NEET-PG 2015 Practice Questions

Q: Trigone of urinary bladder develops from:

Mesoderm. ***Mesoderm*** - The **trigone** of the urinary bladder develops from the **distal ends of the mesonephric (Wolffian) ducts**, which are **mesodermal in origin**. - These ducts are **absorbed into the posterior wall of the bladder**, forming the smooth triangular area between the two ureteric orifices and the internal urethral orifice [1]. - Although the epithelium of the trigone is later **replaced by endodermal epithelium** from the urogenital sinus, the **structural origin remains mesodermal**. - This is a classic example of **epithelial metaplasia** where endodermal epithelium replaces mesodermal tissue. *Endoderm of urachus* - The **urachus** is the fibrous remnant of the allantois that connects the apex of the bladder to the umbilicus. - It forms the **median umbilical ligament** in adults and does **not contribute to the trigone**. - The **urogenital sinus** (endodermal) forms the majority of the bladder body, but not the trigone. *Ectoderm* - The **ectoderm** forms the nervous system, epidermis, and sensory epithelia. - It does **not contribute** to the development of the urinary bladder or its trigone. - The urinary system is derived from **mesoderm** (kidneys, ureters, trigone) and **endoderm** (bladder body, urethra). *None of the options* - This is incorrect because **mesoderm** is the correct embryological origin of the trigone. - The mesonephric ducts that form the trigone are definitively mesodermal structures.

Q: During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?

Illuminate with ultraviolet (UV) light. ***Illuminate with ultraviolet (UV) light*** - **UV light** causes residual tattoo pigments, even faded ones, to **fluoresce**, making them visible again for identification. - This method is particularly effective for **older or faded tattoos** where the pigment has degraded or spread. *Use a spectrophotometer for analysis* - A spectrophotometer is used to measure the **intensity of light** as a function of wavelength, which is useful for **analyzing chemical components or color intensity**. - While it can analyze pigments, it is not the primary or most practical method for merely **identifying the presence and pattern of a faded tattoo** on skin, especially in a postmortem context. *Illuminate with ordinary light* - **Ordinary visible light** is typically insufficient to reveal tattoos that have significantly faded or been subjected to processes that obscure them. - If the tattoo is already faded to the point of being invisible to the naked eye, **ordinary light will not enhance its visibility** as it lacks the specific wavelengths needed to cause fluorescence. *Perform an X-ray examination* - **X-rays** are used to visualize dense structures like **bones and foreign bodies**, not for examining skin or pigments. - Tattoo pigments are generally **not radiopaque** and would not be visible on an X-ray film, rendering this method useless for tattoo identification.

Q: A 50 year old male presents with fever and malaise for 4 months and pain in the knees and ankles. Blood tests are normal apart from a raised ESR. Chest x-ray shows bilateral hilar adenopathy and pulmonary infiltrates most severe in the upper and mid zones. Mantoux test is negative. What is the most likely diagnosis?

Sarcoidosis. ***Sarcoidosis*** - The constellation of **bilateral hilar adenopathy**, pulmonary infiltrates (especially in upper/mid zones), **arthralgia** (knees and ankles), and a **negative Mantoux test** in a patient with unexplained fever and malaise is highly suggestive of sarcoidosis [1]. - A **raised ESR** is a non-specific inflammatory marker often seen in sarcoidosis. *Tuberculosis* - While tuberculosis can cause fever, malaise, pulmonary infiltrates, and elevated ESR, a **negative Mantoux test** makes primary or active tuberculosis less likely in an immunocompetent individual. - **Bilateral hilar adenopathy** is also less typical of primary pulmonary tuberculosis compared to sarcoidosis. *Asbestosis* - This is an **occupational lung disease** caused by asbestos exposure, primarily presenting with **progressive dyspnea** and **restrictive lung disease**. - It characteristically involves the **lower lobes**, causes **pleural plaques**, and is not typically associated with acute arthralgia, fever, or prominent hilar adenopathy. *Berylliosis* - This is another **occupational lung disease** resulting from beryllium exposure, often mimicking sarcoidosis both clinically and pathologically [2]. - However, without a history of **beryllium exposure** and given the classic presentation, sarcoidosis is a more prevalent default diagnosis [2].

Q: Which of the following syndromes is least likely to be associated with obesity?

Sipple syndrome. ***Sipple syndrome*** - Sipple syndrome, also known as **multiple endocrine neoplasia type 2**, is primarily associated with **medullary thyroid carcinoma** and does not typically correlate with obesity. - It includes signs like **pheochromocytoma** and **hyperparathyroidism**, but obesity is not a prominent feature. *Cushing syndrome* - Cushing syndrome leads to **excess cortisol**, commonly resulting in weight gain and central obesity [1]. - Characteristic features include **moon facies**, **buffalo hump**, and easy bruising, all associated with obesity [1]. *Pickwinian syndrome* - Pickwinian syndrome, characterized by **severe obesity**, is a condition primarily affecting physical stature and weight. - It is linked to **hypoventilation** and sleep apnea, reinforcing the presence of obesity. *Prader willi syndrome* - Prader-Willi syndrome is marked by **insatiable hunger** leading to **obesity** due to hypothalamic dysfunction [2]. - Individuals with this condition also demonstrate **hypotonia** and developmental delays, commonly accompanied by obesity [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1127-1129. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Central Nervous System Synapse, pp. 454-455.

