Anesthesiology
2 questionsCocaine was first used as a local anesthetic by?
What is the critical temperature of Nitrous Oxide (N2O)?
NEET-PG 2012 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1051: Cocaine was first used as a local anesthetic by?
- A. Holmer Wells
- B. Morton
- C. Carl Koller (Correct Answer)
- D. None of the options
Explanation: ***Carl Koller*** - **Carl Koller** (1857-1944), an Austrian ophthalmologist, is credited with the first clinical use of cocaine as a local anesthetic in 1884. - He demonstrated its efficacy for topical anesthesia in eye surgery, revolutionizing surgical practices. *Holmer Wells* - **Horace Wells** (not Holmer) was an American dentist who pioneered the use of **nitrous oxide** as an anesthetic in dentistry in the 1840s, preceding Koller's work with cocaine. - His contributions were focused on general anesthesia for pain relief during tooth extractions. *Morton* - **William T.G. Morton** was another American dentist who famously demonstrated the use of **ether** as a surgical anesthetic in 1846. - His work popularized surgical anesthesia, but it was not related to cocaine as a local anesthetic. *None of the options* - This option is incorrect because Carl Koller is historically recognized as the pioneer for the clinical use of **cocaine as a local anesthetic**.
Question 1052: What is the critical temperature of Nitrous Oxide (N2O)?
- A. -118°C
- B. -36°C
- C. -30°C
- D. -36.5°C (Correct Answer)
Explanation: **-36.5°C** - The **critical temperature** of **nitrous oxide (N2O)** is **36.5°C**, which is the temperature above which it cannot be liquefied by pressure alone. - This value is important for understanding the **physical state** and safe handling of N2O, as deviations can lead to phase changes or storage issues. *-118°C* - This temperature is significantly lower than the actual critical temperature of N2O and is incorrect. - This value might be related to the **boiling point of other gases** but not the critical temperature of N2O. *-36°C* - While close, **-36°C** is not the precise critical temperature for nitrous oxide. - This small difference can be significant in contexts requiring **exact physical properties** of gases. *-30°C* - This temperature is incorrect and is higher than the actual critical temperature of N2O. - At this temperature, N2O would still behave as a **liquefiable gas** under sufficient pressure, indicating it is below its critical point.
Dermatology
2 questionsWhich of the following is the MOST characteristic feature of skin tags (acrochordons)?
What type of cell are Tzanck cells commonly associated with in skin conditions?
NEET-PG 2012 - Dermatology NEET-PG Practice Questions and MCQs
Question 1051: Which of the following is the MOST characteristic feature of skin tags (acrochordons)?
- A. They commonly occur on the neck and axilla.
- B. They have malignant potential.
- C. They are associated with seborrhoeic keratosis.
- D. They are typically pedunculated. (Correct Answer)
Explanation: ***They are typically pedunculated.*** - **Skin tags (acrochordons)** are benign soft tissue tumors characterized by their **pedunculated morphology** - they are attached to the skin by a narrow stalk or pedicle. - This **pedunculated appearance** is the **most characteristic** and **defining feature** that distinguishes them from other benign skin lesions. - They are typically **soft, flesh-colored or hyperpigmented**, and range from 1-5 mm in size. *They commonly occur on the neck and axilla.* - While **skin tags** frequently occur in areas of friction such as the neck, axilla, eyelids, groin, and inframammary folds, this **location is not specific**. - Many other skin conditions also favor these sites, so location alone is not a characteristic diagnostic feature. *They are associated with seborrhoeic keratosis.* - There is **no established clinical association** between skin tags and seborrheic keratoses. - Both are common **benign skin growths** in adults but represent different pathological entities with different clinical appearances. *They have malignant potential.* - This is **incorrect**. Skin tags are **benign fibrous polyps** with **no malignant potential**. - They do not require removal unless symptomatic or for cosmetic reasons.
Question 1052: What type of cell are Tzanck cells commonly associated with in skin conditions?
- A. Keratinocyte (Correct Answer)
- B. Neutrophil
- C. Lymphocyte
- D. Fibroblast
Explanation: ***Keratinocyte*** - **Tzanck cells** are **acantholytic keratinocytes** characterized by loss of intercellular connections, resulting in rounded cells with **large nuclei** and **perinuclear halos**. - They are classically seen in **pemphigus vulgaris** and other acantholytic disorders on **Tzanck smear** preparation. - The Tzanck smear is a simple bedside diagnostic test where the base of a blister is scraped and examined microscopically after staining. *Fibroblast* - **Fibroblasts** are mesenchymal cells in the **dermis** that produce **collagen** and extracellular matrix components. - They are not epithelial cells and do not undergo acantholysis to form Tzanck cells. *Neutrophil* - **Neutrophils** are polymorphonuclear leukocytes involved in acute inflammatory responses and fighting bacterial infections. - They may infiltrate skin lesions but do not transform into Tzanck cells, which are specifically altered keratinocytes. *Lymphocyte* - **Lymphocytes** (T cells and B cells) are immune cells involved in **adaptive immunity**. - They are not the cell type from which Tzanck cells originate; Tzanck cells are acantholytic epidermal keratinocytes.
