NEET-PG 2012 Practice Questions

Q: Which of the following local anesthetics has the highest maximum concentration allowed for epidural block?

Chlorprocaine. ***Chlorprocaine*** - **Chlorprocaine** is an ester-type local anesthetic that can be safely used in higher concentrations for epidural blocks up to **3%**, due to its rapid hydrolysis by plasma pseudocholinesterase, leading to a very short half-life and reduced systemic toxicity. - Its rapid metabolism minimizes the risk of accumulation and systemic toxicity, making it a suitable choice when a dense block is needed and a short duration of action is acceptable. *Lidocaine* - **Lidocaine** is an amide-type local anesthetic commonly used in epidural blocks, but its maximum concentration for this application is typically limited to **2%** to avoid systemic toxicity. - Higher concentrations of lidocaine are associated with an increased risk of neurological and cardiovascular adverse effects. *Ropivacaine* - **Ropivacaine** is an amide-type local anesthetic that is less cardiotoxic than bupivacaine, with common concentrations for epidural use ranging from **0.2% to 1%**. - Its maximum concentration is significantly lower than chlorprocaine due to its longer duration of action and potential for systemic toxicity at higher doses. *Bupivacaine* - **Bupivacaine** is a potent amide-type local anesthetic with a high risk of cardiotoxicity, and its maximum concentration for epidural use is generally restricted to **0.5%** or even less for continuous infusions. - Using concentrations above this limit significantly increases the risk of severe cardiovascular complications, including arrhythmias and cardiac arrest.

Q: Which of the following is a 17β-OH steroid?

Androgen. ***Androgen*** - **Testosterone** is the classic example of a **17β-hydroxysteroid**, containing a hydroxyl group (-OH) at the **17β-position** of its steroid nucleus. - Other androgens like **androstenediol** and **dehydroepiandrosterone (DHEA)** derivatives also possess the **17β-OH configuration**. - This structural feature is essential for **androgen receptor binding** and biological activity in target tissues. - The 17β-hydroxyl group distinguishes active androgens from their inactive 17-ketosteroid metabolites. *Estrogen* - **Estradiol**, the primary estrogen, also contains a **17β-hydroxyl group**, making it technically a 17β-OH steroid. - However, in the context of steroid chemistry and clinical biochemistry, **testosterone** (androgen) is more commonly referenced as the prototypical **17β-hydroxysteroid**. - Both androgens and estrogens can be 17β-OH steroids, but androgens are the primary class associated with this terminology in medical literature. *Progesterone* - **Progesterone** is a C21 steroid with a **ketone group at C3 and C20**, not a hydroxyl group. - At position 17, progesterone has an **acetyl side chain** (CH3CO-), not a hydroxyl group. - It lacks the 17β-OH configuration that characterizes androgenic and estrogenic steroids. *None of the options* - This is incorrect because **androgen** (specifically testosterone) is a well-established **17β-hydroxysteroid**. - The measurement of **17-ketosteroids** (oxidized metabolites of 17β-OH steroids) in urine was historically used to assess androgen production.

Q: Which of the following studies has given coronary risk factors?

Framingham. ***Framingham*** - The **Framingham Heart Study** is a landmark prospective cohort study that has identified many of the well-known **risk factors for cardiovascular disease**, including hypertension, high cholesterol, smoking, and diabetes. - This ongoing study, started in 1948, has been instrumental in shaping our understanding of **coronary artery disease** development and prevention strategies. *North Karelia* - The **North Karelia Project** was a comprehensive community-based prevention program in Finland that successfully reduced cardiovascular disease risk factors. - While influential in demonstrating how to **implement prevention strategies**, it applied already-known risk factors rather than discovering new ones. - The program focused on reducing smoking, cholesterol, and blood pressure in the population. *Stanford study* - While Stanford University has conducted numerous influential medical studies, there isn't a single "Stanford study" primarily recognized for giving us the comprehensive list of coronary risk factors. - Many institutions contribute to medical knowledge, but the **Framingham Heart Study** stands out for this specific contribution. *MONICA* - The **MONICA (Monitoring Trends and Determinants in Cardiovascular Disease)** Project was a multinational WHO project that aimed to monitor cardiovascular disease trends and determinants. - While it provided valuable data on the **epidemiology of cardiovascular disease** and its risk factors, it primarily assessed trends in established risk factors rather than initially identifying them.

Q: Best for Incineration of infectious waste?

