NEET-PG 2012 Practice Questions

Q: In apoptosis, cytochrome C acts through:

Apaf1. ***Apaf1*** - Cytochrome C released from the mitochondria binds to **Apaf1**, which leads to the formation of the **apoptosome** [1][2]. - This complex activates **caspase-9**, initiating the caspase cascade that leads to apoptosis [2]. *TNF* - Tumor Necrosis Factor (TNF) is involved in **necrosis** and **inflammatory processes**, not directly in the intrinsic pathway of apoptosis. - It activates **caspase-8**, which is part of the **extrinsic pathway**, differing from the role of cytochrome C [1]. *FADD* - FADD (Fas-associated protein with death domain) is part of the **death receptor pathway**, linking to caspase-8, not associated with cytochrome C [1]. - It does not play a role in the assembly of the apoptosome like Apaf1 does. *Bcl_2* - Bcl-2 is an **anti-apoptotic protein** that inhibits apoptosis rather than inducing it or acting through cytochrome C [1]. - It functions by preventing the release of cytochrome C from mitochondria, thereby opposing the apoptotic process [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, p. 310. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 64-67.

Q: Who is recognized as the father of public health?

John Snow. ***John Snow*** - **John Snow** is widely recognized as the **father of epidemiology and modern public health** for his groundbreaking work in identifying the source of the 1854 Broad Street cholera outbreak in London. - He used **mapping and statistical analysis** to demonstrate that cholera was a waterborne disease, challenging the prevailing miasma theory. - His scientific approach to investigating disease patterns established the foundation for modern epidemiological methods and evidence-based public health interventions. *Edward Jenner* - **Edward Jenner** is known for his pioneering work on the **smallpox vaccine** in the late 18th century, which laid the foundation for immunology. - While his contributions were crucial for preventive medicine, his focus was on vaccination rather than broader public health and epidemiological investigation. *James Lind* - **James Lind** was a Scottish naval surgeon who conducted one of the first recorded controlled clinical trials, demonstrating that **citrus fruits cured scurvy** in the mid-18th century. - His work was significant for nutritional science and clinical trial methodology, but not for the comprehensive scope of public health and disease investigation. *Frederick Griffith* - **Frederick Griffith** was a British bacteriologist whose 1928 experiment with *Streptococcus pneumoniae* demonstrated the process of **bacterial transformation**, suggesting that genetic material could be transferred. - His work was foundational for molecular biology and genetics, not directly related to public health practices or epidemiology.

Q: All are seen in pheochromocytoma except which of the following?

Hypotension. ***Hypotension*** - Pheochromocytoma is characterized by the **overproduction of catecholamines** (epinephrine and norepinephrine), which typically cause **hypertension** rather than hypotension. - The classic symptoms of pheochromocytoma, often described as the "5 Ps," are **pain (headache)**, **palpitations**, **perspiration**, **pallor**, and **paroxysmal hypertension**. *Headaches* - **Severe, throbbing headaches** are a very common symptom in pheochromocytoma due to the **vasospastic effects** of high circulating catecholamines. - These headaches are often sudden in onset and can be debilitating. *Weight loss* - The **hypermetabolic state** induced by excessive catecholamines can lead to **increased caloric expenditure** and subsequently, **weight loss**. - Catecholamines increase **basal metabolic rate** and breakdown of fat stores. *Sweating attacks* - **Diaphoresis** or profuse sweating attacks are a hallmark symptom, caused by **sympathetic nervous system activation** due to high catecholamine levels. - These attacks are often paroxysmal and can be accompanied by an exacerbation of other symptoms.

Q: What is the MOST common cause of amblyopia?

Strabismus. ***Strabismus*** - **Strabismic amblyopia** is the **MOST common cause of amblyopia**, accounting for approximately **50% of cases**. - When the eyes are misaligned, the brain suppresses the image from the deviating eye to avoid **diplopia** (double vision). - The prolonged suppression during the critical period of visual development leads to poor visual acuity in the affected eye. - Early detection and treatment (occlusion therapy, correction of refractive errors, alignment surgery) are crucial. *Refractive errors* - **Refractive amblyopia**, particularly **anisometropia** (significant difference in refractive power between eyes), is the **second most common cause**. - The brain suppresses the blurry image from the eye with greater refractive error, leading to poor visual development. - **Bilateral high refractive errors** (isoametropic amblyopia) can also cause amblyopia, though less commonly than anisometropia. *Cataracts* - **Deprivation amblyopia** results from obstruction of the visual axis (congenital cataract, ptosis, corneal opacity). - This is a **less common but more severe** form of amblyopia requiring urgent treatment. - If untreated during the critical period, it can cause **irreversible vision loss**. *None of the options* - Incorrect, as strabismus is a well-established and the most common cause of amblyopia.

