Which of the following conditions is the classic example of acute intravascular hemolysis triggered by oxidative stress?
Renal vein thrombosis is associated with all of the following conditions except:
What is the most common cause of dissecting hematoma?
Creola bodies are seen in:
What is the term for the collapse of a lung?
Most common cause of nephrotic syndrome in adults?
PNH patients have deficient surface proteins that normally protect red blood cells from activated complements. Which two surface proteins are deficient in these patients?
What is the most common site of gastrointestinal stromal tumors (GISTs)?
All of the following are risk factors for carcinoma of the gallbladder, EXCEPT -
Progressive distal-to-proximal motor recovery following nerve regeneration is most characteristic of which type of nerve injury?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 11: Which of the following conditions is the classic example of acute intravascular hemolysis triggered by oxidative stress?
- A. Hereditary spherocytosis
- B. Sickle cell disease
- C. Acute G6PD deficiency (Correct Answer)
- D. None of the options
Explanation: ***b and c*** - Intravascular hemolysis is commonly associated with both **Acute G6PD deficiency** and **Hereditary spherocytosis**, leading to destruction of red blood cells in the bloodstream [1]. - These conditions are characterized by **high levels of hemoglobinuria** and **low haptoglobin**, indicative of intravascular hemolysis. *Sickle cell ds* - Sickle cell disease primarily causes **extravascular hemolysis** due to splenic sequestration rather than **intravascular** destruction [3]. - The clinical features include **vaso-occlusive crises** and splenic infarction rather than hemolysis within the blood vessels. *Acute G6PD* - While acute G6PD deficiency can lead to hemolysis, it is typically **triggered by oxidative stress** rather than occurring continuously [2]. - The hemolysis in G6PD deficiency occurs more in an **extravascular** manner unless acute stress occurs, which can result in **acute intravascular hemolysis, marked by anemia, hemoglobinemia, and hemoglobinuria** [4]. *Hereditary spherocytosis* - This condition primarily causes **extravascular hemolysis** through the spleen, where abnormal spherocytes are destroyed [1]. - Although it leads to anemia, the hallmark of hereditary spherocytosis is the **spleen's role** in hemocyte destruction rather than intravascular hemolysis.
Question 12: Renal vein thrombosis is associated with all of the following conditions except:
- A. Nephrotic syndrome
- B. Dehydration
- C. Sickle cell anemia
- D. Trauma (Correct Answer)
Explanation: **Trauma** - While trauma to the abdomen can cause **renal injury** and other vascular issues, isolated **renal vein thrombosis** is not a common direct association or complication [1]. - Renal vein thrombosis typically results from conditions that lead to a **hypercoagulable state** or local vascular stasis. *Sickle cell anemia* - Individuals with **sickle cell anemia** are prone to **vaso-occlusive crises** from sickled red blood cells obstructing blood flow [2]. - This can lead to **renal medullary ischemia** and infarction, making them highly susceptible to **renal vein thrombosis**. *Nephrotic syndrome* - **Nephrotic syndrome** is a significant risk factor for **renal vein thrombosis** due to the urinary loss of **antithrombin III**, a natural anticoagulant. - This loss creates a **hypercoagulable state**, increasing the likelihood of thrombus formation in renal veins. *Dehydration* - Severe **dehydration** leads to **hemoconcentration** (increased blood viscosity) and reduced blood flow. - These factors promote a **hypercoagulable state**, increasing the risk of thrombotic events, including **renal vein thrombosis**, especially in vulnerable populations like infants or the elderly.
Question 13: What is the most common cause of dissecting hematoma?
- A. Hypertension (Correct Answer)
- B. Marfan syndrome
- C. Iatrogenic causes
- D. Kawasaki disease
Explanation: ***Hypertension*** - **Chronic hypertension** is the most frequent cause of dissecting hematoma (aortic dissection) due to the constant high pressure stressing the arterial wall [1]. - It leads to **medial degeneration** and predisposition to intimal tear, allowing blood to enter the arterial wall [1]. *Marfan syndrome* - While Marfan syndrome is a significant risk factor for aortic dissection due to **connective tissue weakness** (cystic medial necrosis), it is much less common than hypertension [1]. - It primarily affects younger individuals with a genetic predisposition to **fibrillin-1 mutations**. *Iatrogenic causes* - These include complications from medical procedures like **cardiac catheterization** or surgery [1]. - Though a possible cause, iatrogenic dissection is relatively rare compared to spontaneous dissection due to hypertension [1]. *Kawasaki disease* - Kawasaki disease primarily causes **coronary artery aneurysms** in children. - It is not a common cause of aortic dissecting hematoma in adults.
