NEET-PG 2019 Practice Questions

Q: Which type of study determines the odds ratio?

Case control. ***Case control*** - **Case-control studies** compare individuals with a disease (cases) to individuals without the disease (controls) and look back in time to identify previous exposures. - The **odds ratio** is the primary measure of association used in case-control studies, quantifying the odds of exposure among cases versus controls. *Cohort* - **Cohort studies** follow groups of individuals over time, some exposed to a risk factor and some not, to determine the incidence of a disease. - They typically determine **relative risk**, which is the ratio of incidence rates in exposed versus unexposed groups. *Cross sectional* - **Cross-sectional studies** assess the prevalence of disease and exposure at a single point in time. - They primarily measure **prevalence** and can be used to calculate a **prevalence odds ratio**, but they do not establish temporality between exposure and outcome. *RCT* - **Randomized controlled trials (RCTs)** are interventional studies where participants are randomly assigned to an intervention or control group to determine the effectiveness of a treatment or exposure. - The main measure of effect in RCTs is often the **relative risk reduction**, **absolute risk reduction**, or **number needed to treat**, rather than the odds ratio for observational exposure.

Q: A 25-year-old male presents with localized pain in the tibia and swelling. Imaging reveals a bone abscess. Identify the condition.

Brodie abscess. ***Brodie abscess*** - A Brodie abscess is a **subacute or chronic osteomyelitis** characterized by a well-circumscribed, **radiolucent lesion** (an abscess cavity) often surrounded by a zone of **sclerosis**, representing the body's attempt to wall off the infection. - The presentation of localized pain and swelling in the tibia, with imaging revealing a bone abscess, is consistent with this condition, which is a common form of localized osteomyelitis. *Osteoid osteoma* - This is a **benign bone tumor** characterized by a small, radiolucent nidus surrounded by a large area of **sclerotic bone**. The pain from an osteoid osteoma is typically **worse at night** and dramatically relieved by NSAIDs. - While it can cause localized pain and swelling, the imaging features of a distinct abscess cavity are not characteristic of an osteoid osteoma. *Intracortical hemangioma* - An intracortical hemangioma is a **rare benign vascular lesion** within the cortex of a bone. - Imaging typically shows a **lytic lesion** with a characteristic **"honeycomb" or "sunburst" appearance**, not a well-defined abscess. *Chondromyxoid fibroma* - This is a rare, **benign cartilaginous tumor** that usually presents as an **eccentric lytic lesion** in the metaphysis of long bones, often with a scalloped border and sclerotic rim. - While it can cause localized pain and swelling, the imaging appearance of an abscess with sclerotic margins is not typical of a chondromyxoid fibroma.

Q: What is the PRIMARY mechanism by which Interleukin-1 (IL-1) induces fever?

Endogenous pyrogen. ***Endogenous pyrogen*** - **IL-1** is a potent **endogenous pyrogen** that acts directly on the **hypothalamus**, the body's thermoregulatory center. - It stimulates the production of **prostaglandin E2 (PGE2)** in the hypothalamus, which then resets the body's thermoregulatory set point to a higher temperature, leading to fever. *Stimulates antibody production* - While IL-1 can have broader immune functions and can influence B cell activity, its **primary role in fever** production is not through antibody stimulation. - Antibody production is a function of **B lymphocytes** and is primarily driven by antigen presentation and T cell help. *Inhibits inflammation* - **IL-1** is a key **pro-inflammatory cytokine** that promotes inflammation, rather than inhibiting it. - It induces the expression of various adhesion molecules and inflammatory mediators, contributing to the inflammatory response. *Activates complement cascade* - The **complement cascade** is a part of the innate immune system, typically activated by **antigen-antibody complexes** (classical pathway) or **microbial surfaces** (alternative and lectin pathways). - While IL-1 plays a role in overall immune responses, its direct mechanism for inducing fever does not primarily involve activating the complement system.

