NEET-PG 2020 Practice Questions

Q: Identify the type of cartilage shown in the image.

Fibrocartilage. ***Fibrocartilage*** - The image displays **chondrocytes** arranged in rows between bundles of **collagen fibers**, characteristic of fibrocartilage. This structure provides high tensile strength and shock absorption. - Unlike other cartilage types, fibrocartilage lacks a distinct perichondrium and is found in structures requiring extreme strength, such as intervertebral discs and menisci. *Hyaline cartilage* - Hyaline cartilage has an amorphous, **glassy matrix** with chondrocytes typically arranged in small groups (isogenous groups) within lacunae, without prominent collagen bundles. - It is found in articular surfaces, tracheal rings, and the costal cartilages, providing smooth, low-friction surfaces. *Elastic cartilage* - Elastic cartilage is characterized by a high concentration of **elastic fibers** within its matrix, giving it flexibility and resilience. - Chondrocytes are typically scattered and the matrix stains darker due to the elastic fibers, which are not apparent in the image. *Dense connective tissue* - While dense connective tissue contains abundant **collagen fibers**, it lacks chondrocytes in lacunae, instead containing fibroblasts. - The presence of chondrocytes in the image confirms this is cartilage, not dense connective tissue.

Q: Elderly man with a long-standing mole on his face that is increasing in size and showing an irregular border. Diagnosis:

Lentigo maligna. ***Lentigo maligna*** - This type of melanoma commonly affects **elderly individuals** and presents as a **slowly enlarging, irregularly bordered, flat or slightly raised pigmented lesion** on sun-exposed areas like the face. - It often has a **long radial growth phase** before progressing to invasive lentigo maligna melanoma. *Superficial spreading melanoma* - While common, it typically presents on the **trunk or extremities** and has a faster growth rate compared to lentigo maligna. - It often appears as a **flat, asymmetrical lesion with varied colors and irregular borders**, but the age and location details point away from this. *Nodular melanoma* - This is an **aggressive form** that grows vertically from the start, presenting as a **dark, raised, often ulcerated nodule** and typically has a shorter history of rapid growth. - It lacks the characteristic long-standing, flat growth pattern described in the elderly patient's face. *Acral melanoma* - This rare type occurs on the **palms, soles, or under the nails (subungual)**, not typically on the face. - It often appears as a **pigmented streak or patch** in these acral locations.

Q: What is the surgical procedure for widening of the cartilaginous part of the external auditory canal?

meatoplasty. ***Meatoplasty*** - **Meatoplasty** is a surgical procedure specifically designed to **widen the external auditory canal**, often performed to improve drainage or aid in fitting hearing aids. - This procedure usually involves modifying the **cartilaginous part** of the canal to prevent stenosis or collapse, which can cause conductive hearing loss. *Otoplasty* - **Otoplasty** is a cosmetic surgical procedure primarily focused on reshaping the **external ear (pinna)**, often to correct prominent ears or deformities. - It does not involve widening the external auditory canal. *Myringoplasty* - **Myringoplasty** is a surgical repair of a **perforated tympanic membrane (eardrum)**. - The goal is to close the hole in the eardrum to improve hearing and prevent recurrent infections, without altering the external auditory canal's width. *Tympanoplasty* - **Tympanoplasty** is a broader surgical term that involves the repair of the **tympanic membrane (eardrum)** and/or the **ossicular chain** within the middle ear. - While it addresses middle ear issues and hearing improvement, it typically does not involve widening the external auditory canal as its primary goal.

Q: A 13-year-old child visits the OPD with complaints of not attaining menarche, and has a karyotype of 46,XX. On examination, there is clitoromegaly. Which enzyme is likely deficient?

21-alpha hydroxylase. ***21-alpha hydroxylase*** - A deficiency in **21-alpha hydroxylase** leads to **Congenital Adrenal Hyperplasia (CAH)**, shunting precursors towards **androgen production**. - In a 46,XX individual, this results in **virilization** such as **clitoromegaly** and **primary amenorrhea** due to excess androgens suppressing gonadotropin release and ovarian function. *17-alpha hydroxylase* - Deficiency in **17-alpha hydroxylase** in a 46,XX individual would lead to impaired sex steroid synthesis but **excess mineralocorticoids**, causing **hypertension** and **hypokalemia**. - While it causes **primary amenorrhea** due to lack of estrogen, it typically presents with **female external genitalia** that are underdeveloped, not virilized with clitoromegaly. *11-alpha hydroxylase* - There is no known functional enzyme called **11-alpha hydroxylase** in the steroid synthesis pathway. The relevant enzyme is **11-beta hydroxylase**, which, when deficient, leads to **CAH** with virilization and hypertension. - Assuming it refers to 11-beta hydroxylase, deficiency would cause **virilization** in 46,XX females but also lead to **hypertension** due to accumulation of 11-deoxycorticosterone, which is not mentioned in the presentation. *3-beta hydroxysteroid dehydrogenase* - Deficiency of **3-beta hydroxysteroid dehydrogenase** impairs the synthesis of **all classes of adrenal steroids** (glucocorticoids, mineralocorticoids, and sex steroids). - In 46,XX individuals, it leads to **females with ambiguous genitalia** (due to accumulation of DHEA) and **salt wasting**, but typically does not cause overt clitoromegaly and amenorrhea in the manner seen with 21-hydroxylase deficiency.

