Anatomy
1 questionsWhat anatomical structure is formed after the obliteration of the umbilical vein?
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 591: What anatomical structure is formed after the obliteration of the umbilical vein?
- A. Ligamentum venosum
- B. Ligamentum arteriosum
- C. Medial umbilical ligament
- D. Round ligament of the liver (ligamentum teres) (Correct Answer)
Explanation: ***Round ligament of the liver (ligamentum teres)*** - The **umbilical vein** carries oxygenated blood from the placenta to the fetus during development [1]. - After birth, the umbilical vein obliterates and forms the **round ligament of the liver**, also known as the **ligamentum teres hepatis**. *Ligamentum venosum* - This structure is the obliterated remnant of the **ductus venosus**, which shunted blood from the umbilical vein to the inferior vena cava, bypassing the fetal liver [1]. - It is located in a fissure on the posterior surface of the liver, separate from the round ligament. *Ligamentum arteriosum* - This ligament is the remnant of the **ductus arteriosus**, a fetal blood vessel connecting the pulmonary artery to the aorta. - Its obliteration allows blood to flow through the lungs after birth. *Medial umbilical ligament* - This ligament is formed from the obliterated **umbilical arteries**, which carry deoxygenated blood from the fetus back to the placenta. - There are two medial umbilical ligaments, one from each umbilical artery.
Biochemistry
1 questionsWhich of the following is not an acute phase reactant?
NEET-PG 2013 - Biochemistry NEET-PG Practice Questions and MCQs
Question 591: Which of the following is not an acute phase reactant?
- A. C-reactive protein
- B. Haptoglobin
- C. Endothelin (Correct Answer)
- D. Fibrinogen
Explanation: ***Endothelin*** - Endothelin is a **vasoconstrictive peptide** primarily involved in regulating **blood vessel tone** and blood pressure. - While it plays a role in processes like inflammation and tissue repair, it is not synthesized or regulated in the same rapid, systemic manner as a classic acute phase reactant. *C-reactive protein* - **C-reactive protein (CRP)** is a rapidly responding acute phase reactant produced by the liver in response to **inflammation**, infection, and tissue injury. - Its levels can rise dramatically within hours of an inflammatory stimulus and are used as a marker for disease activity. *Haptoglobin* - **Haptoglobin** is an acute phase reactant that binds to free **hemoglobin** released from red blood cells during hemolysis, preventing oxidative damage. - Its levels typically increase during acute inflammation or infection, although it can also decrease with severe hemolysis. *Fibrinogen* - **Fibrinogen** is a critical acute phase protein involved in the **coagulation cascade** and wound healing. - Its concentration increases significantly during acute inflammation, contributing to the elevated **erythrocyte sedimentation rate (ESR)**.
Community Medicine
2 questionsWhich of the following diseases is classified under category-B of bioterrorism?
Most common mode of transmission of nosocomial infection is -
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 591: Which of the following diseases is classified under category-B of bioterrorism?
- A. Anthrax
- B. Plague
- C. Botulism
- D. Cholera (Correct Answer)
Explanation: ***Cholera*** - **Cholera** is classified under **Category B** agents due to its moderate ease of dissemination, moderate morbidity rates, and low mortality rates. - While it can cause severe diarrheal disease, its treatment is relatively straightforward with **rehydration therapy**, and it poses a lower risk of mass casualties compared to Category A agents. *Anthrax* - **Anthrax** is a **Category A** bioterrorism agent, characterized by its high mortality rate, ease of dissemination, and potential for major public health impact. - It poses a significant threat due to its ability to form **spores** that are highly resistant and can cause severe lung infection. *Plague* - **Plague** is designated as a **Category A** agent because of its high potential for mass dissemination, high mortality if untreated, and potential to cause widespread panic. - It can be spread via **aerosols** and can lead to severe systemic illness. *Botulism* - **Botulism** is classified as a **Category A** agent due to the extreme potency of the **botulinum toxin**, even in minute quantities, which can cause severe flaccid paralysis and death. - It has a high potential for causing severe public health impact and requires complex medical interventions.
Question 592: Most common mode of transmission of nosocomial infection is -
- A. Hand contact (Correct Answer)
- B. Droplet infection
- C. Blood and blood products
- D. Contaminated water
Explanation: ***Hand contact*** - **Direct contact** with healthcare workers' contaminated hands is the primary way pathogens are transferred between patients in a healthcare setting. - Failure to perform adequate **hand hygiene** between patient contacts is the single most important factor contributing to nosocomial infection transmission. *Droplet infection* - While droplet transmission can cause nosocomial infections, especially for respiratory viruses, it is not the most common mode of transmission for the overall burden of healthcare-associated infections. - **Droplets** usually travel short distances and deposit on mucous membranes of the nose, mouth, or eyes of a susceptible host. *Blood and blood products* - Transmission through **blood and blood products** is a significant concern for specific infections (e.g., HIV, hepatitis B/C), but the incidence is relatively low due to stringent screening and safety protocols. - This mode accounts for a small fraction of overall nosocomial infections compared to contact transmission. *Contaminated water* - **Contaminated water** can lead to outbreaks (e.g., *Legionella*, *Pseudomonas*), especially in immunocompromised patients, but it is not the most frequent mode of transmission on a day-to-day basis across all types of nosocomial infections. - Healthcare facilities implement measures to ensure water safety, limiting this as the primary route.
