Occupational Lung Diseases Quiz

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Questions and Answers

What type of lung lesions are associated with silicosis?

Nodular lesions with concentric layers (correct)

Cavitary lesions with purulent fluid

Extensive vascularization throughout the lung

Compacted masses of necrotic tissue

Which of the following accurately describes asbestosis?

Leads to immediate lung infections

Characterized by the presence of asbestos bodies (correct)

Results primarily in alveolar emphysema

Caused by extensive inhalation of coal dust

What is a significant consequence of silica's presence in the lungs?

Development of acute respiratory distress syndrome

Increased cell-mediated immunity

Promotion of pulmonary tuberculosis (correct)

Enhancement of oxygen exchange efficiency

Which of these describes siderosis?

Pigmentation and cellular reaction from iron dust inhalation Signup and view all the answers

What microscopic feature is indicative of asbestosis?

Bamboo-like asbestos bodies Signup and view all the answers

In regards to the macroscopic features of the lungs affected by silicosis, which statement is correct?

Nodular and firm lung structures are evident Signup and view all the answers

What is the main health risk associated with prolonged asbestos exposure?

Development of pleural disease and tumors Signup and view all the answers

What distinguishes the fibrotic response to coal dust from that to asbestos dust?

Asbestos leads to more significant fibrosis despite less dust Signup and view all the answers

What characterizes simple coal workers' pneumoconiosis (CWP)?

Dust-laden macrophages and coal macules Signup and view all the answers

Which statement about complicated CWP is accurate?

It may take many years to develop and is characterized by extensive fibrosis Signup and view all the answers

What is the primary risk factor associated with silicosis?

Exposure to silica particles, particularly in sandblasting and hard-rock mining Signup and view all the answers

Which microscopic feature is characteristic of complicated CWP?

Black carbon particles clustered in interstitial spaces Signup and view all the answers

What is a significant consequence of extensive deposits of carbon in the lungs?

Slight respiratory distress and potential pulmonary injury Signup and view all the answers

Which of the following mediators is NOT associated with the pathogenesis of silicosis?

Transforming growth factor-beta (TGF-beta) Signup and view all the answers

Which condition is characterized by blackened scars larger than 2 cm in the lungs?

Complicated CWP Signup and view all the answers

What is the difference in the appearance of simple versus complicated CWP?

Simple CWP is characterized by coal macules, while complicated CWP shows extensive lung involvement and fibrosis Signup and view all the answers

What is the primary enzyme responsible for the synthesis of melanin in melanocytes?

Tyrosinase Signup and view all the answers

Which condition is characterized by generalized hyperpigmentation of the skin, particularly in areas exposed to light?

Addison's disease Signup and view all the answers

What histological feature can be observed in tissues containing melanin?

Minute brown spherical granules Signup and view all the answers

Which of the following is NOT associated with focal hyperpigmentation?

Chloasma Signup and view all the answers

Albinism is characterized by which of the following defects?

Genetic defect in tyrosinase activity Signup and view all the answers

Which type of pigmentation is specifically associated with chronic arsenical poisoning?

Raindrop pigmentation Signup and view all the answers

Which of the following statements is true regarding melanin storage?

Melanin is stored in melanophores. Signup and view all the answers

What is a common manifestation of generalized hyperpigmentation during pregnancy?

Chloasma Signup and view all the answers

What is the primary characteristic of jaundice?

Yellow discoloration of tissues rich in elastin. Signup and view all the answers

Which of the following best describes prehepatic jaundice?

Results from excessive destruction of red blood cells. Signup and view all the answers

What condition is associated with toxic jaundice?

Failure of hepatocytes to extract and detoxicate bilirubin. Signup and view all the answers

Which of these is not a cause of hemolytic jaundice?

Biliary obstruction. Signup and view all the answers

What mechanism primarily causes posthepatic or obstructive jaundice?

Obstruction to the outflow of conjugated bilirubin. Signup and view all the answers

Which of the following is a physiological cause of icterus in horses?

Deprivation of feed for several days. Signup and view all the answers

In which situation is hemolytic jaundice most likely to manifest?

When there is excessive systemic hemolysis. Signup and view all the answers

What is the effect of liver dysfunction on bilirubin in toxic jaundice?

