Anatomy
1 questionsTraumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 951: Traumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?
- A. Optic canal (Correct Answer)
- B. Intraocular part
- C. Intracranial part
- D. Optic tract
Explanation: ***Optic canal*** - The **optic nerve** is highly susceptible to injury within the **optic canal** due to its tight anatomical confines and the close proximity of the optic nerve to rigid bone. - Trauma to this region can lead to direct compression, shearing injury, or ischemia from damage to surrounding vasculature, resulting in significant visual impairment. *Intra ocular part* - The intraocular part of the optic nerve, including the **optic disc**, is typically protected by the globe and orbit against blunt trauma. - Direct intraocular trauma, such as a penetrating injury, would be required to significantly affect this segment, which is not usually the cause in closed head trauma. *Intracranial part* - The intracranial part of the optic nerve is relatively mobile within the cerebrospinal fluid and is less prone to direct compression or shearing forces from closed head trauma compared to the optic canal. - While it can be affected by diffuse axonal injury or mass effects within the cranium, it is not the most commonly affected segment for traumatic optic neuropathy in closed head injuries. *Optic tract* - The **optic tract** lies posterior to the optic chiasm and is part of the central nervous system pathways for vision, not the optic nerve itself. - Injuries to the optic tract are more likely to cause homonymous hemianopia rather than the profound unilateral vision loss characteristic of traumatic optic neuropathy, and are generally less vulnerable to direct mechanical trauma from closed head injury.
Biochemistry
1 questionsWhich of these is not a part of extracellular matrix:
NEET-PG 2015 - Biochemistry NEET-PG Practice Questions and MCQs
Question 951: Which of these is not a part of extracellular matrix:
- A. Collagen
- B. Laminin
- C. Fibronectin
- D. Integrins (Correct Answer)
Explanation: ***Integrins*** - Integrins are **transmembrane receptors** on the cell surface that facilitate cell-extracellular matrix (ECM) adhesion and cell-cell adhesion. - They are part of the cell membrane, **not** an extracellular component. *Laminin* - **Laminin** is a major protein component of the **basal lamina**, a specialized extracellular matrix that underlies epithelial cells. - It plays a crucial role in cell adhesion, differentiation, and migration within the ECM. *Fibronectin* - **Fibronectin** is a large glycoprotein present in the **extracellular matrix** and in soluble form in blood plasma. - It mediates cell adhesion to the ECM by binding to integrins and various ECM components like collagen and proteoglycans. *Collagen* - **Collagen** is the most abundant protein in the human body and a primary structural component of the **extracellular matrix**. - It provides tensile strength and structural integrity to tissues like skin, bone, tendons, and cartilage.
Internal Medicine
6 questionsWhich of the following is NOT a common cause of acute renal failure?
All are true about GFR except:
Which of the following conditions is a direct indication for initiating dialysis?
Polyuria with low fixed specific gravity urine is seen in ?
Which disease does not recur in the kidney after a renal transplant?
According to standard clinical practice guidelines, significant weight loss requiring medical evaluation is defined as:
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 951: Which of the following is NOT a common cause of acute renal failure?
- A. Chronic kidney disease due to analgesic nephropathy (Correct Answer)
- B. Acute pyelonephritis
- C. Acute kidney injury from snakebite
- D. Acute kidney injury due to rhabdomyolysis
Explanation: Chronic kidney disease due to analgesic nephropathy - This is a cause of chronic kidney disease, characterized by gradual, irreversible kidney damage over a long period due to prolonged use of certain analgesics. [1] - It does not present as an acute, sudden decline in kidney function, which is the hallmark of acute renal failure. [1] Acute pyelonephritis - Severe cases of acute pyelonephritis (kidney infection) can lead to acute kidney injury due to sepsis, inflammation, and potential obstruction. [1] - The systemic inflammatory response and direct tissue damage can impair kidney function rapidly. [1] Acute kidney injury from snakebite - Snake envenomation can cause acute kidney injury through various mechanisms, including hemolysis, rhabdomyolysis, direct nephrotoxicity, and systemic hypotension. - These effects can lead to rapid and severe kidney damage. Acute kidney injury due to rhabdomyolysis - Rhabdomyolysis involves the breakdown of skeletal muscle tissue, releasing large amounts of myoglobin into the bloodstream. [1] - Myoglobin is toxic to the renal tubules, leading to acute tubular necrosis and rapid onset of acute kidney injury. [1]
Question 952: All are true about GFR except:
- A. 30-40% decrease after 70 years of age
- B. GFR is dependent on height in children
- C. Chronic Kidney Disease (CKD) is defined as GFR < 60 ml/min/1.73 m² for 3 months or more.
