NEET-PG 2012 Practice Questions

Q: Unilateral lacrimal gland destruction may be caused by?

Fracture of roof of orbit. ***Fracture of roof of orbit*** - The **lacrimal gland** is situated in the **lacrimal fossa** on the anterior-lateral part of the **orbital roof**. A fracture in this specific area can directly damage the gland. - Trauma to the **orbital roof** can lead to laceration, avulsion, or compression of the lacrimal gland, resulting in its destruction and impairing tear production. *Inferior orbital fissure fracture* - The **inferior orbital fissure** transmits nerves and vessels to the orbit but is located inferior to the lacrimal gland, making direct injury unlikely. - Fractures here are more associated with **infraorbital nerve damage** or disruption of orbital contents into the maxillary sinus, not lacrimal gland destruction. *Fracture of lateral wall* - The **lateral wall of the orbit** forms the outer boundary and protects structures deeper within the orbit, but the lacrimal gland is situated superiorly and anteriorly. - While significant trauma to the lateral wall can impact orbital contents, it is less likely to directly cause unilateral lacrimal gland destruction compared to a direct roof fracture. *Fracture of sphenoid* - Fractures of the **sphenoid bone** are typically more posterior and central, affecting structures like the **optic canal** or **cavernous sinus**. - While it can indirectly affect orbital function, it is not a direct cause of isolated lacrimal gland destruction due to its anatomical location.

Q: What does perinatal mortality include?

Both late fetal deaths and early neonatal deaths. ***Both late fetal deaths and early neonatal deaths*** - Perinatal mortality encompasses deaths occurring both in the **late fetal period** (typically after 20-22 weeks of gestation, or commonly defined as 28 weeks or more) and during the **early neonatal period** (the first 7 days of life). - This broad definition helps to capture mortality related to conditions around the time of birth, including those stemming from **pregnancy complications**, labor, delivery, and immediate postnatal adaptation. *Deaths after 28 weeks of gestation* - This describes **late fetal deaths** (stillbirths) but does not include deaths that occur after birth, thus only covering a part of perinatal mortality. - Perinatal mortality is a broader measure that combines both stillbirths and early infant deaths. *Deaths within the first 7 days after birth* - This specifically defines **early neonatal deaths**, which are a component of perinatal mortality, but it excludes fetal deaths. - Perinatal mortality aims to assess factors impacting survival around the time of birth, both before and immediately after. *From the period of viability* - The period of viability refers to when a fetus can survive outside the uterus, which varies (often cited as 20-24 weeks), and would include very premature fetuses, but it isn't an explicit definition of perinatal mortality itself. - This term describes when a fetus is considered potentially viable but does not define the specific timeframe or types of deaths included in perinatal mortality.

Q: Muttering delirium is seen with: NEET 13

Datura. ***Datura*** - **Datura poisoning** is characterized by an **anticholinergic toxidrome**, which includes central nervous system effects like **muttering delirium, hallucinations**, and disorientation. - The patient exhibits features like **dilated pupils, dry mouth, flushed skin**, and **tachycardia** due to the blockage of muscarinic acetylcholine receptors. *Castor oil plant* - The **castor oil plant** contains **ricin**, a potent toxin that causes **gastrointestinal symptoms** (nausea, vomiting, abdominal pain, bloody diarrhea) and eventually multi-organ failure. - It does not typically cause the central nervous system effects like **muttering delirium** seen with Datura poisoning. *Cocaine (stimulant)* - **Cocaine** is a central nervous system stimulant that causes **euphoria, agitation, paranoia, dilated pupils**, and **tachycardia**. - While it can cause psychosis, the specific **muttering delirium** is not its hallmark presentation; instead, it is associated with a hyperadrenergic state. *Monkshood (Aconitum)* - **Monkshood** contains **aconitine**, a neurotoxin that primarily affects cardiac and neurological function, causing **paresthesias, muscle weakness, bradycardia**, and potentially fatal arrhythmias. - It does not typically cause the **muttering delirium** with features of an anticholinergic syndrome.

Q: Meningitis with rash is seen in -

Neisseria meningitidis. **Neisseria meningitidis** - **Meningococcal meningitis** is classically associated with an acute onset of fever, headache, stiff neck, and a characteristic **petechial or purpuric rash** [1]. - The rash is due to widespread **vasculitis** and disseminated intravascular coagulation (DIC) caused by the bacteria. *H. influenzae* - While *H. influenzae* type b (Hib) was a major cause of bacterial meningitis before vaccination, it typically does not cause a *rash*. - Meningitis caused by *H. influenzae* presents with fever, headache, stiff neck, and altered mental status without dermatological manifestations. *Strepto. agalactiae* - *Streptococcus agalactiae* (Group B Strep) is a common cause of meningitis in **neonates** and infants. - It usually presents with non-specific symptoms like fever, lethargy, and poor feeding, and a rash is not a typical feature of GBS meningitis. *Pneumococcus* - *Streptococcus pneumoniae* (Pneumococcus) is another leading cause of bacterial meningitis in adults and children [1]. - Symptoms include fever, headache, stiff neck, and altered mental status, but a cutaneous rash is not characteristic of pneumococcal meningitis [1].

