Anatomy
2 questionsPodocytes are seen in -
Inferior parathyroid develops from which pharyngeal pouch?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 431: Podocytes are seen in -
- A. Bowman's capsule (Correct Answer)
- B. Proximal convoluted tubule
- C. Distal convoluted tubule
- D. Collecting tubule of the kidney
Explanation: **Bowman's capsule** - **Podocytes** are specialized epithelial cells that form the **visceral layer** of Bowman's capsule. They have foot processes (pedicels) that interdigitate to form slit diaphragms, which are crucial for the **filtration barrier** of the glomerulus [1]. - These cells facilitate the selective passage of water and small solutes from the blood into Bowman's space, while preventing the filtration of large proteins and blood cells. *Proximal convoluted tubule* - The **proximal convoluted tubule** is primarily involved in the **reabsorption** of essential nutrients, ions, and water from the filtrate back into the bloodstream [1]. - Its cells are characterized by a **brush border** (microvilli) and numerous mitochondria, indicating high metabolic activity, and are not podocytes [1]. *Distal convoluted tubule* - The **distal convoluted tubule** plays a role in fine-tuning the reabsorption of ions and water, under the influence of hormones like **aldosterone** and **ADH**. - Its cells lack the specialized foot processes and filtration function characteristic of podocytes. *Collecting tubule of the kidney* - The **collecting tubule** (or collecting duct) is involved in regulating water reabsorption and acid-base balance, responding to **ADH** to concentrate urine. - Its epithelial cells are principal cells and intercalated cells, which are different in structure and function from podocytes.
Question 432: Inferior parathyroid develops from which pharyngeal pouch?
- A. 1st
- B. 2nd
- C. 3rd (Correct Answer)
- D. 4th
Explanation: The inferior parathyroid glands develop from the dorsal wing of the third pharyngeal pouch. Due to their origin, they often migrate further caudally than the superior parathyroid glands, sometimes even locating within the thymus which also develops from the third pouch. *1st* - The first pharyngeal pouch contributes to the formation of the eustachian tube, tympanic cavity, and mastoid air cells. - It has no role in the development of the parathyroid glands. *2nd* - The second pharyngeal pouch mainly gives rise to the palatine tonsils and their crypts. - It is not involved in the development of parathyroid tissue. *4th* - The fourth pharyngeal pouch gives rise to the superior parathyroid glands and the parafollicular cells (C cells) of the thyroid, which produce calcitonin. - While it forms parathyroid tissue, it is for the superior glands, not the inferior ones.
Biochemistry
1 questionsThe anticodon region is an important part of which type of RNA?
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 431: The anticodon region is an important part of which type of RNA?
- A. r-RNA
- B. m-RNA
- C. t-RNA (Correct Answer)
- D. hn-RNA
Explanation: **t-RNA** - The **anticodon region** is a critical component of **transfer RNA (tRNA)**, responsible for recognizing and binding to the complementary codon on mRNA during protein synthesis. - This interaction ensures that the correct **amino acid** is delivered to the growing polypeptide chain according to the genetic code. *r-RNA* - **Ribosomal RNA (rRNA)** is a structural and enzymatic component of **ribosomes**, which are the cellular machinery for protein synthesis. - While rRNA plays a crucial role in forming **peptide bonds** and facilitating translation, it does not possess an anticodon region. *m-RNA* - **Messenger RNA (mRNA)** carries the **genetic code** from DNA to the ribosomes in the form of codons, which specify the sequence of amino acids for protein synthesis. - mRNA molecules have codons, but they do not have an **anticodon region**; instead, they are read by the anticodons of tRNA. *hn-RNA* - **Heterogeneous nuclear RNA (hnRNA)** is a precursor to mRNA in eukaryotic cells, containing both exons and introns. - It undergoes extensive processing, including **splicing**, to become mature mRNA, but it does not have an **anticodon region**.
Internal Medicine
2 questionsWhat is the frequency of renal involvement in Henoch-Schönlein purpura (HSP)?
