Anesthesiology
1 questionsCalcium homeostasis disturbance is the predominant pathophysiological mechanism in
NEET-PG 2012 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1031: Calcium homeostasis disturbance is the predominant pathophysiological mechanism in
- A. Duchenne Muscular Dystrophy (DMD)
- B. Limb Girdle Muscular Dystrophy
- C. Malignant hyperthermia (Correct Answer)
- D. Tibial Muscular Dystrophy
Explanation: ***Malignant hyperthermia*** - Malignant hyperthermia is caused by a genetic defect in the **ryanodine receptor (RYR1)** in skeletal muscle, leading to an uncontrolled release of **intracellular calcium** from the sarcoplasmic reticulum. - This excessive calcium release results in sustained muscle contraction, increased metabolism, and a rapid rise in body temperature. *Duchenne Muscular Dystrophy (DMD)* - DMD is primarily caused by a mutation in the **dystrophin gene**, which leads to the absence or severe deficiency of the **dystrophin protein**. - This deficiency results in muscle fiber fragility, cycles of degeneration and regeneration, and eventual replacement of muscle with fibrous and fatty tissue, rather than a primary calcium homeostasis disturbance. *Limb Girdle Muscular Dystrophy* - This group of disorders is characterized by progressive weakness and wasting of muscles, primarily affecting the **shoulders and hips**. - The pathophysiology involves genetic defects in various proteins that are crucial for muscle function and integrity, such as **sarcoglycans** or **calpain-3**, not primarily calcium dysregulation. *Tibial Muscular Dystrophy* - Tibial muscular dystrophy is a rare, late-onset disorder characterized by progressive weakness of the **anterior tibial muscles**. - It is typically caused by mutations in the **TTN gene**, encoding for the protein **titin**, which plays a vital role in muscle elasticity and structural integrity, rather than a primary calcium imbalance.
Internal Medicine
6 questionsJaw tightness is typically seen in:
Most common symptom of genitourinary TB
In a patient with suspected vitamin B12 deficiency, which condition would result in an abnormal Schilling test?
Secretory diarrhea is not typically associated with which of the following conditions?
What is the daily temperature variation in remittent fever?
Investigation of choice in pheochromocytoma is:
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1031: Jaw tightness is typically seen in:
- A. Coarctation of aorta
- B. Giant cell arteritis (GCA) (Correct Answer)
- C. Polyarteritis nodosa (PAN)
- D. Granulomatosis with Polyangiitis (GPA)
Explanation: ***Giant cell arteritis (GCA)*** - **Jaw claudication** or tightness, difficulty chewing, and pain in the jaw are classic symptoms of GCA, resulting from **ischemia of the masticatory muscles**. [1] - This condition is a **large vessel vasculitis** that frequently affects the **temporal arteries** and can lead to blindness if untreated. [1] *Polyarteritis nodosa (PAN)* - PAN is a **necrotizing vasculitis** that typically affects **medium-sized arteries**, often sparing the pulmonary circulation. [1] - Common symptoms include **neuropathy**, abdominal pain, and skin lesions (e.g., livedo reticularis), but **jaw tightness is not a typical feature**. *Coarctation of aorta* - This is a **congenital narrowing of the aorta**, leading to symptoms like **upper extremity hypertension**, headache, and claudication in the lower extremities. - **Jaw tightness is not a symptom** associated with coarctation of the aorta. *Granulomatosis with Polyangiitis (GPA)* - GPA is a **small-vessel vasculitis** characterized by **granulomatous inflammation** involving the upper and lower respiratory tracts, and glomerulonephritis. - Symptoms often include **sinusitis**, lung nodules, and kidney disease, but **jaw claudication is not a characteristic presentation**.
Question 1032: Most common symptom of genitourinary TB
- A. Increased frequency
- B. Renal colic
- C. Painful micturition
- D. Hematuria (Correct Answer)
Explanation: ***Hematuria*** - **Gross or microscopic hematuria** is the most common symptom of genitourinary tuberculosis, often occurring early in the disease course. - It results from the **inflammatory and destructive changes** caused by Mycobacterium tuberculosis in the urinary tract. *Renal colic* - Renal colic is typically associated with **acute obstruction of the ureter**, often by a renal stone. - While TB can cause strictures leading to obstruction, **colic** itself is not the most common initial symptom. *Increased frequency* - Increased urinary frequency is a common symptom in genitourinary TB, especially with **bladder involvement**. - However, it ranks below hematuria in terms of overall prevalence as the *most common* symptom. *Painful micturition* - **Dysuria** or painful micturition is frequently observed in genitourinary TB, particularly with **bladder or urethral inflammation**. - While common, it is generally less prevalent than hematuria as the presenting complaint.
Question 1033: In a patient with suspected vitamin B12 deficiency, which condition would result in an abnormal Schilling test?