Internal Medicine
1 questionsWhich of the following statements about lepromatous leprosy is true?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1051: Which of the following statements about lepromatous leprosy is true?
- A. Thickened peripheral nerves are a common feature.
- B. Erythema nodosum leprosum occurs in less than 50% of cases.
- C. The lepromin test is usually negative or weakly positive.
- D. Lepromatous leprosy typically presents with multiple cutaneous lesions. (Correct Answer)
Explanation: ***Lepromatous leprosy typically presents with multiple cutaneous lesions.*** - Lepromatous leprosy is characterized by **widespread skin involvement**, often manifesting as numerous, symmetrically distributed nodules, plaques, and macules [1]. - The high bacterial load in lepromatous leprosy leads to extensive skin infiltration due to the host's ineffective cellular immune response. *Thickened peripheral nerves are a common feature.* - While nerve thickening can occur in lepromatous leprosy, it is a **more prominent and early feature** of **tuberculoid leprosy** due to a more robust granulomatous inflammatory response within the nerve [2]. - In lepromatous leprosy, nerve damage is often more diffuse and less demarcated, leading to **insidious nerve loss** rather than clearly palpable thickening. *Erythema nodosum leprosum occurs in less than 50% of cases.* - **Erythema nodosum leprosum (ENL)** is a common type 2 leprosy reaction associated with lepromatous leprosy, estimated to occur in **approximately 30-50% of untreated patients** [1]. - It results from an immune complex deposition and is triggered by changes in bacillary load or drug therapy, and it is observed within the stated percentage range. *The lepromin test is usually negative or weakly positive.* - The lepromin test assesses **cell-mediated immunity** to *Mycobacterium leprae* antigens. - In lepromatous leprosy patients, there is a **deficient cell-mediated immune response**, making the lepromin test typically **negative**, indicating anergy.
Obstetrics and Gynecology
3 questionsWhich drug is known to cause placental abruption?
Which of the following statements about Hegar's sign is false?
In a 5-month pregnant female, which of the following statements regarding physiological changes is true?
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1051: Which drug is known to cause placental abruption?
- A. Amphetamine
- B. Fluoxetine
- C. Methadone
- D. Cocaine (Correct Answer)
Explanation: **Cocaine** - **Cocaine** use during pregnancy is strongly associated with an increased risk of **placental abruption** due to its vasoconstrictive effects on uterine blood vessels. - Its potent **vasoconstrictive properties** lead to uterine ischemia and contractions, which can cause the placenta to detach prematurely from the uterine wall. *Methadone* - While methadone use during pregnancy is associated with risks such as **neonatal abstinence syndrome**, it is not a primary cause of **placental abruption**. - It is often used as a maintenance therapy for opioid-dependent pregnant women to avoid the fluctuating levels of illicit drug use, which can have more severe consequences. *Amphetamine* - Amphetamine use can lead to adverse pregnancy outcomes like **preterm birth** and **low birth weight** due to its stimulant effects. - Although it causes vasoconstriction, its association with **placental abruption** is less direct and less pronounced compared to cocaine. *Fluoxetine* - Fluoxetine, an **SSRI antidepressant**, generally has a relatively safe profile in pregnancy, although some studies suggest a small increased risk of persistent **pulmonary hypertension** in neonates. - It is not known to be a cause of **placental abruption**.
Question 1052: Which of the following statements about Hegar's sign is false?
- A. Bimanual palpation method
- B. Present in 2/3rd of cases (Correct Answer)
- C. Difficult in obese
- D. Can be done at 14 weeks
Explanation: ***Present in 2/3rd of cases*** - This statement is **FALSE** and is the correct answer to this question. - Hegar's sign, while a classic sign of pregnancy, is not consistently present in 2/3rds of cases with such statistical certainty. - Its detectability varies significantly depending on **gestational age** (optimal 6-12 weeks), **uterine position** (retroverted uterus makes it harder), **examiner experience**, and **patient body habitus**. - This specific "2/3rd" frequency claim lacks strong evidence-based support in obstetric literature. *Bimanual palpation method* - This statement is TRUE. - **Hegar's sign** is elicited by **bimanual pelvic examination** where one hand is placed on the abdomen and the other in the vagina to palpate the softening and compressibility of the **lower uterine segment** (isthmus). - The examiner feels the cervix and uterine fundus separately with the soft isthmus compressed between the examining fingers. *Difficult in obese* - This statement is TRUE. - **Obesity** makes any deep abdominal or pelvic palpation more challenging due to increased adipose tissue. - The **softening of the lower uterine segment** is harder to appreciate, reducing the sensitivity of detecting Hegar's sign in obese patients. *Can be done at 14 weeks* - This statement is technically TRUE but represents suboptimal timing. - **Hegar's sign** is most reliably detectable between the **6th and 12th weeks of gestation**. - At **14 weeks**, while the examination can still be performed, the uterus has grown significantly and risen into the abdomen, making the lower uterine segment less compressible and the sign much less prominent or absent. - The statement doesn't claim it's "optimal" at 14 weeks, only that it "can be done," which is technically accurate even if clinically impractical.
