NEET-PG 2020 Practice Questions

Q: The upward extension of thyroid swelling is prevented by which of the following structures

Pretracheal fascia. ***Pretracheal fascia*** - The **pretracheal fascia** is a deep cervical fascia layer that **envelops the thyroid gland** and is continuous with the fibrous capsule of the gland. - Due to its attachments, particularly to the **cricoid cartilage** and **recurrent laryngeal nerve sheath**, it anchors the thyroid gland and **restricts its upward movement** during swallowing. *Sternothyroid* - The **sternothyroid muscle** depresses the larynx and thyroid gland, but it does **not inherently prevent upward extension** of a thyroid swelling. - Its action is on the **movement of the larynx** and thyroid, rather than an anatomical barrier to swelling. *Thyrohyoid membrane* - The **thyrohyoid membrane** connects the thyroid cartilage to the hyoid bone and allows for movement between them, but it has no direct role in **preventing upward extension of a thyroid swelling**. - It is mainly involved in **laryngeal elevation** during swallowing. *Ligament of Berry* - The **ligament of Berry** (or lateral suspensory ligament) connects the thyroid gland to the **cricoid cartilage** and **trachea** [1]. - While it offers some stability to the thyroid gland, its primary role is to **anchor the gland posteriorly** rather than prevent the upward extension of a swelling [1].

Q: Which of the following is the rich source of Vitamin B12?

Meat. ***Meat*** - **Vitamin B12** is primarily found in **animal products** because it is synthesized by bacteria in the digestive tracts of animals. - **Meat**, especially red meat and liver, is an excellent source of this vitamin. *Mango* - Mangoes are a good source of **Vitamin C** and **Vitamin A**, but they contain negligible amounts of Vitamin B12. - As a fruit, mangos are a plant-based food and generally **do not contain B12**. *Carrot* - Carrots are rich in **beta-carotene** (a precursor to Vitamin A) and **fiber**, but they are not a source of Vitamin B12. - Being a vegetable, carrots are a **plant-based food** and lack Vitamin B12. *Spinach* - Spinach is known for its high content of **iron**, **folate**, and **Vitamin K**, but it does not contain Vitamin B12. - Like other plant-based foods, spinach **naturally lacks Vitamin B12**.

Q: NO is synthesized from:

L-arginine. ***L-arginine*** - **Nitric oxide (NO)** is synthesized from the amino acid **L-arginine** by the enzyme **nitric oxide synthase (NOS)**. - This reaction requires **molecular oxygen** and **NADPH** as cofactors, producing **L-citrulline** as a co-product. - **Three NOS isoforms** exist: neuronal (nNOS), inducible (iNOS), and endothelial (eNOS). - **Clinical significance**: NO is crucial for **vascular smooth muscle relaxation**, **neurotransmission**, and **immune defense**. *L-citrulline* - **L-citrulline** is the co-product (not precursor) of the NO synthesis reaction. - While it can be recycled back to **L-arginine** via the **citrulline-arginine cycle**, it does not directly yield NO without first being converted to arginine. - This recycling pathway helps sustain NO production in endothelial cells. *Glycine* - **Glycine** is involved in various metabolic processes, including **heme synthesis**, **purine synthesis**, and as a neurotransmitter. - It plays no direct role in **nitric oxide** biosynthesis. - Not a substrate for any **NOS isoform**. *Lysine* - **Lysine** is an essential amino acid important for **protein synthesis**, **collagen formation**, and **carnitine synthesis**. - It is structurally distinct from arginine and is not recognized by **nitric oxide synthase**. - Not involved in the NO synthesis pathway.

Q: A farmer presented with a black mole on the cheek. It increased in size, more than 6mm with irregular borders and a central black lesion, what could be the diagnosis?

Superficial spreading melanoma. ***Superficial spreading melanoma*** - This is the most common type of melanoma and often presents as a **mole with irregular borders**, varying colors, and a diameter greater than 6mm, consistent with the description. - The lesion typically grows **radially** across the skin surface before beginning vertical growth, indicated by the increase in size. *Acral lentigo melanoma* - This type of melanoma primarily affects the **palms, soles, and nail beds**, which is inconsistent with a lesion on the cheek. - It often appears as a **dark brown or black patch** that slowly enlarges, but its location is characteristic. *Lentigo maligna melanoma* - This melanoma typically occurs in **chronically sun-damaged skin** of the elderly, often on the head and neck, but usually presents as a **flat, irregularly shaped, tan or brown patch** with varying shades, which may not fit the description of a central black lesion within a larger mole. - It has a dominant **radial growth phase** and progresses slowly over many years before developing a nodular component. *Nodular melanoma* - This type is characterized by its **rapid vertical growth** and appearance as a **raised, dark, often dome-shaped lesion** from the outset. - While it can be black, the description of an "increased in size" mole with irregular borders and a central black lesion points more towards a spreading type rather than a rapidly growing nodule from the beginning.

Q: A 32-year-old patient with Restless leg syndrome comes to the OPD. What is the most appropriate first line treatment?