Loss of capacity to detoxicate and secrete bilirubin. Signup and view all the answers

What primarily characterizes the deposits found in the articular form of gout?

Needle-shaped crystals of calcium urate Signup and view all the answers

Which joint is most commonly affected by articular gout?

First metatarsophalangeal joint Signup and view all the answers

What is the appearance of tophi in affected tissues?

White, chalky material with a metallic sheen Signup and view all the answers

What type of cell reaction is stimulated by urate deposits in both articular and visceral forms of gout?

Granulomatous reaction with giant cells Signup and view all the answers

What is a significant microscopical feature observed in visceral gout?

Crystalline or amorphous materials that do not stain Signup and view all the answers

What characterizes chronic venous congestion (CVC) of the spleen?

Calcific deposits associated with fibrous tissue Signup and view all the answers

What processes are involved in the initiation phase of calcification?

Influx of calcium into cytoplasm and vesicles Signup and view all the answers

Which type of necrosis is most commonly associated with dystrophic calcification?

Caseous necrosis Signup and view all the answers

What is a common cause of calcification in cysts?

Long-term presence of cysts Signup and view all the answers

Which statement about Mönckeberg’s sclerosis is correct?

It shows calcification in the tunica media Signup and view all the answers

In which type of necrosis do dead parasites commonly lead to calcification?

Dystrophic calcification Signup and view all the answers

Which is NOT a characteristic feature of calcinosis cutis?

Deposits are confined to smooth muscle Signup and view all the answers

What effect does fat necrosis have following acute pancreatitis?

It stimulates formation of calcium soaps Signup and view all the answers

Study Notes

Cellular Injury III: Disturbance in Pigment Metabolism

Pigments are colored substances found in most living beings, including humans.
Pigments are classified into exogenous (outside the body) and endogenous (inside the body).

Exogenous Pigments

Inhaled pigments
Ingested pigments
Injected pigments (tattoos)

Endogenous Pigments

Melanin
Hemoprotein-derived pigments (haemosiderin, hemosiderin granules, acid hematin, bilirubin, biliverdin, porphyrins)
Lipofuscin (wear-and-tear pigment)

Pneumoconiosis

A non-neoplastic lung reaction to mineral dust inhalation.
The lungs and lymph nodes accumulate various dust particles.
Dust particles act as mild irritants, increasing connective tissue build-up (fibrosis) and accumulating macrophages.
Associated with certain occupations, considered occupational lung diseases.
The three common mineral dusts causing pneumoconiosis are coal dust, silica, and asbestos.

Anthracosis

Deposition of carbon or coal dust in the lungs.
Observed in horses and mules used in coal mines.
Also seen in dogs living in areas with significant coal dust, soot, and smoke pollution.
Pulmonary anthracosis is a common exogenous pigment-induced pulmonary lesion in coal miners and smokers.
Inhaled carbon pigment is engulfed by alveolar macrophages and accumulates in connective tissue, including the pleural lymphatics and lymph nodes.
Pulmonary anthracosis occurs without noticeable symptoms (asymptomatic).
Classified into two types:
Simple coal worker's pneumoconiosis (CWP)- Macrophage accumulations with minimal pulmonary dysfunction.
Complicated CWP or progressive massive fibrosis- Extensive fibrosis and lung function impairment. Anthracosis can progress into complicated form over years.

Silicosis

Deposition of fine silica (silicon dioxide) particles in the lungs.
More prevalent in humans than animals.
Workers in sandblasting and hard-rock mining are at higher risk.
A slowly progressing nodular, fibrosing pneumoconiosis (silicotic fibrotic nodules).
After inhalation, silica particles interact with epithelial cells and macrophages, triggering mediator release (IL-1, TNF, fibronectin, lipid mediators, oxygen-derived free radicals, and fibrogenic cytokines)
Affected lungs are nodular and firm, with fibrotic lesions in lymph nodes and the pleura.
The involved tissues exhibit concentric layers of hyalinized center surrounded by inflammatory cells and fibroblasts.

Asbestosis

A type of exogenous pigment due to asbestos (magnesium silicate) inhalation.
Characterized by diffuse pulmonary interstitial fibrosis, with presence of characteristic asbestos bodies. These fibers are coated with glycoprotein and hemosiderin, presenting as beaded or dumbbell-shaped structures.
Asbestos bodies stain positively for Prussian blue reaction.
Affected lungs are small, gray, and firm, with variable degrees of pulmonary fibrosis (especially in subpleural and basal areas).
Prolonged asbestos dust exposure can lead to asbestosis, pleural disease, and lung tumors.

