Anesthesiology
1 questionsDepth of Anesthesia is best measured by:
NEET-PG 2019 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 171: Depth of Anesthesia is best measured by:
- A. TOF
- B. MAC
- C. BIS (Correct Answer)
- D. Post Tetanic Potentiation
Explanation: ***BIS*** - The **BIS (Bispectral Index)** is an EEG-derived parameter that provides a quantitative measure of the patient's level of consciousness or depth of anesthesia. - A typical range for adequate surgical anesthesia is a BIS score between **40 and 60**, indicating a low probability of consciousness and recall. *TOF* - **TOF (Train-of-Four)** monitoring is used to assess the level of neuromuscular blockade, measuring the response of a muscle to a series of four electrical stimuli. - While important for managing **muscle relaxants**, it does not directly measure the depth of anesthesia or consciousness. *MAC* - **MAC (Minimum Alveolar Concentration)** is a measure of the potency of an inhaled anesthetic, defined as the concentration at which 50% of patients do not respond to a surgical stimulus. - It reflects the **ED50 of the anesthetic agent** itself rather than the patient's individual depth of anesthesia at a given moment. *Post Tetanic Potentiation* - **Post Tetanic Potentiation (PTP)** is a phenomenon observed during neuromuscular monitoring where a single twitch response is enhanced following a brief tetanus (rapid series of high-frequency stimuli). - PTP is used to assess **deep neuromuscular blockade** and recovery from paralytics, not the depth of anesthesia.
Biochemistry
1 questionsRetinitis pigmentosa is associated with deficiency of:
NEET-PG 2019 - Biochemistry NEET-PG Practice Questions and MCQs
Question 171: Retinitis pigmentosa is associated with deficiency of:
- A. Timnodonic acid
- B. DHA (Correct Answer)
- C. Eicosa pentaenoic acid
- D. Arachidonic acid
Explanation: ***DHA*** - **Docosahexaenoic acid (DHA)** is the major polyunsaturated fatty acid in the **retinal photoreceptor outer segments** and is crucial for their function. - Deficiency in DHA has been linked to several retinal degeneration disorders, including **retinitis pigmentosa**, suggesting its importance in maintaining retinal health. *Timnodonic acid* - This is an older term for **eicosapentaenoic acid (EPA)**, which is an omega-3 fatty acid. - While EPA is beneficial for overall health, it is **not the primary fatty acid** associated with the direct structural and functional health of retinal photoreceptors as DHA is. *Eicosa pentaenoic acid* - **Eicosapentaenoic acid (EPA)** is an omega-3 fatty acid found in fish oil, known for its anti-inflammatory properties. - While important for general health, EPA is **not as abundant or critical for retinal structure and function** as DHA. *Arachidonic acid* - **Arachidonic acid (AA)** is an omega-6 fatty acid found in cell membranes and is a precursor to pro-inflammatory mediators. - While present in the retina, AA is generally **not associated with a protective or causative role in retinitis pigmentosa** in the same way DHA is.
