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Questions and Answers
Which of the following mechanisms is most directly responsible for the accumulation of fat in hepatocytes in cases of non-alcoholic steatohepatitis (NASH)?
Which of the following mechanisms is most directly responsible for the accumulation of fat in hepatocytes in cases of non-alcoholic steatohepatitis (NASH)?
- Deficiency in carnitine palmitoyltransferase I (CPT-I), preventing fatty acids from entering the mitochondria for beta-oxidation.
- Impaired synthesis of very-low-density lipoproteins (VLDL), hindering the export of triglycerides from the liver. (correct)
- Enhanced autophagy of lipid droplets within hepatocytes, overwhelming the cellular capacity to process triglycerides.
- Increased activity of hormone-sensitive lipase, leading to excessive mobilization of free fatty acids from adipose tissue.
Why does the carbon pigment in anthracosis persist within lung tissue even after macrophages phagocytose it?
Why does the carbon pigment in anthracosis persist within lung tissue even after macrophages phagocytose it?
- Macrophages immediately undergo apoptosis after phagocytosis, releasing the carbon pigment back into the tissue.
- Carbon pigment is resistant to degradation by macrophages, which lack the necessary enzymes to break it down. (correct)
- Macrophages rapidly migrate out of the lung tissue and into the bloodstream, carrying the carbon pigment with them.
- The carbon pigment stimulates a fibrotic reaction that encapsulates the macrophages, preventing further interaction with the tissue.
What is the underlying mechanism by which hyperparathyroidism leads to metastatic calcification?
What is the underlying mechanism by which hyperparathyroidism leads to metastatic calcification?
- Elevated parathyroid hormone levels enhance the production of vitamin D, leading to increased intestinal absorption of calcium and subsequent tissue deposition.
- Hyperparathyroidism induces systemic inflammation, causing increased vascular permeability and leakage of calcium into the surrounding tissues.
- Parathyroid hormone directly stimulates osteoblast activity, resulting in widespread deposition of calcium matrix in soft tissues.
- Increased bone resorption elevates serum calcium levels, causing calcium phosphate to precipitate in tissues with a high pH. (correct)
How does the accumulation of mutated alpha-1 antitrypsin protein in hepatocytes ultimately lead to liver injury?
How does the accumulation of mutated alpha-1 antitrypsin protein in hepatocytes ultimately lead to liver injury?
Why do cytokeratin intermediate filaments persist as a structural component in dying liver cells?
Why do cytokeratin intermediate filaments persist as a structural component in dying liver cells?
In the context of atherosclerosis, what is the primary mechanism by which dystrophic calcification occurs within atheromatous plaques?
In the context of atherosclerosis, what is the primary mechanism by which dystrophic calcification occurs within atheromatous plaques?
Which cellular process is most directly impaired, leading to the accumulation of glycogen within lysosomes in glycogen storage diseases?
Which cellular process is most directly impaired, leading to the accumulation of glycogen within lysosomes in glycogen storage diseases?
What is the role of macrophages in the formation of 'fatty streaks' in the aorta during the early stages of atherosclerosis?
What is the role of macrophages in the formation of 'fatty streaks' in the aorta during the early stages of atherosclerosis?
How does the Congo red stain, when used with polarized light, differentiate amyloid deposits from other protein aggregates in tissues?
How does the Congo red stain, when used with polarized light, differentiate amyloid deposits from other protein aggregates in tissues?
Which mechanism primarily explains the formation of neurofibrillary tangles composed of tau protein in neurons affected by Alzheimer's disease?
Which mechanism primarily explains the formation of neurofibrillary tangles composed of tau protein in neurons affected by Alzheimer's disease?
Flashcards
Steatosis
Steatosis
Fat accumulation within hepatocytes, often due to alcohol or non-alcoholic steatohepatitis (NASH), disrupting triglyceride metabolism.
Anthracosis
Anthracosis
Accumulation of carbon pigment in the lungs, common in urban environments due to air pollution.
Hemosiderin
Hemosiderin
Brown/golden-brown pigment in the liver, indicating iron storage; confirmed with Prussian blue stain.
Dystrophic Calcification
Dystrophic Calcification
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Metastatic Calcification
Metastatic Calcification
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Amyloid Accumulation
Amyloid Accumulation
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Alpha-1 Antitrypsin Accumulation
Alpha-1 Antitrypsin Accumulation
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Neurofibrillary Tangles
Neurofibrillary Tangles
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Lipofuscin
Lipofuscin
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Fatty streaks
Fatty streaks
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Study Notes
Overview of Accumulations
- Most substance accumulations arise from pathological conditions.
- Abnormal amounts of substances accumulate inside or outside cells, necessitating understanding and recognition.
Types of Accumulations
- Includes lipids, cholesterol, glycogen, various pigments, calcium, and various proteins.
Lipid or Cholesterol Accumulations
- Steatosis refers to fat accumulation in the liver, indicating fatty changes.
- Causes include alcohol use or non-alcoholic steatohepatitis (NASH).
- Triglyceride fat metabolism disruption occurs within hepatocytes.
- Increased liver fat can impair normal hepatocyte function.
- Cholesterol can accumulate in the gallbladder as bile contains cholesterol and bile salts.
- Macrophages may phagocytize excess cholesterol.
- Fatty streaks, yellow streaks on the aorta's internal surface, represent early atheroma and atherosclerosis development as fat deposits beneath the intima.
Glycogen Accumulation
- Glycogen storage diseases feature glycogen accumulation within lysosomes due to inherited genetic conditions.
- A variety of inheritable glycogen storage disorders exist.
Pigment Accumulations
- Lipofuscin presence in myocardium indicates cell injury and aging; increased amounts signal heightened injury and aging.
- Lipofuscin accumulation appears as age spots on the skin of older individuals.
- Anthracosis denotes carbon pigment accumulation, especially in lung tissue.
- Inhaling air pollution introduces carbon pigment, accumulating in alveolar macrophages.
- Macrophages phagocytose pigment but cannot break it down, resulting in long-term tissue retention.
- Tattoo pigments reside within the dermis indefinitely.
- Hemosiderin in the liver appears as brown or golden-brown particles with hematoxylin stain and Prussian blue iron stain turns it blue.
Calcium Accumulation
- Dystrophic calcifications result from cell death or injury in atherosclerosis or atheroma.
- Calcium remains as a remnant of cell injury, appearing purplish-blue in tissue sections.
- Metastatic calcification, occurring due to hyperparathyroidism, causes calcium to deposit in tissues.
- Calcium deposits can form circular clusters called somomal bodies that can be present in tumors.
Protein Accumulation
- Amyloid accumulation highlighted by Congo red stain, showing deposits in blood vessel walls.
- Under polarized light, amyloid shifts from red to apple-green or chartreuse.
- Alpha-1 antitrypsin, a mutated protein, accumulates in hepatocytes due to its inability to be excreted, causing liver cell injury and death.
- Mallory bodies are pink protein accumulations and indicate liver cell injury.
Neurofibrillary Tangles
- Tau protein accumulation in neurons is characteristic of Alzheimer's disease.
Cytokeratin Accumulation
- Cytokeratin intermediate filaments persist as the last structural components when liver cells die.
Plasma Cells
- Plasma cells exhibit bubbly cytoplasm due to endoplasmic reticulum presence, featuring pale globules (endoglobulins) in cytoplasmic vesicles.
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