- A. Amylase deficiency
- B. Pancreatic endocrine insufficiency
- C. Lipase deficiency
- D. Intrinsic factor deficiency (Correct Answer)
Explanation: ***Intrinsic factor deficiency*** - The Schilling test assesses the absorption of **vitamin B12**. **Intrinsic factor** is crucial for B12 absorption in the ileum. - Deficiency of intrinsic factor, as seen in **pernicious anemia**, directly impairs B12 absorption, leading to an abnormal Schilling test result [1]. *Amylase deficiency* - **Amylase** is an enzyme involved in the digestion of carbohydrates, not vitamin B12 absorption [2]. - Its deficiency would primarily cause carbohydrate malabsorption symptoms, not an abnormal Schilling test. *Pancreatic endocrine insufficiency* - **Pancreatic endocrine function** relates to hormone production (e.g., insulin, glucagon), while exocrine function involves digestive enzymes. - Impairment of endocrine function does not directly affect vitamin B12 absorption or the Schilling test. *Lipase deficiency* - **Lipase** is an enzyme essential for the digestion of fats [2]. - Its deficiency would lead to fat malabsorption (steatorrhea) but would not affect vitamin B12 absorption or the Schilling test results.
Question 1034: Secretory diarrhea is not typically associated with which of the following conditions?
- A. Phenolphthalein
- B. Cholera
- C. Celiac disease (Correct Answer)
- D. VIPoma
Explanation: ***Celiac disease*** [1] - Characterized by **malabsorption** due to immune-mediated damage to the intestinal mucosa, leading to **osmotic diarrhea** rather than secretory diarrhea [1]. - Symptoms include **bloating**, **weight loss**, and **steatorrhea**, which are not consistent with secretory processes. *Cholera* - Caused by **Vibrio cholerae**, leading to **massive secretory diarrhea** due to the action of cholera toxin on intestinal epithelial cells. - Presents with **watery diarrhea**, potentially leading to **dehydration** and electrolyte imbalances. *Addison's Disease* - This condition may cause **diarrhea** but typically results in **non-secretory diarrhea**, often associated with adrenal insufficiency symptoms. - Presenting features include **fatigue**, **weight loss**, and **hyperpigmentation**, not primarily secretory processes. *Phenolphthalein* - A laxative that can induce **secretory diarrhea** through its stimulant effects on the bowel. - Its mechanism leads to increased fluid secretion in the intestines, thus contributing to secretory diarrhea.
Question 1035: What is the daily temperature variation in remittent fever?
- A. < 0.5 °C
- B. > 1.0 °C (Correct Answer)
- C. < 1.0 °C
- D. > 2.0 °C
Explanation: ***> 1.0 °C*** - In **remittent fever**, the temperature fluctuates by **more than 1.0 °C** (or 2°F) over a 24-hour period. [1] - Despite the significant variation, the temperature **never returns to normal** during the day. [1] *< 0.5 °C* - A variation of less than 0.5 °C (or 1°F) is more characteristic of a **sustained or continuous fever**, where the temperature remains elevated with minimal fluctuation. [1] - This pattern is seen in conditions like **typhoid fever** or **pneumonia**. *< 1.0 °C* - While reflecting some fluctuation, a variation of less than 1.0 °C is not sufficient to classify a fever as remittent. - Remittent fever specifically requires a **larger daily swing** in temperature. *> 2.0 °C* - While a variation greater than 2.0 °C would certainly fall under the definition of remittent fever (as it's > 1.0 °C), the defining lower limit for remittent fever is typically **> 1.0 °C (or 2°F)**. - A larger fluctuation might occur, but > 1.0 °C is the minimum threshold.
Question 1036: Investigation of choice in pheochromocytoma is:
- A. CT scan
- B. Urinary catecholamines (Correct Answer)
- C. MIBG scan
- D. MRI Scan
Explanation: ***Urinary catecholamines*** - Measurement of **24-hour urinary fractionated metanephrines and catecholamines** is the initial **biochemical test of choice**. - These biochemical tests are preferred over plasma levels due to the **episodic release** of hormones from a pheochromocytoma, which can lead to high false-negative rates in single plasma measurements. *CT scan* - While a **CT scan** is a crucial **imaging modality** for localizing a pheochromocytoma once the biochemical diagnosis is established [1], it is not the *initial* diagnostic investigation. - Imaging should be performed only after **biochemical confirmation** to avoid unnecessary investigations of incidental adrenal masses [1]. *MIBG scan* - An **MIBG scan** (metaiodobenzylguanidine scan) is a **functional imaging study** used primarily for **localizing metastatic pheochromocytomas** [1] or for cases where CT/MRI is equivocal. - It is not the initial investigation but rather a **secondary imaging test** [1]. *MRI Scan* - **MRI** is an alternative **imaging modality** to CT for localizing pheochromocytomas [1], especially in pregnant women or when radiation exposure is a concern. - Like CT, it serves as a **localization tool** after biochemical confirmation, not the diagnostic test itself.
Ophthalmology
1 questionsIris coloboma is most common in which location?
