NEET-PG 2018 Practice Questions

Q: Nasopharyngeal chordoma arises from:-

Notochord. Correct Option: Notochord - **Chordomas** are rare malignant tumors that arise from embryonic remnants of the **notochord** [1] - The notochord is a flexible rod-like structure that forms the primitive axial skeleton during embryonic development - Chordomas typically occur along the **midline** at sites where notochordal remnants persist, most commonly at the **skull base (clivus/nasopharynx)** and **sacrococcygeal region** [1] Incorrect Option: Luschka's bursa - **Luschka's bursa** (also known as the pharyngeal bursa) is a small indentation or pocket in the nasopharynx posterior to the pharyngeal tonsil - While located in the nasopharynx, it is a **normal anatomical structure**, not an embryological remnant that gives rise to tumors - Not associated with chordoma development Incorrect Option: Pharyngeal bursa - **Pharyngeal bursa** is another term for **Luschka's bursa** (they are synonymous) - It is a normal anatomical structure in the nasopharynx - Not related to the embryonic remnants that give rise to chordomas Incorrect Option: Rathke's pouch - **Rathke's pouch** is an embryonic invagination of the stomodeum (primitive oral cavity) that gives rise to the **anterior pituitary gland** - Tumors arising from remnants of Rathke's pouch are **craniopharyngiomas**, which are distinct from chordomas - Craniopharyngiomas are typically suprasellar, while chordomas are more commonly found at the clivus or sacrum

Q: During acute tonsillitis, referred pain from the tonsil to the middle ear occurs via which nerve?

Glossopharyngeal nerve. ***Glossopharyngeal nerve*** - The **glossopharyngeal nerve (CN IX)** provides sensory innervation to the palatine tonsil via its tonsillar branches - CN IX also supplies the middle ear via the **tympanic nerve (Jacobson's nerve)**, which forms the tympanic plexus - This shared sensory pathway explains **referred otalgia** (ear pain) during acute tonsillitis - Inflammation of the tonsil stimulates CN IX, and the brain misinterprets this as pain from the middle ear *Facial nerve* - The **facial nerve (CN VII)** primarily provides motor innervation to muscles of facial expression and taste to the anterior two-thirds of the tongue - While it has a small sensory component (nervus intermedius) for the external auditory canal, it does not innervate the tonsil - Cannot serve as the pathway for referred pain from tonsil to middle ear *Trigeminal nerve* - The **trigeminal nerve (CN V)** provides sensory innervation to the face, anterior scalp, and oral cavity - Does not innervate the palatine tonsil or the middle ear cavity - Not involved in tonsillar referred otalgia *Vagus nerve* - The **vagus nerve (CN X)** provides sensory innervation to parts of the pharynx, larynx, and external auditory canal (via Arnold's nerve) - While it contributes to pharyngeal sensation, the **glossopharyngeal nerve is the primary pathway** for referred otalgia from tonsillar inflammation due to its direct innervation of both the tonsil and middle ear

Q: Which of the following hematological problems may be precipitated by parvovirus?

Aplastic crisis. ***Aplastic crisis*** - Parvovirus B19 preferentially infects and destroys **erythroid progenitor cells** in the bone marrow, leading to a temporary halt in red blood cell production [1]. - This can precipitate an **aplastic crisis**, especially in individuals with underlying chronic hemolytic anemias (e.g., **sickle cell disease** or **hereditary spherocytosis**), where red blood cell lifespan is already shortened [2]. *Hemolytic crisis* - A hemolytic crisis involves an **accelerated destruction of red blood cells**, leading to a sudden drop in hemoglobin. - While parvovirus can indirectly worsen anemia, it primarily affects red cell production rather than directly increasing their destruction, acting more as a trigger for a production problem than a hemolytic one [1]. *Thrombocytopenia* - **Thrombocytopenia** is characterized by a low platelet count, which can lead to bleeding disorders. - While viral infections can sometimes cause mild myelosuppression affecting platelets, parvovirus B19 is not typically associated with severe or primary thrombocytopenia. *Pancytopenia* - **Pancytopenia** is a reduction in all three blood cell lines (red blood cells, white blood cells, and platelets). - While parvovirus can cause a transient aplastic crisis (affecting red cells), it rarely causes a severe, sustained suppression of all cell lines to be classified as true pancytopenia, though some transient leukopenia may occur [1].