- D. Best estimated by creatinine clearance (Correct Answer)
Explanation: ***Best estimated by creatinine clearance*** - While **creatinine clearance** can be used as a measure of GFR, it is not the *best* estimate; it tends to slightly **overestimate** GFR due to tubular secretion of creatinine. [1] - The gold standard for measuring GFR involves methods like **inulin clearance**, but in clinical practice, GFR is often *estimated* using equations based on **serum creatinine** (e.g., CKD-EPI, MDRD). [2] *30-40% decrease after 70 years of age* - **Aging** is associated with a physiological decline in GFR, with a general decrease often cited as 30-40% after the age of 70 years. - This decline is part of the normal **age-related changes in renal function**. *GFR is dependent on height in children* - In children, GFR is often adjusted for **body surface area (BSA)**, which is calculated based on both **height and weight**, making height an important factor. [1] - This adjustment is crucial for accurate assessment of renal function in a growing pediatric population. *Chronic Kidney Disease (CKD) is defined as GFR < 60 ml/min/1.73 m² for 3 months or more.* - This statement accurately reflects the widely accepted definition of **Chronic Kidney Disease (CKD)** according to clinical guidelines. [3] - A GFR below this threshold sustained for more than three months indicates persistent kidney damage or dysfunction.
Question 953: Which of the following conditions is a direct indication for initiating dialysis?
- A. Severe metabolic acidosis
- B. Fluid overload
- C. Severe hyperkalemia (Correct Answer)
- D. Acute kidney injury
Explanation: ### Severe hyperkalemia - **Severe hyperkalemia** (potassium levels typically >6.5 mEq/L or rapidly rising, especially with ECG changes) is an immediate life-threatening indication for dialysis when conservative measures fail or are insufficient [1]. - Dialysis effectively removes **excess potassium** from the blood, preventing fatal cardiac arrhythmias. *Severe metabolic acidosis* - While **severe metabolic acidosis** (pH <7.1-7.2) can be an indication, it is often managed first with bicarbonate administration and is typically not a stand-alone **direct** *emergency* indication for dialysis unless accompanied by other severe features or resistance to medical therapy. - The decision to dialyze for acidosis often depends on the underlying cause, degree of renal failure, and response to initial management [2]. *Fluid overload* - **Fluid overload** is a common complication of kidney failure, but it becomes a *direct* indication for dialysis when it is **refractory to diuretic therapy** and causes life-threatening symptoms such as **pulmonary edema** [2]. - Without such refractory state and immediate danger, fluid overload itself is not always an *immediate* trigger for dialysis compared to severe hyperkalemia. *Acute kidney injury* - **Acute kidney injury** (AKI) is the underlying *condition* that can lead to indications for dialysis, but AKI itself is not a *direct indication* for dialysis. - Dialysis is initiated for the *complications* of AKI, such as refractory hyperkalemia, severe metabolic acidosis, or fluid overload, rather than the diagnosis of AKI alone [2].
Question 954: Polyuria with low fixed specific gravity urine is seen in ?
