Anatomy
4 questionsInterosseous membrane of forearm is pierced by?
Which of the following statements about the great saphenous vein is true?
Esophagus is present in which mediastinum?
Which chamber of the heart forms the posterior surface?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 281: Interosseous membrane of forearm is pierced by?
- A. Brachial artery
- B. Anterior interosseous artery (Correct Answer)
- C. Posterior interosseous artery
- D. Ulnar recurrent artery
Explanation: ***Anterior interosseous artery*** - The **anterior interosseous artery** pierces the **interosseous membrane** in the **distal forearm** (approximately 5 cm above the wrist) to anastomose with the **posterior interosseous artery** and contribute to the **palmar carpal arch**. - This artery arises from the **common interosseous artery**, a branch of the **ulnar artery**. - This is the **classically taught structure** that pierces the interosseous membrane and is the standard answer in examination contexts. *Brachial artery* - The **brachial artery** is the main artery of the arm and terminates in the **cubital fossa** by dividing into the **radial** and **ulnar arteries**. - It does not pierce the **interosseous membrane** of the forearm as it is located in the arm, not the forearm. *Posterior interosseous artery* - The **posterior interosseous artery** arises from the **common interosseous artery** and passes **posteriorly between the oblique cord and the upper border of the interosseous membrane** to enter the posterior compartment of the forearm. - While it may pierce the membrane distally to anastomose anteriorly, the **anterior interosseous artery** is the structure **classically described** as piercing the membrane in standard anatomical teaching and examination contexts. *Ulnar recurrent artery* - The **ulnar recurrent arteries** (anterior and posterior branches) arise from the **ulnar artery** near the **cubital fossa** and ascend to participate in the **anastomosis around the elbow joint**. - These arteries do not pierce the **interosseous membrane** of the forearm.
Question 282: Which of the following statements about the great saphenous vein is true?
- A. It begins at lateral end of dorsal venous arch
- B. It runs anterior to medial malleolus (Correct Answer)
- C. Terminates into popliteal vein
- D. It is accompanied by the sural nerve
Explanation: **It runs anterior to medial malleolus** - The **great saphenous vein** originates from the medial end of the **dorsal venous arch** of the foot and ascends anterior to the **medial malleolus** [1]. - This anatomical relationship makes it accessible for various clinical procedures, such as **venous cutdown** for rapid intravenous access [1]. *It begins at lateral end of dorsal venous arch* - The **great saphenous vein** actually begins at the **medial end** of the dorsal venous arch, not the lateral end [1]. - The **small saphenous vein** arises from the lateral end of the dorsal venous arch [1]. *It is accompanied by the sural nerve* - The **sural nerve** typically accompanies the **small saphenous vein**, not the great saphenous vein, in the posterior leg [1]. - The **saphenous nerve**, a branch of the femoral nerve, accompanies the great saphenous vein throughout its course in the leg. *Terminates into popliteal vein* - The **great saphenous vein** normally terminates by draining into the **femoral vein** in the femoral triangle, not the popliteal vein [1]. - The **small saphenous vein** is the one that typically drains into the popliteal vein [1].
Question 283: Esophagus is present in which mediastinum?
- A. Anterior
- B. Posterior (Correct Answer)
- C. Middle
- D. Superior
Explanation: ***Posterior*** - The **esophagus** is primarily located in the **posterior mediastinum**, where the bulk of its length (from T4/T5 to T10) traverses [2]. - It lies **posterior** to the **trachea** and **heart**, anterior to the vertebral column [2]. - For examination purposes, the esophagus is considered a **key structure of the posterior mediastinum** [2]. - Note: The uppermost part (cervical and upper thoracic) does pass through the superior mediastinum, but the majority lies in the posterior compartment. *Anterior* - The **anterior mediastinum** is a small space located between the **sternum** and the pericardium. - It primarily contains **connective tissue**, remnants of the thymus, lymph nodes, and the internal thoracic vessels [1]. - The esophagus does not traverse this compartment. *Middle* - The **middle mediastinum** is centrally located and prominently contains the **heart** and the roots of the great vessels [1]. - It also houses the **pericardium**, the main bronchi, and the phrenic nerves [1]. - The esophagus passes **posterior** to this compartment, not through it. *Superior* - The **superior mediastinum** extends from the thoracic inlet to the level of the sternal angle (T4/T5). - It contains large vessels like the **aortic arch** and its branches, the SVC, trachea, and thymus [1]. - While the **uppermost part of the thoracic esophagus** does pass through the superior mediastinum, this represents only a small portion of its total length.
Question 284: Which chamber of the heart forms the posterior surface?