Double - chamber. ***Correct: Double-chamber*** - **Double-chamber incinerators** are considered the best for infectious waste as they allow for complete combustion in two stages. - The first chamber burns the waste at a lower temperature (800°C), while the second chamber burns the remaining gases at a higher temperature (>1050°C), ensuring destruction of pathogens and minimizing emissions. - They are the standard recommendation under **Biomedical Waste Management Rules** for infectious waste disposal. *Incorrect: Triple-chamber* - While more advanced, **triple-chamber incinerators** are often overkill for standard infectious waste and are typically used for more complex or hazardous waste streams, or for very large volumes. - Their additional complexity and cost may not be justified for routine infectious waste disposal compared to double-chamber units. *Incorrect: Single-chamber* - **Single-chamber incinerators** are less efficient in burning infectious waste completely due to inadequate temperature control and gas retention time. - They tend to produce more harmful emissions and ash, making them unsuitable for effective and safe disposal of infectious materials. *Incorrect: None of the options* - This option is incorrect because **double-chamber incinerators** are specifically designed and widely recommended for the effective and safe incineration of infectious waste.

Q: Neurofibromatosis true all, except-

Autosomal recessive. Autosomal recessive - Neurofibromatosis types 1 and 2 are autosomal dominant disorders, not autosomal recessive. - This indicates that only one copy of the mutated gene is sufficient to cause the condition, and it can be passed from one affected parent to their children with a 50% probability. Associated with cataract - Juvenile posterior subcapsular cataracts are a known ocular manifestation, particularly in Neurofibromatosis type 2 (NF2). - This is a common finding and one of the diagnostic criteria for NF2. Multiple fibroma - Neurofibromas (benign tumors of peripheral nerves) are characteristic features of Neurofibromatosis type 1 (NF1). - These can be cutaneous, subcutaneous, or plexiform and are often numerous. Scoliosis - Scoliosis (curvature of the spine) is a common musculoskeletal complication associated with Neurofibromatosis, especially NF1. - It can be dystrophic or non-dystrophic and may require surgical intervention in severe cases.

Q: All of the following cause Fournier's gangrene except:

Clostridium. ***Clostridium*** - While *Clostridium* species (especially *C. perfringens*) **CAN be isolated** from Fournier's gangrene cases and contribute to gas formation and tissue necrosis, they are **less commonly identified as primary pathogens** compared to other organisms. - In the context of this question, *Clostridium* is considered the "except" option because it is **relatively less frequently implicated** in Fournier's gangrene compared to the other listed organisms, though it is NOT entirely excluded from the microbiology of this condition. - *Clostridium* species are more classically associated with **gas gangrene (clostridial myonecrosis)** in traumatic wounds and deep muscle tissue. *Bacteroides* - ***Bacteroides fragilis*** and other **anaerobic gram-negative bacilli** are among the **most commonly isolated organisms** in Fournier's gangrene. - They produce enzymes that facilitate tissue destruction and contribute significantly to the **polymicrobial synergistic necrotizing infection**. - Essential component of the typical microbial flora in perianal and genital infections. *Streptococcus* - ***Streptococcus pyogenes*** (Group A Streptococcus) and other streptococcal species are **frequently isolated** from Fournier's gangrene. - They produce toxins and enzymes causing **rapid necrotizing fasciitis** with systemic toxicity. - Major contributor to the aggressive nature and rapid progression of the infection. *Staphylococcus* - ***Staphylococcus aureus*** (including MRSA) is **commonly found** in polymicrobial Fournier's gangrene infections. - Contributes to local tissue destruction through toxin production and enzyme activity. - Often isolated from perianal and genital skin flora, facilitating its involvement in these infections.

Q: What is seen on x-ray with posterior elbow dislocation

Coronoid process posterior to humerus. ***Coronoid process posterior to humerus*** - In a **posterior elbow dislocation**, the **ulna and radius** (including the coronoid process) are displaced *posteriorly* relative to the distal humerus. - This anatomical relationship identifies the most common form of elbow dislocation. *Coronoid process anterior to humerus* - This would imply an **anterior elbow dislocation**, which is significantly less common and would show the ulna and radius displaced *anteriorly* relative to the humerus. - This anatomical arrangement is contrary to what is seen in a posterior dislocation. *Coronoid process below humerus* - This description is vague and does not accurately capture the specific **anteroposterior displacement** characteristic of elbow dislocations. - "Below" could imply an inferior displacement, which is not the primary diagnostic feature of a posterior dislocation. *None of the options* - This is incorrect because one of the provided options accurately describes the radiological findings of a posterior elbow dislocation.

Q: Which of the following is true about NREM sleep?

