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 is the potential respiratory complication associated with the use of Trilene in combination with Sodalime?

Airway irritation and inflammation. ***Airway irritation and inflammation*** - The interaction between **Trilene (trichloroethylene)** and **soda lime** in a closed anesthetic circuit can produce **dichloroacetylene**. - **Dichloroacetylene** is a highly toxic compound that can cause severe airway irritation, inflammation, and even **necrosis** of the respiratory tract. *Renal toxicity* - While some halogenated anesthetics (e.g., methoxyflurane) are associated with **renal toxicity** due to fluoride ion release, this is not the primary or most severe respiratory complication of Trilene with soda lime. - The main concern with Trilene and soda lime is the formation of a **toxic airway irritant**. *Hepatotoxicity* - **Halothane** is more classically associated with **hepatotoxicity** (halothane hepatitis) due to metabolism into toxic intermediates. - **Trilene** itself is not primarily known for causing severe hepatotoxicity, and the interaction with soda lime does not specifically target the liver for toxicity. *Myocardial depression* - Many inhaled anesthetics, including Trilene, can cause some degree of **myocardial depression**. - However, this is a general effect of the anesthetic on cardiac function and is not a unique or specific complication arising from the **interaction with soda lime** that produces dichloroacetylene.

Q: Vector of scrub typhus in man?

Leptotrombidium deliense. ***Leptotrombidium deliense*** - This is the **chigger mite** species primarily responsible for transmitting **scrub typhus** to humans. - **Larval mites (chiggers)** of this species feed on human skin and transmit the bacterium *Orientia tsutsugamushi*. *O. tsutsugamushi* - This is the **causative agent** of scrub typhus, not the vector. - It is a **rickettsial bacterium** transmitted by infected chiggers. *Lice* - **Lice** (e.g., *Pediculus humanus corporis*) are vectors for diseases like **epidemic typhus** (caused by *Rickettsia prowazekii*) and **relapsing fever**, but not scrub typhus. - They are **blood-sucking insects** distinct from mites. *Pediculus humanus* - This refers to **human lice**, specifically *Pediculus humanus capitis* (head louse) or *Pediculus humanus corporis* (body louse). - As mentioned, lice transmit diseases like epidemic typhus, not **scrub typhus**.

Q: Which of the following poisonings presents with abdominal pain, diarrhea, Mees lines on nails, and myelosuppression?

Arsenic. ***Arsenic*** - **Arsenic poisoning** is characterized by gastrointestinal symptoms like severe **abdominal pain** and **diarrhea**, as well as dermatological signs such as **Mees lines** (transverse white bands on fingernails). - It also causes **myelosuppression**, leading to anemia, leukopenia, and thrombocytopenia, and can affect the cardiovascular and nervous systems. *Lead* - **Lead poisoning** typically presents with diffuse **abdominal pain** (lead colic), **constipation** (not diarrhea), and neurological symptoms like **foot drop** and **encephalopathy**. - While it can cause anemia due to impaired heme synthesis, **Mees lines** and significant myelosuppression are not primary features. *Alcohol* - **Alcohol intoxication** or chronic alcoholism primarily affects the central nervous system, liver, and pancreas, leading to symptoms like **ataxia**, **hepatitis**, and **pancreatitis**. - It does not cause **Mees lines** or the specific combination of severe gastrointestinal issues and myelosuppression seen with arsenic. *Mercury* - **Mercury poisoning** typically manifests with neurological symptoms (tremors, emotional lability, **peripheral neuropathy**), stomatitis, and renal dysfunction. - While it can cause gastrointestinal upset, **Mees lines** and **myelosuppression** are not characteristic features of mercury toxicity.

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: Which of the following is a synthetic estrogen?

Diethylstilbestrol. ***Diethylstilbestrol*** - **Diethylstilbestrol (DES)** is a **synthetic non-steroidal estrogen** that was historically used as a medication, particularly to prevent miscarriage. - Its use was discontinued after being linked to various adverse effects, including **vaginal clear cell adenocarcinoma** in female offspring whose mothers took DES during pregnancy. *Estrone* - **Estrone** is one of the three major **naturally occurring endogenous estrogens** in humans. - It is the primary estrogen during **menopause** and is derived from androstenedione. *Estriol* - **Estriol** is another of the three major **naturally occurring estrogens**, predominantly produced during **pregnancy** by the placenta. - It is often used as a marker for fetal well-being. *Estradiol* - **Estradiol** is the **most potent and abundant naturally occurring estrogen** in women during their reproductive years. - It plays a crucial role in the development and maintenance of female reproductive tissues and secondary sexual characteristics.

Q: Which of the following medications does not interact with warfarin?

Benzodiazepines. ***Benzodiazepines*** - **Benzodiazepines** are generally considered safe to use with warfarin as they are extensively metabolized in the liver, but they do not typically alter the **cytochrome P450 enzymes** responsible for warfarin metabolism. - They also do not interfere with **vitamin K recycling** or **platelet function**, which are key mechanisms through which other drugs interact with warfarin. *Barbiturate* - **Barbiturates** are **potent inducers of hepatic enzymes**, particularly CYP2C9, which is responsible for metabolizing warfarin. - This enzyme induction leads to **increased warfarin metabolism**, reducing its anticoagulant effect and necessitating higher warfarin doses. *Oral contraceptive* - **Oral contraceptives** can **reduce the anticoagulant effect of warfarin** by inducing clotting factors or inhibiting warfarin metabolism. - This interaction can increase the risk of **thromboembolic events** in patients on warfarin. *Cephalosporins* - Certain **cephalosporins**, especially those with a **methylthiotetrazole (MTT) side chain** (e.g., Cefamandole, Cefoperazone, Moxalactam), can **inhibit vitamin K epoxide reductase**. - This inhibition leads to a **decrease in vitamin K-dependent clotting factors**, thus potentiating the anticoagulant effect of warfarin and increasing bleeding risk.