- A. Diabetes mellitus
- B. Diabetes insipidus
- C. Chronic glomerulonephritis (Correct Answer)
- D. Potomania
Explanation: ***Chronic glomerulonephritis*** - Damage to the **renal tubules** in chronic glomerulonephritis impairs their ability to concentrate urine, leading to polyuria with a **low, fixed specific gravity**. [1] - This fixed specific gravity reflects the kidneys' inability to adjust urine concentration in response to hydration status, a hallmark of **chronic kidney disease**. [2] *Diabetes mellitus* - Polyuria in diabetes mellitus is caused by **osmotic diuresis** due to high glucose levels in the urine, leading to increased urinary volume. [2] - While there is polyuria, the specific gravity is not necessarily fixed and can vary, often being high due to the presence of glucose. *Diabetes insipidus* - Diabetes insipidus causes polyuria and dilute urine due to either a deficiency of **ADH (central DI)** or renal unresponsiveness to ADH **(nephrogenic DI)**. - While it causes polyuria with low specific gravity, it's typically *not* fixed; the urine specific gravity can still fluctuate to some extent depending on the patient's hydration, or in response to ADH if it's central DI. *Potomania* - Potomania, or **primary polydipsia**, is excessive water intake that leads to dilutional hyponatremia and polyuria. - The kidneys are otherwise healthy and can still concentrate urine to some extent if water intake is restricted, preventing a truly fixed low specific gravity.
Question 955: Which disease does not recur in the kidney after a renal transplant?
- A. Alport syndrome (Correct Answer)
- B. Amyloidosis
- C. Goodpasture's syndrome
- D. Diabetic nephropathy (due to uncontrolled diabetes)
Explanation: **Alport syndrome** * **Alport syndrome** is a genetic disorder affecting type IV collagen, primarily in the kidney; recurrence is not observed in a renal allograft because the transplanted kidney provides new, healthy type IV collagen [2]. * The disease is due to a genetic defect in the recipient's collagen genes, so the transplanted kidney, which is genetically distinct, is not susceptible to the same primary disease process [2]. *Amyloidosis* * **Amyloidosis** can recur in the transplanted kidney, as it is a systemic disease where abnormal proteins continue to deposit in various organs, including the new kidney. * The underlying cause of amyloid production is typically not cured by a kidney transplant, making the new organ vulnerable to recurrence. *Goodpasture's syndrome* * **Goodpasture's syndrome** is an autoimmune disease where antibodies target type IV collagen in the glomerular basement membrane; these autoantibodies can attack the new kidney if they are still present at the time of transplant or re-emerge [1]. * Recurrence is a significant concern, although it can often be prevented by ensuring the patient is antibody-negative before transplantation and through immunosuppression [1]. *Diabetic nephropathy (due to uncontrolled diabetes)* * **Diabetic nephropathy** almost invariably recurs in the transplanted kidney if the recipient's diabetes remains uncontrolled after transplantation. * The metabolic environment, characterized by hyperglycemia, directly contributes to the damage of the new kidney, leading to the development of diabetic nephropathy over time.
Question 956: According to standard clinical practice guidelines, significant weight loss requiring medical evaluation is defined as:
- A. 5% weight loss in 1-2 months
- B. 10% weight loss in 2-3 months (Correct Answer)
- C. 5% weight loss in 2-3 months
- D. 10% weight loss in 1-2 months
Explanation: ***10% weight loss in 2-3 months*** - **Unexplained weight loss** of **10%** or more of usual body weight over a period of **2-3 months** is generally considered a significant amount requiring medical evaluation. - This degree of weight loss can be indicative of underlying serious medical conditions like cancer, gastrointestinal disorders, endocrine disorders, or chronic infections [1]. *5% weight loss in 1-2 months* - While any unexplained weight loss should be noted, a **5% loss** in this timeframe is usually not considered immediately "significant" enough to warrant an aggressive workup unless other concerning symptoms are present. - It might be due to minor lifestyle changes, temporary illness, or benign factors. *5% weight loss in 2-3 months* - A **5% weight loss** over **2-3 months** is a less critical threshold than 10% for initiating an extensive medical evaluation for serious underlying disease. - This level of weight change could be due to a variety of less severe causes or even normal fluctuations. *10% weight loss in 1-2 months* - While a **10% weight loss** is significant, the **1-2 month** timeframe is generally considered slightly too short to immediately classify it as "requiring medical evaluation" in the strictest sense compared to the 2-3 month period which allows for better observation. - Rapid weight loss over a very short period might sometimes be related to acute illness or dehydration rather than chronic underlying conditions, though still warrants attention.
