Anatomy
1 questionsAnterior Mediastinal nodes are included in which level of lymph nodes?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 1171: Anterior Mediastinal nodes are included in which level of lymph nodes?
- A. I
- B. V
- C. VI (Correct Answer)
- D. VII
Explanation: ***VI*** - Level VI lymph nodes are the **prevascular and retrotracheal nodes** located in the **anterior mediastinum** [1]. - According to the **IASLC (International Association for the Study of Lung Cancer)** lymph node mapping system, Level 6 nodes are specifically classified as anterior mediastinal nodes [1]. - These include nodes anterior to the superior vena cava and ascending aorta, and nodes between the trachea and esophagus [1]. *I* - Level I lymph nodes are located in the **low cervical, supraclavicular, and sternal notch** regions. - These are **extra-thoracic nodes** and not part of the mediastinal compartments. - They represent the highest mediastinal, supraclavicular, and sternal notch nodes [1]. *V* - Level V lymph nodes are the **subaortic (aortopulmonary window)** nodes [1]. - These are located in the space between the **aorta and pulmonary artery**, lateral to the ligamentum arteriosum [1]. - While mediastinal, they are specifically in the aortopulmonary window, not classified as anterior mediastinal. *VII* - Level VII lymph nodes are the **subcarinal nodes** located below the carina in the **middle mediastinum** [1]. - These nodes are positioned in the space beneath where the trachea bifurcates into the main bronchi [1]. - They are classified as middle mediastinal nodes, not anterior mediastinal nodes.
Internal Medicine
3 questionsCrush Syndrome is associated with all of the following features except -
Which of the following types of kidney stones are commonly associated with urinary tract infections?
Which zone of the prostate is primarily involved in Benign Prostatic Hyperplasia (BPH)?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1171: Crush Syndrome is associated with all of the following features except -
- A. Hypercalcemia (Correct Answer)
- B. Hypocalcemia
- C. Hyperkalemia
- D. Increased serum creatinine
Explanation: ***Hypercalcemia*** - Crush syndrome involves massive **muscle damage** leading to the release of intracellular contents, but hypercalcemia is not typically seen acutely. - While skeletal muscle contains calcium, its release, if any, is usually outweighed by other electrolyte shifts and renal dysfunction, often leading to **hypocalcemia** due to calcium binding to damaged tissues and phosphate. *Hypocalcemia* - This is a common feature of **crush syndrome** because calcium ions move into damaged cells and bind to free fatty acids and damaged tissue. - The elevated **phosphate levels** released from damaged cells can also bind to circulating calcium, further reducing serum calcium. *Hyperkalemia* - One of the most dangerous complications of **crush syndrome**, resulting from the massive release of **intracellular potassium** from damaged muscle cells. - Can lead to **life-threatening arrhythmias** if not promptly managed. *Increased serum creatinine* - Damaged muscle releases large amounts of **creatinine**, which is a byproduct of muscle metabolism; this, along with **myoglobin** (leading to acute kidney injury), causes a significant increase in serum creatinine levels. - **Acute kidney injury** due to rhabdomyolysis is a hallmark of crush syndrome, leading to impaired clearance of waste products.
Question 1172: Which of the following types of kidney stones are commonly associated with urinary tract infections?
- A. Struvite stones (Correct Answer)
- B. Cystine stones
- C. Xanthine stones
- D. Calcium oxalate stones
Explanation: ***Struvite stones*** - **Struvite stones** (magnesium ammonium phosphate) are strongly associated with **urinary tract infections (UTIs)** caused by urease-producing bacteria like *Proteus* and *Klebsiella*. - These bacteria hydrolyze urea into ammonia and carbon dioxide, increasing urine pH and promoting the precipitation of struvite, often forming **staghorn calculi** [1]. *Cystine stones* - **Cystine stones** are caused by a **genetic defect** in amino acid transport, leading to increased excretion of cystine, ornithine, lysine, and arginine (COLA) in the urine. - They are not directly associated with UTIs but rather with a rare inherited metabolic disorder called **cystinuria**. *Xanthine stones* - **Xanthine stones** are very rare and typically occur in individuals with **xanthinuria**, a genetic disorder characterized by a deficiency in xanthine oxidase. - They are also not linked to UTIs but are a consequence of abnormal purine metabolism. *Calcium oxalate stones* - **Calcium oxalate stones** are the most common type of kidney stone, resulting from high levels of calcium and oxalate in the urine, often due to dietary factors, malabsorption, or idiopathic hypercalciuria. - While UTIs can complicate any kidney stone, **calcium oxalate stones** are not primarily *caused* by UTIs. [1]
Question 1173: Which zone of the prostate is primarily involved in Benign Prostatic Hyperplasia (BPH)?