Q: Which of the following antibiotics is known to cause bleeding due to its effect on blood clotting?

Moxalactam. Moxalactam - Moxalactam is a **third-generation cephalosporin** known to cause **hypoprothrombinemia** and platelet dysfunction, leading to an increased risk of bleeding. - This effect is due to its **N-methylthiotetrazole (NMTT) side chain**, which inhibits vitamin K-dependent clotting factor synthesis. Cefaloridine - This is a **first-generation cephalosporin** that does not have the NMTT side chain and is not commonly associated with significant bleeding risks. - Its primary adverse effect of concern is **nephrotoxicity** at high doses, rather than coagulopathy. Ceftazidime - Ceftazidime is a **third-generation cephalosporin** primarily used for *Pseudomonas aeruginosa* infections but does **not contain the NMTT side chain** responsible for bleeding complications. - While broad-spectrum, it generally has a favorable safety profile concerning coagulation. *Cefazolin* - Cefazolin is a **first-generation cephalosporin** [1] widely used for surgical prophylaxis and skin infections [1], and it does **not interfere with coagulation** pathways. - Its main side effects are typical for penicillin-related antibiotics, such as hypersensitivity reactions [1],[2].

Q: All are true regarding Sunitinib except which of the following?

It is excreted primarily in urine. ***It is excreted primarily in urine*** - **Sunitinib** is predominantly metabolized in the **liver** by CYP3A4 and primarily excreted in the **feces**, not urine. - Its major active metabolite, N-desethyl sunitinib, is also primarily eliminated via the fecal route. *It inhibits tyrosine kinase receptors* - **Sunitinib** is a **multitargeted receptor tyrosine kinase (RTK) inhibitor**. - It blocks several RTKs involved in tumor growth, angiogenesis, and metastatic progression, such as **VEGFR, PDGFR, KIT, and FLT3**. *It is used for the treatment of GIST* - **Sunitinib** is approved for the treatment of **imatinib-refractory** or **imatinib-intolerant gastrointestinal stromal tumors (GIST)**. - Its mechanism in GIST involves inhibiting KIT and PDGFR, which are often mutated and constitutively active in this cancer. *It is used for renal cell carcinoma* - **Sunitinib** is a standard first-line treatment for **advanced renal cell carcinoma (RCC)**. - Its efficacy in RCC is primarily due to its inhibition of VEGFR, which targets the high vascularity characteristic of kidney tumors.

Q: Which of the following is not a selective serotonin reuptake inhibitor?

Buspirone. ***Buspirone*** - **Buspirone** is an anxiolytic that primarily acts as a **serotonin 5-HT1A receptor partial agonist**, not an SSRI. - It does not significantly affect the reuptake of serotonin, distinguishing it from SSRIs. *Fluoxetine* - **Fluoxetine** is a well-known and widely used **SSRI**. - It works by selectively inhibiting the reuptake of serotonin, thereby increasing its concentration in the synaptic cleft. *Fluvoxamine* - **Fluvoxamine** is another antidepressant classified as an **SSRI**. - It is often used for the treatment of **obsessive-compulsive disorder (OCD)** due to its strong serotonin reuptake inhibition. *Citalopram* - **Citalopram** is an **SSRI** frequently prescribed for depression and anxiety disorders. - Its mechanism involves potent and selective inhibition of **serotonin reuptake**.

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

What is the potential respiratory complication associated with the use of Trilene in combination with Sodalime?

Accepted Answer

Airway irritation and inflammation

Answer

Renal toxicity

Answer

Hepatotoxicity

Answer

Myocardial depression

Question 3

Vector of scrub typhus in man?

Accepted Answer

Leptotrombidium deliense

Answer

O. tsutsugamushi

Answer

Lice

Answer

Pediculus humanus

Question 4

Which of the following poisonings presents with abdominal pain, diarrhea, Mees lines on nails, and myelosuppression?

Accepted Answer

Arsenic

Answer

Lead

Answer

Alcohol

Answer

Mercury

Question 5

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 6

Which of the following is a synthetic estrogen?

Accepted Answer

Diethylstilbestrol

Answer

Estrone

Answer

Estriol

Answer

Estradiol

Question 7

Which of the following medications does not interact with warfarin?

Accepted Answer

Benzodiazepines

Answer

Barbiturate

Answer

Oral contraceptive

Answer

Cephalosporins

Question 8

Which of the following antibiotics is known to cause bleeding due to its effect on blood clotting?

Accepted Answer

Moxalactam

Answer

Cefaloridine

Answer

Cefazolin

Answer

Ceftazidime

Question 9

All are true regarding Sunitinib except which of the following?

Accepted Answer

It is excreted primarily in urine

Answer

It inhibits tyrosine kinase receptors

Answer

It is used for the treatment of GIST

Answer

It is used for renal cell carcinoma

Question 10

Which of the following is not a selective serotonin reuptake inhibitor?

Accepted Answer

Buspirone

Answer

Citalopram

Answer

Fluoxetine

Answer

Fluvoxamine

NEET-PG 2012

Anatomy

Anesthesiology

Community Medicine

Forensic Medicine

Pharmacology