Anatomy
1 questionsWallenberg syndrome involves which artery?
NEET-PG 2018 - Anatomy NEET-PG Practice Questions and MCQs
Question 191: Wallenberg syndrome involves which artery?
- A. Subclavian artery
- B. Posterior cerebral artery
- C. Posterior inferior cerebellar artery (Correct Answer)
- D. Anterior inferior cerebellar artery
Explanation: ***Posterior inferior cerebellar artery*** - **Wallenberg syndrome**, also known as **lateral medullary syndrome**, is most commonly caused by an infarction in the territory supplied by the **posterior inferior cerebellar artery (PICA)**. - The PICA supplies the **lateral medulla**, which contains several crucial nuclei and tracts, including the nucleus ambiguus, trigeminal nucleus, vestibular nuclei, and spinothalamic tract, leading to the characteristic clinical presentation of Wallenberg syndrome. *Subclavian artery* - The **subclavian artery** is a large artery in the upper thorax that supplies blood to the upper limbs, head, and neck. - While it can be involved in conditions like **subclavian steal syndrome**, it does not directly supply the lateral medulla responsible for Wallenberg syndrome. *Posterior cerebral artery* - The **posterior cerebral artery** primarily supplies the occipital lobe, temporal lobe, and parts of the thalamus and midbrain. - Infarction in the PCA territory typically leads to symptoms like **hemianopia**, visual field defects, and memory deficits, not the constellation of symptoms seen in Wallenberg syndrome. *Anterior inferior cerebellar artery* - The **anterior inferior cerebellar artery (AICA)** supplies the anterior and lateral parts of the cerebellum and the pontomedullary junction, leading to **lateral pontine syndrome** when infarcted. - Symptoms of AICA infarction include ipsilateral facial paralysis, hearing loss, and cerebellar ataxia, which are distinct from Wallenberg syndrome.
Biochemistry
2 questionsThe enzyme deficient in Galactosemia is:-
Serotonin is also known as?
NEET-PG 2018 - Biochemistry NEET-PG Practice Questions and MCQs
Question 191: The enzyme deficient in Galactosemia is:-
- A. Galactose-1-phosphate uridyltransferase (GALT) (Correct Answer)
- B. Sphingomyelinase
- C. Glucocerebrosidase
- D. Hexosaminidase
Explanation: ***Galactose-1-phosphate uridyltransferase (GALT)*** - Deficiency of **GALT** leads to the accumulation of **galactose-1-phosphate** in tissues, which is toxic and causes the symptoms of **classical galactosemia**. - This enzyme is crucial for the second step in the Leloir pathway, converting **galactose-1-phosphate** and UDP-glucose into UDP-galactose and glucose-1-phosphate. *Sphingomyelinase (associated with Niemann-Pick disease)* - Deficiency in **sphingomyelinase** causes the accumulation of **sphingomyelin**, leading to **Niemann-Pick disease**, characterized by hepatosplenomegaly and neurological deterioration. - This enzyme is involved in the catabolism of lipids, distinct from carbohydrate metabolism. *Glucocerebrosidase (associated with Gaucher's disease)* - Deficiency of **glucocerebrosidase** results in the accumulation of **glucocerebroside**, leading to **Gaucher's disease**, which affects the spleen, liver, bone marrow, and sometimes the brain. - This is a lysosomal storage disorder involving glycosphingolipids, not galactose metabolism. *Hexosaminidase (associated with Tay-Sachs disease)* - Deficiency of **hexosaminidase A** causes the accumulation of **GM2 ganglioside**, resulting in **Tay-Sachs disease**, a severe neurodegenerative disorder. - This enzyme primarily functions in the breakdown of gangliosides, which are complex lipids, not galactose.
Question 192: Serotonin is also known as?
- A. 3-Methoxytyramine
- B. Phenethylamine
- C. N-methyl phenylamine
- D. 5-hydroxytryptamine (5-HT) (Correct Answer)
Explanation: ***5-hydroxytryptamine (5-HT)*** - **Serotonin** is the common name for the neurotransmitter **5-hydroxytryptamine (5-HT)**. - This chemical name reflects its structure, derived from tryptophan, indicating a **hydroxyl group** at the 5-position of the **indole ring** and an **ethylamine side chain**. *3-Methoxytyramine* - **3-Methoxytyramine** is a metabolite of **dopamine**, not serotonin. - It is formed by the action of **catechol-O-methyltransferase (COMT)** on dopamine. *Phenethylamine* - **Phenethylamine** is a naturally occurring trace amine that acts as a **neuromodulator** or neurotransmitter. - It is structurally similar to certain recreational drugs but is not serotonin. *N-methyl phenylamine* - **N-methyl phenylamine** or N-methylaniline is an **organic chemical** used in dyes and other industrial applications. - It is not a neurotransmitter and has no relation to serotonin.
Internal Medicine
2 questionsVMA is elevated in which of the following condition?
All of the following are true about ulcerative colitis except:
NEET-PG 2018 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 191: VMA is elevated in which of the following condition?