Q: Most characteristic cardiovascular defect seen in Rubella-

Patent ductus arteriosus. ***Patent ductus arteriosus*** - **Patent ductus arteriosus (PDA)** is the most characteristic cardiovascular defect associated with congenital rubella syndrome [1]. - The rubella virus can interfere with the normal closure of the **ductus arteriosus** during fetal development [1]. *Coarctation of the aorta* - **Coarctation of the aorta** is a narrowing of the aorta and is not typically linked to congenital rubella syndrome [1]. - It is often associated with syndromes like **Turner syndrome** or bicuspid aortic valve, which are not mentioned here [1]. *Ventricular septal defect* - **Ventricular septal defects (VSDs)** are common congenital heart defects, but they are not specifically characteristic of congenital rubella [1]. - VSDs are more frequently associated with conditions like **Down syndrome** or can occur in isolation [1]. *Pulmonary artery stenosis* - While **pulmonary artery stenosis** can occur as a congenital heart defect, it is less commonly the primary cardiovascular manifestation of congenital rubella syndrome. - **Peripheral pulmonary artery stenosis** can be seen in rubella, but PDA is the most characteristic overarching defect [1].

Q: What should be the correct treatment for a 14-year-old child with newly diagnosed Juvenile Rheumatoid Arthritis?

DMARDs with a short course of steroids. ***DMARDs with a short course of steroids*** - For **newly diagnosed rheumatoid arthritis** in children (juvenile idiopathic arthritis), the primary goal is to **control inflammation** and prevent joint damage with **disease-modifying antirheumatic drugs (DMARDs)**. - A **short course of corticosteroids** is often used as a **bridging therapy** to rapidly reduce inflammation while the DMARDs take effect. - This approach ensures **early aggressive treatment** to prevent joint damage while minimizing long-term steroid exposure. *Incorrect: Only NSAIDs* - **NSAIDs** alone provide **symptomatic relief** but do not alter the course of the disease or prevent joint damage in rheumatoid arthritis. - Relying solely on NSAIDs can lead to **progressive joint erosion** and functional impairment. *Incorrect: DMARDs after initial treatment with NSAIDs* - While NSAIDs can be used for initial symptom control, delaying **DMARD initiation** is generally not recommended as it allows for continued joint inflammation and potential damage. - Early and aggressive treatment with DMARDs is crucial for **optimizing long-term outcomes** and preserving joint function. *Incorrect: Monotherapy with TNF inhibitors* - **TNF inhibitors** are potent **biologic DMARDs** and are typically considered for patients who have **failed conventional DMARDs** (e.g., methotrexate). - They are not usually the **first-line monotherapy** for treatment-naive rheumatoid arthritis due to their cost, potential side effects, and the availability of other effective options. *Incorrect: Long-term high-dose corticosteroid therapy* - **Prolonged corticosteroid use** at high doses is associated with significant side effects including growth suppression, osteoporosis, increased infection risk, and cushingoid features. - While steroids are useful as **bridging therapy** for a short duration, long-term high-dose use is avoided in pediatric patients whenever possible.

Q: True about decorticate rigidity:

Rigidity is less pronounced than decerebrate rigidity. ***Rigidity is less pronounced than decerebrate rigidity*** - **Decorticate rigidity** indicates damage above the **red nucleus**, disrupting descending inhibitory pathways from the cortex. [1] - While reflecting serious brain injury, it is generally considered a **less severe prognosis** than decerebrate rigidity because the red nucleus and some rubrospinal tract functions remain intact. *Flexion of lower limbs & extension of upper limbs* - **Decorticate rigidity** typically presents with **flexion of the upper limbs** (adduction, internal rotation, elbow flexion, wrist flexion), and **extension of the lower limbs** (adduction, extension, internal rotation) [1]. - This characteristic posture, often described as "mummy baby" or "posture of salvation," is due to uninhibited activity of the **rubrospinal tract** and the absence of cortical input [1]. *Removal of cerebral cortex and basal ganglia* - **Decorticate rigidity** results from lesions that interrupt the descending pathways **above the red nucleus** (e.g., in the cerebral hemispheres or internal capsule) [1]. - This specifically means the **cerebral cortex** is "removed" in terms of its functional input, but the basal ganglia are within the affected region. *None of the options* - This option is incorrect because the statement about decorticate rigidity being **less pronounced than decerebrate rigidity** is accurate. - The other clinical description and neurological basis are distinct from true decorticate rigidity.

Q: A blood grouping test shows clumping with Anti-A serum, clumping with Anti-B serum, and no clumping in the control. What blood group does this indicate?