Q: HBsAg is based on which principle

ELISA. ***ELISA*** - **Enzyme-linked immunosorbent assay (ELISA)** is a widely used laboratory test to detect and quantify antigens (like HBsAg) or antibodies in a sample. - It involves an enzyme-linked antibody that reacts with a substrate to produce a detectable signal, making it highly sensitive and specific for **HBsAg detection**. *Immunochromatography assays* - These are typically **rapid diagnostic tests (RDTs)** that provide quick qualitative results, often used for point-of-care testing. - While they can detect HBsAg, they generally have lower sensitivity and specificity compared to ELISA. *Chemiluminescence* - This is a detection method used in some immunoassays where a chemical reaction emits light, often providing higher sensitivity than colorimetric detection. - While it can be incorporated into HBsAg testing platforms, it is a *detection principle* rather than the primary assay principle like ELISA itself. *Immunofluorescence* - This technique uses **fluorescently labeled antibodies** to visualize antigens in cells or tissues under a fluorescence microscope [1]. - It is used for localization and identification of antigens, but not typically the primary method for routine quantitative HBsAg serology [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 259-260.

Q: What is the best treatment option for a septate uterus?

Transcervical hysteroscopic resection of the septum. ***Transcervical hysteroscopic resection of the septum*** - This procedure involves using a **hysteroscope** to visualize and resect the **fibrous or muscular septum** that divides the uterine cavity, restoring a normal uterine shape. - It is considered the gold standard due to its **minimally invasive nature**, effectiveness in improving reproductive outcomes, and lower risk of complications compared to abdominal approaches. *Tompkins Metroplasty* - This is an **abdominal surgical procedure** primarily used for the repair of a **bicornuate uterus**, not typically for a septate uterus. - It involves resecting the uterine fundus to create a single uterine cavity, which is more invasive than hysteroscopic septum resection. *Jones metroplasty* - This procedure is also an **abdominal approach** used for the surgical correction of a **bicornuate uterus**, not a septate uterus. - It involves excising the septal portion and approximating the uterine walls. *Strassmann metroplasty* - This is another **abdominal surgical technique** that is primarily indicated for the repair of a **bicornuate or didelphys uterus**, where a large defect needs to be corrected. - It involves reconstructing the uterus through a fundal incision, which is significantly more invasive than hysteroscopic septal resection for a septate uterus.

Q: Most common cause of death in SLE in children

Anemia and infections. ***Anemia and infections*** - **Infections** are a leading cause of death in pediatric SLE patients, often due to immunosuppression from the disease itself or its treatment. Although pediatric Systemic Lupus Erythematosus (SLE) is not a primary immune deficiency, the susceptibility to encapsulated bacteria and recurrent infections seen in primary B- and T-lymphocyte deficiencies mirrors the infection risks managed in these patients [1]. - **Anemia** can contribute to overall morbidity and mortality, although it is less directly a cause of death than severe infections or organ failure. *Lupus nephritis* - While **lupus nephritis** is a common and severe manifestation of SLE in children and a major cause of morbidity, particularly long-term kidney failure, it is not the most frequent immediate cause of death. - Advancements in treatment for nephritis have improved prognosis, shifting the leading cause of mortality to other factors. *Lupus cerebritis* - **Lupus cerebritis** (neuropsychiatric SLE) can be life-threatening, causing seizures, stroke, or psychosis, but it is less common as the primary cause of death compared to infections. - Its presence usually indicates severe disease requiring intensive treatment, but not the most common direct cause of death. *Libman sacks endocarditis* - **Libman-Sacks endocarditis** involves sterile vegetations on heart valves and is a known complication of SLE, but it rarely causes acute mortality in children. - It is more often associated with chronic complications like valvular dysfunction or a source of emboli rather than being the most common cause of death.

Q: What is the most serious complication of measles?

Pneumonia. ***Pneumonia*** - **Pneumonia**, particularly **giant cell pneumonia**, is the most common cause of **measles-related deaths** in young children. - It results from the **direct viral infection** of the lungs or a **secondary bacterial superinfection**. *Croup* - **Croup (laryngotracheobronchitis)** can be a complication of measles, but it is typically **less severe** and **less life-threatening** than pneumonia. - It primarily affects the **upper airways**, causing a barking cough and stridor. *Meningo-encephalitis* - **Meningo-encephalitis** is a serious, albeit **less common**, complication of measles, occurring in approximately 1 in 1,000 cases. - While potentially fatal or leading to neurological sequelae, it is **outranked by pneumonia** in terms of overall mortality attributed to measles. *Otitis media* - **Otitis media** (middle ear infection) is a common complication of measles, but it is generally **not life-threatening**. - It usually responds well to **antibiotic treatment** and rarely leads to severe outcomes.

Q: Which of the following is not considered a prokinetic agent?