Q: Neutralization test is

Nagler reaction. ***Nagler reaction*** - The **Nagler reaction** is a biochemical test used to identify **Clostridium perfringens**, based on its ability to produce **alpha-toxin (lecithinase)**, which hydrolyzes lecithin in egg yolk agar. - It is a neutralization test because the lecithinase activity can be **inhibited (neutralized)** by antitoxin, leading to a diminished zone of opalescence or turbidity around colonies grown on egg yolk agar. *Widal test* - The **Widal test** is an **agglutination test** used to diagnose **typhoid fever** by detecting antibodies against *Salmonella typhi* O and H antigens in a patient's serum. - It measures the presence of antibodies that cause bacterial clumping, not the neutralization of a toxin. *Weil-Felix test* - The **Weil-Felix test** is an **agglutination test** used to diagnose **rickettsial infections** like epidemic typhus, scrub typhus, and Rocky Mountain spotted fever. - It detects antibodies that cross-react with specific **Proteus vulgaris** antigens, and is not a neutralization assay for toxins or enzymes. *Paul Bunnel test* - The **Paul-Bunnell test** is an **agglutination test** used to diagnose **infectious mononucleosis** by detecting heterophile antibodies that agglutinate sheep red blood cells. - It relies on the clumping of red blood cells by antibodies and does not involve the neutralization of a microbial product.

Q: Which of the following describes the points marked in the diagram of pelvic measurements?

Diagonal conjugate. ***Diagonal conjugate*** - The image depicts a **bimanual examination** where one hand is inserted vaginally to measure the distance from the **lower border of the pubic symphysis** to the **sacral promontory**. - This measurement directly corresponds to the **diagonal conjugate**, which is a clinically estimated measurement of the pelvic inlet. *Obstetric conjugate measurement* - The **obstetric conjugate** is the smallest anteroposterior diameter through which the fetal head must pass. - It extends from the **middle of the sacral promontory** to the **innermost aspect of the pubic symphysis** and cannot be measured directly by clinical examination. *True conjugate measurement* - The **true conjugate**, also known as the anatomical conjugate, extends from the **sacral promontory** to the **upper border of the pubic symphysis**. - Like the obstetric conjugate, it is not directly palpable and must be estimated from the diagonal conjugate (true conjugate = diagonal conjugate - 1.5 to 2 cm). *Oblique conjugate measurement* - The **oblique conjugate** measures the distance between the sacroiliac joint on one side to the iliopectineal eminence on the opposite side. - This measurement is not typically assessed during a routine pelvic examination as depicted and is more relevant for identifying asymmetric pelvic deformities.

Q: Which of the following is not a known cause of neuroregression in children?

ADHD. ***ADHD*** - **Attention-deficit/hyperactivity disorder (ADHD)** is a neurodevelopmental disorder characterized by persistent patterns of inattention, hyperactivity, and impulsivity. It is **not** a cause of neuroregression. - While ADHD can impact cognitive and behavioral functioning, it does not involve a loss of previously acquired developmental milestones or skills. *Wilson's disease* - **Wilson's disease** is an inherited disorder that causes **copper accumulation** in organs, particularly the liver and brain. - Neurological symptoms, including **neuroregression**, can occur due to copper toxicity in the central nervous system. *Vitamin B12 deficiency* - **Vitamin B12 deficiency** can lead to neurological complications such as **subacute combined degeneration** of the spinal cord and peripheral neuropathy. - In children, severe or prolonged deficiency can impair brain development and lead to **developmental regression**. *Ataxia telangiectasia* - **Ataxia telangiectasia** is a rare, neurodegenerative, inherited disease that affects multiple body systems. - It is characterized by progressive **cerebellar ataxia**, leading to **neuroregression** and intellectual disability over time.

Q: What is the mechanism of action of duloxetine?

Inhibition of both serotonin and norepinephrine reuptake. ***Inhibition of both serotonin and norepinephrine reuptake*** - **Duloxetine** is a **serotonin-norepinephrine reuptake inhibitor (SNRI)**, meaning it blocks the reuptake of both neurotransmitters, increasing their concentrations in the synaptic cleft [2]. - This dual action contributes to its efficacy in treating **depression**, **anxiety disorders**, and **neuropathic pain** [2], [3]. *Selective serotonin reuptake inhibition* - This describes the mechanism of **SSRIs (Selective Serotonin Reuptake Inhibitors)**, such as fluoxetine or sertraline, which primarily target serotonin [1]. - Duloxetine's mechanism is broader, affecting both serotonin and norepinephrine [2]. *Selective norepinephrine reuptake inhibition* - This mechanism is characteristic of medications like **atomoxetine**, used for ADHD, which primarily targets norepinephrine. - Duloxetine has a dual action, not selective to norepinephrine alone. *No effect on neurotransmitter reuptake* - Medications with no effect on neurotransmitter reuptake would not typically be effective as antidepressants or treatments for neuropathic pain. - Duloxetine's therapeutic effects are directly linked to its inhibition of reuptake for both serotonin and norepinephrine [2], [4].

