General Pathology Practice Questions

Q: Irregular opaque areas are found on radiographs of lower anterior teeth. The teeth are vital. What may be the cause?

Subgingival calculus. **Explanation:** The presence of **irregular opaque areas** on radiographs of lower anterior teeth, specifically when the teeth are **vital**, is a classic presentation of **subgingival calculus**. Calculus is mineralized plaque that contains calcium phosphate salts, making it radiopaque [1]. On a radiograph, it typically appears as irregular, spicule-like, or wedge-shaped projections on the proximal surfaces of the teeth. The lower anterior region is a high-predilection site due to its proximity to the openings of the submandibular and sublingual salivary ducts. **Analysis of Incorrect Options:** * **Cementoma (Periapical Cemento-osseous Dysplasia):** While it appears as a radiopacity in its mature stage, it is located within the bone at the apex of the tooth, not on the tooth surface. * **Condensing Osteitis:** This is a reaction to low-grade infection or inflammation. It presents as a diffuse radiopacity at the root apex and is associated with **non-vital** or pulpally involved teeth. * **Chronic Apical Periodontitis:** This typically presents as a **radiolucency** (not opacity) at the apex, indicating bone resorption due to pulpal necrosis. **Clinical Pearls for NEET-PG:** * **Vitality is the key:** If the teeth are vital, inflammatory periapical pathologies like condensing osteitis or apical periodontitis are ruled out. * **Calculus "Spurs":** Radiographically, calculus is often described as "spurs" or "ring-like" opacities around the cervical neck of the tooth [1]. * **Location:** The most common sites for calculus are the lingual surfaces of mandibular incisors and the buccal surfaces of maxillary molars (near Stensen’s duct) [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 734-735.

Q: Green discoloration on the surface of teeth is due to which of the following?

Nasmyth's membrane. **Explanation:** The correct answer is **Nasmyth’s membrane** (Option C). **1. Why Nasmyth’s Membrane is Correct:** Nasmyth’s membrane, also known as the **primary enamel cuticle**, is a thin, delicate tissue derived from the reduced enamel epithelium and the oral epithelium. It covers the crown of newly erupted deciduous and permanent teeth. This membrane has a high affinity for picking up extrinsic stains from chromogenic bacteria and food debris, which often results in a characteristic **greenish or yellowish-green discoloration** on the tooth surface. It eventually wears away through mastication and toothbrushing. **2. Analysis of Incorrect Options:** * **A. Porphyria:** Congenital erythropoietic porphyria causes a **reddish-brown or purplish** discoloration (erythrodontia) due to the deposition of porphyrins in the dentin and enamel. These teeth fluoresce red under Wood’s lamp. * **B. Internal Resorption:** This is a pathological process where dentin is resorbed from the inside out. It typically presents as a **"Pink Spot of Mummery"** because the vascular pulp tissue becomes visible through the thinned remaining enamel. * **C. Silver:** Chronic exposure to silver (Argyria) or the use of silver-containing dental materials (like amalgams) typically results in a **grey or black** discoloration. **3. NEET-PG High-Yield Pearls:** * **Tetracycline Staining:** Causes yellow/brown/grey bands; occurs if taken during tooth calcification (avoid in pregnancy and children 1.5-2 ppm fluoride in water). * **Bilirubin (Erythroblastosis Fetalis):** Can cause a **greenish-blue** intrinsic discoloration due to bile pigment deposition in the primary teeth.

Q: Pyroptosis is associated with which of the following cytokines?