Teeth grinding. ***Teeth grinding*** - **Bruxism** (teeth grinding) commonly occurs during **NREM sleep stages**, particularly stage N2. - It is an **involuntary motor activity** that can lead to dental issues and jaw pain. *Narcolepsy* - Narcolepsy is a neurological condition characterized by overwhelming daytime sleepiness and involves dysregulation of **REM sleep**. - Patients often experience **sudden REM sleep onset** during waking hours, not typically an NREM sleep phenomenon. *Nightmares* - Nightmares are generally vivid, disturbing dreams that occur during **REM sleep**. - While other sleep disturbances can occur in NREM, classic nightmares are a **REM-related parasomnia**. *Sleep paralysis* - Sleep paralysis is a temporary inability to move or speak that occurs when waking up or falling asleep, often associated with **REM sleep**. - It involves the persistence of **REM atonia** into the waking state.

Q: Hypothalamus increases release of all hormones from the pituitary except ?

Prolactin. ***Prolactin*** - The hypothalamus primarily **inhibits prolactin release** from the anterior pituitary via **dopamine** (prolactin-inhibiting hormone). - All other hormones listed (ACTH, TSH, FSH/LH, GH) are stimulated by their respective hypothalamic releasing hormones. *ACTH* - The hypothalamus **increases ACTH release** by secreting **corticotropin-releasing hormone (CRH)**, which acts on the anterior pituitary. - CRH stimulates corticotrophs to synthesize and release ACTH, which then acts on the adrenal glands. *TSH* - The hypothalamus **increases TSH release** by secreting **thyrotropin-releasing hormone (TRH)**, which stimulates thyrotrophs in the anterior pituitary. - TRH also has a minor stimulatory effect on prolactin release, but its primary role is TSH stimulation. *FSH* - The hypothalamus **increases FSH release** (along with LH) by secreting **gonadotropin-releasing hormone (GnRH)** in a pulsatile manner. - GnRH stimulates gonadotrophs in the anterior pituitary to produce and secrete both FSH and LH.

Q: What primarily causes vasoconstriction in skin?

Sympathetic. ***Sympathetic*** - The **sympathetic nervous system** primarily controls vasoconstriction in the skin via **adrenergic receptors** on vascular smooth muscle. - Activation of these nerves releases **norepinephrine**, leading to the contraction of smooth muscle and thus narrowing of blood vessels. *Warm climate* - A warm climate typically causes **vasodilation** in the skin, allowing for increased blood flow to the surface to facilitate heat loss. - This is a physiological response to prevent **overheating**, not to vasoconstrict. *Wheal and flare* - A **wheal and flare reaction** is a localized immune response, often to allergens, characterized by histamine release causing **vasodilation** (flare) and edema (wheal). - This reaction involves localized vasodilation, not systemic or primary vasoconstriction. *Parasympathetic* - The **parasympathetic nervous system** generally has minimal direct control over cutaneous vascular tone, especially regarding vasoconstriction. - Its primary role in the skin is related to **glandular secretions**, such as sweat production.

Question 1

Which of the following local anesthetics has the highest maximum concentration allowed for epidural block?

Accepted Answer

Chlorprocaine

Answer

Lidocaine

Answer

Ropivacaine

Answer

Bupivacaine

Question 2

Which of the following is a 17β-OH steroid?

Accepted Answer

Androgen

Answer

Estrogen

Answer

Progesterone

Answer

None of the options

Question 3

Which of the following studies has given coronary risk factors?

Accepted Answer

Framingham

Answer

Stanford study

Answer

MONICA

Answer

North Karelia

Question 4

Best for Incineration of infectious waste?

Accepted Answer

Double - chamber

Answer

Triple - chamber

Answer

Single - chamber

Answer

None of the options

Question 5

Neurofibromatosis true all, except-

Accepted Answer

Autosomal recessive

Answer

Associated with cataract

Answer

Multiple fibroma

Answer

Scoliosis

Question 6

All of the following cause Fournier's gangrene except:

Accepted Answer

Clostridium

Answer

Bacteroides

Answer

Streptococcus

Answer

Staphylococcus

Question 7

What is seen on x-ray with posterior elbow dislocation

Accepted Answer

Coronoid process posterior to humerus

Answer

None of the options

Answer

Coronoid process anterior to humerus

Answer

Coronoid process below humerus

Question 8

Which of the following is true about NREM sleep?

Accepted Answer

Teeth grinding

Answer

Narcolepsy

Answer

Nightmares

Answer

Sleep paralysis

Question 9

Hypothalamus increases release of all hormones from the pituitary except ?

Accepted Answer

Prolactin

Answer

ACTH

Answer

TSH

Answer

FSH

Question 10

What primarily causes vasoconstriction in skin?

Accepted Answer

Sympathetic

Answer

Warm climate

Answer

Wheal and flare

Answer

Parasympathetic

NEET-PG 2012

Anesthesiology

Biochemistry

Community Medicine

Internal Medicine

Microbiology

Orthopaedics

Physiology