Anesthesiology
1 questionsCalcium homeostasis disturbance is the predominant pathophysiological mechanism in
NEET-PG 2012 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1061: 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
1 questionsInvestigation of choice in pheochromocytoma is:
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1061: 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.
Pharmacology
1 questionsWhich amino acid-derived neurotransmitter is primarily targeted in the pharmacological treatment of depression?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 1061: Which amino acid-derived neurotransmitter is primarily targeted in the pharmacological treatment of depression?
- A. Histamine
- B. None of the options
- C. Serotonin (Correct Answer)
- D. Acetylcholine
Explanation: ***Serotonin*** - **Serotonin** is an amino acid-derived neurotransmitter (from **tryptophan**) known to play a crucial role in mood regulation, sleep, appetite, and other functions, making it a primary target for **antidepressant medications**. - Medications like **Selective Serotonin Reuptake Inhibitors (SSRIs)** increase serotonin levels in the brain to alleviate symptoms of depression. *Histamine* - **Histamine** is an amino acid-derived neurotransmitter (from **histidine**) primarily involved in allergic reactions, inflammation, and regulating wakefulness. - While it has some central nervous system effects, its primary role is not directly in the treatment of **depression**. *Acetylcholine* - **Acetylcholine** is a neurotransmitter involved in muscle contraction, learning, memory, and attention, and is not derived from amino acids; it is synthesized from **choline** and acetyl-CoA. - It is not directly used for treating **depression**, although imbalances can play a role in cognitive aspects of some psychiatric disorders. *None of the options* - This option is incorrect because **Serotonin** is indeed an amino acid-derived neurotransmitter (from tryptophan) targeted for treating **depression**. - Many antidepressant drugs work by modulating **serotonergic pathways**.
Physiology
1 questionsNarcolepsy is due to abnormality in ?
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 1061: Narcolepsy is due to abnormality in ?
- A. Hypothalamus (Correct Answer)
- B. Neocortex
- C. Cerebellum
- D. Medulla oblongata
Explanation: **Hypothalamus** - Narcolepsy is primarily caused by the loss of **orexin (hypocretin)** producing neurons in the **hypothalamus**, which are crucial for maintaining wakefulness. - This deficiency leads to dysregulation of **sleep-wake cycles**, causing excessive daytime sleepiness and other narcolepsy symptoms. *Neocortex* - The neocortex is involved in higher-level cognitive functions, sensory perception, and voluntary movement, but it is not the primary site of pathology in narcolepsy. - While sleep stages involve cortical activity, the core deficit in narcolepsy does not originate here. *Cerebellum* - The cerebellum is mainly responsible for motor control, coordination, and balance. - Its dysfunction is associated with ataxic gait and coordination problems, not the sleep disturbances characteristic of narcolepsy. *Medulla oblongata* - The medulla oblongata controls vital autonomic functions like breathing, heart rate, and blood pressure. - While involved in sleep regulation pathways, it is not the primary anatomical location affected in narcolepsy.
Psychiatry
2 questionsWhich of the following is not a characteristic of schizoid personality disorder?
Which of the following factors is most commonly associated with suicidal tendencies?
NEET-PG 2012 - Psychiatry NEET-PG Practice Questions and MCQs
Question 1061: Which of the following is not a characteristic of schizoid personality disorder?
- A. Prone to fantasy
- B. Introspective
- C. Aloof & detached
- D. Suspicious (Correct Answer)
Explanation: ***Suspicious*** - **Suspiciousness** and mistrust of others are core features of **paranoid personality disorder**, not schizoid personality disorder. - Individuals with schizoid personality disorder are typically apathetic towards others rather than actively distrustful. *Aloof & detached* - Individuals with schizoid personality disorder are characterized by a pervasive pattern of **detachment from social relationships** and a restricted range of emotional expression. - They often appear emotionally cold and indifferent to praise or criticism, indicating their aloof nature. *Prone to fantasy* - People with schizoid personality disorder frequently engage in **excessive daydreaming** and imaginative fantasy as an escape from reality. - This tendency is a coping mechanism for their limited social interaction and emotional expression. *Introspective* - Schizoid individuals tend to be **preoccupied with their inner world** and thoughts, often to the exclusion of external social interactions. - Their introspective nature contributes to their social withdrawal and isolation.
Question 1062: Which of the following factors is most commonly associated with suicidal tendencies?
- A. Female gender
- B. Severe depression (Correct Answer)
- C. Chronic illness
- D. Younger age group
Explanation: ***Severe depression*** - **Major depressive disorder** is the strongest and most common risk factor for suicidal ideation and attempts, significantly increasing suicidal tendencies [1]. - The profound **hopelessness**, **worthlessness**, and altered cognitive processing associated with severe depression contribute largely to suicidal thoughts [2]. - Depression is present in approximately **90%** of individuals who die by suicide. *Female gender* - While **females** have higher rates of **suicide attempts** and self-harm, **males** have a higher rate of completed suicides using more lethal methods. - Female gender alone is not the most common risk factor for suicidal tendencies compared to the profound impact of severe mental illness like depression [1]. *Chronic illness* - **Chronic medical conditions** can increase the risk of depression and subsequent suicidal ideation due to pain, functional limitations, and loss of independence [3]. - However, chronic illness is generally considered an **indirect risk factor**, often mediating its effect through the development of mental health disorders like depression [3]. *Younger age group* - Suicide is a leading cause of death in **adolescents and young adults**, highlighting significant concern in this demographic [1]. - While younger age is a risk factor, especially with concurrent mental health issues or stressors, it is not as universally predictive of suicidal tendencies as severe depression across all age groups [1].
Radiology
3 questionsPopcorn calcification is seen in:
Investigation of choice for intramedullary SOL is -
Which of the following is not typically seen on a chest X-ray in pulmonary artery hypertension?