Siderosis

Deposition of iron in the lungs, accompanied by pigmentation and cellular reaction.
Resulting from iron dust inhalation, seen in horses, mules and dogs working in or around iron mines, smelters, and foundries.
Initially, iron dust causes focal brown/rusty-red pigmentation due to macrophage accumulation.
Pigmentation becomes diffuse as dust accumulates.
Iron is mildly irritating, so only slight fibrosis is noted.
If silica is present, substantial lung fibrosis results.
Prussian blue test (iron placed in potassium ferrocyanide solution and hydrochloric acid) yields blue-colored tissue.
Not usually clinically significant unless iron and/or silicon levels are extreme.

Ingested Pigments

Chronic ingestion of certain metals can cause pigmentation:
Argyria (silver compounds) - brownish pigmentation in skin, bowel, and kidneys.
Chronic lead poisoning (plumbism) - characteristic blue lines on teeth
Melanosis coli (certain cathartics) -pigmentation of the colon.
Carotenaemia (carrots) - yellowish-red skin coloration.

Injected Pigments (Tattooing)

Pigments like India ink, cinnabar, and carbon introduced into dermis; taken up by macrophages and remain permanent in connective tissues.
Prolonged use of mercury-containing ointments, wound contamination, tattooing by dyes are additional causes of injected pigments.

Hemoprotein-Derived Pigments

Hematogenous pigments are the most important endogenous pigments derived from hemoglobin, cytochromes, and their breakdown products.
The average life span of an erythrocyte is approximately 120 days.
Degradation of red blood cells within phagocytic cells (spleen, liver, bone marrow) releases hemoglobin components: globin, iron, and heme.
Globin is soluble and removed by blood/lymph.
Iron is normally stored as ferritin micelles, within cells.
Ferritin forms hemosiderin granules, which are visible with light microscopy.
Hemosiderin pigment represents large aggregates of ferritin micelles.

Jaundice (Icterus)

Bilirubin is a normal non-iron containing pigment found in bile.
Derived from the porphyrin ring of heme in hemoglobin.
Normal bilirubin level in blood is less than 1 mg/dL.
Excess bilirubin, or hyperbilirubinemia, causes jaundice (yellow discoloration of tissues rich in elastin, such as aorta, skin, and sclera).
Hyperbilirubinemia can be unconjugated or conjugated.
Prehepatic (hemolytic) causes include excessive red blood cell destruction.
Hepatic (intrahepatic) causes include liver cell damage.
Post-hepatic (obstructive) causes include bile duct obstruction.

Lipofuscin (Wear and Tear Pigment)

Insoluble yellowish-brown granular intracellular pigment (lipofuscin or lipofuscin granules).
Generally found in atrophied cells of older animals.
Also observed in various cells during wasting diseases, unrelated to aging, such as hepatocytes, myocardial fibers, Leydig cells in testes and neurons in senile dementia
Lipofuscin is a product of free radical damage to cell components and accumulation of undigested substances within the cells.

Pathological Calcification

Abnormal calcium salt deposits in soft tissues other than ossified tissues (such as bone and teeth).
May be categorized as dystrophic or metastatic:
Dystrophic calcification: Deposits in dead or degenerating tissues, with normal serum calcium levels
Metastatic calcification: Deposits in normal tissues, with abnormal calcium metabolism and hypercalcemia.

Gout (Urates & Uric Acids)

A retrogressive disease characterized by urate and uric acid crystal deposition in various tissues, mainly joints.
Deposition stems from an increase in uric acid concentration within blood (hyperuricemia).
Causes can be primary (unknown) and secondary (known cause of hyperuricemia). Possible causes include :Renal dysfunction • High-protein diet or unique type of protein • Vitamin A deficiency due to lack of green food • Insufficient exercise Hereditary predisposition

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Test your knowledge on the lung lesions and diseases associated with silicosis, asbestosis, and siderosis. This quiz covers key health risks and microscopic features pertinent to these occupational lung conditions. Perfect for students and professionals in medical or health-related fields.