All of the following are risk factors for carcinoma of the gallbladder, EXCEPT -
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 431: What is the frequency of renal involvement in Henoch-Schönlein purpura (HSP)?
- A. 25-35%
- B. 60-80%
- C. 40-60% (Correct Answer)
- D. 5-10%
Explanation: ***40-60%*** - Renal involvement in Henoch-Schönlein purpura (HSP) is common, affecting approximately **40-60% of patients**. - Renal complications can range from microscopic hematuria to proteinuria, and in some cases, **progressive glomerulonephritis** leading to renal failure. *25-35%* - This percentage underestimates the actual frequency of **renal complications** in HSP. - While mild symptoms might fall within this range, a broader spectrum of renal manifestations is observed. *60-80%* - This percentage overestimates the reported frequency of **renal involvement** in HSP. - Although it is common, a majority of patients do not develop renal symptoms. *5-10%* - This range is too low for the frequency of **renal involvement** in HSP. - Even though it's benign in many cases, some form of renal pathology like hematuria is quite frequent.
Question 432: 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.
Obstetrics and Gynecology
1 questionsWhich structure do cytotrophoblasts invade during implantation?
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 431: Which structure do cytotrophoblasts invade during implantation?
- A. Decidua capsularis
- B. Decidua vera
- C. Decidua basalis (Correct Answer)
- D. Decidua parietalis
Explanation: ***Decidua basalis*** - The **cytotrophoblasts** invade the maternal **decidua basalis**, which is the portion of the **endometrium** directly underlying the implanted embryo, forming the maternal component of the **placenta**. - This invasion is crucial for establishing the **placenta** and allowing for nutrient and waste exchange between the mother and the fetus. *Decidua parietalis* - The **decidua parietalis** is the portion of the **endometrium** lining the rest of the **uterine cavity**, not directly involved in the immediate implantation site. - It plays a role later in pregnancy, fusing with the **decidua capsularis** as the **embryo** grows. *Decidua capsularis* - The **decidua capsularis** is the portion of the endometrium that overlies the implanted embryo, separating it from the uterine lumen. - It does not undergo invasion by the **cytotrophoblasts** in the same way the **decidua basalis** does. *Decidua vera* - The **decidua vera** is another term for the **decidua parietalis**, referring to the endometrial lining of the uterine cavity that is not involved in the implantation site. - It is not directly invaded by **cytotrophoblasts** during implantation.
Pathology
2 questionsWhich type of immunoglobulin is primarily associated with cold agglutinin disease?
Nutmeg liver is associated with which condition?
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 431: Which type of immunoglobulin is primarily associated with cold agglutinin disease?
- A. IgG
- B. IgM (Correct Answer)
- C. IgA
- D. IgD
Explanation: ***IgM*** - Cold agglutinins are primarily composed of **IgM antibodies** [1] which are produced in response to certain infections, notably Mycoplasma pneumoniae. - They can cause **cold agglutinin disease**, leading to hemolytic anemia when the blood is exposed to cooler temperatures [2]. *IgG* - While IgG is the most abundant antibody in blood, it is not responsible for cold agglutination. - IgG typically functions in **immune memory** and neutralization rather than agglutination at cold temperatures. *IgD* - IgD is mainly found on the surface of **B cells** and has a role in initiating B cell activation. - It plays a minimal role in the antibody response and does not participate in cold agglutination. *IgA* - IgA is primarily involved in mucosal immunity, found in secretions like saliva and tears. - It does not function as a cold agglutinin; hence, it is not associated with cold temperature-related agglutination. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 154-155. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 651-652.
Question 432: Nutmeg liver is associated with which condition?