Q: A patient with sore throat has a positive Paul Bunnell test, indicating infectious mononucleosis. The causative organism is?

EBV. ***Correct: EBV*** - The **Paul-Bunnell test** (monospot test) detects **heterophile antibodies**, which are characteristic of acute **Epstein-Barr virus (EBV)** infection. - **EBV** is the primary causative agent of **infectious mononucleosis**, commonly known as "mono." *Incorrect: Adenovirus* - **Adenoviruses** can cause various infections, including **pharyngitis** and **conjunctivitis**, but are not associated with a positive **Paul-Bunnell test** or heterophile antibodies. - While it can cause sore throat, the presence of a **positive Paul-Bunnell test** differentiates it from EBV. *Incorrect: CMV* - **Cytomegalovirus (CMV)** can cause a mononucleosis-like syndrome, but it typically results in a **negative Paul-Bunnell test** (i.e., it is heterophile antibody-negative). - CMV mononucleosis is often seen in individuals who are **immunocompromised** or in infants as a congenital infection. *Incorrect: HSV (Herpes Simplex Virus)* - **Herpes simplex virus (HSV)** causes infections such as **oral herpes (cold sores)** and **genital herpes**, and in some cases, **pharyngitis**. - HSV infection is not associated with a positive **Paul-Bunnell test** or the production of heterophile antibodies.

Q: Child with mild squint. Intrauterine, birth history, developmental history till date all normal. Corneal light reflex normal. All other eye parameters normal except exaggerated epicanthal fold. Diagnosis ?

Pseudostrabismus. ***Pseudostrabismus*** * The presence of **exaggerated epicanthal folds** can create the optical illusion of a child having misaligned eyes, even when the eyes are perfectly straight. * The normal **corneal light reflex** (Hirschberg test) confirms that the eyes are properly aligned, and the perceived "squint" is not a true strabismus. *Exophoria (outward drift)* * This condition involves a **tendency for the eyes to drift outwards**, which would be detected by specific cover/uncover tests. * An outward drift would usually result in an abnormal corneal light reflex, and the exaggerated epicanthal folds would not explain this type of misalignment. *Esophoria (inward drift)* * This is a **tendency for the eyes to drift inwards**, which would also be revealed by tests for phorias and often by an abnormal corneal reflex. * The clinical presentation points away from a true inward deviation, as the corneal reflex is normal. *Accommodative esotropia* * This is a **true inward turning of the eye** (strabismus) that is often linked to uncorrected farsightedness (hyperopia). * It would present with an **abnormal corneal light reflex** and would not be explained solely by epicanthal folds, as it involves actual ocular deviation.

Q: Ewing's sarcoma arises from which type of cells?

Primitive neuroectodermal cells. ***Primitive neuroectodermal cells*** - **Ewing's sarcoma** is a malignant small round blue cell tumor largely believed to arise from **primitive neuroectodermal cells**. - This cellular origin explains why it's often grouped under the term **PNET (Primitive Neuroectodermal Tumor)**. *G cells* - **G cells** are specialized **enteroendocrine cells** found in the stomach and duodenum that secrete **gastrin**. - They are involved in regulating gastric acid secretion and have no association with Ewing's sarcoma. *Totipotent cells* - **Totipotent cells** have the ability to differentiate into **any type of cell**, including embryonic and extraembryonic tissues. - While all cancers originate from cellular changes, Ewing's sarcoma originates from a more specific, committed cell lineage, not totipotent stem cells. *Neurons* - **Neurons** are the basic functional units of the nervous system, responsible for transmitting electrical and chemical signals. - While Ewing's sarcoma has neuroectodermal characteristics, it does not arise from fully differentiated neurons but rather from more **primitive precursors**.

Q: What is the primary cardiotoxic effect of bupivacaine?

Depressed pacemaker activity. ***Depressed pacemaker activity*** - **Bupivacaine** is a potent **local anesthetic** that blocks voltage-gated **sodium channels** in myocardial cells with **high affinity** and **slow dissociation kinetics**. - This prolonged channel blockade leads to decreased cardiac excitability and **depressed automaticity** of pacemaker cells, particularly affecting the **SA node** and **His-Purkinje system**. - Results in slowing of the **heart rate**, **bradyarrhythmias**, **conduction blocks**, and potentially **ventricular arrhythmias** or **asystole**. - Bupivacaine is **more cardiotoxic** than other local anesthetics due to its **lipophilicity** and prolonged binding to cardiac sodium channels. *Toxic compound damaging myocardial cells* - While **bupivacaine** is cardiotoxic, its primary mechanism is not direct **cellular damage** through cytotoxic effects, oxidative stress, or cell membrane lysis. - The toxicity is predominantly due to **electrophysiological effects** on ion channels, interfering with normal cardiac conduction and contractility. *Depressed neural control on heart* - **Bupivacaine's** cardiotoxicity primarily affects the **myocardium directly** through sodium channel blockade, rather than indirectly through the **autonomic nervous system**. - Although high systemic concentrations can affect the **central nervous system** (causing seizures and CNS depression), the direct cardiac effects occur independently of neural influence. *Vascular thrombosis and Myocardial ischemia* - **Bupivacaine** cardiotoxicity does not typically involve formation of **thrombi** or mechanisms leading to **myocardial ischemia** through coronary artery occlusion. - Its effects are predominantly on the **electrical conduction system**, **myocardial contractility**, and **cardiac ion channels**, not the vascular supply to the heart.

