Anatomy
1 questionsThe commonest site of aspiration of a foreign body in the supine position is into the:
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 941: The commonest site of aspiration of a foreign body in the supine position is into the:
- A. Right upper lobe apical
- B. Left basal
- C. Right middle lobe medial segment
- D. Right lower lobe superior segment (Correct Answer)
Explanation: ***Right lower lobe superior segment*** - When an individual is in the **supine position**, the most dependent portion of the lung (where gravity would pull aspirated material) is the **superior segment of the right lower lobe**. - This anatomical orientation, combined with the **wider and more vertical right main bronchus**, increases the likelihood of aspirated foreign bodies entering and settling in this specific segment. - The superior segment of the right lower lobe is **posteriorly located** and becomes the most dependent when lying supine. *Right upper lobe apical* - While the right upper lobe is on the favored side for aspiration due to the anatomy of the main bronchi, the **apical segment** is not the most dependent in the supine position. - Aspiration into the apical segment is generally less common than into more dependent segments when lying flat. *Left basal* - The **left main bronchus** is narrower and takes a more acute angle compared to the right, making aspiration into the left lung less common. - Even if aspiration were to occur in the left lung, the **basal segments** are not the most dependent in the supine position. *Right middle lobe medial segment* - The medial segment of the middle lobe is **not as posteriorly positioned** as the superior segment of the right lower lobe in the supine position. - While aspiration can occur into the middle lobe, it is **less common** than into the superior segment of the right lower lobe when supine due to the anatomical positioning and gravity effects.
Pathology
2 questionsWhich of the following statements BEST characterizes the clinical significance of Barrett's esophagus?
All of the following are features of juvenile CML except which of the following?
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 941: Which of the following statements BEST characterizes the clinical significance of Barrett's esophagus?
- A. Barrett's esophagus is a precancerous condition (Correct Answer)
- B. Barrett's esophagus involves metaplasia of esophageal cells
- C. Intestinal type is the most common type
- D. It does not predispose to SCC but to adenocarcinoma
Explanation: ***Predisposes to SCC*** - Barrett's esophagus primarily predisposes individuals to **adenocarcinoma**, not squamous cell carcinoma (SCC) [2][3]. - SCC is associated with other conditions, such as **smoking** and **chronic irritation**, not Barrett's [3]. *Intestinal type is the most common type* - The intestinal type is indeed **common** in Barrett's esophagus, but it's not the only type present [2]. - Barrett's esophagus can also have a **gastric** type, but the intestinal type predominates in adenocarcinoma risk. *Metaplasia of cells* - This condition is defined by **intestinal metaplasia**, where squamous epithelium is replaced by columnar epithelium [2]. - Metaplasia is a **hallmark** of Barrett's esophagus and crucial for its diagnosis [2]. *Precancerous condition* - Barrett's esophagus is considered a **precancerous condition** because it increases the risk of transitioning to esophageal adenocarcinoma [1][2]. - The progression from Barrett's to cancer is well-documented in medical literature [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 764-765. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 348-349. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 766-767.
Question 942: All of the following are features of juvenile CML except which of the following?
- A. Fetal Hb is increased
- B. Lymphadenopathy
- C. Thrombocytopenia
- D. Philadelphia chromosome is positive (Correct Answer)
Explanation: ***Philadelphia chromosome is positive*** - **Juvenile Chronic Myeloid Leukemia (JCML)**, now known as **Chronic Myelomonocytic Leukemia (CMML)** of childhood, is characterized by the **absence** of the **Philadelphia chromosome (Ph chromosome)**. - The Ph chromosome, a t(9;22)(q34;q11) translocation forming the **BCR-ABL1 fusion gene**, is the hallmark of adult Chronic Myeloid Leukemia (CML), but not JCML. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a common feature in JCML due to ineffective hematopoiesis and bone marrow infiltration. - This contrasts with adult CML, where **thrombocytosis** (high platelet count) is more characteristic of the chronic phase. *Fetal Hb is increased* - An **increased level of fetal hemoglobin (HbF)** is a characteristic laboratory finding in children with JCML. - This elevation is related to the dysregulated hematopoiesis and is a useful diagnostic marker. *Lymphadenopathy* - **Lymphadenopathy** (enlarged lymph nodes) is a frequent clinical manifestation in JCML, reflecting the widespread infiltration of monocytic cells. - This is part of the systemic involvement seen in this aggressive myeloproliferative disorder.
Surgery
7 questionsHow much length is increased in Z-plasty when it is done at 60 degrees?
What is the ideal angle for Z-plasty?
What is the most common abdominal surgical procedure for complete rectal prolapse?
What are the metabolic consequences of ureterosigmoidostomy?
What is the primary condition treated by the Kasai operation?
In the Bismuth-Corlette classification, which type involves the hepatic duct confluence WITHOUT extension into secondary intrahepatic ducts?
What is the investigation of choice for detecting recurrence after parathyroid gland surgery?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 941: How much length is increased in Z-plasty when it is done at 60 degrees?
