NEET-PG 2019 Practice Questions

Q: Structure derived from first pharyngeal arch:

Anterior belly of digastric. ***Anterior belly of digastric*** - The **first pharyngeal arch** (mandibular arch) gives rise to the muscles of mastication, including the **anterior belly of the digastric muscle**. Others are the **mylohyoid muscle**, and the **tensor tympani** and **tensor veli palatini muscles**. - Its nerve supply is the **mandibular nerve (V3)**, which is the nerve of the first pharyngeal arch. *Levator palatini* - The **levator palatini muscle** is derived from the **fourth pharyngeal arch**. - It is innervated by the **pharyngeal plexus**, which contains fibers from the **vagus nerve (CN X)** (nerve of the fourth arch). *Buccinator* - The **buccinator muscle** is derived from the **second pharyngeal arch** (hyoid arch). - It is innervated by the **facial nerve (CN VII)**, which is the nerve of the second pharyngeal arch. *Stylohyoid* - The **stylohyoid muscle** is derived from the **second pharyngeal arch** (hyoid arch). - It is innervated by the **facial nerve (CN VII)**, which is the nerve of the second pharyngeal arch.

Q: In Wilson’s disease, which of the following substances is excreted in lower amounts in the urine?

Methyl- Histidine. **Important Note:** In Wilson's disease with Fanconi syndrome (proximal renal tubular dysfunction), most substances show **increased** urinary excretion, not decreased. This question appears to test knowledge of what is NOT characteristically elevated. ***Methyl-Histidine*** (Most appropriate answer) - **Methyl-histidine** (3-methylhistidine) is a marker of **muscle protein breakdown** and is not directly affected by the renal tubular dysfunction in Wilson's disease - Unlike phosphate, amino acids, and glucose which are pathologically increased in urine due to Fanconi syndrome, methyl-histidine excretion remains **normal** or is unrelated to copper-induced renal damage - This represents the substance least affected by Wilson's disease pathology *Phosphorus* (Actually INCREASED, not decreased) - **Medically incorrect as stated**: Phosphorus (phosphate) is actually **INCREASED** in urine in Wilson's disease, not decreased - Fanconi syndrome causes **renal phosphate wasting**, leading to hyperphosphaturia and resultant hypophosphatemia - This is a characteristic feature of proximal tubular dysfunction *Serine* (INCREASED due to aminoaciduria) - **Serine** and other amino acids show **generalized aminoaciduria** in Wilson's disease due to impaired proximal tubular reabsorption - Urinary serine is **elevated**, not decreased *Phosphotyrosine* - A phosphorylated amino acid involved in cell signaling, not routinely measured clinically - Not characteristically implicated in Wilson's disease urinary patterns

Q: Which health center is located in the remotest area for planning and management of health schemes?

Sub-centre. ***Sub-centre*** - A **sub-centre** is the most peripheral and first contact point between the primary healthcare system and the community, usually located in the **remotest areas**. - It serves a population of 3,000-5,000 (3,000 in tribal/hilly areas). - It plays a crucial role in the planning and management of various health schemes at the grassroots level, focusing on basic healthcare services like immunization, antenatal care, and health education. *Anganwadi* - An **Anganwadi** is part of the Integrated Child Development Services (ICDS) program, primarily focusing on nutritional and preschool education services for children and expectant/nursing mothers. - While important for community welfare, it is not a health center under the formal healthcare delivery system. *Block centre* - A **Block centre** (Community Health Centre/CHC) serves a larger population of approximately 80,000-120,000 people at the block level. - It provides secondary healthcare and referral services but is not the remotest point of contact for basic healthcare planning. *PHC* - A **Primary Health Centre (PHC)** serves a population of about 20,000-30,000 people and is located at the intermediate level between sub-centres and CHCs. - While PHCs coordinate health scheme management, they are not positioned in the remotest areas—sub-centres occupy that role.

Q: Which one of the following is an autosomal recessive disorder?