AB. ***AB*** - The results show **clumping with both Anti-A and Anti-B serum**, indicating the presence of both A and B antigens on the red blood cells. - The absence of clumping in the control confirms that the **agglutination with Anti-A and Anti-B is due to specific antigen-antibody reactions**, not nonspecific agglutination. - Blood group AB individuals have both A and B antigens on their RBCs and no anti-A or anti-B antibodies in their serum. *A* - Blood group A would show **clumping with Anti-A serum only** and no clumping with Anti-B serum. - This is incorrect because the sample shows clumping with both antisera. *B* - Blood group B would show **clumping with Anti-B serum only** and no clumping with Anti-A serum. - This is incorrect because the sample shows clumping with both antisera. *O* - Blood group O would show **no clumping with either Anti-A or Anti-B serum**, as it lacks both A and B antigens. - This is incorrect because the sample clearly shows clumping with both Anti-A and Anti-B sera.

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.

Q: Identify the surgical instrument based on its characteristics: a small, triangular blade used for precise incisions.

Blade no. 11. ***Blade no. 11*** - This blade has a **triangular shape** with a strong, pointed tip, making it ideal for **stab incisions** and precise, short cuts. - Its design allows for sharp, accurate penetration, often used in procedures requiring **minimal tissue disruption**. *Blade no. 15* - This is a small, curved blade, primarily used for **fine, precise cuts** in superficial tissues. - Its small size and rounded belly make it suitable for tasks like excising skin lesions or making incisions in delicate areas, not for triangular stab incisions. *Blade no. 10* - The No. 10 blade has a **large, curved cutting edge** and is generally used for making large incisions in skin and muscle. - It is not designed for precise, triangular stab incisions, but rather for broader, sweeping cuts. *Blade no. 12* - This blade is **sickle-shaped** with the cutting edge on the inside curve, used primarily for mucogingival surgery or removing sutures. - Its unique shape allows it to get into tight spaces and cut from a different angle, but it does not have a triangular tip for precise stab incisions.

Question 1

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 2

Which type of study determines the odds ratio?

Accepted Answer

Case control

Answer

Cohort

Answer

Cross sectional

Answer

RCT

Question 3

A 25-year-old male presents with localized pain in the tibia and swelling. Imaging reveals a bone abscess. Identify the condition.

Accepted Answer

Brodie abscess

Answer

Osteoid osteoma

Answer

Intracortical hemangioma

Answer

Chondromyxoid fibroma

Question 4

What is the PRIMARY mechanism by which Interleukin-1 (IL-1) induces fever?

Accepted Answer

Endogenous pyrogen

Answer

Stimulates antibody production

Answer

Inhibits inflammation

Answer

Activates complement cascade

Question 5

Most characteristic cardiovascular defect seen in Rubella-

Accepted Answer

Patent ductus arteriosus

Answer

Coarctation of the aorta

Answer

Ventricular septal defect

Answer

Pulmonary artery stenosis

Question 6

What should be the correct treatment for a 14-year-old child with newly diagnosed Juvenile Rheumatoid Arthritis?

Accepted Answer

DMARDs with a short course of steroids

Answer

Only NSAIDs

Answer

DMARDs after initial treatment with NSAIDs

Answer

Monotherapy with TNF inhibitors

Answer

Long-term high-dose corticosteroid therapy

Question 7

True about decorticate rigidity:

Accepted Answer

Rigidity is less pronounced than decerebrate rigidity

Answer

Flexion of lower limbs & extension of upper limbs

Answer

Removal of cerebral cortex and basal ganglia

Answer

None of the options

Question 8

A blood grouping test shows clumping with Anti-A serum, clumping with Anti-B serum, and no clumping in the control. What blood group does this indicate?

Accepted Answer

AB

Answer

A

Answer

B

Answer

O

Question 9

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

Question 10

Identify the surgical instrument based on its characteristics: a small, triangular blade used for precise incisions.

Accepted Answer

Blade no. 11

Answer

Blade no. 15

Answer

Blade no. 10

Answer

Blade no. 12

NEET-PG 2019

Biochemistry

Community Medicine

Orthopaedics

Pathology

Pediatrics

Physiology

Surgery