- A. 75% (Correct Answer)
- B. 50%
- C. 25%
- D. 100%
Explanation: ***75%*** - A **60-degree Z-plasty** lengthens the central limb by approximately **75%** of its original length. This configuration provides a balance between length gain and flap viability. - The greater the angle of the Z-plasty limbs, the greater the theoretical lengthening, but also the larger the flaps and the increased risk of complications. *25%* - A **30-degree Z-plasty** typically provides about **25% lengthening** of the central limb. This angle offers less lengthening but is useful for smaller scars or when skin mobility is limited. - While it provides some lengthening, it falls significantly short of the length achieved with a 60-degree Z-plasty. *50%* - A **45-degree Z-plasty** generally results in approximately **50% lengthening**. This is an intermediate option, providing moderate lengthening. - This option does not match the significant lengthening associated with the larger 60-degree angle. *100%* - To achieve approximately **100% length gain**, larger angles such as **75 or 90-degree Z-plasty** might be considered. However, these angles are less commonly used due to increased flap size and tension at the base. - A standard 60-degree Z-plasty does not provide a 100% increase in length.
Question 942: What is the ideal angle for Z-plasty?
- A. 90°
- B. 45°
- C. 60° (Correct Answer)
- D. 75°
Explanation: ***60°*** - An angle of **60°** is considered ideal for Z-plasty because it provides the best balance between **lengthening the scar** and maintaining **tissue viability**. - This angle typically results in a **75% gain in length** along the central limb of the Z-plasty, while ensuring the flaps have a broad enough base for adequate blood supply. *90°* - While a **90°** angle would provide the most lengthening (around 100%), it creates very **thin, narrow flap tips** that are highly susceptible to **ischemia and necrosis** due to compromised blood supply. - This angle is generally avoided in Z-plasty due to the high risk of **flap complications**. *45°* - A **45°** angle results in less lengthening (approximately 50% gain) compared to a 60° angle, which may not be sufficient for significant release of scar contractures. - While it offers excellent flap viability due to wider bases, the **suboptimal lengthening** makes it less efficient for many Z-plasty applications. *75°* - An angle of **75°** would yield greater lengthening than 60°, but it also compromises flap viability making the flap susceptible to **necrosis**. - The benefits of increased length are often outweighed by the increased **risk of complications** when using this angle.
Question 943: What is the most common abdominal surgical procedure for complete rectal prolapse?
- A. Rectal mucosal stapling
- B. Placation/wiring
- C. Rectopexy (Correct Answer)
- D. Mucosal resection
Explanation: ***Rectopexy*** - **Rectopexy** is the most common abdominal surgical procedure for full-thickness rectal prolapse - It involves fixing the rectum to the sacral promontory or presacral fascia (with sutures or mesh) to prevent prolapse - Various modifications exist including suture rectopexy, mesh rectopexy, ventral rectopexy, and resection rectopexy - **Abdominal approach** is preferred in fit patients with better long-term outcomes compared to perineal procedures *Rectal mucosal stapling* - This procedure refers to **stapled hemorrhoidopexy (PPH)** or **STARR procedure** - Primarily used for **internal mucosal prolapse** and hemorrhoids, not full-thickness external rectal prolapse - Involves excising redundant rectal mucosa using circular staplers - Does not address the full-thickness prolapse or provide proper fixation *Placation/wiring* - **Thiersch wiring** is a historical perineal procedure involving placement of a wire or suture around the anus to narrow the anal canal - Now largely abandoned due to high recurrence rates and complications - **Plication** refers to folding tissue but is not a standalone procedure name for rectal prolapse - This terminology is not standard in modern colorectal surgery *Mucosal resection* - Refers to **Delorme's procedure**, a perineal approach involving mucosal sleeve resection with underlying muscle plication - Used in elderly or high-risk patients who cannot tolerate abdominal surgery - Associated with higher recurrence rates compared to abdominal rectopexy - Does not provide the same level of fixation as abdominal procedures
Question 944: What are the metabolic consequences of ureterosigmoidostomy?
- A. Hyperchloremic with hypokalemic acidosis (Correct Answer)
- B. Hyperkalemia
- C. Metabolic alkalosis
- D. Hyponatremia
Explanation: ***Hyperchloremic with hypokalemic acidosis*** - In ureterosigmoidostomy, the reabsorption of urinary constituents like **chloride** and **urea** from the bowel mucosa leads to **hyperchloremia**. - The exchange of **chloride** for **bicarbonate** and the concomitant loss of **potassium** from the colon results in **hypokalemic metabolic acidosis**. *Hyperkalemia* - Colonic reabsorption of urinary products typically causes **potassium wasting** and **hypokalemia**, not hyperkalemia. - While some potassium is reabsorbed, the overall effect due to the exchange for hydrogen ions and fluid loss from the colon is a net decrease in serum potassium. *Metabolic alkalosis* - Metabolic alkalosis involves an increase in **bicarbonate**, which is the opposite of what occurs in ureterosigmoidostomy where bicarbonate is lost. - The increased reabsorption of urea and chloride from the urine in the colon leads to an **acidic state** due to increased **hydrogen ion production** and **bicarbonate depletion**. *Hyponatremia* - Although some **sodium** reabsorption can occur, the primary electrolyte imbalances are related to chloride, potassium, and bicarbonate. - While some intestinal urinary diversion procedures can lead to hyponatremia due to volume changes or syndrome of inappropriate antidiuretic hormone (SIADH), it is not the most characteristic or direct metabolic consequence of ureterosigmoidostomy itself.