Q: Features of vernal conjunctivitis are:

All of the options. ***All of the options*** - **Vernal conjunctivitis (VKC)** is a severe form of allergic conjunctivitis characterized by chronic inflammation of the conjunctiva, impacting the cornea in advanced stages. - **Shield ulcers**, **Horner-Trantas dots**, and **papillary hypertrophy** are all classic clinical features observed in VKC. *Shield ulcer* - This is a **corneal complication** of severe vernal conjunctivitis, characterized by epithelial defects that can lead to significant pain and vision impairment. - It develops due to corneal abrasion from the giant papillae on the upper tarsal conjunctiva and direct corneal toxicity from inflammatory mediators. *Horner-Trantas spots* - These are **gelatinous aggregations** of epithelial cells and eosinophils that appear as white dots at the limbus, particularly evident at the superior limbus. - They are one of the **pathognomonic signs** of vernal conjunctivitis, indicating significant allergic inflammation. *Papillary hypertrophy* - Characterized by the development of **large, flattened papillae** (often described as "cobblestone" papillae) on the upper tarsal conjunctiva. - This hypertrophy is a result of chronic inflammation and proliferation of mast cells, eosinophils, and lymphocytes in the conjunctival stroma.

Q: What is the histological appearance of the brain in Creutzfeldt-Jakob disease?

Spongiform changes. ***Spongiform changes*** - The hallmark histological feature of **Creutzfeldt-Jakob disease (CJD)** is **spongiform degeneration**, characterized by vacuolation of neuronal cell bodies [1]. - It results in a **spongy appearance** of the affected brain regions, particularly in the **cerebral cortex** and **basal ganglia** [1]. *Neuronophagia (can occur in various contexts, not specific to CJD)* - Neuronophagia refers to the phagocytic activity involving **dying neurons**, which can occur in various conditions but is not a defining feature of CJD [2]. - It indicates the presence of **inflammation** or a response to neuronal injury rather than specific changes seen in CJD. *Demyelination (associated with multiple sclerosis)* - Demyelination is primarily associated with conditions like **multiple sclerosis** and is characterized by loss of **myelin sheaths** around neurons. - This is not related to CJD, which involves **prion protein accumulation** and subsequent neuronal degeneration. *Micro abscess (indicative of bacterial infections)* - Micro abscesses indicate localized collections of **pus** typically seen in **bacterial infections**, which is incongruent with the pathophysiology of CJD. - In CJD, there are no signs of **inflammation** or **neutrophilic infiltration** associated with abscess formation [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1284-1286. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Peripheral Nerves and Skeletal Muscles, pp. 1255-1256.

Q: Which of the following drugs is known to cross the blood-brain barrier?

Physostigmine. ***Physostigmine*** - **Physostigmine** is a **tertiary amine** that is uncharged at physiological pH, allowing it to readily cross the **lipophilic blood-brain barrier**. - Its ability to enter the central nervous system makes it useful for treating **central anticholinergic toxicity**, as it can inhibit acetylcholinesterase in the brain. *Glycopyrrolate* - **Glycopyrrolate** is a **quaternary ammonium compound**, meaning it carries a permanent positive charge. - This charge prevents it from crossing the **blood-brain barrier** effectively, limiting its effects to the peripheral nervous system. *Neostigmine* - **Neostigmine** is also a **quaternary ammonium compound**, similar to glycopyrrolate, making it highly ionized. - Due to its poor lipid solubility and charge, **neostigmine** has very limited penetration into the **central nervous system**. *All of the options* - This option is incorrect because both **glycopyrrolate** and **neostigmine** are charged molecules that do not readily cross the **blood-brain barrier**. - Only **physostigmine** among the listed drugs possesses the necessary lipophilicity to enter the central nervous system.

Q: According to the classical monoamine hypothesis of depression, deficiency of which of the following neurotransmitters is MOST commonly emphasized in modern antidepressant therapy?

Serotonin. ***Serotonin*** - The **classical monoamine hypothesis** of depression posits deficiencies in monoamine neurotransmitters including **serotonin (5-HT), norepinephrine, and dopamine**. - Among these, **serotonin** is the **most commonly emphasized** in modern antidepressant therapy, given its central role in mood regulation, sleep, appetite, and cognition. - The majority of first-line antidepressants, such as **SSRIs (Selective Serotonin Reuptake Inhibitors)** and **SNRIs**, primarily target serotonergic pathways, reflecting its clinical importance. - **Clinical relevance**: Serotonin deficiency is associated with depressed mood, anxiety, sleep disturbances, and appetite changes. *Acetylcholine* - **Acetylcholine** is a neurotransmitter involved in cognitive function, memory, and muscle contraction. - It is **not a monoamine** and is not part of the classical monoamine hypothesis of depression. - Acetylcholine deficiency is primarily implicated in **Alzheimer's disease** and other cognitive disorders, not depression. *Dopamine* - **Dopamine** is one of the three monoamines implicated in the classical hypothesis and plays a role in pleasure, reward, motivation, and motor control. - Dopamine deficiency can contribute to symptoms of **anhedonia** (inability to feel pleasure) and lack of motivation in depression. - However, dopamine-targeting antidepressants (like bupropion) are less commonly used as first-line therapy compared to serotonergic agents, making serotonin the most emphasized in clinical practice. *GABA* - **GABA (gamma-aminobutyric acid)** is the primary **inhibitory neurotransmitter** in the central nervous system. - It is **not a monoamine** and is not part of the classical monoamine hypothesis of depression. - GABA dysfunction is primarily associated with **anxiety disorders, seizures, and insomnia**, not depression as per the classical hypothesis.