Q: Resistance to Methotrexate develops due to?

Increased production of dihydrofolate reductase (DHFR). ***Increased production of dihydrofolate reductase (DHFR)*** - Methotrexate acts by inhibiting **dihydrofolate reductase (DHFR)**, an enzyme essential for **folate metabolism** and DNA synthesis. - An **increased production of DHFR** (through gene amplification or overexpression) by cancer cells allows them to bypass the drug's inhibitory effects, leading to resistance. - This is the **most common mechanism** of methotrexate resistance. *Rapid proliferation of cancer cells* - While **rapid cell proliferation** is a characteristic of cancer, it doesn't directly explain resistance to methotrexate. - Methotrexate targets fast-dividing cells (S-phase specific), so rapid proliferation often makes them **more susceptible**, not resistant, as long as the drug's mechanism is effective. *Thymidylate kinase deficiency* - **Thymidylate kinase** is involved in the phosphorylation of **thymidine** to produce **dTMP** (deoxythymidine monophosphate). - A deficiency in this enzyme would likely hinder DNA synthesis, potentially increasing sensitivity to DNA-targeting agents, rather than causing resistance to methotrexate. *Thymidylate synthetase deficiency* - **Thymidylate synthetase** converts dUMP to dTMP using **5,10-methylene-THF** as a cofactor. - Methotrexate **indirectly inhibits** thymidylate synthetase by depleting tetrahydrofolate cofactor pools through DHFR inhibition. - A **deficiency** of this enzyme would not cause resistance; rather, **increased thymidylate synthetase** expression can be an alternative resistance mechanism, though less common than DHFR overexpression.

Question 1

Unilateral lacrimal gland destruction may be caused by?

Accepted Answer

Fracture of roof of orbit

Answer

Inferior orbital fissure fracture

Answer

Fracture of lateral wall

Answer

Fracture of sphenoid

Question 2

In community medicine practice, what aspects are primarily studied to understand health outcomes?

Accepted Answer

Both individual health behaviors and community social factors

Answer

Individual health behaviors

Answer

Community health relationships

Answer

None of the above

Question 3

What does perinatal mortality include?

Accepted Answer

Both late fetal deaths and early neonatal deaths

Answer

Deaths after 28 weeks of gestation

Answer

Deaths within the first 7 days after birth

Answer

From the period of viability

Question 4

Muttering delirium is seen with: NEET 13

Accepted Answer

Datura

Answer

Castor oil plant

Answer

Cocaine (stimulant)

Answer

Monkshood (Aconitum)

Question 5

Meningitis with rash is seen in -

Accepted Answer

Neisseria meningitidis

Answer

H. influenzae

Answer

Strepto. agalactae

Answer

Pneumococcus

Question 6

A patient with sore throat has a positive Paul Bunnell test, indicating infectious mononucleosis. The causative organism is?

Accepted Answer

EBV

Answer

Adenovirus

Answer

CMV

Answer

HSV (Herpes Simplex Virus)

Question 7

Child with mild squint. Intrauterine, birth history, developmental history till date all normal. Corneal light reflex normal. All other eye parameters normal except exaggerated epicanthal fold. Diagnosis ?

Accepted Answer

Pseudostrabismus

Answer

Exophoria (outward drift)

Answer

Esophoria (inward drift)

Answer

Accommodative esotropia

Question 8

Ewing's sarcoma arises from which type of cells?

Accepted Answer

Primitive neuroectodermal cells

Answer

G cells

Answer

Totipotent cells

Answer

Neurons

Question 9

What is the primary cardiotoxic effect of bupivacaine?

Accepted Answer

Depressed pacemaker activity

Answer

Toxic compound damaging myocardial cells

Answer

Depressed neural control on heart

Answer

Vascular thrombosis and Myocardial ischemia

Question 10

Resistance to Methotrexate develops due to?

Accepted Answer

Increased production of dihydrofolate reductase (DHFR)

Answer

Rapid proliferation of cancer cells

Answer

Thymidylate kinase deficiency

Answer

Thymidylate synthetase deficiency

NEET-PG 2012

Anatomy

Community Medicine

Forensic Medicine

Internal Medicine

Microbiology

Ophthalmology

Pathology

Pharmacology