IL-1. **Explanation:** **Pyroptosis** is a specialized form of programmed cell death that uniquely triggers an intense inflammatory response. It is primarily mediated by the activation of the **Inflammasome** (a multi-protein intracellular complex) [1]. 1. **Why IL-1 is Correct:** The hallmark of pyroptosis is the activation of **Caspase-1** (and sometimes Caspase-4/5/11). Caspase-1 performs two critical functions: * It cleaves the precursor **Pro-IL-1̢** into its active, potent inflammatory form, **IL-1̢** [1]. * It cleaves **Gasdermin D**, which forms pores in the plasma membrane. These pores allow the swelling, osmotic lysis of the cell, and the massive release of IL-1 into the extracellular space, recruiting further inflammatory cells. 2. **Why Other Options are Incorrect:** * **IL-2:** Primarily a T-cell growth factor involved in adaptive immunity and lymphocyte proliferation. * **IL-5:** Involved in eosinophil activation and recruitment; it is a key cytokine in Type I hypersensitivity and helminthic infections. * **IL-6:** A major pro-inflammatory cytokine involved in the acute phase response (CRP production), but it is not the direct product of the inflammasome-caspase-1 pathway that defines pyroptosis. **High-Yield Clinical Pearls for NEET-PG:** * **Key Molecule:** **Gasdermin D** is the "pore-forming" protein essential for pyroptosis. * **Mechanism:** Unlike apoptosis (which is "silent"), pyroptosis is **pro-inflammatory** due to the release of IL-1 and IL-18 [1]. * **Infectious Link:** It is often triggered by intracellular pathogens (e.g., *Salmonella*, *Shigella*) to eliminate the niche of the pathogen while alerting the immune system. * **Distinction:** While apoptosis uses Caspase-3, 8, and 9, pyroptosis is defined by **Caspase-1** [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, p. 196.

Q: This gene mapping indicates:

Down’s syndrome. ***Down's syndrome*** - The gene mapping/karyotype shows **trisomy 21** (47,XY+21 or 47,XX+21), which is the characteristic chromosomal abnormality for Down's syndrome. - This extra chromosome 21 causes the classic features including **intellectual disability**, **characteristic facial features**, and increased risk of **congenital heart defects**. *Klinefelter syndrome* - Caused by **XXY karyotype** (47,XXY), not trisomy 21 as shown in the gene mapping. - Presents with **hypogonadism**, **tall stature**, and **infertility** in males, not the features associated with chromosome 21. *Cri du chat syndrome* - Results from **deletion of chromosome 5p** (5p- syndrome), not an extra chromosome 21. - Characterized by a distinctive **high-pitched cry**, **microcephaly**, and **severe intellectual disability**. *Eagle's syndrome* - This is **not a chromosomal disorder** and would not be identified through gene mapping or karyotype analysis. - It's an anatomical condition involving **elongated styloid process** causing throat and neck pain, unrelated to genetic abnormalities.

Question 1

Which of the following is FALSE regarding a granuloma?

Accepted Answer

Aspiration shows straw-colored fluid.

Answer

Size is lesser than a periapical cyst.

Answer

Volume of injection of radiopaque dye intake is less.

Answer

Electrophoresis shows a faint to moderate pattern in the albumin zone.

Question 2

Fats are stained by which of the following methods?

Accepted Answer

Oil red O

Answer

Hematoxylin and eosin

Answer

Periodic Acid Schiff

Answer

GMS Silver Stain

Question 3

Which of the following is an example of physiological atrophy?

Accepted Answer

Decrease in uterus size after delivery

Answer

Disuse atrophy

Answer

Atrophy of a muscle after nerve damage

Answer

Senile atrophy

Question 4

All of the following can trigger sensors of cell damage in the cytoplasm, except:

Accepted Answer

Increased intracellular potassium ion concentration

Answer

Adenosine triphosphate

Answer

Deoxyribonucleic acid

Answer

Uric acid

Question 5

Which fixative is commonly used in histopathology?

Accepted Answer

10% buffered neutral formalin

Answer

Bouin's fixative

Answer

Glutaraldehyde

Answer

Ethyl alcohol

Question 6

The gene that predisposes to retinoblastoma is located at which chromosomal band?

Accepted Answer

Chromosome 13q14

Answer

Chromosome 15q11

Answer

Chromosome 11p13

Answer

Chromosome 22q11

Question 7

Irregular opaque areas are found on radiographs of lower anterior teeth. The teeth are vital. What may be the cause?

Accepted Answer

Subgingival calculus

Answer

Cementoma

Answer

Condensing osteitis

Answer

Chronic apical periodontitis

Question 8

Green discoloration on the surface of teeth is due to which of the following?

Accepted Answer

Nasmyth's membrane

Answer

Porphyra

Answer

Internal resorption

Answer

Silver

Question 9

Pyroptosis is associated with which of the following cytokines?

Accepted Answer

IL-1

Answer

IL-2

Answer

IL-5

Answer

IL-6

Question 10

This gene mapping indicates:

Accepted Answer

Down’s syndrome

Answer

Klinefelter syndrome

Answer

Cri du chat syndrome

Answer

Eagle’s syndrome

General Pathology — MCQs

General Pathology — MCQs

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