- A. Tuberous sclerosis
- B. Addison disease
- C. Pheochromocytoma (Correct Answer)
- D. Conn Syndrome
Explanation: Pheochromocytoma - Pheochromocytoma is a tumor of the adrenal medulla that secretes excessive amounts of catecholamines (epinephrine and norepinephrine). - Vanillylmandelic acid (VMA) is a breakdown product of these catecholamines [1], so its levels are elevated in the urine of patients with pheochromocytoma. Tuberous sclerosis - Tuberous sclerosis is a genetic disorder characterized by the growth of numerous non-cancerous tumors in various organs. - While it can be associated with renal angiomyolipomas or brain lesions, it does not directly cause elevated VMA levels. Addison disease - Addison disease is characterized by adrenal insufficiency [2], meaning the adrenal glands produce insufficient amounts of hormones like cortisol and aldosterone. - This condition is not associated with the overproduction of catecholamines or elevated VMA. Conn Syndrome - Conn syndrome (primary hyperaldosteronism) is due to an overproduction of aldosterone by the adrenal glands, often caused by an adrenal adenoma [3]. - Aldosterone is a mineralocorticoid, and its overproduction does not lead to increased catecholamine metabolism or elevated VMA levels.
Question 192: All of the following are true about ulcerative colitis except:
- A. Surgery is required in a subset of severe cases.
- B. Extra-intestinal problems of UC are managed medically
- C. The highest risk of UC requiring surgery in 1st year
- D. Steroid dependent cases need surgery (Correct Answer)
Explanation: ***Steroid dependent cases need surgery*** - While **steroid dependency** in ulcerative colitis (UC) indicates a need for alternative or escalate medications, it does not automatically necessitate surgery [1]. - Many steroid-dependent patients can be managed effectively with **immunomodulators** or **biologic therapies**, avoiding surgery. *Surgery is required in a subset of severe cases.* - **Severe ulcerative colitis** that is refractory to medical therapy, or complicated by toxic megacolon, perforation, or severe bleeding, often requires surgical intervention [1]. - This statement is true, as surgery can be curative for UC by removing the affected colon [1]. *Extra-intestinal problems of UC are managed medically* - **Extra-intestinal manifestations** of ulcerative colitis, such as arthritis, skin lesions (erythema nodosum), and eye inflammation (uveitis), are typically managed with medications specific to those conditions, often in conjunction with UC treatment [1], [2]. - This statement is true, as these manifestations rarely require surgical intervention themselves. *The highest risk of UC requiring surgery in 1st year* - The risk of surgery in ulcerative colitis is indeed highest in the **first year after diagnosis**, particularly for patients presenting with severe disease. - This initial period often determines the disease course and responsiveness to medical treatment.
Obstetrics and Gynecology
2 questionsShoulder dystocia is managed by all of the following except:-
In Peripartum cardiomyopathy, cardiac failure occurs at:-
NEET-PG 2018 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 191: Shoulder dystocia is managed by all of the following except:-
- A. Woods cork screw method
- B. Supra pubic pressure
- C. Fundal pressure by an able nurse (Correct Answer)
- D. Zavanelli maneuver
Explanation: ***Fundal pressure by an able nurse*** - **Fundal pressure** is contraindicated in shoulder dystocia because it can worsen the impaction of the anterior shoulder against the symphysis pubis and potentially lead to uterine rupture or fetal injury. - Applying pressure from above pushes the fetus further into the birth canal obstruction, increasing the risk of **fetal asphyxia** and **brachial plexus injury**. *Woods cork screw method* - This maneuver involves rotating the fetal shoulders by applying pressure to the posterior aspect of the **posterior shoulder**, which often helps to disimpact the anterior shoulder. - It is a recognized and effective technique used to resolve **shoulder dystocia**. *Supra pubic pressure* - **Suprapubic pressure** is applied externally over the maternal suprapubic bone to dislodge the anterior shoulder from behind the symphysis pubis. - This maneuver is often performed first after the initial attempts at fetal head traction and **McRoberts maneuver** to help release the impacted shoulder. *Zavanelli maneuver* - The **Zavanelli maneuver** involves pushing the fetal head back into the uterus and performing an immediate cesarean section. - It is considered a **last-resort maneuver** for severe shoulder dystocia when other techniques have failed, carrying significant risks but sometimes necessary to prevent fetal death.
Question 192: In Peripartum cardiomyopathy, cardiac failure occurs at:-
- A. Within 24 months after delivery.
- B. Within 5 months after delivery. (Correct Answer)
- C. Within 6 weeks after delivery.
- D. Within 7 days after delivery.