Gabapentin. ***Gabapentin*** - **Gabapentin** and other alpha-2-delta ligands (e.g., pregabalin) are considered **first-line agents** for moderate to severe Restless Legs Syndrome (RLS), particularly when symptoms are bothersome and daily. - They work by modulating **calcium channels** and are effective in reducing RLS symptoms with a generally favorable side effect profile. *Iron Supplementation* - **Iron supplementation** is appropriate as first-line treatment only if **serum ferritin levels** are below 75 mcg/L, indicating iron deficiency. - While RLS is associated with **iron deficiency**, it's not the universal first-line treatment without biochemical confirmation [1]. *Pramipexole* - **Dopamine agonists** like pramipexole are effective for RLS but are generally **second-line treatments** due to concerns about augmentation (worsening of RLS symptoms) and impulse control disorders. - Augmentation is a significant side effect where symptoms worsen paradoxically with continued use, particularly with higher doses. *Vitamin B12* - **Vitamin B12 deficiency** can cause neurological symptoms, but it is **not a primary cause or treatment** for Restless Legs Syndrome. - Supplementation with **Vitamin B12** would only be considered if a confirmed deficiency exists, which is not stated as a contributing factor in this patient.

Q: Superior temporal gyrus lesion leads to?

Wernicke's aphasia. ***Wernicke's aphasia*** - A lesion in the **superior temporal gyrus** (Wernicke's area) leads to Wernicke's aphasia, characterized by impaired **comprehension of language** [1]. - Patients with Wernicke's aphasia exhibit **fluent but meaningless speech** (word salad) and are often unaware of their deficits [1]. *Anomic aphasia* - Characterized by difficulty finding words, particularly nouns and verbs, and is often associated with lesions in the **angular gyrus** or **temporal lobe** [1]. - Speech remains fluent and grammatically correct, but it is marked by frequent pauses and circumlocutions as the individual struggles to retrieve specific words. *Broca's aphasia* - Results from damage to **Broca's area** in the posterior inferior frontal gyrus, causing **non-fluent speech** and difficulty with speech production [1]. - While comprehension is relatively preserved, patients struggle to form complete sentences and may exhibit agrammatism. *Non-fluent aphasia* - A broad category of aphasias, including Broca's aphasia, where speech production is notably impaired, and the output is effortful and characterized by **agrammatism** and **short, telegraphic sentences**. - **Wernicke's aphasia** is typically considered a **fluent aphasia**, as speech production itself is not interrupted, though its content is often incomprehensible [1].

Q: Which is the most common site of gastrinoma in MEN 1 syndrome?

Duodenum. ***Duodenum*** - In **MEN 1 syndrome**, gastrinomas (gastrin-secreting tumors) are most commonly found in the **duodenum**, often multiple and small. - This location accounts for a significant majority of gastrinomas, particularly in patients with **Zollinger-Ellison syndrome (ZES)** associated with MEN 1. *Stomach* - While gastrinomas can occasionally be found in the stomach, this is a **much less common site** compared to the duodenum, especially in the context of MEN 1 syndrome. - Gastric gastrinomas are typically associated with conditions like **atrophic gastritis** and **pernicious anemia**, leading to G-cell hyperplasia and often hypergastrinemia, but tend to be less aggressive. *Ileum* - The **ileum** is an **uncommon site** for gastrinomas; these types of neuroendocrine tumors (NETs) are rarely found there. - NETs in the ileum are more typically associated with the secretion of other hormones, such as **serotonin**, leading to carcinoid syndrome, rather than gastrin. *Jejunum* - Gastrinomas in the **jejunum** are also **rare**, similar to the ileum. - While neuroendocrine tumors can arise throughout the small bowel, the jejunum is not a typical or primary location for gastrin-producing tumors within the context of **MEN 1**.

Q: Nosocomial infections are diagnosed after how many hours of hospitalization / admission?

48 hours. ***48 hours*** - Nosocomial infections, also known as **hospital-acquired infections (HAIs)**, are defined as infections that develop at least **48 hours** after hospital admission. - This time frame helps differentiate infections acquired in the hospital setting from those the patient was incubating upon admission. *96 hours* - A 96-hour threshold is **too long** for the standard definition of a nosocomial infection. - Infections emerging after this extended period would almost certainly be considered hospital-acquired, but the conventional diagnostic window is shorter. *72 hours* - While 72 hours might capture many HAIs, it is **not the universally accepted or most common cutoff** for defining a nosocomial infection. - The 48-hour mark is more widely used for epidemiological and diagnostic purposes. *24 hours* - Infections diagnosed within **24 hours** of admission are typically considered to have been present or incubating **prior to hospitalization**. - This short timeframe is generally insufficient to classify an infection as hospital-acquired.

Q: Loss of foot processes seen on electron microscopy of renal biopsy is a classical feature in which of the following?