Obstetrics and Gynecology
1 questionsIn which part of the fallopian tube is ectopic pregnancy most likely to survive longer?
NEET-PG 2015 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 951: In which part of the fallopian tube is ectopic pregnancy most likely to survive longer?
- A. Isthmus
- B. Ampulla
- C. Cornua
- D. Interstitial (Correct Answer)
Explanation: ***Interstitial*** - An **interstitial (intramural) pregnancy** occurs in the portion of the fallopian tube that passes through the muscular wall of the uterus, known as the **cornua**. This position allows for a larger and more distensible space, potentially accommodating the pregnancy for a longer duration before rupture. - The surrounding **myometrial tissue** can provide a temporary blood supply and structural support, leading to later presentation (often up to 12-16 weeks) and often more significant hemorrhage upon rupture due to the rich vascularization of the uterine wall. - Interstitial pregnancies account for approximately 2-4% of all ectopic pregnancies but have a higher mortality rate due to massive hemorrhage when rupture occurs. *Isthmus* - The **isthmus** is the narrowest part of the fallopian tube, making it less accommodating for an ectopic pregnancy. - Pregnancies here tend to rupture earlier (typically by 6-8 weeks) due to limited space and thinner muscular walls. - Accounts for approximately 12% of tubal ectopic pregnancies. *Ampulla* - The **ampulla** is the most common site for ectopic pregnancies (approximately 70-80%), but pregnancies here typically rupture earlier than interstitial ones (usually by 8-12 weeks). - While wider than the isthmus, it lacks the substantial myometrial support of the interstitial portion. - The ampullary wall is thin and distensible but cannot sustain pregnancy as long as the interstitial portion. *Cornua* - While the interstitial part of the tube is located within the uterine wall (cornua), \"cornua\" itself refers to the upper angles of the uterus where the fallopian tubes enter. - The term **\"cornual pregnancy\"** is sometimes used interchangeably with **\"interstitial pregnancy,\"** though some authorities distinguish between them based on precise location. - Without the specific context of \"interstitial,\" this option is less precise in identifying the segment of the fallopian tube associated with prolonged survival.
Pathology
1 questionsBasket weave appearance of glomerular basement membrane on electron microscopy is seen in
NEET-PG 2015 - Pathology NEET-PG Practice Questions and MCQs
Question 951: Basket weave appearance of glomerular basement membrane on electron microscopy is seen in
- A. Alport syndrome (Correct Answer)
- B. Polyarteritis nodosa
- C. Giant cell arteritis
- D. Acute post-streptococcal glomerulonephritis
Explanation: ***Alport syndrome*** - **Alport syndrome** is characterized by a "basket weave" appearance of the **glomerular basement membrane (GBM)** on electron microscopy due to irregular thickening, thinning, and splitting of the lamina densa. - This structural abnormality results from mutations in genes encoding **Type IV collagen**, particularly **COL4A5**, leading to progressive kidney disease, hearing loss, and ocular abnormalities. *Polyarteritis nodosa* - This is a **necrotizing vasculitis** primarily affecting medium-sized arteries, and its renal involvement typically manifests as a focal or diffuse necrotizing glomerulonephritis, often without specific GBM changes. - The electron microscopic findings would generally show inflammatory cell infiltration and fibrinoid necrosis of vessel walls, not a characteristic GBM pattern. *Giant cell arteritis* - **Giant cell arteritis** is a vasculitis affecting large- and medium-sized arteries, typically in the elderly, and often involves the temporal arteries. - Renal involvement is rare, and the characteristic pathological finding is **granulomatous inflammation** within the arterial wall with giant cells, not GBM changes. *Acute post-streptococcal glomerulonephritis* - This condition is characterized by **subepithelial immune deposits ("humps")** on electron microscopy, not a "basket weave" pattern of the GBM. - The GBM itself may show minor changes but does not exhibit the lamellated and split appearance seen in Alport syndrome.