Q: Which of the following is an indication for use of Hormone Replacement Therapy in menopausal women:-

Hot flushes. ***Hot flushes*** - Hormone Replacement Therapy (HRT) is highly effective in alleviating **vasomotor symptoms** like hot flushes and night sweats, which can severely impact quality of life in menopausal women. - The primary goal of using HRT is to manage these **menopausal symptoms** when they are bothersome. *Post menopausal bleeding* - **Postmenopausal bleeding** is a contraindication, not an indication, for new HRT initiation as it requires investigation to rule out endometrial pathology, including cancer. - If a woman on HRT experiences bleeding, it warrants immediate investigation to determine its cause and may necessitate stopping or changing the HRT regimen. *Cardiovascular protection* - While earlier beliefs suggested HRT offered cardiovascular protection, current evidence, particularly from the **Women's Health Initiative (WHI) study**, showed that HRT does not provide primary or secondary cardiovascular protection. - In fact, HRT may increase the risk of **cardiovascular events** like stroke and venous thromboembolism, especially when initiated many years after menopause. *Pyelonephritis* - **Pyelonephritis** is an infection of the kidney, typically caused by bacteria, and is not directly related to menopausal symptoms or hormonal status. - Treatment for pyelonephritis involves **antibiotics** and supportive care, not HRT.

Q: Which among the following is not a premalignant lesion of vulva?

Bacterial Vaginosis. ***Bacterial Vaginosis*** - This is a common **vaginal infection** caused by an imbalance of normal vaginal bacteria, characterized by specific symptoms like increased discharge and odor. - Bacterial vaginosis is not considered a premalignant lesion and does not increase the risk of developing vulvar cancer. *Paget's disease* - This is a rare form of intraepithelial adenocarcinoma that can occur on the vulva, presenting as a red, itchy, scaly rash. - While it is a **carcinoma in situ**, it has the potential to become invasive, thus considered a premalignant or pre-invasive condition. *Bowen's disease* - This is a form of **squamous cell carcinoma in situ (SCCIS)**, typically appearing as a slow-growing, red, scaly patch on the skin. - It is considered a premalignant lesion because it can progress to invasive squamous cell carcinoma if left untreated. *Lichen Sclerosus* - This is a chronic inflammatory skin condition primarily affecting the anogenital region, leading to thinning, whitening, and scarring of the skin. - Although it is a benign condition, individuals with vulvar lichen sclerosus have an increased risk (3-5%) of developing **vulvar squamous cell carcinoma**, making it a premalignant condition.

Q: Coagulation testing is needed for:

Lepirudin (direct thrombin inhibitor). ***Lepirudin (direct thrombin inhibitor)*** - **Lepirudin**, being a direct thrombin inhibitor, necessitates **coagulation testing** (such as aPTT) to monitor its anticoagulant effect and adjust dosing, especially in patients with renal impairment. - Its narrow therapeutic window and potential for bleeding complications require careful monitoring to ensure patient safety and drug efficacy, as it lacks a specific antidote. *Dabigatran (oral anticoagulant)* - **Dabigatran** is a **direct oral anticoagulant (DOAC)** that typically does not require routine coagulation monitoring due to its predictable pharmacokinetic and pharmacodynamic profiles. - While specific tests can assess its effect in emergencies, they are not part of standard management, distinguishing it from drugs requiring regular monitoring. *Enoxaparin (low molecular weight heparin)* - **Enoxaparin**, a **low molecular weight heparin (LMWH)**, usually does not require routine coagulation monitoring in most patients due to its predictable dose-response relationship. - Monitoring with anti-Xa levels may be considered in specific populations, such as those with renal insufficiency, extremes of weight, or in pediatric and pregnant patients. *Fondaparinux (synthetic pentasaccharide)* - **Fondaparinux** is a synthetic pentasaccharide that **does not require routine coagulation monitoring** as its anticoagulant effect is highly predictable and dose-dependent. - Its action is mediated through selective inhibition of **Factor Xa**, and standard coagulation tests like aPTT or PT are not sensitive to its effects.

