the pancreas.
Glycogen storage diseases
Enzymatic defects
Carbon
The most common exogenous pigment
In the lung and the hilar lymph nodes
Anthracosis
Carbon aggregates in the lung and hilar lymph nodes
Endogenous pigments
Lipofuscin, melanin and hemosiderin
an endogenous, brown-black pigment formed by melanocytes.
Melanin
represents complexes of lipid and protein that derive from the free radical-catalyzed peroxidation of polyunsaturated lipids of subcellular membranes.
Lipofuscin
not injurious to the cell but is important marker of past free radical injury.
Lipofuscin
accumulates in tissues when there is a local or systemic excess of iron
represents large aggregates of ferritin
Hemosiderin
pigment appears as perinuclear electron-dense granules
“brown atrophy” if apparent grossly
Lipofuscin
Affects mainly the interstitium of blood vessels, kidneys, lungs, and gastric mucosa.
Does not generally cause clinical dysfunction, unless the process is severe.
Metastatic calcification
in aortic valve is an important cause of aortic stenosis in the elderly
Dystrophic calcification
nephrocalcinosis
Metastatic calcification
adjacent basal keratinocytes in the skin can also accumulate the pigment (e.g., in freckles), or it may be accumulated in dermal macrophages.
Melanin
Haemoglobin derived golden-yellow to brown pigment.
Hemosiderin
abnormal deposition of calcium salts, together with smaller amounts of iron, magnesium and other minerals.
Pathological calcification
Deposition of calcium on dead or dying cells.
Normal levels of serum calcium
Dystrophic calcification
Wear and tear pigment
Lipofuscin
Grossly appears as fine white granules.
Microscopically: intracellular or extracellular basophilic deposits.
Dystrophic calcification
Deposition of calcium in normal tissue in the presence of hypercalcemia.
Metastatic calcification
Causes of hypercalcemia:
Increased secretion of parathyroid hormone.
Destruction of bone by tumors.
Vitamin-D related disorders.
Renal failure.
fatty liver
Abnormal metabolism of substances
alpha-1 antitrypsin deficiency
Defective folding and transport of proteins
storage diseases
Genetic or acquired lack of enzyme