Q: Simian crease is not seen in which of the following?

Atopic dermatitis. ***Atopic dermatitis*** - **Atopic dermatitis** is a chronic inflammatory skin condition characterized by **eczematous lesions** and **itching**, and does not involve congenital hand abnormalities. - A **Simian crease** (single palmar crease) is a feature associated with certain chromosomal disorders, not skin conditions. *Down* - **Down syndrome** (Trisomy 21) is strongly associated with the presence of a **Simian crease**, along with other distinctive facial and physical features. - This chromosomal anomaly affects development and often results in characteristic dermatoglyphic patterns. *Trisomy 13* - **Trisomy 13** (Patau syndrome) is a severe chromosomal disorder that frequently presents with a **Simian crease** as one of its many congenital abnormalities. - Other features include **polydactyly**, **cleft lip/palate**, and severe intellectual disability. *Trisomy 18* - **Trisomy 18** (Edwards syndrome) is another severe chromosomal disorder commonly associated with a **Simian crease**. - Other features include **clenched fists with overlapping fingers**, **rocker-bottom feet**, and severe intellectual disability. *Noonan syndrome* - While not as classically associated as Down or Trisomy 13, **Noonan syndrome** can sometimes include a **Simian crease** among its varied developmental features. - It is a genetic condition characterized by distinctive facial features, **short stature**, and heart defects, rather than a chromosomal anomaly.

Q: Indications for emergency thoracotomy are all of the following except:

Tension pneumothorax. ***Tension pneumothorax*** - While a life-threatening condition, a **tension pneumothorax** is initially managed with **needle decompression** or **chest tube insertion**, not an immediate emergency thoracotomy. - Emergency thoracotomy is reserved for situations requiring direct repair or control of massive bleeding that cannot be addressed by less invasive means. *Major tracheobronchial injuries* - These injuries can lead to severe **airway obstruction**, **massive air leak**, and **hemorrhage**, necessitating direct surgical repair via emergency thoracotomy. - Prompt surgical intervention is crucial to restore airway integrity and prevent life-threatening respiratory collapse. *Cardiac tamponade* - **Cardiac tamponade** can be caused by penetrating or blunt trauma, leading to circulatory collapse due to compression of the heart. - While initial management may involve pericardiocentesis, persistent or rapidly recurring tamponade, especially after trauma, often requires an **emergency thoracotomy** for direct repair of cardiac injury and evacuation of blood. *Penetrating injuries to anterior chest* - **Penetrating anterior chest injuries** carry a high risk of damage to vital structures such as the heart, great vessels, and major airways. - These injuries often result in rapid **hemodynamic instability**, severe hemorrhage, or cardiac arrest, making emergency thoracotomy essential for direct exploration and definitive repair.

Question 1

In apoptosis, cytochrome C acts through:

Accepted Answer

Apaf1

Answer

FADD

Answer

TNF

Answer

Bcl-2

Question 2

Who is recognized as the father of public health?

Accepted Answer

John Snow

Answer

Edward Jenner

Answer

James Lind

Answer

Frederick Griffith

Question 3

All are seen in pheochromocytoma except which of the following?

Accepted Answer

Hypotension

Answer

Headaches

Answer

Weight loss

Answer

Sweating attacks

Question 4

What is the MOST common cause of amblyopia?

Accepted Answer

Strabismus

Answer

Cataracts

Answer

Refractive errors

Answer

None of the options

Question 5

Features of vernal conjunctivitis are:

Accepted Answer

All of the options

Answer

Papillary hypertrophy

Answer

Horner-Trantas spots

Answer

Shield ulcer

Question 6

What is the histological appearance of the brain in Creutzfeldt-Jakob disease?

Accepted Answer

Spongiform changes

Answer

Neuronophagia

Answer

Micro abscess

Answer

Demyelination

Question 7

Which of the following drugs is known to cross the blood-brain barrier?

Accepted Answer

Physostigmine

Answer

Glycopyrrolate

Answer

Neostigmine

Answer

All of the options

Question 8

According to the classical monoamine hypothesis of depression, deficiency of which of the following neurotransmitters is MOST commonly emphasized in modern antidepressant therapy?

Accepted Answer

Serotonin

Answer

Acetylcholine

Answer

Dopamine

Answer

GABA

Question 9

Simian crease is not seen in which of the following?

Accepted Answer

Atopic dermatitis

Answer

Trisomy 13

Answer

Noonan syndrome

Answer

Down

Answer

Trisomy 18

Question 10

Indications for emergency thoracotomy are all of the following except:

Accepted Answer

Tension pneumothorax

Answer

Cardiac tamponade

Answer

Major tracheobronchial injuries

Answer

Penetrating injuries to anterior chest

NEET-PG 2012

Biochemistry

Community Medicine

Internal Medicine

Ophthalmology

Pathology

Pharmacology

Psychiatry

Surgery