Internal Medicine
1 questionsA 25-year-old female presented to ER unconscious. Her mother tells you about her having recurrent syncopal episodes. Her BP is 80/60 mm Hg and you order an ECG. Treatment is
NEET-PG 2019 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 171: A 25-year-old female presented to ER unconscious. Her mother tells you about her having recurrent syncopal episodes. Her BP is 80/60 mm Hg and you order an ECG. Treatment is
- A. Cathether Ablation
- B. Adenosine
- C. DC shock (Correct Answer)
- D. Radiofrequency ablation
Explanation: ***DC shock*** - The ECG shows a **wide complex tachycardia** with alternating morphology in the QRS complex, consistent with **Torsades de Pointes**. - Given the patient's **unconsciousness** and **hypotension (80/60 mmHg)**, she is hemodynamically unstable, making immediate **electrical cardioversion (DC shock)** the treatment of choice irrespective of the cause. *Catheter Ablation* - **Catheter ablation** is an invasive procedure used for definitive treatment of recurrent arrhythmias, often considered in patients who are *hemodynamically stable*. - It is not an acute, emergency treatment for an **unstable patient** in a life-threatening arrhythmia. *Adenosine* - **Adenosine** is primarily used to terminate **supraventricular tachycardias (SVTs)** and can be harmful in wide complex tachycardias, especially if due to ventricular tachycardia or Wolff-Parkinson-White syndrome. - Its use is contraindicated in wide complex tachycardias like Torsades de Pointes, and it would not be effective in an **unstable patient** with Torsades de Pointes. *Radiofrequency ablation* - **Radiofrequency ablation** is a type of catheter ablation, which ablates or destroys abnormal electrical pathways in the heart. - Similar to other ablative therapies, it is a **definitive treatment** for recurrent arrhythmias in *stable patients*, not an emergency measure for an unconscious, hypotensive patient with an acute arrhythmia.
Pathology
2 questionsMcCallum patches/plaques are usually seen in which chamber of the heart?
False statement about Barrett esophagus is:
NEET-PG 2019 - Pathology NEET-PG Practice Questions and MCQs
Question 171: McCallum patches/plaques are usually seen in which chamber of the heart?
- A. Right atrium
- B. Left ventricle
- C. Left atrium (Correct Answer)
- D. Right ventricle
Explanation: Left atrium - **McCallum patches** are typically found in the **left atrium**, predominantly on the left atrial endocardium [1]. - They are associated with the regurgitant jet of **rheumatic mitral valve disease**, leading to endocardial thickening and fibrosis [1]. Right atrium - While rheumatic heart disease can affect the right side of the heart, particularly the tricuspid valve, **McCallum patches have a specific association with the left atrium** due to mitral valve involvement [1]. - Endocardial changes in the right atrium are less commonly described as McCallum patches. Left ventricle - The left ventricle is primarily a pumping chamber; while it can undergo hypertrophy or dilation in rheumatic heart disease, **McCallum patches are specific endocardial lesions of the atrium** [1]. - **Jet lesions** can occur in the ventricle due to aortic regurgitation, but these are distinct from atrial McCallum patches. Right ventricle - The right ventricle is also a pumping chamber, and endocardial changes here are not typically referred to as McCallum patches. - Rheumatic involvement of the tricuspid valve can cause right heart strain, but **McCallum patches are characteristic of left atrial involvement** [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 566.
Question 172: False statement about Barrett esophagus is:
- A. Chronic GERD is the predisposing factor
- B. May lead to malignancy after few years
- C. Goblet cells seen on histology
- D. Columnar to squamous metaplasia (Correct Answer)
Explanation: ***Columnar to squamous metaplasia*** - Barrett esophagus is characterized by the replacement of the normal **squamous epithelium** of the distal esophagus with **columnar epithelium** [1]. - Therefore, the statement "Columnar to squamous metaplasia" is incorrect as it describes the opposite process, making it the false statement. *Chronic GERD is the predisposing factor* - **Chronic gastroesophageal reflux disease (GERD)** causes repeated exposure of the esophageal lining to stomach acid, leading to cellular damage [1][2]. - This chronic irritation is the primary risk factor for the development of Barrett esophagus [1]. *May lead to malignancy after few years* - Barrett esophagus is a significant risk factor for the development of **esophageal adenocarcinoma** [1][3]. - The metaplastic columnar epithelium can undergo further dysplastic changes, which can progress to invasive cancer over time [2]. *Goblet cells seen on histology* - The distinctive histological feature of Barrett esophagus is the presence of **intestinal metaplasia**, which includes the identification of **goblet cells** within the columnar epithelium [1]. - These goblet cells are a key diagnostic marker for Barrett esophagus [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 348-349. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 764-765. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 765-766.
