Anatomy
1 questionsWhich of the following is not a neural plate inducer?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 501: Which of the following is not a neural plate inducer?
- A. FGF upregulation
- B. Prechordal mesoderm
- C. High BMP (Correct Answer)
- D. Notochord appearance
Explanation: High BMP - **Bone Morphogenetic Proteins (BMPs)** are primarily involved in promoting epidermal differentiation in the ectoderm, and actively **inhibiting neural differentiation**. - Therefore, high levels of BMP would **prevent neural plate formation**, rather than induce it. *FGF upregulation* - **Fibroblast Growth Factors (FGFs)** are crucial in the early development of the nervous system. - They play a key role in **inducing neural plate formation** and maintaining its identity. *Prechordal mesoderm* - The **prechordal mesoderm**, located anterior to the notochord, is an important signalling center during early embryonic development. - It contributes to the **induction of the forebrain** and plays a role in patterning the anterior neural plate. *Notochord appearance* - The **notochord**, a transient rod-like structure, is a primary inducer of the neural plate. - It secretes factors like **Sonic Hedgehog (Shh)** which induce the overlying ectoderm to differentiate into neuroectoderm, forming the neural plate.
Anesthesiology
1 questionsWhat is the potential respiratory complication associated with the use of Trilene in combination with Sodalime?
NEET-PG 2012 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 501: What is the potential respiratory complication associated with the use of Trilene in combination with Sodalime?
- A. Renal toxicity
- B. Hepatotoxicity
- C. Myocardial depression
- D. Airway irritation and inflammation (Correct Answer)
Explanation: ***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.
Community Medicine
1 questionsSchistosomiasis is an example of which type of zoonosis that requires an intermediate host?
NEET-PG 2012 - Community Medicine NEET-PG Practice Questions and MCQs
Question 501: Schistosomiasis is an example of which type of zoonosis that requires an intermediate host?
- A. Meta-zoonoses (Correct Answer)
- B. Cyclo-zoonoses
- C. Direct-zoonoses
- D. Sporo-zoonoses
Explanation: ***Meta-zoonoses*** - **Meta-zoonoses** are defined as zoonotic diseases that require an **intermediate invertebrate host** for the completion of the parasite's life cycle. - **Schistosomiasis** fits this definition as it involves fresh water snails acting as an intermediate host, where the parasite undergoes essential developmental stages. *Cyclo-zoonoses* - **Cyclo-zoonoses** require **more than one vertebrate host species** but no invertebrate host for the completion of the infectious agent's life cycle. - An example would be **Taeniasis**, which involves humans and cattle or pigs, but not an invertebrate. *Direct-zoonoses* - **Direct-zoonoses** are transmitted directly from an **infected vertebrate host to a susceptible vertebrate host** without the need for an intermediate host or vector. - Examples include **rabies** or **brucellosis**, which are passed directly from animals to humans. *Sporo-zoonoses* - **Sporo-zoonoses** are zoonoses where the infectious agent undergoes **sporogonic development in an invertebrate host**, but this term is not a standard or widely recognized category in the same way as direct, cyclo-, or meta-zoonoses. - The more appropriate term for diseases involving an invertebrate intermediate host is **meta-zoonoses**.
Obstetrics and Gynecology
1 questionsWhich of the following is not a recognized risk factor for endometrial carcinoma?
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 501: Which of the following is not a recognized risk factor for endometrial carcinoma?
- A. Infertility
- B. Obesity
- C. Smoking (Correct Answer)
- D. Tamoxifen
Explanation: ***Smoking*** - Smoking is generally not considered a risk factor for endometrial carcinoma; in fact, some studies suggest it may paradoxically **decrease risk** by altering estrogen metabolism. - While smoking is a known risk factor for many cancers, its effect on **estrogen-dependent cancers** like endometrial cancer is complex and often opposite to that of other cancers. *Obesity* - Obesity is a significant risk factor due to the increased peripheral conversion of **androgens to estrogens** in adipose tissue, leading to unopposed estrogen stimulation of the endometrium. - This **elevated estrogen exposure** promotes endometrial hyperplasia and increases the risk of malignant transformation. *Infertility* - Infertility, particularly anovulatory infertility, is often associated with **unopposed estrogen exposure** due to a lack of progesterone production. - This hormonal imbalance can lead to endometrial hyperplasia and an increased risk of developing endometrial cancer. *Tamoxifen* - Tamoxifen, a **selective estrogen receptor modulator (SERM)**, acts as an estrogen antagonist in breast tissue but as an estrogen agonist in the endometrium. - This estrogenic effect on the endometrium can lead to **endometrial hyperplasia** and increase the risk of endometrial cancer, particularly when used long-term.