- A. Right Atrium (RA)
- B. Left Atrium (LA) (Correct Answer)
- C. Left Ventricle (LV)
- D. Right Ventricle (RV)
Explanation: ***Left Atrium (LA)*** - The **left atrium** forms the posterior surface of the heart, lying in front of the esophagus and thoracic aorta [1]. - Its posterior position makes it susceptible to enlargement, which can compress the **esophagus** and cause dysphagia [1]. *Right Atrium (RA)* - The **right atrium** primarily forms the right border of the heart and receives deoxygenated blood from the systemic circulation. - It lies anteriorly and to the right, behind the sternum and costal cartilages. *Left Ventricle (LV)* - The **left ventricle** forms the apex of the heart and part of the left border. - It is positioned *inferiorly* and *anteriorly*, contributing significantly to the *diaphragmatic surface* of the heart. *Right Ventricle (RV)* - The **right ventricle** forms the majority of the anterior surface of the heart, directly behind the sternum. - It also contributes to the *inferior surface* of the heart, resting on the diaphragm.
Internal Medicine
1 questionsCryoprecipitate is useful in which of the following conditions?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 281: Cryoprecipitate is useful in which of the following conditions?
- A. Hemophilia A
- B. Thrombosthenia
- C. Warfarin reversal
- D. Afibrinogenemia (Correct Answer)
Explanation: ***Afibrinogenemia*** - Cryoprecipitate is rich in **fibrinogen**, factor VIII, factor XIII, von Willebrand factor, and fibronectin. It is the only blood product with a substantial concentration of fibrinogen. - **Afibrinogenemia** (or hypofibrinogenemia) is a condition characterized by low or absent levels of fibrinogen, a critical clotting factor that cryoprecipitate replaces effectively. *Hemophilia A* - Hemophilia A is a deficiency of **Factor VIII**. While cryoprecipitate contains factor VIII, **recombinant Factor VIII concentrates** are the preferred treatment due to better safety (reduced risk of viral transmission) and more precise dosing [1]. - Cryoprecipitate was historically used for Hemophilia A before the availability of safer, more specific factor concentrates [2]. *Thrombosthenia* - Thrombasthenia is a platelet function disorder characterized by defective **glycoprotein IIb/IIIa receptors** on platelets, leading to impaired platelet aggregation. - Cryoprecipitate does not contain platelets or factors that directly correct platelet function, making **platelet transfusions** the treatment of choice for severe bleeding in thrombasthenia. *Warfarin reversal* - Warfarin reversal is primarily achieved using **Vitamin K**, which restores levels of functional clotting factors II, VII, IX, and X. - For rapid reversal in emergencies, **prothrombin complex concentrate (PCC)** is preferred because it contains high concentrations of these vitamin K-dependent factors, addressing the primary deficiency caused by warfarin [1].
Pathology
2 questionsHurthle cell carcinoma is a variant of which type of carcinoma?
Flexner-Wintersteiner rosette is seen in-
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 281: Hurthle cell carcinoma is a variant of which type of carcinoma?
- A. Medullary carcinoma
- B. Papillary carcinoma
- C. Follicular carcinoma (Correct Answer)
- D. Anaplastic carcinoma
Explanation: **Follicular carcinoma** - **Hürthle cell carcinoma**, also known as **oxyphilic follicular carcinoma**, is a specific variant of **follicular carcinoma of the thyroid**. - It is characterized by the presence of large polygonal cells with abundant eosinophilic, granular cytoplasm known as **Hürthle cells** (or oxyphil cells) within the neoplastic growth. *Medullary carcinoma* - **Medullary carcinoma** originates from the **parafollicular C cells** of the thyroid, which produce calcitonin. - It is histologically distinct, featuring nests or cords of cells often associated with **amyloid deposits**, and is not related to Hürthle cell morphology. *Papillary carcinoma* - **Papillary carcinoma** is the most common type of thyroid cancer, characterized by distinctive **nuclear features** such as **Orphan Annie eye nuclei**, nuclear grooves, and intranuclear cytoplasmic inclusions. - Its histological origin and morphological appearance are different from Hürthle cell neoplasms, which are follicular in origin. *Anaplastic carcinoma* - **Anaplastic carcinoma** is a highly aggressive and undifferentiated thyroid malignancy with a very poor prognosis. - It is characterized by pleomorphic, giant, and spindle cells and lacks the specific differentiation seen in follicular or Hürthle cell tumors.