Question 945: What is the primary condition treated by the Kasai operation?
- A. Biliary atresia (Correct Answer)
- B. Choledochal cyst
- C. Hepatocellular carcinoma
- D. Primary biliary cirrhosis
Explanation: ***Biliary atresia*** - The **Kasai operation**, or **hepatoportoenterostomy**, is the primary surgical treatment for **biliary atresia**, a condition where the bile ducts are blocked or absent. - The procedure aims to establish bile flow from the liver to the small intestine to prevent liver damage. *Choledochal cyst* - A **choledochal cyst** is a congenital dilation of the bile ducts and is typically treated by surgical excision of the cyst and a **Roux-en-Y hepaticojejunostomy**. - While it involves the biliary system, it is a distinct condition from biliary atresia and requires a different surgical approach. *Hepatocellular carcinoma* - **Hepatocellular carcinoma** is a primary liver cancer, and its treatment options range from **surgical resection** and **transplantation** to **chemotherapy** and **radiation**, which are distinctly different from the Kasai operation. - The Kasai operation is not used for malignant conditions of the liver or bile ducts. *Primary biliary cirrhosis* - **Primary biliary cirrhosis** is a chronic autoimmune disease affecting the small bile ducts within the liver, causing progressive cholestasis. - Its management is primarily medical, focusing on symptom control and preventing disease progression with drugs like **ursodeoxycholic acid**, and surgery is not a primary treatment.
Question 946: In the Bismuth-Corlette classification, which type involves the hepatic duct confluence WITHOUT extension into secondary intrahepatic ducts?
- A. Type II (Correct Answer)
- B. Type IIIb
- C. Type I
- D. Type IV
- E. Type IIIa
- F. Type III
Explanation: ***Type II*** - This classification specifically describes **cholangiocarcinomas** located at the **hepatic duct confluence** without extension into secondary intrahepatic ducts. - **Type II tumors** involve the hepatic duct confluence but **do not extend** into the right or left secondary intrahepatic ducts. - This is the defining feature that distinguishes Type II from Type III variants. *Type I* - **Type I tumors** are located at least **2 cm distal to the hepatic duct bifurcation**. - This type involves the **common hepatic duct** and **spares the confluence** completely. - Does not meet the criteria of involving the confluence. *Type IIIa* - **Type IIIa tumors** involve the **hepatic duct confluence** with extension into the **right secondary intrahepatic ducts**. - This represents extension **beyond** the confluence, unlike Type II. - The extension into secondary ducts is the key differentiating feature. *Type IIIb* - **Type IIIb tumors** involve the **hepatic duct confluence** with extension into the **left secondary intrahepatic ducts**. - This represents extension **beyond** the confluence, unlike Type II. - The extension pattern differs from Type IIIa by involving the left rather than right system.
Question 947: What is the investigation of choice for detecting recurrence after parathyroid gland surgery?
- A. SPECT
- B. MRI
- C. Neck ultrasound
- D. Sestamibi scan (Correct Answer)
Explanation: ***Sestamibi scan*** - A **sestamibi scan** is the investigation of choice for **localizing recurrent or persistent hyperparathyroidism** because **parathyroid tissue preferentially retains the tracer** longer than thyroid tissue. - This nuclear medicine imaging technique helps identify ectopic or very small parathyroid adenomas, which may be difficult to locate with other methods. *SPECT* - **Single-photon emission computed tomography (SPECT)** can be used as an adjunct to a sestamibi scan (SPECT-Sestamibi) to provide 3D images and improve localization, but it is typically not the initial or standalone investigation of choice for recurrence. - While SPECT offers increased sensitivity and specificity over planar imaging by removing superimposed structures, the **sestamibi uptake itself is the crucial diagnostic marker**. *MRI* - **Magnetic resonance imaging (MRI)** is generally used for detailed anatomical assessment of the neck and mediastinum, especially if there's concern for **ectopic glands or complex anatomy**. - However, it is less sensitive than sestamibi for detecting small or recurrent hyperactive parathyroid tissue due to its reliance on anatomical rather than functional abnormalities. *Neck ultrasound* - **Neck ultrasound** is an excellent initial imaging modality for primary hyperparathyroidism due to its **affordability and ability to visualize cervical parathyroid glands**. - For detecting recurrence, its utility is limited, especially in cases of **ectopic glands** (e.g., in the mediastinum) or if scar tissue hinders clear visualization.