Microbiology
5 questionsAn adolescent male developed vomiting and diarrhea 1 hour after having food from a restaurant. The most likely pathogen is?
What is the typical bacterial count in the duodenum?
Which of the following bacteria is known to exhibit antigenic variation?
Most common organism causing ventilator associated pneumonia -
Which fungus is commonly known as golden yellow jelly fungus?
NEET-PG 2013 - Microbiology NEET-PG Practice Questions and MCQs
Question 591: An adolescent male developed vomiting and diarrhea 1 hour after having food from a restaurant. The most likely pathogen is?
- A. Clostridium perfringens
- B. Vibrio parahaemolyticus
- C. Staphylococcus aureus (Correct Answer)
- D. Salmonella
Explanation: ***Staphylococcus aureus*** - The rapid onset of symptoms (within 1 hour) strongly suggests **pre-formed toxin ingestion**, which is characteristic of *Staphylococcus aureus* food poisoning. - While the typical incubation period is **1-6 hours** (average 2-4 hours), onset within 1 hour can occur with **high toxin loads** in contaminated food. - **Vomiting** is often the predominant symptom, occurring shortly after consuming contaminated food, which distinguishes it from other bacterial causes. *Clostridium perfringens* - Onset of symptoms caused by *Clostridium perfringens* is typically **8-16 hours** after ingestion, which is much longer than observed here. - It primarily causes **diarrhea and abdominal cramps** due to toxin production in the intestine, with minimal vomiting. *Vibrio parahaemolyticus* - Symptoms usually appear **4-96 hours** (average 12-24 hours) after consuming contaminated seafood, which is a longer incubation period than described. - It typically causes **watery diarrhea**, abdominal cramps, nausea, and occasional vomiting, but not within 1 hour. *Salmonella* - The incubation period for *Salmonella* infection is typically **6-72 hours** (average 12-36 hours), making it highly unlikely for symptoms to appear within 1 hour. - **Diarrhea, fever, and abdominal cramps** are common with *Salmonella*, but rapid-onset vomiting from pre-formed toxin is not its mechanism.
Question 592: What is the typical bacterial count in the duodenum?
- A. 10^2 per gram (Correct Answer)
- B. 10^1 per gram
- C. 10^10 per gram
- D. 10^5 per gram
Explanation: ***10^2 per gram*** - The duodenum has a **relatively low bacterial count** (typically 10^2-10^4 CFU/gram) due to the **acidic environment** from gastric acid and **rapid transit** of contents. - A count of **10^2 CFU/gram** represents the **lower end of the normal range** for the proximal duodenum, where gastric acid effects are strongest. - This sparse bacterial population contrasts sharply with the dense colonization seen in the distal gut. *10^1 per gram* - This represents an **extremely low count** more characteristic of the **stomach**, not the duodenum. - Such minimal bacterial presence is due to the **hostile acidic environment** (pH 1-3) in the stomach. - The duodenum, while having low counts, consistently has higher bacterial densities than this. *10^5 per gram* - This count is characteristic of the **distal small intestine (ileum)**, where bacterial concentrations progressively increase. - A bacterial count of **10^5 per gram in the duodenum** would be considered **abnormal** and suggest **small intestinal bacterial overgrowth (SIBO)**. - SIBO occurs when colonic-type bacteria colonize the small intestine inappropriately. *10^10 per gram* - This bacterial density is typical of the **colon** (which harbors 10^11-10^12 CFU/gram), the most densely colonized part of the human gut. - Such a high count in the duodenum would indicate **severe bacterial overgrowth** or gross contamination. - The colon's anaerobic environment supports this massive bacterial population.
Question 593: Which of the following bacteria is known to exhibit antigenic variation?