NEET-PG 2012 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 1031: Iris coloboma is most common in which location?
- A. Superotemporal
- B. Inferonasal (Correct Answer)
- C. Inferotemporal
- D. Superonasal
Explanation: ***Inferonasal*** - **Iris coloboma** most commonly occurs in the **inferonasal quadrant** (at approximately the **6 o'clock position**) - This location corresponds to the site of the **embryonic fetal fissure** (choroidal fissure), which normally closes during the **5th to 7th week of gestation** - When the fetal fissure fails to close completely, it results in a **keyhole-shaped defect** in the iris, and potentially involves other ocular structures (ciliary body, choroid, retina, optic nerve) along the same inferonasal axis - This is a well-established anatomical pattern seen in **congenital colobomas** *Inferotemporal* - The inferotemporal quadrant is **not the typical location** for iris coloboma - Embryologically, the fetal fissure does not extend into the temporal region, making colobomas in this location extremely rare - Colobomas outside the inferonasal location are usually **atypical colobomas** caused by different mechanisms *Superotemporal* - The superotemporal quadrant is **not associated** with the fetal fissure closure pathway - Colobomas in this location would be considered atypical and not related to embryonic fissure closure defects - This is not a common presentation for congenital iris coloboma *Superonasal* - The superonasal quadrant is also **not part of the fetal fissure pathway** - While superior colobomas can occasionally occur as atypical variants, they do not represent the classic congenital coloboma pattern - The embryological basis for typical coloboma formation does not involve the superior regions of the eye
Pediatrics
1 questionsA 9-month-old child of a diabetic mother presents with tachypnea and hepatomegaly. Echocardiography shows normal cardiac morphology with asymmetric septal hypertrophy. Which of the following medications is indicated for the management of this child's condition?
NEET-PG 2012 - Pediatrics NEET-PG Practice Questions and MCQs
Question 1031: A 9-month-old child of a diabetic mother presents with tachypnea and hepatomegaly. Echocardiography shows normal cardiac morphology with asymmetric septal hypertrophy. Which of the following medications is indicated for the management of this child's condition?
- A. Digoxin
- B. Frusemide
- C. Propranolol (Correct Answer)
- D. Isoptin
Explanation: ***Propranolol*** - **Propranolol** is a **beta-blocker** that is indicated for **hypertrophic cardiomyopathy** (HCM) in infants, especially those of diabetic mothers. - It works by reducing the **heart rate** and **myocardial contractility**, which decreases the **left ventricular outflow tract (LVOT) obstruction** caused by the hypertrophied septum. *Digoxin* - **Digoxin** is a **positive inotrope**, meaning it increases the force of myocardial contraction. - This effect would worsen the **outflow tract obstruction** in hypertrophic cardiomyopathy and is therefore contraindicated. *Frusemide* - **Frusemide** is a **diuretic** used to manage **fluid overload** and **congestive heart failure**. - While fluid management can be part of heart failure treatment, frusemide does not directly address the underlying **asymmetric septal hypertrophy** or **LVOT obstruction** in this context. *Isoptin* - **Isoptin** (verapamil) is a **non-dihydropyridine calcium channel blocker**. - While some calcium channel blockers can be used in adult hypertrophic cardiomyopathy, verapamil is generally avoided in infants with HCM due to its potential for **negative inotropic effects** and worsening hypotension, especially in the presence of outflow obstruction, and the risk of significant **bradycardia** and **atrioventricular block**.
Pharmacology
1 questionsAll of the following are used for treatment of *H. pylori*, except:
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 1031: All of the following are used for treatment of *H. pylori*, except:
- A. Metronidazole
- B. Amoxicillin
- C. Clarithromycin
- D. Gentamicin (Correct Answer)
Explanation: ***Gentamicin*** - **Gentamicin** is an **aminoglycoside antibiotic** primarily used for severe Gram-negative bacterial infections and is **not effective** against *H. pylori*. - Its mechanism of action and **toxicity profile** (ototoxicity, nephrotoxicity) make it unsuitable for typical *H. pylori* eradication regimens. *Clarithromycin* - **Clarithromycin** is a **macrolide antibiotic** frequently used in **triple therapy regimens** for *H. pylori* eradication. - It works by **inhibiting bacterial protein synthesis**, significantly contributing to the eradication of the bacteria. *Metronidazole* - **Metronidazole** is an **antibiotic** and **antiprotozoal agent** commonly included in *H. pylori* **quadruple therapy** or when penicillin allergies are present. - It acts by forming **cytotoxic compounds** that disrupt bacterial DNA, making it effective against anaerobic and microaerophilic bacteria like *H. pylori*. *Amoxicillin* - **Amoxicillin** is a **beta-lactam antibiotic** that is a cornerstone of many *H. pylori* **eradication regimens**, particularly in standard triple therapy. - It works by **inhibiting bacterial cell wall synthesis**, leading to bacterial lysis.