Pathology
1 questionsGlomus tumor is seen in -
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 501: Glomus tumor is seen in -
- A. Rare locations such as retroperitoneum
- B. Long bones and vertebrae
- C. Proximal portion of digits (less common site)
- D. Distal portion of digits (Correct Answer)
Explanation: ***Distal portion of digits*** - **Glomus tumors** are most commonly found in the **distal extremities**, especially the **subungual region** (under the nail) of the fingers and toes. - This location accounts for over 75% of all glomus tumors, where they originate from specialized **neuromyoarterial glomus bodies** involved in thermoregulation. - The classic clinical triad includes **paroxysmal pain, point tenderness, and cold sensitivity**. *Rare locations such as retroperitoneum* - While glomus tumors can occur in unusual sites, the **retroperitoneum** is an exceptionally rare location for primary glomus tumors. - Extradigital glomus tumors account for approximately 25% of cases and can occur in various soft tissue sites. *Long bones and vertebrae* - Glomus tumors do not typically arise in **bone tissue** as they originate from glomus bodies in soft tissue. - Bone involvement, when present, is usually secondary due to pressure erosion from an adjacent soft tissue tumor rather than primary bone origin. *Proximal portion of digits (less common site)* - While glomus tumors can occasionally be found in less common digital locations, the **proximal portion of digits** is significantly less frequent than the distal, and particularly the subungual, region. - Their primary association remains with the **distal phalanx** and nail bed.
Pharmacology
5 questionsWhich of the following is NOT caused by Prostaglandin E2 (PGE2)?
What is a key difference between fosphenytoin and phenytoin?
Which medication increases the efficacy of salmeterol when used together?
Desmopressin is preferred over vasopressin because it:
Which of the following has the least glucocorticoid activity?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 501: Which of the following is NOT caused by Prostaglandin E2 (PGE2)?
- A. None of the options (Correct Answer)
- B. Water retention
- C. Flushing
- D. Uterine contraction
Explanation: ***None of the options*** - All three listed effects (water retention, uterine contraction, and flushing) **ARE caused by Prostaglandin E2 (PGE2)**, making this the correct answer to the question asking what is NOT caused by PGE2. - Since PGE2 actually causes all the listed effects, "None of the options" is the accurate response. *Water retention* - PGE2 **stimulates ADH (vasopressin) release** from the posterior pituitary gland. - PGE2 also **enhances ADH action** on renal collecting ducts, promoting water reabsorption. - While PGE2 has complex renal effects including natriuresis, its net effect includes **promoting water retention** through the ADH mechanism. - This is an important effect of PGE2 on fluid balance. *Uterine contraction* - PGE2 is a **potent stimulator of uterine smooth muscle contraction**. - It is used clinically for **labor induction** and **cervical ripening** (dinoprostone). - PGE2 plays a crucial role in **parturition** and is involved in **dysmenorrhea**. *Flushing* - PGE2 causes **peripheral vasodilation**, particularly in cutaneous blood vessels. - This vasodilatory effect leads to **increased skin blood flow**, manifesting as **flushing** and warmth. - This is commonly seen as part of the **inflammatory response** and contributes to erythema.
Question 502: What is a key difference between fosphenytoin and phenytoin?
- A. Can be used in absence seizures
- B. Can be mixed with saline (Correct Answer)
- C. Can be given orally
- D. It is the drug of choice for myoclonic seizures
Explanation: **Can be mixed with saline** - **Fosphenytoin** is a water-soluble prodrug that is converted to phenytoin in the body; its solubility allows it to be **mixed with saline** solutions for intravenous administration, minimizing the risk of precipitation. - Unlike phenytoin, fosphenytoin's formulation avoids the need for propylene glycol, which is associated with adverse cardiovascular effects and makes phenytoin incompatible with saline. *Can be used in absence seizures* - Neither **fosphenytoin nor phenytoin** is effective for treating **absence seizures**, and they can sometimes worsen them. - **Ethosuximide** or **valproic acid** are the drugs of choice for absence seizures. *Can be given orally* - While **phenytoin** is commonly available in oral forms (capsules, chewable tablets, suspension), **fosphenytoin** is primarily designed for **parenteral administration** (intravenous or intramuscular). - Fosphenytoin is a prodrug that is rapidly converted to phenytoin *in vivo*, but it is not typically available or indicated for direct oral administration. *It is the drug of choice for myoclonic seizures* - Neither **fosphenytoin nor phenytoin** is the drug of choice for **myoclonic seizures**; they can exacerbate this type of seizure. - **Valproic acid** and **levetiracetam** are preferred treatments for myoclonic seizures due to their broader spectrum of activity.
Question 503: Which medication increases the efficacy of salmeterol when used together?