Minimal change disease. ***Minimal change disease*** - **Loss of foot processes** (podocyte effacement) is the hallmark ultrastructural finding in **minimal change disease** on electron microscopy [1]. - This effacement of podocyte foot processes leads to increased permeability of the **glomerular filtration barrier** to albumin, causing **nephrotic syndrome** [1], [2]. *IgA nephropathy* - Characterized by **IgA immune complex deposition** in the **mesangium** on immunofluorescence. - Electron microscopy typically shows **mesangial immune deposits**, not primarily foot process effacement. *Membranous nephropathy* - Identified by the presence of **subepithelial immune deposits** and **thickening of the glomerular basement membrane** (GBM) [3]. - On electron microscopy, these deposits are visible, often with overlying **spikes** of GBM material separating them. *Rapidly progressive glomerulonephritis* - Defined by the rapid loss of renal function and the presence of **crescents** in more than 50% of glomeruli on light microscopy [2]. - While there may be secondary podocyte changes due to severe inflammation, **foot process effacement** is not its primary diagnostic feature. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 927-928. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 527-528. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 532-533.

Q: A 4-year-old male child presents with muscle weakness. His mother reports that her child has difficulty in climbing stairs and getting up from the floor. On muscle biopsy, small degenerated muscle fibers and absence of dystrophin were found. What is the diagnosis?

Duchenne muscular dystrophy. ***Duchenne muscular dystrophy*** - The classic presentation of a young boy with **progressive muscle weakness**, difficulty climbing stairs (**Gowers' sign**), and **absent dystrophin** on muscle biopsy is characteristic of Duchenne muscular dystrophy. - It is an **X-linked recessive disorder** that leads to severe muscle degeneration and weakness due to a complete lack of functional dystrophin protein. *Myotonic dystrophy* - This condition is characterized by **myotonia** (delayed relaxation of muscles after contraction) and typically affects adults, although congenital forms exist. - While it causes muscle weakness, the primary differentiating feature of **myotonia** and its later onset are not present in this case. *Becker's muscle dystrophy* - Becker's muscular dystrophy (BMD) is also an X-linked recessive disorder and a milder form of muscular dystrophy, caused by a **reduced but still functional dystrophin** protein. - Patients with BMD typically present later in childhood or adolescence with slower progression and **some dystrophin** presence, unlike the absent dystrophin and early onset here. *Limb-girdle muscular dystrophy* - This is a group of muscular dystrophies that primarily affect the **pelvic and shoulder girdle muscles**. - It can present with similar weakness, but the **complete absence of dystrophin** found on biopsy points specifically to Duchenne muscular dystrophy, not typical limb-girdle dystrophy, which involves other genetic defects.

Question 1

The upward extension of thyroid swelling is prevented by which of the following structures

Accepted Answer

Pretracheal fascia

Answer

Sternothyroid

Answer

Thyrohyoid membrane

Answer

Ligament of berry

Question 2

Which of the following is the rich source of Vitamin B12?

Accepted Answer

Meat

Answer

Mango

Answer

Carrot

Answer

Spinach

Question 3

NO is synthesized from:

Accepted Answer

L-arginine

Answer

L-citrulline

Answer

Glycine

Answer

Lysine

Question 4

A farmer presented with a black mole on the cheek. It increased in size, more than 6mm with irregular borders and a central black lesion, what could be the diagnosis?

Accepted Answer

Superficial spreading melanoma

Answer

Acral lentigo melanoma

Answer

Lentigo maligna melanoma

Answer

Nodular melanoma

Question 5

A 32-year-old patient with Restless leg syndrome comes to the OPD. What is the most appropriate first line treatment?

Accepted Answer

Gabapentin

Answer

Iron Supplementation

Answer

Pramipexole

Answer

Vitamin B12

Question 6

Superior temporal gyrus lesion leads to?

Accepted Answer

Wernicke's aphasia

Answer

Anomic aphasia

Answer

Broca's aphasia

Answer

Non-fluent aphasia

Question 7

Which is the most common site of gastrinoma in MEN 1 syndrome?

Accepted Answer

Duodenum

Answer

Stomach

Answer

Ileum

Answer

Jejunum

Question 8

Nosocomial infections are diagnosed after how many hours of hospitalization / admission?

Accepted Answer

48 hours

Answer

96 hours

Answer

72 hours

Answer

24 hours

Question 9

Loss of foot processes seen on electron microscopy of renal biopsy is a classical feature in which of the following?

Accepted Answer

Minimal change disease

Answer

Membranous nephropathy

Answer

Rapidly progressive glomerulonephritis

Answer

IgA nephropathy

Question 10

A 4-year-old male child presents with muscle weakness. His mother reports that her child has difficulty in climbing stairs and getting up from the floor. On muscle biopsy, small degenerated muscle fibers and absence of dystrophin were found. What is the diagnosis?

Accepted Answer

Duchenne muscular dystrophy

Answer

Myotonic dystrophy

Answer

Becker's muscle dystrophy

Answer

Limb-girdle muscular dystrophy

NEET-PG 2020

Anatomy

Biochemistry

Dermatology

Internal Medicine

Microbiology

Pathology

Pediatrics