NEET-PG 2015 Practice Questions

Q: Abnormal proteins which are bound to ubiquitin are degraded in -

Proteasomes. ***Proteasomes*** - **Proteasomes** are multi-subunit protein complexes responsible for degrading **ubiquitin-tagged proteins**. - This degradation is a tightly regulated process essential for cell cycle control, gene expression, and immune response. *Golgi apparatus* - The **Golgi apparatus** primarily functions in modifying, sorting, and packaging proteins and lipids synthesized in the Endoplasmic Reticulum. - It does not directly participate in the degradation of **ubiquitin-bound proteins**. *Smooth ER* - The **smooth endoplasmic reticulum (SER)** is involved in lipid synthesis, detoxification of drugs and poisons, and storage of calcium ions. - It lacks ribosomes and is not directly implicated in the degradation of misfolded proteins tagged with ubiquitin. *Lysosomes* - **Lysosomes** are organelles containing various hydrolytic enzymes that break down waste materials and cellular debris, as well as foreign invaders like bacteria. - While they degrade proteins, they primarily target **extracellular proteins** taken up by endocytosis or cellular components via **autophagy**, not specifically ubiquitin-bound proteins.

Q: Lines of Zahn are LEAST likely to be seen in -

Lung. ***Lung*** - **Lines of Zahn are LEAST likely in the lungs** because most pulmonary thrombi are actually **emboli that formed elsewhere** (typically in deep leg veins) and then **lodged in pulmonary vessels**. - These pre-formed thrombi developed in **low-flow venous environments** and therefore **lack the characteristic layered appearance** of Lines of Zahn. - Even when thrombi form in situ in pulmonary vessels, the vascular bed characteristics make Lines of Zahn formation less common compared to other sites. *Heart* - **Mural thrombi** in heart chambers (especially post-MI in left ventricle or in atrial fibrillation) commonly show **Lines of Zahn**. - The **high-flow, turbulent environment** with continuous cardiac contractions creates ideal conditions for alternating platelet-fibrin and RBC layer deposition. - These are classic examples of antemortem thrombi with visible Lines of Zahn. *Liver* - **Portal vein thrombosis** and **hepatic vein thrombosis** (Budd-Chiari syndrome) can exhibit **Lines of Zahn**. - Despite being venous, these vessels have **sufficient flow velocity and turbulence** to allow layered thrombus formation. - Lines of Zahn indicate the thrombus formed during life with flowing blood. *Kidney* - **Renal artery thrombosis** and **renal vein thrombosis** frequently show **Lines of Zahn**. - Both arterial and venous renal circulation have adequate flow dynamics for layered thrombus formation. - These represent antemortem thrombi formed in vessels with active blood flow.

Q: Which of the following is a type of small vessel vasculitis?

Granulomatosis with polyangiitis (GPA). ***Granulomatosis with polyangiitis (GPA)*** - GPA is a prototypic **ANCA-associated small vessel vasculitis** characterized by necrotizing granulomas and vasculitis [1], [2]. - It commonly involves the **upper and lower respiratory tracts** and the **kidneys** with necrotizing granulomatous inflammation [1], [2]. - Classified as small vessel vasculitis according to the **Chapel Hill Consensus Conference** classification. *Classical PAN* - This refers to **Polyarteritis Nodosa (PAN)**, which is a **medium-sized vessel vasculitis**. - PAN is characterized by multifocal inflammatory and necrotizing lesions of medium-sized muscular arteries, **not small vessels**. *Giant cell arteritis* - **Giant cell arteritis (GCA)** is a **large vessel vasculitis** that primarily affects the aorta and its major branches, particularly the temporal artery [3]. - Symptoms include headache, jaw claudication, and visual disturbances, reflecting the involvement of larger blood vessels [3]. *None of the options* - This option is incorrect because Granulomatosis with polyangiitis (GPA) is a clear example of a small vessel vasculitis. - There is a correct answer among the provided choices. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 519-520. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 536-537. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 515-516.

Q: Which type of white blood cell plays a primary role in cardiac remodeling and chronic inflammation in heart failure?

Macrophages. ***Macrophages*** - **Macrophages** are increasingly recognized for their critical role in the pathogenesis and progression of **heart failure**, contributing to **cardiac remodeling**, chronic inflammation, and fibrosis - They infiltrate failing myocardium and play dual roles: promoting both **inflammation** and **tissue repair** - Their activation state (M1 vs M2 phenotypes) can significantly influence cardiac function and prognosis in heart failure patients - They secrete **cytokines**, **growth factors**, and **matrix metalloproteinases** that contribute to ventricular remodeling *Eosinophils* - **Eosinophils** are primarily involved in **allergic reactions** and defense against **parasitic infections** - While they can contribute to inflammation in specific cardiac conditions (e.g., **eosinophilic myocarditis**, **Loeffler endocarditis**), they are not primarily associated with the general pathophysiology of chronic heart failure *T cells* - **T cells** are central to **adaptive immunity**, including cell-mediated responses and modulation of immune reactions - Though T cells play a role in inflammatory processes in certain forms of heart disease, particularly **viral myocarditis**, they are not the predominant immune cell driving chronic cardiac remodeling in heart failure *B cells* - **B cells** are responsible for producing **antibodies** and are key players in humoral immunity - While B cells can contribute to autoimmune forms of heart disease and certain inflammatory processes, they are not typically the primary immune cell associated with the progression of chronic heart failure