Q: Amphotericin B acts on:-

Cell membrane. ***Cell membrane*** Amphotericin B primarily targets the **ergosterol** in the fungal **cell membrane** [1]. It binds to **ergosterol**, forming pores and disrupting the membrane's integrity, leading to leakage of cellular contents and ultimately cell death [1]. *Cytoplasm* The cytoplasm is the internal fluid of the cell where many metabolic processes occur, but it is **not the primary target** of amphotericin B's fungicidal action. While cytoplasmic contents leak out due to membrane damage, the drug does not directly act on cytoplasmic components to exert its effect. *Nucleus* The nucleus contains the genetic material of the fungal cell, but amphotericin B does **not directly interact with nuclear components** or DNA. Damage to the cell membrane is the primary mechanism, with nuclear function only indirectly affected by overall cellular disruption. *Cell wall* Fungal cell walls are composed of **chitin and glucans**, but amphotericin B **does not target these components**. Its action is distinct from drugs that inhibit cell wall synthesis, such as echinocandins.

Q: Drug which lacks intrinsic activity against anaerobes is:-

Aminoglycosides. ***Aminoglycosides*** - Aminoglycosides require an **oxygen-dependent transport system** to enter bacterial cells and exert their effects. - Due to the **anaerobic environment**, this transport system is inactive, rendering aminoglycosides ineffective against anaerobic bacteria. *Beta lactams* - Many beta-lactam antibiotics, especially certain **cephalosporins (e.g., cefoxitin, cefotetan)** and **carbapenems (e.g., imipenem, meropenem)**, have significant activity against anaerobes. - They inhibit **cell wall synthesis** and are a common choice for infections involving anaerobes. *Metronidazole* - **Metronidazole** is a potent and widely used antibiotic specifically effective against a broad spectrum of **anaerobic bacteria** and protozoa. - It acts by forming **cytotoxic reduced products** that disrupt bacterial DNA synthesis in anaerobic conditions. *Chloramphenicol* - **Chloramphenicol** is a broad-spectrum antibiotic that is highly effective against both aerobic and **anaerobic bacteria**. - It works by binding to the **50S ribosomal subunit**, thereby inhibiting bacterial protein synthesis.

Q: The CT thorax image shows:

Ascending aortic dissection. ***Ascending aortic dissection*** - The CT image shows a **classic intimal flap** separating the true and false lumens in the ascending aorta, which is the hallmark feature of an aortic dissection. - This represents a **Stanford Type A dissection** involving the ascending aorta, which is a life-threatening emergency requiring **immediate surgical intervention** due to high risk of complications including rupture, cardiac tamponade, and acute aortic regurgitation. - The presence of the intimal flap creating two distinct channels (true and false lumens) is pathognomonic for dissection. *Descending aortic dissection* - While the intimal flap is characteristic of dissection, the image specifically shows involvement of the **ascending aorta** (proximal to the left subclavian artery), not the descending thoracic aorta. - Descending aortic dissections (Stanford Type B) are typically managed **medically** with blood pressure control, unlike ascending dissections which require surgery. *Aortic aneurysm* - An **aortic aneurysm** represents focal dilatation of the aortic wall (>50% increase in diameter) without separation of the intimal layers. - While aneurysms can be a risk factor for dissection, the key finding here is the **intimal flap dividing the lumen**, which defines dissection rather than simple aneurysmal dilatation. - The image does not show the uniform circumferential enlargement typical of aneurysms. *Aortic coarctation* - **Aortic coarctation** is a congenital narrowing of the aorta, typically located at the aortic isthmus (near the ligamentum arteriosum), distal to the left subclavian artery. - CT would show focal narrowing with pre-stenotic dilatation and collateral vessel formation, not an intimal flap. - This is a completely different pathology without the characteristic dissection flap seen in this image.