- A. Central zone
- B. Peripheral zone
- C. Transitional zone (Correct Answer)
- D. Prostate capsule
Explanation: ***Transitional zone*** - The **transitional zone** surrounds the urethra and is the primary site of origin and enlargement in **Benign Prostatic Hyperplasia (BPH)**. - Its hypertrophy leads to compression of the urethra, causing **lower urinary tract symptoms (LUTS)**. *Central zone* - The **central zone** surrounds the ejaculatory ducts and is less commonly involved in BPH. - It is more frequently associated with the development of **prostate carcinoma**. *Peripheral zone* - The **peripheral zone** is the largest zone of the prostate and is where the majority of prostate cancers originate. - While it can be affected by BPH, it is not the primary zone for hypertrophy. *Prostate capsule* - The **prostate capsule** is the outer fibrous layer that encloses the prostate gland. - It does not undergo hyperplasia in BPH; rather, it encases the enlarging gland.
Obstetrics and Gynecology
1 questionsWhich is false about stress urinary incontinence?
NEET-PG 2015 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1171: Which is false about stress urinary incontinence?
- A. More common in men (Correct Answer)
- B. It is due to weakening of pelvic floor muscles
- C. Prostate surgery may be a cause
- D. It occurs during increased abdominal pressure
Explanation: ***More common in men*** - **Stress urinary incontinence (SUI)** is significantly more prevalent in **women** due to anatomical differences and factors like childbirth. - While it can occur in men, especially after prostate surgery, the overall incidence is higher in females. *It is due to weakening of pelvic floor muscles* - Weakening of the **pelvic floor muscles** is a primary cause of SUI, leading to insufficient support for the urethra and bladder neck. - This weakness compromises the ability to maintain urethral closure pressure during activity. *Prostate surgery may be a cause* - **Radical prostatectomy** for prostate cancer is a common cause of SUI in men, as it can damage the urethral sphincter. - Damage to the internal or external urethral sphincter during surgery impairs the ability to control urine flow. *It occurs during increased abdominal pressure* - SUI characteristically involves involuntary urine leakage during activities that increase **intra-abdominal pressure**, such as coughing, sneezing, laughing, or exercising. - This increased pressure overcomes the weakened urethral resistance, leading to urine loss.
Pediatrics
1 questionsWhich of the following urethral anomalies is the most common?
NEET-PG 2015 - Pediatrics NEET-PG Practice Questions and MCQs
Question 1171: Which of the following urethral anomalies is the most common?
- A. Hypospadias (Correct Answer)
- B. Pinhole meatus
- C. Epispadias
- D. Stricture of the urethra
Explanation: ***Hypospadias*** - **Hypospadias** is the most common urethral anomaly, occurring when the **urethral opening** is located on the underside of the penis rather than at the tip. - Its prevalence ranges from approximately **1 in 150 to 1 in 300 live male births**, making it significantly more frequent than other urethral malformations. *Pinhole meatus* - A **pinhole meatus** refers to an abnormally small urethral opening. - While it can be a component or consequence of other anomalies, it is **less common as a standalone finding** compared to hypospadias. *Epispadias* - **Epispadias** is a rare anomaly where the urethra opens on the **dorsal (top) aspect** of the penis. - Its incidence is much lower than hypospadias, estimated at **1 in 100,000 to 1 in 500,000 live births**. *Stricture of the urethra* - A **urethral stricture** is a narrowing of the urethra, often due to **scar tissue** from inflammation, trauma, or infection. - Although it can present at any age, it is more commonly an **acquired condition** rather than a congenital anomaly like hypospadias or epispadias.
Surgery
4 questionsWhat is the optimal timing for administering antibiotic prophylaxis before surgery?
Which of the following is NOT a feature of membranous urethral injury?
A high-riding prostate is indicative of which injury?
Prostate cancer that is limited to the capsule and not the urethra would be staged as -
NEET-PG 2015 - Surgery NEET-PG Practice Questions and MCQs
Question 1171: What is the optimal timing for administering antibiotic prophylaxis before surgery?