Albinism. ***Albinism*** - **Albinism** is an **autosomal recessive disorder** characterized by a partial or complete lack of melanin pigment in the skin, hair, and eyes [1], [2]. - This condition is inherited when an individual receives **two copies of the defective gene**, one from each parent [1]. *Huntington's disease* - **Huntington's disease** is an **autosomal dominant disorder**, meaning only one copy of the mutated gene is sufficient to cause the disease. - It is characterized by progressive neurodegeneration, leading to uncontrolled movements, cognitive decline, and psychiatric problems. *Marfan's syndrome* - **Marfan's syndrome** is an **autosomal dominant disorder** affecting connective tissue, primarily impacting the skeletal, ocular, and cardiovascular systems. - It results from a mutation in the **FBN1 gene** which encodes for fibrillin-1, a component of elastic fibers. *Neurofibromatosis-1* - **Neurofibromatosis type 1 (NF1)** is an **autosomal dominant disorder** caused by a mutation in the NF1 gene, leading to the growth of tumors along nerves. - Clinical features include **café-au-lait spots**, neurofibromas, and Lisch nodules. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 150-151. [2] 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. 119-120.

Q: What is the primary mechanism by which colchicine exerts its anti-inflammatory effects in acute gout?

Acts by inhibiting neutrophil migration. ***Acts by inhibiting neutrophil migration*** - Colchicine primarily functions by **disrupting microtubule formation** in neutrophils, which impairs their chemotaxis and migration to sites of inflammation. - This inhibition of neutrophil activity is crucial in dampening the **inflammatory response** triggered by uric acid crystals in acute gout. *Acts primarily as a uricosuric agent* - While other medications like **probenecid** are uricosuric and increase uric acid excretion, colchicine does not have this primary mechanism of action. - Its main anti-inflammatory effect is independent of uric acid metabolism or excretion. *Is the first-line treatment for chronic gout management* - Colchicine is effective for **acute gout attacks** and as a prophylactic against attacks during initiation of urate-lowering therapy. - However, **allopurinol** and **febuxostat** are the first-line treatments for chronic gout because they reduce uric acid production. *Has no effect on microtubule function* - This statement is incorrect; colchicine's entire mechanism of action is dependent on its ability to **bind to tubulin** and inhibit microtubule polymerization. - This disruption of microtubules is responsible for its anti-inflammatory effects and also its common side effects.

Q: Hormone predominantly secreted after 14 days that acts on the endometrium is?

Progesterone. ***Progesterone*** - After **ovulation** (around day 14 of a typical 28-day cycle), the **corpus luteum** forms and begins secreting large amounts of progesterone. - Progesterone's primary role is to prepare the **endometrium** for potential implantation by making it secretory and vascularized. *Estrogen* - Estrogen levels are highest during the **proliferative phase** (days 1-14), promoting endometrial growth and thickening. - While present after day 14, its predominant role shifts to preparing the uterus, but not as the *main* hormone secreted to support the post-ovulatory endometrium. *LH (Luteinizing Hormone)* - LH is crucial for triggering **ovulation** itself, with a surge occurring just before day 14. - After ovulation, LH levels decrease and its primary role is not direct endometrial modification. *FSH (Follicle-Stimulating Hormone)* - FSH is primarily active in the **follicular phase** (days 1-14), stimulating ovarian follicle growth. - Its levels decrease after ovulation, and it does not directly regulate endometrial changes in the post-ovulatory period.

Q: What is the PRIMARY vascular function of PGI2 (prostacyclin)?

Inhibits platelet aggregation and causes vasodilation. ***Inhibits platelet aggregation and causes vasodilation*** - **PGI2 (prostacyclin)** is a potent **vasodilator** that relaxes smooth muscle in blood vessels, increasing blood flow. - It also effectively **inhibits platelet aggregation**, preventing the formation of blood clots. *Promotes platelet aggregation and causes vasoconstriction* - This describes the primary actions of **thromboxane A2 (TXA2)**, not PGI2. - TXA2 is produced by platelets and plays a key role in **hemostasis** by constricting blood vessels and promoting platelet clumping. *Acts primarily as a bronchoconstrictor* - While some prostaglandins can affect bronchial tone, **PGI2's primary vascular role** is vasodilation and anti-aggregation. - **Leukotrienes** and certain **prostaglandins (e.g., PGD2, PGF2α)** are more classically associated with bronchoconstriction. *Stimulates inflammatory cell chemotaxis* - This is primarily a function of other inflammatory mediators such as **leukotriene B4 (LTB4)** and **C5a anaphylatoxin**. - While other eicosanoids can indirectly influence inflammation, **PGI2's main actions** are vascular and anti-platelet.