NEET-PG 2012 - Radiology NEET-PG Practice Questions and MCQs
Question 1061: Popcorn calcification is seen in:
- A. Pulmonary hamartoma (Correct Answer)
- B. Bronchogenic carcinoma
- C. Tuberculosis
- D. Pulmonary metastases
Explanation: ***Pulmonary hamartoma*** - **Popcorn calcification** is a pathognomonic radiographic finding highly suggestive of **pulmonary hamartoma**, a **benign tumor** composed of cartilage, fat, and connective tissue - This characteristic calcification pattern is due to the presence of **chondroid (cartilaginous) tissue** within the lesion - Appears as coarse, irregular calcifications resembling popcorn on chest X-ray or CT scan *Bronchogenic carcinoma* - Malignant lung lesions typically show **irregular, spiculated, or ill-defined margins** and tend to grow rapidly - While calcification can occur in some lung malignancies, it usually appears as **eccentric, stippled, or amorphous** rather than the distinctive popcorn pattern - Popcorn calcification is not a feature of primary lung cancers *Tuberculosis* - **Granulomatous infections** such as tuberculosis often lead to calcification, but it usually presents as **laminated, clustered, or target-like patterns** in lymph nodes or within granulomas (Ghon lesion, Ranke complex) - **Popcorn calcification** is not a typical feature of active or healed tuberculous lesions *Pulmonary metastases* - **Metastatic lesions** are generally not calcified, although a few primary tumors (e.g., mucinous adenocarcinoma, osteosarcoma, chondrosarcoma) can metastasize as calcified nodules - When calcification is present in metastases, it is rarely in the specific **popcorn pattern** and is usually diffuse, punctate, or amorphous
Question 1062: Investigation of choice for intramedullary SOL is -
- A. MRI (Correct Answer)
- B. USG
- C. CT
- D. X-ray
Explanation: ***MRI*** - **Magnetic Resonance Imaging (MRI)** is the investigation of choice for intramedullary lesions due to its superior **soft tissue contrast** and ability to visualize the **spinal cord** parenchyma. - It provides detailed information on lesion size, location, and internal characteristics, which is crucial for diagnosis and surgical planning. *USG* - **Ultrasound (USG)** has limited utility for intramedullary lesions as a primary diagnostic tool because **bone impedes sound waves**, making it difficult to visualize structures within the spinal canal. - It might be used for neonatal spinal screening or intraoperative guidance, but not for definitive diagnosis of intramedullary lesions in adults. *CT* - **Computed Tomography (CT)** excels at visualizing **bone structures** and calcifications, but it provides less detailed information about soft tissue elements like the spinal cord compared to MRI. - While it can identify bony changes associated with intramedullary lesions, it is not the preferred initial imaging modality for characterizing the lesion itself. *X-ray* - **X-rays** provide basic imaging of bone but offer essentially **no visualization of soft tissues** such as the spinal cord or intramedullary lesions. - They are primarily used to identify gross bony abnormalities like fractures or severe degenerative changes, not for subtle intraspinal pathologies.
Question 1063: Which of the following is not typically seen on a chest X-ray in pulmonary artery hypertension?
- A. Enlargement of central arteries
- B. Peripheral pruning
- C. Narrowing of central arteries (Correct Answer)
- D. None of the options
Explanation: ***Narrowing of central arteries*** - **Pulmonary artery hypertension** is characterized by the **enlargement of the central pulmonary arteries** due to increased pressure. - **Narrowing of central arteries** would contradict the hemodynamic changes seen in pulmonary hypertension. - This is the finding that is **NOT typically seen**, making this the correct answer. *Enlargement of central arteries* - This is a **hallmark radiographic finding** in pulmonary hypertension, reflecting the **dilatation of the main and proximal pulmonary arteries** due to increased pressure. - The **pulmonary artery segment becomes prominent**, often appearing convex on the left heart border. *Peripheral pruning* - This refers to the **abrupt tapering and loss of peripheral pulmonary vascular markings**, indicating reduced blood flow to the distal lung parenchyma. - It is a **common finding in advanced pulmonary hypertension**, as the distal vessels constrict and become obliterated. *None of the options* - This is incorrect since **narrowing of central arteries** is clearly not a typical finding in pulmonary hypertension.
Surgery
1 questionsHirschsprung disease is confirmed by ?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 1061: Hirschsprung disease is confirmed by ?
- A. Rectal biopsy (Correct Answer)
- B. Per/Rectal examination
- C. Rectal manometry
- D. X-ray abdomen
Explanation: ***Rectal biopsy*** - A **rectal biopsy** is the most definitive diagnostic test for Hirschsprung disease, revealing the absence of **ganglion cells** in the submucosal and myenteric plexuses. - This procedure involves taking a small tissue sample from the rectum, which is then examined under a microscope for characteristic histological changes. *Per/Rectal examination* - A **per/rectal examination** may reveal an empty rectum followed by a gush of stool and gas upon withdrawal of the finger, which is suggestive but not diagnostic. - It is a **clinical finding** that prompts further investigation but does not provide histological confirmation of aganglionosis. *Rectal manometry* - **Rectal manometry** measures pressures within the rectum and can detect the absence of the **rectoanal inhibitory reflex** (RAIR), a hallmark of Hirschsprung disease. - While highly sensitive, it is a **physiological test** indicating functional abnormalities, but it does not provide the definitive histological diagnosis of aganglionosis. *X-ray abdomen* - An **X-ray of the abdomen** may show dilated loops of bowel proximal to a narrowed, aganglionic segment, indicating intestinal obstruction. - This imaging study is useful for **initial assessment** and identifying signs of obstruction, but it is not specific for Hirschsprung disease and cannot confirm the absence of ganglion cells.