- A. Corticosteroid (Correct Answer)
- B. Theophylline
- C. Ipratropium
- D. Sodium cromoglycate
Explanation: ***Corticosteroid*** - **Corticosteroids** act synergistically with **beta-2 agonists** like salmeterol by increasing the number and sensitivity of beta-2 receptors on bronchial smooth muscle cells. - They also reduce inflammation, which contributes to airway hyperresponsiveness, thereby improving the overall efficacy of bronchodilators. *Theophylline* - **Theophylline** is a methylxanthine that causes bronchodilation through inhibition of phosphodiesterase, but it is not directly synergistic with **salmeterol** in potentiating its primary action. - While both treat airway obstruction, their mechanisms are distinct, and theophylline has a narrow therapeutic index with significant side effects. *Ipratropium* - **Ipratropium** is an **anticholinergic bronchodilator** that blocks muscarinic receptors, leading to bronchodilation. - Its mechanism of action is different from that of **salmeterol (a beta-2 agonist)**, and while they can be used together for additive bronchodilation, ipratropium does not directly increase the efficacy of salmeterol itself. *Sodium cromoglycate* - **Sodium cromoglycate** is a **mast cell stabilizer** that prevents the release of inflammatory mediators, primarily used for asthma prophylaxis. - It does not have direct bronchodilatory effects and does not enhance the bronchodilatory action of **salmeterol**.
Question 504: Desmopressin is preferred over vasopressin because it:
- A. Is more potent and has little vasoconstrictor activity (Correct Answer)
- B. Is more potent than vasopressin
- C. Has little vasoconstrictor activity
- D. Is more selective for V2 receptors than vasopressin
Explanation: **Is more potent and has little vasoconstrictor activity** - **Desmopressin** is a synthetic analog of **vasopressin** (ADH) that is modified to have much higher selectivity for **V2 receptors** in the renal collecting ducts, leading to potent **antidiuretic effects** [1], [3]. - This selective action results in significantly **reduced vasoconstrictor activity** (mediated by V1 receptors) compared to natural vasopressin, making it safer for clinical use to manage water balance without significant cardiovascular side effects [1], [3]. *Is more potent than vasopressin* - While desmopressin is indeed more potent in its **antidiuretic effect** due to increased affinity for **V2 receptors**, this option alone doesn't specify the critical advantage of *reduced vasoconstrictor activity* [3]. - Its superior potency alone doesn't fully explain its preference over vasopressin, as the **side-effect profile** is a major consideration. *Has little vasoconstrictor activity* - This statement is true and highlights a key advantage of desmopressin, but it omits the fact that **desmopressin is also more potent** in its desired antidiuretic effect compared to natural vasopressin [1]. - Both the **potency** and **reduced vasoconstrictor activity** contribute to its superior clinical profile [3]. *Is more selective for V2 receptors than vasopressin* - **Desmopressin's increased selectivity** for **V2 receptors** is the mechanistic basis for its preferred properties, leading to both greater antidiuretic potency and reduced vasoconstriction [1], [4]. - However, the option "Is more potent and has little vasoconstrictor activity" describes the *clinical consequences* of this selectivity, which are the direct reasons for its preferred use [2].
Question 505: Which of the following has the least glucocorticoid activity?
- A. Fludrocortisone
- B. Cortisone (Correct Answer)
- C. Dexamethasone
- D. Betamethasone
Explanation: ***Cortisone*** - **Cortisone has the LEAST glucocorticoid activity** among the options listed. - It is a **prodrug** that must be converted to **hydrocortisone (cortisol)** by 11β-hydroxysteroid dehydrogenase in the liver to become active. - Its glucocorticoid potency is approximately **0.8** relative to hydrocortisone (when hydrocortisone = 1). - Due to variable hepatic conversion, it has **lower and less predictable glucocorticoid effects** compared to other agents. *Fludrocortisone* - Primarily used for its **potent mineralocorticoid activity** (125× that of hydrocortisone). - However, it retains **significant glucocorticoid activity** approximately **10-15 times** that of hydrocortisone. - Despite being marketed as a mineralocorticoid, its glucocorticoid potency is **considerably higher than cortisone**. *Dexamethasone* - **Highly potent synthetic glucocorticoid** with negligible mineralocorticoid activity. - Glucocorticoid potency is approximately **25-30 times** that of hydrocortisone. - Long duration of action (36-72 hours) and excellent CNS penetration. *Betamethasone* - **Highly potent synthetic glucocorticoid**, structurally similar to dexamethasone (differs only in stereochemistry at C-16). - Glucocorticoid potency is approximately **25-30 times** that of hydrocortisone. - Minimal mineralocorticoid activity, with similar clinical applications to dexamethasone.