- A. Right sided heart failure (Correct Answer)
- B. Increased pulmonary pressure
- C. Decreased pulmonary pressure
- D. Left sided heart failure
Explanation: ***Right sided heart failure*** - **Nutmeg liver** is a classic finding associated with **congestion** in the liver due to **right-sided heart failure**, leading to the characteristic mottled appearance [1][2]. - **Impaired venous return** from the systemic circulation causes hepatic congestion, resulting in **enlargement and fibrosis** of the liver over time [2]. *Left sided heart failure* - Left-sided heart failure primarily affects the **lungs**, leading to pulmonary congestion rather than hepatic changes. - While it can cause secondary effects on the liver over time, it does not directly cause **nutmeg liver**. *Increased pulmonary pressure* - Increased pulmonary pressure is generally associated with conditions like **pulmonary hypertension**, affecting primarily the **lungs** rather than the liver directly. - It does not lead to the **congestive changes** observed in nutmeg liver [1], which is related to right heart function. *Decreased pulmonary pressure* - Decreased pulmonary pressure would typically improve pulmonary blood flow, therefore having no association with liver congestion. - It does not contribute to the **venous stasis** seen in right heart failure, which is pivotal for nutmeg liver. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, p. 126. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 870-872.
Pediatrics
1 questionsWhat is the venous hematocrit level at which you will diagnose polycythemia in a newborn?
NEET-PG 2012 - Pediatrics NEET-PG Practice Questions and MCQs
Question 431: What is the venous hematocrit level at which you will diagnose polycythemia in a newborn?
- A. 55%
- B. 60%
- C. 65% (Correct Answer)
- D. 70%
Explanation: ***Correct: 65%*** - **Polycythemia** in a newborn is typically diagnosed when the **venous hematocrit** is **≥65%**. - This threshold indicates an abnormally high concentration of **red blood cells**, increasing blood viscosity. *Incorrect: 55%* - A venous hematocrit of 55% is generally considered within the **normal range** for a newborn, especially within the first few hours of life. - It does not meet the criteria for diagnosing **polycythemia**. *Incorrect: 60%* - While 60% is elevated compared to adult norms, it is still generally within the higher end of the **normal range** for an infant. - This level alone is usually **not sufficient** to diagnose **polycythemia** or warrant intervention without other clinical signs. *Incorrect: 70%* - A venous hematocrit of 70% definitely indicates **polycythemia** and significant **hyperviscosity**. - However, the diagnostic threshold for polycythemia is **65%**, meaning the condition is identified earlier.
Radiology
1 questionsCentral stellate scar is typically associated with which of the following conditions?
NEET-PG 2012 - Radiology NEET-PG Practice Questions and MCQs
Question 431: Central stellate scar is typically associated with which of the following conditions?
- A. Focal nodular hyperplasia (FNH) (Correct Answer)
- B. Hepatic adenoma
- C. Chronic liver disease
- D. Hepatocellular carcinoma
Explanation: ***Focal nodular hyperplasia (FNH)*** - FNH is a benign liver lesion characterized by a central fibrous scar with radiating septa, giving it the characteristic appearance of a **central stellate scar** on imaging. - This scar contains **malformed blood vessels** and bile ductules, which are key diagnostic features. - On dynamic imaging, FNH typically shows **spoke-wheel arterial enhancement** pattern and the central scar shows **delayed enhancement** on MRI. *Hepatic adenoma* - Hepatic adenomas are typically composed of sheets of **hepatocytes** with absent portal triads and are usually **homogeneous** on imaging without a central scar. - They are associated with **oral contraceptive use** and have a risk of hemorrhage and malignant transformation. *Chronic liver disease* - Chronic liver disease, such as **cirrhosis**, is characterized by widespread **fibrosis** and **nodule formation** throughout the liver, but it does not typically present with a solitary lesion with a central stellate scar. - The scarring in cirrhosis is diffuse and leads to architectural distortion, rather than a focal central scar. *Hepatocellular carcinoma* - Hepatocellular carcinoma (HCC) typically presents as a **vascular mass** that may or may not be solitary, usually arising in the context of chronic liver disease or cirrhosis. - Although the **fibrolamellar variant of HCC** (seen in younger patients without cirrhosis) can show a central scar, this is less common and the scar typically shows **hypointensity on T2-weighted imaging**, unlike FNH where the scar is **hyperintense on T2**. - Typical HCC does not show a distinct central stellate scar as a characteristic feature.