- A. Immediately before induction of anesthesia
- B. 30-60 minutes before incision (Correct Answer)
- C. 2-3 hours before surgery
- D. Immediately after surgery
Explanation: ***30-60 minutes before incision*** - This is the **optimal timing** recommended by WHO, CDC, and major surgical guidelines for most commonly used prophylactic antibiotics (cefazolin, cefuroxime). - Ensures **peak tissue and serum concentrations** are achieved at the time of incision, providing maximum protection against surgical site infections. - Based on **pharmacokinetic principles**: the antibiotic must be present at bactericidal concentrations in tissues when bacterial contamination occurs. - Studies show this timing significantly reduces surgical site infection rates compared to other timings. *Immediately before induction of anesthesia* - While acceptable in some protocols, this may be too early if there is a delay between induction and incision. - Could result in **declining antibiotic levels** by the time the incision is made, especially for antibiotics with shorter half-lives. *2-3 hours before surgery* - This is **too early** for most antibiotics. - Tissue levels may have already **declined below therapeutic concentrations** by the time of incision. - Does not provide adequate protection during the critical period of bacterial contamination. *Immediately after surgery* - This is **treatment, not prophylaxis**. - Offers **no preventive benefit** against intraoperative contamination. - By this time, bacteria introduced during surgery have already adhered to tissues and begun forming biofilms.
Question 1172: Which of the following is NOT a feature of membranous urethral injury?
- A. blood at the meatus
- B. Retention of urine
- C. Pelvic fracture
- D. Perineal butterfly hematoma (Correct Answer)
Explanation: ***Perineal butterfly hematoma*** - A **perineal butterfly hematoma** is more characteristic of an injury to the **anterior urethra**, specifically the bulbar urethra, often caused by a straddle injury. - It occurs due to the extravasation of blood into the subcutaneous tissue of the perineum, outlining the shape of a butterfly. *blood at the meatus* - **Blood at the meatus** is a classic sign of urethral injury, regardless of the segment (anterior or posterior). - It indicates disruption of the urethral mucosa and bleeding from the damaged blood vessels. *Retention of urine* - **Retention of urine** can occur due to either a complete or partial urethral transection, preventing normal urine flow. - The inability to void can lead to bladder distension and is a significant symptom in assessing urethral trauma severity. *Pelvic fracture* - **Pelvic fractures** are frequently associated with **membranous urethral injuries** because the membranous urethra is fixed within the pelvic ring. - Shear forces from pelvic trauma can cause the prostatomembranous junction to avulse.
Question 1173: A high-riding prostate is indicative of which injury?
- A. Extraperitoneal Bladder rupture
- B. Intraperitoneal Bladder Rupture
- C. Membranous Urethral Injury (Correct Answer)
- D. Bulbar Urethral Injury
Explanation: ***Membranous Urethral Injury*** - A **high-riding prostate** is a classic sign of **membranous urethral injury**, often resulting from **pelvic fractures**. - The disruption of the **urethra** above the perineal membrane causes the prostate to be displaced superiorly and appear "high." *Extraperitoneal Bladder rupture* - This typically occurs with **pelvic fractures** and involves urine leaking into the **retropubic space**. - While associated with pelvic trauma, it does not directly cause a high-riding prostate; the bladder itself may be ruptured, but the relative position of the prostate is not significantly altered. *Intraperitoneal Bladder Rupture* - This type of rupture usually results from a direct blow to a **full bladder** and involves urine extravasating into the **peritoneal cavity**. - It does not cause a high-riding prostate, as the injury is to the dome of the bladder, not the structures supporting the prostate. *Bulbar Urethral Injury* - A **bulbar urethral injury** usually results from a **straddle injury** and is located in the anterior urethra. - This type of injury does not affect the anatomical position of the prostate, which is posterior and superior to the bulbar urethra.
Question 1174: Prostate cancer that is limited to the capsule and not the urethra would be staged as -
- A. T1
- B. T2 (Correct Answer)
- C. T3
- D. T0
Explanation: ***T2*** - A T2 stage indicates that the prostate cancer is **confined within the prostate capsule**, meaning it has not spread beyond the outer layer of the prostate gland. - While it is not limited to the urethra, the key defining characteristic of T2 is **capsular confinement**, which is described in the question. *T1* - T1 stage prostate cancer is typically **non-palpable** on digital rectal exam (DRE) and not visible on imaging. - It is often found incidentally, for example, during a **transurethral resection of the prostate (TURP)** for benign prostatic hyperplasia. *T3* - A T3 stage indicates that the prostate cancer has **extended beyond the prostate capsule**, but has not metastasized to distant sites. - This typically involves invasion into the **seminal vesicles** or other periprostatic tissues. *T0* - T0 means there is **no evidence of primary tumor**, which is not consistent with a diagnosed prostate cancer. - This staging is used when there is no measurable tumor.