Q: The ideal synthetic material used for femoropopliteal bypass when autologous vein is unavailable is:

ePTFE. ***ePTFE (Expanded Polytetrafluoroethylene)*** - **ePTFE** is the preferred synthetic graft for femoropopliteal bypass when autologous vein is unavailable - Offers good **biocompatibility** and relative resistance to **thrombosis** - Provides superior patency rates in above-knee femoropopliteal bypasses compared to other synthetic materials (5-year patency ~50-60%) - The expanded structure allows tissue ingrowth and better integration *Dacron (Polyethylene terephthalate)* - Generally used for **larger diameter vessels** (e.g., aortoiliac grafts) - Has **inferior patency rates** in smaller diameter femoropopliteal position compared to ePTFE - More prone to kinking and associated with higher rates of intimal hyperplasia in peripheral circulation *Saphenous vein* - The autologous saphenous vein is the **gold standard** for femoropopliteal bypass with superior long-term patency (5-year patency ~70-80%) - However, this question specifically asks for synthetic material when vein is unavailable or unsuitable - Not always available or of adequate quality in all patients *PTFE (non-expanded)* - **Non-expanded PTFE** lacks the porous structure of ePTFE - Not used for vascular grafts due to absence of tissue ingrowth capability - The **expanded** form is specifically engineered for vascular applications

Question 1

Nasopharyngeal chordoma arises from:-

Accepted Answer

Notochord

Answer

Luschka's bursa

Answer

Pharyngeal bursa

Answer

Rathke's pouch

Question 2

During acute tonsillitis, referred pain from the tonsil to the middle ear occurs via which nerve?

Accepted Answer

Glossopharyngeal nerve

Answer

Facial nerve

Answer

Trigeminal nerve

Answer

Vagus nerve

Question 3

Which of the following hematological problems may be precipitated by parvovirus?

Accepted Answer

Aplastic crisis

Answer

Hemolytic crisis

Answer

Thrombocytopenia

Answer

Pancytopenia

Question 4

Which of the following is an indication for use of Hormone Replacement Therapy in menopausal women:-

Accepted Answer

Hot flushes

Answer

Post menopausal bleeding

Answer

Cardiovascular protection

Answer

Pyelonephritis

Question 5

Which among the following is not a premalignant lesion of vulva?

Accepted Answer

Bacterial Vaginosis

Answer

Paget's disease

Answer

Bowen's disease

Answer

Lichen Sclerosus

Question 6

Coagulation testing is needed for:

Accepted Answer

Lepirudin (direct thrombin inhibitor)

Answer

Dabigatran (oral anticoagulant)

Answer

Enoxaparin (low molecular weight heparin)

Answer

Fondaparinux (synthetic pentasaccharide)

Question 7

Amphotericin B acts on:-

Accepted Answer

Cell membrane

Answer

Cytoplasm

Answer

Nucleus

Answer

Cell wall

Question 8

Drug which lacks intrinsic activity against anaerobes is:-

Accepted Answer

Aminoglycosides

Answer

Beta lactams

Answer

Metronidazole

Answer

Chloramphenicol

Question 9

The CT thorax image shows:

Accepted Answer

Ascending aortic dissection

Answer

Descending aortic dissection

Answer

Aortic aneurysm

Answer

Aortic coarctation

Question 10

The ideal synthetic material used for femoropopliteal bypass when autologous vein is unavailable is:

Accepted Answer

ePTFE

Answer

Dacron

Answer

Xenograft

Answer

Saphenous vein

Answer

PTFE (non-expanded)

Answer

Cryopreserved vein graft

Answer

Polyethylene terephthalate (PET)

Answer

Allograft

NEET-PG 2018

Anatomy

Internal Medicine

Obstetrics and Gynecology

Pharmacology

Radiology

Surgery