Q: Obliterative endarteritis in vasa vasorum is seen in -

Tertiary Syphilis. ***Tertiary Syphilis*** - **Obliterative endarteritis** of the **vasa vasorum** is a hallmark pathological finding in tertiary syphilis, particularly affecting the **aorta**. - This inflammation and occlusion of the small blood vessels supplying the aorta lead to **ischemic injury** of the aortic wall, causing **aneurysms** and **aortic regurgitation**. *Essential Hypertension* - While hypertension can lead to vascular changes like **arteriolosclerosis** and **hyperplastic arteriolosclerosis**, it does not typically involve obliterative endarteritis of the vasa vasorum. - The vascular damage in essential hypertension is more generalized to smaller arteries and arterioles, not specifically the vasa vasorum. *Systemic Lupus Erythematosus* - SLE is an **autoimmune disease** that can cause **vasculitis**, but the specific pattern of obliterative endarteritis of the vasa vasorum is not characteristic. - Vascular involvement in SLE is diverse, ranging from small vessel vasculitis to accelerated atherosclerosis, but distinct from syphilitic changes. *Pulmonary Tuberculosis* - Tuberculosis is primarily an **infectious granulomatous disease** affecting the lungs and other organs; it does not typically cause obliterative endarteritis of the vasa vasorum. - Although it can cause vascular complications like **aneurysms** (e.g., Rasmussen's aneurysm) due to erosion, the underlying mechanism is not the same as syphilitic changes.

Q: Which type of artery is most commonly involved in PAN?

Muscular. ***Muscular*** - **Polyarteritis nodosa (PAN)** predominantly affects **medium to small-sized muscular arteries**, leading to inflammation, necrosis, and microaneurysms [1]. - This involvement often causes **organ ischemia** and symptoms related to the affected organs, such as the kidneys, gastrointestinal tract, and skin [1]. *Elastic* - **Elastic arteries**, such as the aorta and its major branches, are typically spared in PAN due to their larger size and distinct histological structure. - Diseases like **Takayasu arteritis** or **Giant cell arteritis** are more commonly associated with vasculitis affecting large elastic arteries. *Arterioles* - While arterioles can be affected in various forms of vasculitis, they are not the primary target in classic PAN. - Involvement of arterioles is more characteristic of **microscopic polyangiitis** or **Churg-Strauss syndrome** [2]. *Capillaries* - **Capillaries** are the smallest blood vessels, and their involvement is rare in PAN. - Conditions like **Henoch-Schönlein purpura** or some drug-induced vasculitides more typically affect capillaries, often resulting in palpable purpura [2].

Q: Which of the following statements is true regarding the Duffy Fy(a-b-) blood group?

lacks Fy(b) antigen. ***lacks Fy(b) antigen*** - The **Duffy Fy(a-b-)** phenotype indicates absence of both Fy a and Fy b antigens on red blood cells. - Since the phenotype is **Fy(a-b-)**, it definitively lacks the **Fy b antigen** (indicated by the "b-" notation). - This phenotype is common in people of **African descent** and confers natural **resistance to Plasmodium vivax malaria**, as these antigens serve as receptors for the parasite to enter RBCs. *lacks H- antigen* - The **H antigen** belongs to the **H/h blood group system** and is a precursor to A and B antigens in the ABO system. - The absence of H antigen (Bombay phenotype - Oh) is completely **unrelated to the Duffy blood group system**. - Duffy antigens are on the **DARC (Duffy Antigen Receptor for Chemokines)** protein, distinct from the H antigen. *lacks A-antigen* - The **A antigen** is part of the **ABO blood group system** and defines blood types A and AB. - The Duffy blood group system is **genetically and structurally independent** from the ABO system. - Having Fy(a-b-) phenotype does not affect A antigen expression. *All of the options* - This is incorrect because the Duffy Fy(a-b-) phenotype **specifically refers only to the absence of Duffy antigens** (Fy a and Fy b ). - It has **no relationship** with A, B, or H antigens, which belong to different blood group systems controlled by different genes on different chromosomes.

Q: Which of the following is the most characteristic sexual side effect of SSRIs?