Question 14: Creola bodies are seen in:
- A. Emphysema
- B. Chronic bronchitis
- C. Bronchiectasis
- D. Bronchial asthma (Correct Answer)
Explanation: ***Bronchial asthma*** - **Creola bodies** are clusters of **desquamated columnar epithelial cells** found in the sputum of patients with asthma. [1] - Their presence indicates ongoing **bronchial inflammation** and epithelial damage, characteristic of asthma exacerbations. *Chronic bronchitis* - Characterized by **mucus hypersecretion** and **chronic productive cough**, without the specific finding of Creola bodies. - Histologically, it involves **goblet cell hyperplasia** and **mucous gland enlargement**. *Emphysema* - Defined by irreversible enlargement of airspaces distal to the terminal bronchioles with **destruction of alveolar walls**, not specific cell aggregates. [1] - The primary defect is loss of **elastic recoil** and **airflow limitation**. *Bronchiectasis* - Involves **permanent abnormal dilation** of the bronchi due to destruction of the muscular and elastic components of the bronchial wall. [1] - Sputum typically contains inflammatory cells and bacteria, but Creola bodies are not a defining feature.
Question 15: What is the term for the collapse of a lung?
- A. Emphysema
- B. Atelectasis (Correct Answer)
- C. Bronchitis
- D. Bronchiectasis
Explanation: ***Atelectasis*** - **Atelectasis** is the technical term for the **collapse of a lung** or a part of a lung, leading to reduced or absent gas exchange. - It can be caused by **obstruction of the airway** (e.g., mucus plug, foreign body) or external compression on the lung [1]. *Emphysema* - **Emphysema** is a chronic lung disease characterized by the **destruction of the alveoli**, leading to permanent enlargement of airspaces [2]. - It results in reduced elastic recoil of the lungs and is a type of **COPD (chronic obstructive pulmonary disease)** [2]. *Bronchiectasis* - **Bronchiectasis** is a chronic condition where the airways (bronchi) become **abnormally widened** and scarred. - This widening leads to a buildup of mucus, making the lungs vulnerable to **recurrent infections**. *Bronchitis* - **Bronchitis** is an inflammation of the lining of the bronchial tubes, which carry air to and from your lungs. - It typically causes a **cough** with mucus production and can be acute or chronic.
Question 16: Most common cause of nephrotic syndrome in adults?
- A. Minimal change disease
- B. Acute GN
- C. Membranous glomerulonephritis
- D. Focal Segmental Glomerulosclerosis (FSGS) (Correct Answer)
Explanation: ***Membranous glomerulonephritis*** - Membranous glomerulonephritis is the **most common cause of nephrotic syndrome** in adults, often associated with **autoimmune diseases** or certain medications. [1] - Patients typically present with **heavy proteinuria**, edema, and a normal renal function in early stages. *Focal GN* - Focal glomerulosclerosis typically affects young individuals and may not usually present as nephrotic syndrome. - It is associated with **obesity** and **HIV**, often leading to more significant renal impairment compared to membranous glomerulonephritis. [1] *Acute GN* - Acute glomerulonephritis generally presents with **hematuria**, **hypertension**, and **renal failure**, rather than nephrotic syndrome. [1] - It can have different causes, such as infections or systemic diseases, but is not the primary condition leading to nephrotic syndrome in adults. *Minimal change disease* - Minimal change disease is more prevalent in **children** [1], and while it can occur in adults, it is less common as a cause of nephrotic syndrome in this demographic. - It is characterized by **responsive edema** to steroids, but its incidence is not as high as membranous glomerulonephritis in adults.
Question 17: PNH patients have deficient surface proteins that normally protect red blood cells from activated complements. Which two surface proteins are deficient in these patients?