Question 282: Flexner-Wintersteiner rosette is seen in-
- A. Retinoblastoma (Correct Answer)
- B. Hepatoblastoma
- C. Nephroblastoma
- D. Neuroblastoma
Explanation: ***Retinoblastoma*** - Flexner-Wintersteiner rosettes are **characteristic histological features** seen in retinoblastoma, indicating retinal differentiation [1]. - These rosettes reflect the **presence of photoreceptor-like structures**, which are specific to this type of tumor [1]. *Hepatoblastoma* - Histologically, hepatoblastoma shows **primitive epithelial cells** and **mixed patterns**, not Flexner-Wintersteiner rosettes. - It is primarily associated with **liver** and does not present with retinal differentiation. *Nephroblastoma* - Nephroblastoma, or Wilms tumor, typically exhibits **triphasic histology** (epithelial, stromal, and blastemal components) without rosette formation. - It primarily affects the **kidney** and does not involve the retina. *Neuroblastoma* - Neuroblastoma is characterized by **small round blue cells** and **neuroid differentiation** but lacks Flexner-Wintersteiner rosettes. - This tumor usually arises in the **adrenal glands** or sympathetic nervous system, not in retinal tissue. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Eye, p. 1342.
Pharmacology
3 questionsWhich of the following drugs is used for Smoking Cessation?
Which of the following statements is true regarding omalizumab?
Muscarinic cholinergic receptors are seen at all sites, except?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 281: Which of the following drugs is used for Smoking Cessation?
- A. Bupropion (Correct Answer)
- B. Methadone
- C. Buprenorphine
- D. Naltrexone
Explanation: ***Bupropion*** - **Bupropion** is an antidepressant that is also approved as a smoking cessation aid. It works by inhibiting the reuptake of **dopamine** and **norepinephrine**, which can help reduce nicotine cravings and withdrawal symptoms. - It is often prescribed as a first-line pharmacotherapy for smoking cessation, with a typical treatment duration of 7-12 weeks. *Buprenorphine* - **Buprenorphine** is a partial opioid agonist primarily used to treat opioid addiction. It is not indicated for smoking cessation. - While it can help manage withdrawal symptoms from opioids, it has no direct mechanism of action that would reduce nicotine dependence or cravings. *Methadone* - **Methadone** is a full opioid agonist primarily used for the treatment of opioid use disorder (OUD) and chronic pain management. It is not used for smoking cessation. - Its mechanism involves binding to opioid receptors to prevent withdrawal symptoms and reduce cravings for other opioids. *Naltrexone* - **Naltrexone** is an opioid antagonist used primarily for the treatment of alcohol dependence and opioid use disorder. It is not indicated for smoking cessation. - It blocks the effects of opioids and reduces alcohol cravings, but does not affect nicotine pathways or dependence.
Question 282: Which of the following statements is true regarding omalizumab?
- A. Anti-IgE
- B. Given subcutaneously
- C. Used as add-on therapy in moderate to severe asthma prophylaxis
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** is correct because each statement is true: **Anti-IgE** - Omalizumab is a **humanized monoclonal antibody** that specifically targets and binds to **free IgE** in the circulation - By binding free IgE, it prevents IgE from attaching to **high-affinity receptors** on mast cells and basophils - This reduces the allergic cascade and prevents release of inflammatory mediators **Given subcutaneously** - Omalizumab is administered via **subcutaneous injection** only - Dosing is typically every **2 to 4 weeks** based on patient's body weight and baseline IgE levels - Not available in oral or intravenous formulations for asthma treatment **Used as add-on therapy in moderate to severe asthma prophylaxis** - FDA approved as **add-on maintenance treatment** for patients aged ≥6 years with **moderate to severe persistent allergic asthma** - Indicated when asthma is **inadequately controlled** with inhaled corticosteroids - Reduces frequency of asthma exacerbations and improves asthma control - Also approved for chronic spontaneous urticaria All three statements accurately describe omalizumab's mechanism, administration route, and clinical indication, making **"All of the options"** the correct answer.
Question 283: Muscarinic cholinergic receptors are seen at all sites, except?
- A. Stomach
- B. CNS
- C. Glands
- D. Neuromuscular junction (Correct Answer)
Explanation: ***Neuromuscular junction*** - The **neuromuscular junction** primarily contains **nicotinic cholinergic receptors**, not muscarinic receptors. - Activation of these nicotinic receptors by acetylcholine causes muscle contraction. *Stomach* - The stomach contains **muscarinic M3 receptors** which mediate gastric acid secretion and smooth muscle contraction. - Activation by acetylcholine via the vagus nerve promotes digestion. *CNS* - The **central nervous system** has various subtypes of **muscarinic receptors (M1-M5)** distributed throughout, playing roles in learning, memory, and motor control. - These receptors modulate neuronal excitability and neurotransmitter release. *Glands* - Most exocrine glands (e.g., salivary, lacrimal, sweat glands) are richly supplied with **muscarinic receptors**, primarily **M3**. - Activation leads to increased glandular secretion.