Explanation: ***Within 5 months after delivery.*** - Peripartum cardiomyopathy (PPCM) is defined as the development of **cardiac failure** in the **last month of pregnancy** or within **5 months after delivery**, in the absence of any other identifiable cause. - Among the given options, "within 5 months after delivery" represents the **postpartum component** of the diagnostic timeframe and is the most complete answer. - This time frame is a key diagnostic criterion recognized by major cardiology societies (some recent guidelines extend this to 6 months postpartum). - **Note:** The complete definition includes both antepartum (last month of pregnancy) and postpartum (up to 5 months) periods. *Within 24 months after delivery.* - This timeframe is **too broad** and does not align with the standard diagnostic criteria for PPCM. - While some women may experience ongoing cardiac dysfunction or relapse, the initial diagnosis of PPCM is restricted to within 5 months postpartum. - Extended cardiac issues beyond 5 months may represent persistent PPCM or dilated cardiomyopathy rather than new-onset PPCM. *Within 6 weeks after delivery.* - While many cases of PPCM manifest within **6 weeks postpartum** (the traditional puerperium), this definition is **too restrictive**. - Symptoms can appear up to **5 months after delivery**, and using only 6 weeks would miss a significant proportion of cases. - This period captures the most acute presentations but doesn't encompass the entire recognized diagnostic window. *Within 7 days after delivery.* - The onset within **7 days after delivery** represents only the **immediate postpartum period** and is an overly narrow definition. - PPCM can develop much later in the postpartum period (up to 5 months), making this timeframe inadequate for diagnosis. - Using this restrictive criterion would result in many missed diagnoses.
Pathology
1 questionsHyperacute rejection occurs within:-
NEET-PG 2018 - Pathology NEET-PG Practice Questions and MCQs
Question 191: Hyperacute rejection occurs within:-
- A. 12 hours
- B. 24 hours
- C. 6 hours
- D. Minutes to hours (Correct Answer)
Explanation: ***Minutes to hours*** - **Hyperacute rejection** is a rapidly occurring complication post-transplant, characterized by its onset within minutes to hours after **organ reperfusion** [1]. - This type of rejection is mediated by pre-formed **recipient antibodies** that recognize donor antigens, leading to immediate graft damage [1]. *12 hours* - While plausible, 12 hours is a bit too broad as **hyperacute rejection** primarily begins much sooner, typically within the first few hours [1]. - This timeframe might overlap with the initial stages of **acute cellular rejection**, which typically occurs days to weeks later [1]. *24 hours* - **Hyperacute rejection** is almost always observed and causes graft failure well before the 24-hour mark, if it is going to happen. - Rejection occurring within this extended period is more indicative of **accelerated acute rejection** rather than true hyperacute rejection. *6 hours* - While hyperacute rejection certainly can occur within 6 hours, "minutes to hours" better captures the immediate onset, often within seconds or minutes [1]. - Some cases of **hyperacute rejection** can be so rapid that the 6-hour mark would be considered a late presentation. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 241-242.
Surgery
2 questionsMost common site of chronic gastric ulcer:
Using a small fine probe, a single lactiferous duct is excised. What is the name of the procedure:
NEET-PG 2018 - Surgery NEET-PG Practice Questions and MCQs
Question 191: Most common site of chronic gastric ulcer:
- A. Lesser curve near proximal stomach
- B. Pylorus of stomach
- C. Greater curvature
- D. Lesser curve near incisura (Correct Answer)
Explanation: ***Lesser curve near incisura*** - The **lesser curve** of the stomach, particularly the **incisura angularis** or the angular notch, is the most common site for gastric ulcers. - This area is susceptible to ulceration due to its anatomical location, which experiences significant **acid exposure** and **motility stress**. *Lesser curve near proximal stomach* - While the lesser curve is a common site, ulcers tend to be more prevalent in the **distal part** of the lesser curve, near the incisura, rather than the proximal stomach (cardia or fundus). - Gastric ulcers in the proximal stomach are less frequent compared to the **antrum** and **incisura region**. *Pylorus of stomach* - The **pylorus** is more commonly associated with duodenal ulcers but can occasionally be a site for gastric ulcers. - However, it is not the most common location for **chronic gastric ulcers** when compared to the lesser curve near the incisura. *Greater curvature* - Ulcers on the **greater curvature** are relatively rare and often raise suspicion for **malignancy**, necessitating careful biopsy and investigation. - The greater curvature is less exposed to the erosive effects of gastric acid and pepsin compared to the lesser curve, making ulcers there less common.
Question 192: Using a small fine probe, a single lactiferous duct is excised. What is the name of the procedure:
- A. Microdochectomy (Correct Answer)
- B. Hadfield operation
- C. Webster operation
- D. Macrodochectomy
Explanation: ***Microdochectomy*** - This procedure involves the **excision of a single, lactiferous duct** often identified using a fine probe or ductoscope. - It is typically performed to investigate or treat **pathological nipple discharge** originating from a specific duct. *Hadfield operation* - This is a more extensive procedure known as a **total duct excision** or **subareolar duct excision**. - It involves the removal of **all major lactiferous ducts** under the nipple, not just a single one. *Webster operation* - The Webster operation refers to an **inferior pedicle reduction mammoplasty** technique. - It is a type of **breast reduction surgery** and is not related to the excision of an isolated lactiferous duct. *Macrodochectomy* - This term is **not a recognized medical procedure** in the context of duct excision. - While "macro" implies large, it does not describe a specific surgical technique for duct removal.