Q: What is the most likely diagnosis for the parotid mass with mixed consistency shown in the image?

Pleomorphic adenoma. ***Pleomorphic adenoma*** - The **mixed consistency** of the parotid mass indicates a **benign tumor**, predominantly of epithelial and mesenchymal origin, typical of pleomorphic adenomas. - This type of tumor is usually **pain-free** and can exhibit a **soft** and **firm** texture on examination [1]. *Sebaceous cyst* - Typically presents as a **smooth, fluctuant nodule** and usually has a **firm consistency** rather than mixed. - Generally not seen as a parotid mass; usually found on the skin in areas with sebaceous glands. *Dermoid cyst* - Generally presents as a **well-defined, soft, and mobile mass**, not commonly associated with mixed consistency. - Often contains **keratin** and has a more homogenous consistency rather than the mixed characteristics of pleomorphic adenoma. *All* - As not all options are suitable for the description of a **mixed consistency parotid mass**, this option is incorrect. - Only **pleomorphic adenoma** aligns with the specific clinical presentation detailed in the question [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Head and Neck, pp. 751-753.

Question 1

Structure derived from first pharyngeal arch:

Accepted Answer

Anterior belly of digastric

Answer

Levator palatini

Answer

Buccinator

Answer

Stylohyoid

Question 2

Which of the following statements regarding mitochondrial DNA is FALSE?

Accepted Answer

All respiratory proteins are synthesized within the mitochondria

Answer

Double stranded

Answer

Inherited from mother

Answer

High mutation rate

Question 3

In Wilson’s disease, which of the following substances is excreted in lower amounts in the urine?

Accepted Answer

Methyl- Histidine

Answer

Phosphotyrosine

Answer

Phosphorus

Answer

Serine

Question 4

Which health center is located in the remotest area for planning and management of health schemes?

Accepted Answer

Sub-centre

Answer

Anganwadi

Answer

Block centre

Answer

PHC

Question 5

What is the primary method for diagnosing Pneumocystis jirovecii pneumonia?

Accepted Answer

Bronchoalveolar lavage (BAL)

Answer

Sputum microscopy

Answer

Chest X-ray findings

Answer

Serum beta-D-glucan assay

Question 6

Which one of the following is an autosomal recessive disorder?

Accepted Answer

Albinism

Answer

Marfan’s syndrome

Answer

Neurofibromatosis-1

Answer

Huntington's disease

Question 7

What is the primary mechanism by which colchicine exerts its anti-inflammatory effects in acute gout?

Accepted Answer

Acts by inhibiting neutrophil migration

Answer

Acts primarily as a uricosuric agent

Answer

Is the first-line treatment for chronic gout management

Answer

Has no effect on microtubule function

Question 8

Hormone predominantly secreted after 14 days that acts on the endometrium is?

Accepted Answer

Progesterone

Answer

Estrogen

Answer

LH

Answer

FSH

Question 9

What is the PRIMARY vascular function of PGI2 (prostacyclin)?

Accepted Answer

Inhibits platelet aggregation and causes vasodilation

Answer

Promotes platelet aggregation and causes vasoconstriction

Answer

Acts primarily as a bronchoconstrictor

Answer

Stimulates inflammatory cell chemotaxis

Question 10

What is the most likely diagnosis for the parotid mass with mixed consistency shown in the image?

Accepted Answer

Pleomorphic adenoma

Answer

Sebaceous cyst

Answer

Dermoid cyst

Answer

None of the options

NEET-PG 2019

Anatomy

Biochemistry

Community Medicine

Microbiology

Pathology

Pharmacology

Physiology

Surgery