Q: Which of the following is the only clinically available depolarizing muscle relaxant?

Suxamethonium. ***Suxamethonium*** - **Suxamethonium** (also known as succinylcholine) is currently the **only depolarizing neuromuscular blocker** available for clinical use. - It works by mimicking acetylcholine, binding to and activating nicotinic acetylcholine receptors at the **neuromuscular junction**, causing initial muscle fasciculations followed by relaxation. *Decamethonium* - **Decamethonium** is a depolarizing neuromuscular blocker but is **no longer clinically available** due to its prolonged action and side effects. - It also acts by opening nicotinic acetylcholine receptor channels, leading to depolarization and muscle paralysis. *Mivacurium* - **Mivacurium** is a **nondepolarizing neuromuscular blocker**, meaning it acts as a competitive antagonist at the acetylcholine receptor. - It is known for its **short duration of action** due to rapid hydrolysis by plasma cholinesterases but is not depolarizing. *None of the options* - This option is incorrect because suxamethonium is indeed a clinically available depolarizing muscle relaxant. - The question specifically asks for the *only* clinically available one, which suxamethonium fulfills.

Q: Epidural hematoma on CT scan shows which of the following?

Biconvex hyperdense lesion. ***Biconvex hyperdense lesion*** - An epidural hematoma is characterized by a **biconvex** (lens-shaped) collection of blood between the dura mater and the skull. - Since it is an acute hemorrhage, the blood appears **hyperdense** (bright white) on a CT scan. *Crescent-shaped hyperdense lesion* - A **crescent shape** is characteristic of an **acute subdural hematoma**, not an epidural hematoma. - While acute subdural hematomas are also hyperdense, their crescent shape (following the contour of the brain) distinguishes them from the biconvex epidural hematomas. - Epidural hematomas are limited by suture lines and appear lens-shaped, while subdural hematomas can cross suture lines. *Biconcave hypodense lesion* - A **biconcave** shape is not a standard description in neuroradiology and does not represent epidural hematoma. - **Hypodense** would indicate an older lesion or other pathology, not acute hemorrhage. *Ring-enhancing hypodense lesion* - **Ring-enhancing lesions** are typically associated with abscesses, glioblastoma, or metastatic tumors, not an acute hematoma. - A **hypodense** (darker) center with enhancement would indicate an abscess or necrotic tumor, not a fresh extravasation of blood.

Question 1

Trigone of urinary bladder develops from:

Accepted Answer

Mesoderm

Answer

Ectoderm

Answer

None of the options

Answer

Endoderm of urachus

Question 2

During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?

Accepted Answer

Illuminate with ultraviolet (UV) light

Answer

Use a spectrophotometer for analysis

Answer

Illuminate with ordinary light

Answer

Perform an X-ray examination

Question 3

A 50 year old male presents with fever and malaise for 4 months and pain in the knees and ankles. Blood tests are normal apart from a raised ESR. Chest x-ray shows bilateral hilar adenopathy and pulmonary infiltrates most severe in the upper and mid zones. Mantoux test is negative. What is the most likely diagnosis?

Accepted Answer

Sarcoidosis

Answer

Tuberculosis

Answer

Asbestosis

Answer

Berylliosis

Question 4

Which of the following syndromes is least likely to be associated with obesity?

Accepted Answer

Sipple syndrome

Answer

Cushing syndrome

Answer

Prader willi syndrome

Answer

Pickwickian syndrome

Question 5

Neutralization test is

Accepted Answer

Nagler reaction

Answer

Widal test

Answer

Weil-Felix test

Answer

Paul-Bunnell test

Question 6

Which of the following describes the points marked in the diagram of pelvic measurements?

Accepted Answer

Diagonal conjugate

Answer

Obstetric conjugate measurement

Answer

True conjugate measurement

Answer

Oblique conjugate measurement

Question 7

Which of the following is not a known cause of neuroregression in children?

Accepted Answer

ADHD

Answer

Vitamin B12 deficiency

Answer

Ataxia telangiectasia

Answer

Wilson's disease

Question 8

What is the mechanism of action of duloxetine?

Accepted Answer

Inhibition of both serotonin and norepinephrine reuptake

Answer

Selective serotonin reuptake inhibition

Answer

Selective norepinephrine reuptake inhibition

Answer

No effect on neurotransmitter reuptake

Question 9

Which of the following is the only clinically available depolarizing muscle relaxant?

Accepted Answer

Suxamethonium

Answer

Decamethonium

Answer

Mivacurium

Answer

None of the options

Question 10

Epidural hematoma on CT scan shows which of the following?

Accepted Answer

Biconvex hyperdense lesion

Answer

Crescent-shaped hyperdense lesion

Answer

Biconcave hypodense lesion

Answer

Ring-enhancing hypodense lesion

NEET-PG 2015

Anatomy

Forensic Medicine

Internal Medicine

Microbiology

Obstetrics and Gynecology

Pediatrics

Pharmacology

Radiology