Pharmacology
3 questionsDrug of choice for Digoxin induced Ventricular Tachycardia:
Drug inhibiting granulocyte migration is:-
Cilastatin is given in combination with Imipenem because:-
NEET-PG 2019 - Pharmacology NEET-PG Practice Questions and MCQs
Question 171: Drug of choice for Digoxin induced Ventricular Tachycardia:
- A. Diltiazem
- B. Propranolol
- C. Lignocaine (Correct Answer)
- D. Verapamil
Explanation: ***Lignocaine*** - **Lignocaine** (also known as lidocaine) is the drug of choice for digoxin-induced ventricular tachycardia due to its ability to suppress ventricular arrhythmias without further compromising cardiac contractility [1]. - It works by blocking **sodium channels** in the myocardium, reducing automaticity and stabilizing the cardiac membrane [1]. *Diltiazem* - **Diltiazem** is a calcium channel blocker primarily used for supraventricular tachycardias and angina [1]. - It is contraindicated in digoxin toxicity as it can worsen myocardial depression and AV nodal blockade [1]. *Propranolol* - **Propranolol** is a beta-blocker that can suppress some arrhythmias but is generally not the first-line treatment for digoxin-induced ventricular tachycardia [1]. - Beta-blockers can worsen **bradycardia** and **AV block** often seen in digoxin toxicity [1]. *Verapamil* - **Verapamil** is a calcium channel blocker similar to diltiazem and can exacerbate digoxin toxicity [1]. - It is known to increase serum **digoxin levels** and can worsen the underlying cardiotoxic effects.
Question 172: Drug inhibiting granulocyte migration is:-
- A. Montelukast
- B. Colchicine (Correct Answer)
- C. Cromoglycate
- D. Felbamate
Explanation: ***Colchicine*** - **Colchicine** inhibits **granulocyte migration** by binding to tubulin, thereby disrupting microtubule assembly and function [2]. - This action is crucial in its use for conditions like **gout**, where it reduces the inflammatory response by preventing neutrophil chemotaxis to crystal deposits [1], [2]. *Montelukast* - **Montelukast** is a **leukotriene receptor antagonist** that primarily reduces bronchoconstriction and inflammation. - While it affects inflammatory pathways, its direct action is not inhibiting granulocyte migration but rather blocking the effects of leukotrienes. *Cromoglycate* - **Cromoglycate** (e.g., cromolyn sodium) is a **mast cell stabilizer** that prevents the release of inflammatory mediators. - Its main mechanism involves preventing mast cell degranulation, not directly inhibiting granulocyte migration. *Felbamate* - **Felbamate** is an **antiepileptic drug** used in the treatment of seizures. - Its mechanism of action involves blocking NMDA receptors and modulating GABAergic transmission; it has no known role in inhibiting granulocyte migration.
Question 173: Cilastatin is given in combination with Imipenem because:-
- A. Inhibits the enzymes that digest Imipenem in stomach
- B. Cilastatin prevents degradation of Imipenem in kidney (Correct Answer)
- C. Reduces side effects of Imipenem
- D. Cilastatin increases absorption of Imipenem
Explanation: ***Cilastatin prevents degradation of Imipenem in kidney*** - **Imipenem** is extensively metabolized in the renal tubules by the enzyme **dihydropeptidase-I**, leading to its inactivation and potential nephrotoxicity. - **Cilastatin** is a **dihydropeptidase-I inhibitor** that prevents this enzymatic breakdown, increasing the bioavailability and efficacy of imipenem and reducing the risk of renal damage. *Inhibits the enzymes that digest Imipenem in stomach* - **Imipenem** is a parenteral antibiotic and is not administered orally; therefore, degradation in the stomach is not a relevant concern. - Its combination with cilastatin is specifically to address renal metabolism, not gastric degradation. *Cilastatin increase absorption of Imipenem* - **Cilastatin** does not enhance the absorption of imipenem; its role is primarily to inhibit renal metabolism. - Imipenem is administered intravenously, bypassing the need for gastrointestinal absorption. *Reduces side effects of Imipenem* - While cilastatin does prevent the formation of nephrotoxic metabolites of imipenem, its primary role is to **maintain therapeutic levels** and prevent drug inactivation. - The reduction in **nephrotoxicity** is a consequence of preventing degradation, rather than a direct mitigation of general side effects.