Delayed ejaculation. ***Delayed ejaculation*** - **Delayed ejaculation** is a common and characteristic sexual side effect of SSRIs due to their impact on serotonin pathways involved in sexual response. - This effect can lead to significant distress and non-adherence to treatment, and often requires dose adjustment or switching to an alternative antidepressant. *Erectile dysfunction* - While **erectile dysfunction** can occur with SSRIs, it is a less specific and less consistently reported sexual side effect compared to ejaculatory dysfunction. - Many factors, including underlying mood disorder and comorbidities, can contribute to erectile dysfunction, making it less characteristic of SSRI use alone. *Retrograde ejaculation* - **Retrograde ejaculation** is a condition where semen enters the bladder during orgasm, and while it can be a side effect of some medications (e.g., alpha-blockers), it is not a hallmark sexual side effect of SSRIs. - SSRIs primarily affect the process of emission and expulsion, leading more commonly to delayed or absent ejaculation rather than retrograde flow. *Anxiety* - **Anxiety** is generally a *primary symptom* of the conditions SSRIs are prescribed to treat, such as depression or anxiety disorders, not a sexual side effect of the medication itself. - Although SSRIs can initially cause or worsen anxiety in some patients before therapeutic effects are seen, this is a systemic side effect, not a sexual one.

Q: In patients with emphysematous bullae, total lung volume is best determined by?

Plethysmography. ***Plethysmography*** - This method accurately measures **total lung capacity (TLC)**, functional residual capacity (FRC), and residual volume (RV) by determining the **volume of gas in the thorax**. - It is particularly useful in conditions like **emphysema** with air trapping and bullae, as it accounts for **non-communicating air spaces** that other methods miss. *Spirometry* - Spirometry measures volumes of air that can be **exhaled or inhaled forcibly**, such as FVC and FEV1. - It cannot measure residual volume (RV) or total lung capacity (TLC) directly, especially in cases of **air trapping** where trapped air cannot be exhaled. *Helium dilution method* - The helium dilution method measures **communicating lung volumes**, like functional residual capacity (FRC), by assessing the dilution of a known concentration of helium after rebreathing. - In conditions with **emphysematous bullae** and air trapping, it **underestimates total lung volume** because it cannot measure air in non-communicating or poorly communicating spaces. *Any of the above* - Only plethysmography can accurately measure total lung volume in the presence of **emphysematous bullae** due to its ability to measure both communicating and non-communicating air spaces. - Spirometry and helium dilution methods would provide **inaccurate or incomplete measurements** in this clinical scenario.

Q: Vital capacity is measured by:

Spirometer. ***Spirometer*** - A **spirometer** is a device used to measure lung volumes and capacities, including **vital capacity**. - It measures the volume of air inspired and expired by evaluating mechanical changes in the volume of air in the lungs. *Plethysmography* - **Plethysmography** is primarily used to measure **residual volume** and **total lung capacity**, not vital capacity directly. - This method measures changes in body volume to infer changes in lung volume. *Gas-dilution method* - The **gas-dilution method**, typically using helium, is used to measure the **functional residual capacity (FRC)** and subsequently calculate residual volume and total lung capacity. - It involves rebreathing a known concentration of gas to determine the volume of gas already in the lungs. *Nitrogen washout technique* - The **nitrogen washout technique** is also used to measure **functional residual capacity (FRC)** and detect uneven ventilation. - It involves breathing 100% oxygen to wash out all nitrogen from the lungs, allowing for calculation of lung volumes.

Question 1

Abnormal proteins which are bound to ubiquitin are degraded in -

Accepted Answer

Proteasomes

Answer

Golgi apparatus

Answer

Smooth ER

Answer

Lysosomes

Question 2

Lines of Zahn are LEAST likely to be seen in -

Accepted Answer

Lung

Answer

Liver

Answer

Kidney

Answer

Heart

Question 3

Which of the following is a type of small vessel vasculitis?

Accepted Answer

Granulomatosis with polyangiitis (GPA)

Answer

Classical PAN

Answer

Giant cell arteritis

Answer

None of the options

Question 4

Which type of white blood cell plays a primary role in cardiac remodeling and chronic inflammation in heart failure?

Accepted Answer

Macrophages

Answer

Eosinophils

Answer

T cells

Answer

B cells

Question 5

Obliterative endarteritis in vasa vasorum is seen in -

Accepted Answer

Tertiary Syphilis

Answer

Essential Hypertension

Answer

Systemic Lupus Erythematosus

Answer

Pulmonary Tuberculosis

Question 6

Which type of artery is most commonly involved in PAN?

Accepted Answer

Muscular

Answer

Capillaries

Answer

Elastic

Answer

Arterioles

Question 7

Which of the following statements is true regarding the Duffy Fy(a-b-) blood group?

Accepted Answer

lacks Fy(b) antigen

Answer

lacks H- antigen

Answer

lacks A-antigen

Answer

All of the options

Question 8

Which of the following is the most characteristic sexual side effect of SSRIs?

Accepted Answer

Delayed ejaculation

Answer

Retrograde ejaculation

Answer

Erectile dysfunction

Answer

Anxiety

Question 9

In patients with emphysematous bullae, total lung volume is best determined by?

Accepted Answer

Plethysmography

Answer

Spirometry

Answer

Any of the above

Answer

Helium dilution method

Question 10

Vital capacity is measured by:

Accepted Answer

Spirometer

Answer

Plethysmography

Answer

Nitrogen washout technique

Answer

Gas-dilution method

NEET-PG 2015

Biochemistry

Pathology

Pharmacology

Physiology