- A. CD 55 and CD 58
- B. CD 45 and CD 55 (Correct Answer)
- C. CD 55 and CD 59
- D. CD 51 and CD 55
Explanation: ***CD 55 and CD 59*** - **CD 55 (decay accelerating factor)** and **CD 59 (protectin)** are crucial for inhibiting the complement system, protecting red blood cells from lysis in PNH. - Deficiencies in these proteins lead to increased **susceptibility** of red cells to **complement-mediated hemolysis**. *CD58 and CD 59* - **CD 58** is involved in T-cell interaction but does not solely protect red cells from complement. - While **CD 59** is a correct answer, the absence of **CD 55** makes this option incorrect for PNH. *CD 45 and CD 59* - **CD 45** is primarily a **leukocyte common antigen**, not involved in protecting red cells from complement activation. - This orrectly mentions **CD 59**, but lacks **CD 55**, making it unsuitable as an answer. *CD 51 and CD 59* - **CD 51** is associated with integrin functions and does not play a role in protecting red blood cells from complements. - Although **CD 59** is relevant, the deficiency in **CD 55** highlights the incompleteness of this option.
Question 18: What is the most common site of gastrointestinal stromal tumors (GISTs)?
- A. Ileum
- B. Esophagus
- C. Colon
- D. Stomach (Correct Answer)
Explanation: Stomach - The stomach is the most common site for gastrointestinal stromal tumors (GISTs), accounting for approximately 60-70% of cases. - GISTs in the stomach often present with symptoms like abdominal pain or bleeding and are associated with mutations in the KIT gene. Ileum - Although GISTs can occur in the ileum, they are far less common than those found in the stomach, representing about 10-15% of cases [1]. - GISTs in the ileum tend to present differently, often with intestinal obstruction or pain [1]. Esophagus - Esophageal GISTs are rare and account for only about 5% of GIST cases, making them an uncommon location. - Symptoms are usually related to dysphagia or chest pain, not typical for GISTs arising from more common sites. Colon - Although GISTs can occur in the colon, their frequency is much lower compared to the stomach and represents a small percentage of cases. - Clinical features in colonic GISTs can mimic other colorectal tumors, often causing obstruction or bleeding rather than classic GIST symptoms.
Question 19: All of the following are risk factors for carcinoma of the gallbladder, EXCEPT -
- A. Adenomatous gall bladder polyps
- B. Choledochal cysts
- C. Oral contraceptives (Correct Answer)
- D. Typhoid carriers
Explanation: ***Oral contraceptives*** - While **oral contraceptives** can increase the risk of **gallstones**, they are not directly recognized as a specific risk factor for **gallbladder carcinoma**. - The impact of oral contraceptives on gallbladder cancer risk is generally considered to be minor or non-existent compared to established risk factors. *Typhoid carriers* - **Chronic asymptomatic carriers of Salmonella Typhi** have a significantly increased risk of developing **gallbladder carcinoma**, likely due to chronic inflammation and cellular damage. - The bacteria can reside in the gallbladder for years, leading to a persistent inflammatory state and genetic mutations. *Adenomatous gall bladder polyps* - **Adenomatous polyps** in the gallbladder are considered **premalignant lesions**, especially if they are larger than 10 mm, and are associated with an increased risk of progression to adenocarcinoma. - Their presence indicates a need for careful monitoring and often surgical removal due to their malignant potential. *Choledochal cysts* - **Choledochal cysts**, congenital dilations of the bile ducts, are well-established risk factors for **cholangiocarcinoma** (bile duct cancer) and, less commonly, **gallbladder carcinoma**. - The stasis and reflux of bile within these cysts lead to chronic irritation and inflammation, increasing the risk of malignant transformation.
Question 20: Progressive distal-to-proximal motor recovery following nerve regeneration is most characteristic of which type of nerve injury?
- A. Axonotmesis (Correct Answer)
- B. Neurotmesis
- C. Neuropraxia
- D. Nerve injury
Explanation: ***Axonotmesis*** - Involves damage to the **axon** and myelin sheath, while the surrounding **epineurium** remains intact. - This preservation of the connective tissue allows for guided **regeneration** of axons from distal to proximal, leading to a good prognosis for recovery [1]. *Neurotmesis* - Refers to the **complete transection** of the nerve, including the axon, myelin, and all connective tissue sheaths. - Recovery is often **incomplete** or requires surgical repair, as significant misdirection of regenerating axons is common. *Neuropraxia* - Characterized by a **temporary block** in nerve conduction, typically due to **demyelination**, with the axon remaining intact. - Recovery is usually **rapid** and complete, occurring within days to weeks, as no axonal regeneration is needed. *Nerve injury* - This is a **general term** that encompasses all types of nerve damage, from mild to severe. - It does not specify a particular mechanism or pattern of recovery, making it less precise than the more specific classifications.