Physiology
1 questionsAll are true about Decerebrate posture except:-
NEET-PG 2019 - Physiology NEET-PG Practice Questions and MCQs
Question 171: All are true about Decerebrate posture except:-
- A. Exaggerated gamma motor neuron discharge
- B. Flexion of upper extremity and extension of lower extremity (Correct Answer)
- C. Extension of both upper and lower extremity
- D. Reticulo spinal tract is also involved
Explanation: ***Flexion of upper extremity and extension of lower extremity*** - This description corresponds to **decorticate rigidity**, not decerebrate rigidity. - In decorticate rigidity, there is **flexion** of the **upper extremities** and **extension** of the **lower extremities**, indicating a lesion above the red nucleus. *Exaggerated gamma motor neuron discharge* - Decerebrate rigidity is characterized by an **increase in muscle tone** due to disinhibition of extensor muscles, which is mediated by increased **gamma motor neuron activity**. - This increased discharge leads to potentiation of the **stretch reflex**, contributing to the rigidity. *Extension of both upper and lower extremity* - **Decerebrate posture** is defined by **extension of all four limbs** (both upper and lower extremities). - This posture results from a lesion in the brainstem **below the red nucleus** but above the vestibular nuclei, causing disinhibition of the pontine reticular formation and vestibular nuclei, which primarily excite extensor muscles. *Reticulo spinal tract is also involved* - The **reticulospinal tracts** (both pontine and medullary) play a crucial role in regulating muscle tone and posture. - In decerebrate rigidity, the **pontine reticulospinal tract** is overactive due to loss of cortical inhibition, leading to **increased extensor tone**.
Radiology
1 questionsA 75-year-old female has chronic backache. X-ray of the spine is shown. What is the most likely diagnosis?
NEET-PG 2019 - Radiology NEET-PG Practice Questions and MCQs
Question 171: A 75-year-old female has chronic backache. X-ray of the spine is shown. What is the most likely diagnosis?
- A. Osteoporosis (Correct Answer)
- B. Spondylodiscitis
- C. Pott's spine
- D. Spondylolisthesis
Explanation: ***Osteoporosis*** - The X-ray shows diffuse **osteopenia** (reduced bone density) and **vertebral compression fractures**, particularly visible in the lateral view, which are characteristic findings in elderly patients with osteoporosis and chronic backache. - The vertebral bodies appear **demineralized** and some exhibit a loss of height, suggesting collapse due to weakened bone structure. *Spondylodiscitis* - This condition involves **inflammation of the vertebral body and adjacent intervertebral disc**, typically showing **erosions** of the vertebral endplates and **narrowing of the disc space** on X-ray, which are not clearly evident here as the primary issue. - While it can cause back pain, the dominant finding on this X-ray is widespread bone density loss and fractures, rather than localized infection-related changes. *Pott's spine* - Pott's spine (**tuberculous spondylitis**) is a form of osteomyelitis that causes **destruction of vertebral bodies** and adjacent discs, often leading to a **gibbus deformity** (sharp posterior angulation of the spine). - The X-ray does not show extensive vertebral destruction, paraspinal abscess formation, or typical kyphotic deformity associated with Pott's spine. *Spondylolisthesis* - Spondylolisthesis is characterized by the **forward slippage of one vertebral body over another**, often due to a defect in the pars interarticularis. - While there may be some degenerative changes, there is no clear evidence of significant anterior translation of a vertebral body on the lateral X-ray that would indicate spondylolisthesis.