- A. Yersinia
- B. Bordetella
- C. Brucella
- D. Borrelia (Correct Answer)
Explanation: ***Borrelia*** - *Borrelia* species, particularly *Borrelia burgdorferi* (causing **Lyme disease**), are known for extensive **antigenic variation** of their outer surface proteins (Osps), especially OspC. - This variation helps the bacteria evade the host's immune response, contributing to persistent infection. *Yersinia* - While *Yersinia* species produce various virulence factors, including proteins that interfere with immune cell function, they are not primarily known for the type of rapid and extensive **antigenic variation**seen in *Borrelia*. - Their immune evasion strategies often involve modifying host cell signaling pathways and resisting phagocytosis. *Bordetella* - *Bordetella pertussis*, causative agent of **whooping cough**, varies its expression of adhesins and toxins through **phase variation**, which is a form of phenotypic switching. - However, this is distinct from the frequent and sequential changes in surface antigens (antigenic variation) observed in *Borrelia*. *Brucella* - *Brucella* species are **intracellular pathogens** that primarily evade the immune system by surviving and replicating within host cells. - They do not typically engage in significant **antigenic variation** of their surface components as a primary immune evasion mechanism.
Question 594: Most common organism causing ventilator associated pneumonia -
- A. Legionella
- B. Pneumococcus
- C. Pseudomonas (Correct Answer)
- D. Coagulase negative staphylococcus
Explanation: ***Pseudomonas*** - **Pseudomonas aeruginosa** is one of the most common causes of **ventilator-associated pneumonia (VAP)**, particularly in **late-onset VAP** (≥5 days) and in patients with prolonged mechanical ventilation, prior antibiotic exposure, or underlying lung disease. - Its ability to form **biofilms** and its intrinsic antibiotic resistance contribute to its prevalence in hospital-acquired infections. - Along with **Staphylococcus aureus** (especially MRSA), Pseudomonas is consistently among the leading causes of VAP in ICU settings. *Legionella* - **Legionella** is a less common cause of VAP and is typically associated with contaminated water sources, manifesting as **Legionnaires' disease**. - It usually causes severe, rapidly progressive pneumonia and is often harder to culture than other bacteria. *Pneumococcus* - **Streptococcus pneumoniae (Pneumococcus)** is the most common cause of **community-acquired pneumonia (CAP)**, but it is less frequently implicated in VAP. - While it can cause severe pneumonia and may be seen in **early-onset VAP**, its incidence in late-onset VAP is lower compared to Gram-negative rods like Pseudomonas. *Coagulase negative staphylococcus* - **Coagulase-negative Staphylococci** (e.g., *Staphylococcus epidermidis*) are common **contaminants** in cultures and primarily cause device-related infections, such as those associated with central venous catheters. - They are rarely a primary cause of VAP, as they typically have low virulence in the respiratory tract.
Question 595: Which fungus is commonly known as golden yellow jelly fungus?
- A. T. tonsurans
- B. Tremella mesenterica (Correct Answer)
- C. Epidermophyton floccosum
- D. T. mentagrophytes
Explanation: ***Tremella mesenterica*** - This fungus is commonly referred to as **golden yellow jelly fungus** or **witch's butter** due to its distinctive golden-yellow, gelatinous, and brain-like appearance. - It is a **jelly fungus** that typically grows on dead hardwood branches, especially after rain, and is known for its pliable, quivering texture. *T. tonsurans* - This refers to **Trichophyton tonsurans**, a dermatophytic fungus primarily known for causing **tinea capitis** (ringworm of the scalp). - Its common name relates to its effect on hair, causing breakage and a "black dot" appearance, rather than a golden yellow, jelly-like form. *Epidermophyton floccosum* - This is a dermatophytic fungus that specifically causes infections of the **skin and nails**, particularly **tinea pedis** (athlete's foot) and **tinea cruris** (jock itch). - It does not produce a fruiting body and is not described as a jelly-like fungus. *T. mentagrophytes* - This refers to **Trichophyton mentagrophytes**, another common dermatophyte responsible for various superficial fungal infections, including **tinea pedis**, **tinea corporis**, and **tinea unguium**. - Its clinical presentation is not that of a golden yellow jelly fungus.
Pathology
1 questionsABO isoantibodies are of which class?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 591: ABO isoantibodies are of which class?
- A. IgG
- B. IgM (Correct Answer)
- C. IgD
- D. IgA
Explanation: ***IgM*** - Naturally occurring **ABO isoantibodies** are predominantly of the **IgM class**. - These **pentameric antibodies** are highly effective at causing **agglutination** of incompatible red blood cells, which is crucial in transfusion reactions [1]. *IgG* - While IgG antibodies can be formed against ABO antigens (e.g., in hemolytic disease of the newborn), the **naturally occurring isoantibodies** are primarily IgM. - IgG antibodies are **monomeric** and can cross the **placenta**, which is a key difference from the primary IgM ABO antibodies. *IgD* - **IgD** antibodies are primarily found on the surface of **B cells** and play a role in B cell activation. - They are **not a primary mediator** of ABO isoantibody response or red blood cell agglutination. *IgA* - **IgA** antibodies are predominantly found in **mucosal secretions** and play a role in mucosal immunity. - While some IgA may be present, it is **not the predominant class** for naturally occurring ABO isoantibodies involved in transfusion reactions. **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.