Diphenylmethane. Diphenylmethane derivatives (e.g., bisacodyl, sodium picosulfate) are stimulant laxatives, not prokinetic agents. While they do increase colonic motility, they work by direct stimulation of the colonic mucosa and myenteric plexus, causing increased water secretion and peristalsis [3]. Prokinetic agents specifically enhance coordinated gastrointestinal motility through modulation of neurotransmitters (acetylcholine, dopamine, serotonin, motilin), whereas laxatives work through different mechanisms (osmotic effects, stimulation, bulk formation). Therefore, diphenylmethane derivatives are classified as laxatives, not prokinetics. Dopamine antagonist - Dopamine antagonists like metoclopramide and domperidone block D2 receptors in the chemoreceptor trigger zone and GI tract, enhancing acetylcholine release and promoting gastric emptying [2]. - They are commonly used as prokinetic agents and antiemetics [2]. 5HT4 agonist - 5HT4 agonists (e.g., cisapride, prucalopride) stimulate serotonin receptors in the enteric nervous system, increasing acetylcholine release and enhancing colonic motility [1]. - They are effective prokinetic agents for conditions like chronic constipation and gastroparesis [1]. Macrolides - Certain macrolide antibiotics, such as erythromycin, act as motilin receptor agonists at sub-antibiotic doses. - By mimicking motilin, they stimulate gastric and intestinal contractions (phase III of migrating motor complex), functioning as prokinetic agents.

Q: What is the Drug of Choice (DOC) for Onychomycosis?

Terbinafine. ***Terbinafine*** - **Terbinafine** is considered the **drug of choice** for **onychomycosis** due to its potent fungicidal activity against **dermatophytes**, which are the most common cause of nail infections [1]. - It accumulates in the nail plate at therapeutic levels, leading to high cure rates and a relatively good safety profile [2]. *Fluconazole* - While effective against some fungi, **fluconazole** is primarily fungistatic and generally less effective against dermatophytes compared to terbinafine for onychomycosis, resulting in lower cure rates [1]. - It is often preferred for **mucocutaneous candidiasis** and other systemic fungal infections [1]. *Itraconazole* - **Itraconazole** is an alternative for onychomycosis, often administered in pulse doses, but it can have more significant drug interactions and a higher risk of hepatic toxicity compared to terbinafine [1]. - Its efficacy against dermatophytes is comparable to terbinafine, but its side effect profile makes it a second-line option [1]. *Nystatin* - **Nystatin** is a topical antifungal effective primarily against **Candida species**, and is not effective against **dermatophytes**, which are the main pathogens in onychomycosis. - It is typically used for mucocutaneous candidiasis, such as oral thrush or vaginal yeast infections, and is not absorbed systemically.

Question 1

Identify the type of cartilage shown in the image.

Accepted Answer

Fibrocartilage

Answer

Hyaline cartilage

Answer

Elastic cartilage

Answer

Dense connective tissue

Question 2

Elderly man with a long-standing mole on his face that is increasing in size and showing an irregular border. Diagnosis:

Accepted Answer

Lentigo maligna

Answer

Superficial spreading melanoma

Answer

Nodular melanoma

Answer

Acral melanoma

Question 3

What is the surgical procedure for widening of the cartilaginous part of the external auditory canal?

Accepted Answer

meatoplasty

Answer

otoplasty

Answer

myringoplasty

Answer

tympanoplasty

Question 4

A 13-year-old child visits the OPD with complaints of not attaining menarche, and has a karyotype of 46,XX. On examination, there is clitoromegaly. Which enzyme is likely deficient?

Accepted Answer

21-alpha hydroxylase

Answer

17-alpha hydroxylase

Answer

11-alpha hydroxylase

Answer

3-beta hydroxysteroid dehydrogenase

Question 5

HBsAg is based on which principle

Accepted Answer

ELISA

Answer

Chemiluminescence

Answer

Immunofluorescence

Answer

Immunochromatography assays

Question 6

What is the best treatment option for a septate uterus?

Accepted Answer

Transcervical hysteroscopic resection of the septum

Answer

Tompkins Metroplasty

Answer

Jones metroplasty

Answer

Strassmann metroplasty

Question 7

Most common cause of death in SLE in children

Accepted Answer

Anemia and infections

Answer

Libman sacks endocarditis

Answer

Lupus cerebritis

Answer

Lupus nephritis

Question 8

What is the most serious complication of measles?

Accepted Answer

Pneumonia

Answer

Croup

Answer

Otitis media

Answer

Meningo-encephalitis

Question 9

Which of the following is not considered a prokinetic agent?

Accepted Answer

Diphenylmethane

Answer

Dopamine antagonist

Answer

5HT4 agonist

Answer

Macrolides

Question 10

What is the Drug of Choice (DOC) for Onychomycosis?

Accepted Answer

Terbinafine

Answer

Fluconazole

Answer

Itraconazole

Answer

Nystatin

NEET-PG 2020

Anatomy

Dermatology

ENT

Internal Medicine

Microbiology

Obstetrics and Gynecology

Pediatrics

Pharmacology