Question 1053: In a 5-month pregnant female, which of the following statements regarding physiological changes is true?
- A. Cardiac output is reduced
- B. Systemic vascular resistance is increased
- C. Increase in CVP
- D. 80-90% have soft systolic murmur (Correct Answer)
Explanation: ***80-90% have soft systolic murmur*** - The **increased blood volume** and **cardiac output** during pregnancy lead to increased flow across the aortic and pulmonic valves, often resulting in a **physiological systolic ejection murmur**. - This murmur is typically heard best at the **left sternal border** and usually resolves after delivery. *Cardiac output is reduced* - **Cardiac output actually increases** significantly during pregnancy, typically by 30-50%, to meet the metabolic demands of the fetus and placenta. - This increase is due to both an **increase in heart rate** and **stroke volume**. *Systemic vascular resistance is increased* - **Systemic vascular resistance (SVR) decreases** during pregnancy, primarily due to the **vasodilating effects of progesterone** and the creation of a **low-resistance placental circulation**. - The drop in SVR contributes to the physiological **decrease in blood pressure** often observed in mid-pregnancy. *Increase in CVP* - **Central venous pressure (CVP) typically remains unchanged or slightly decreases** during normal pregnancy. - While blood volume increases, the accompanying **vasodilation and decreased SVR** usually prevent a significant rise in CVP.
Pharmacology
1 questionsWhich of the following is the prototypical sympathomimetic agent with both alpha and beta-adrenergic activity?
NEET-PG 2012 - Pharmacology NEET-PG Practice Questions and MCQs
Question 1051: Which of the following is the prototypical sympathomimetic agent with both alpha and beta-adrenergic activity?
- A. Epinephrine (Correct Answer)
- B. Isoproterenol
- C. Norepinephrine
- D. Dopamine
Explanation: ***Epinephrine*** - Epinephrine (adrenaline) is a potent direct-acting **sympathomimetic** that stimulates both **alpha and beta-adrenergic receptors**. - Its diverse effects on the cardiovascular, respiratory, and other systems make it the prototypical agent for demonstrating both receptor activities. *Norepinephrine* - While norepinephrine (noradrenaline) also acts on **alpha and beta-1 receptors**, its affinity for **beta-2 receptors** is significantly lower than epinephrine. - This results in a predominant effect on **vasoconstriction** and cardiac contractility rather than bronchodilation or peripheral vasodilation. *Isoproterenol* - Isoproterenol is a **non-selective beta-adrenergic agonist**, meaning it primarily stimulates **beta-1 and beta-2 receptors**. - It has minimal or no activity at **alpha-adrenergic receptors**, differentiating it from epinephrine's mixed activity. *Dopamine* - Dopamine's effects are **dose-dependent**; at low doses, it primarily stimulates **dopamine receptors** and at moderate doses, it activates **beta-1 receptors**. - At high doses, it can stimulate **alpha-adrenergic receptors**, but its primary and distinguishing characteristic is its agonism at **dopamine receptors**, which epinephrine does not share.
Physiology
1 questionsIn pregnancy, plasma volume increase is maximum at what gestational age?
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 1051: In pregnancy, plasma volume increase is maximum at what gestational age?
- A. 10 wks
- B. 20 wks
- C. 25 wks
- D. 30 wks (Correct Answer)
Explanation: ***30 wks*** - **Plasma volume** typically reaches its maximum expansion around **30-34 weeks of gestation**, increasing by approximately 40-50% compared to pre-pregnancy levels. - This increase is crucial for supporting the **fetoplacental unit**, enhancing nutrient delivery, and protecting against supine hypotension. *10 wks* - At **10 weeks**, the increase in plasma volume is still modest, with significant expansion primarily occurring in the **second trimester**. - Most of the rapid expansion begins after the **first trimester**, around the 12-week mark. *20 wks* - While plasma volume is significantly increasing by **20 weeks**, it has not yet reached its peak. - The continuous expansion continues through the **third trimester** before stabilizing. *25 wks* - At **25 weeks**, plasma volume is substantially elevated, but the maximum expansion is usually observed a few weeks later. - The peak is generally in the **early third trimester**, around 30-34 weeks.