Anatomy
7 questionsWhich of the following is a tributary of the coronary sinus?
Which of the following is not a boundary of Koch's triangle?
Which is the primary segment of the liver drained by the right hepatic vein?
Where is the Bartholin gland situated?
What is the lower limit of the retropharyngeal space?
Maxillary bone does not articulate with:
The thyrocervical trunk is a branch of which part of subclavian artery?
NEET-PG 2012 - Anatomy NEET-PG Practice Questions and MCQs
Question 131: Which of the following is a tributary of the coronary sinus?
- A. Anterior cardiac vein
- B. Smallest cardiac vein
- C. Thebesian vein
- D. Great cardiac vein (Correct Answer)
Explanation: ***Great cardiac vein*** - The **great cardiac vein** is a major tributary that drains into the **coronary sinus**, carrying deoxygenated blood from the anterior and left ventricular walls [1]. - It travels alongside the **anterior interventricular artery** (LAD) and then wraps around the left side of the heart to join the coronary sinus [1]. *Anterior cardiac vein* - The **anterior cardiac veins** typically collect blood directly into the **right atrium**, bypassing the coronary sinus [1]. - They primarily drain the anterior wall of the right ventricle. *Thebesian vein* - **Thebesian veins** (or venae cordis minimae) are small veins that drain blood from the **myocardium directly into the heart chambers**, predominantly the atria [1]. - They represent a direct communication between the myocardial capillaries and the heart chambers, not tributaries of the coronary sinus. *Smallest cardiac vein* - The term "smallest cardiac vein" is often used synonymously with **Thebesian veins** [1]. - These veins empty directly into the **heart chambers**, serving as an ancillary drainage system, rather than converging into the coronary sinus.
Question 132: Which of the following is not a boundary of Koch's triangle?
- A. Limbus fossa ovalis (Correct Answer)
- B. Tricuspid valve ring
- C. Coronary sinus
- D. Tendon of Todaro
Explanation: ***Limbus fossa ovalis*** - The **limbus fossa ovalis** is a prominent oval ridge on the **interatrial septum** that surrounds the fossa ovalis. - It is **not involved** in forming the boundaries of Koch's triangle, which is located in the **right atrium** near the AV node [1]. *Tricuspid valve ring* - The **tricuspid valve ring** (or annulus) forms one of the key anatomical boundaries of **Koch's triangle**, specifically its base [1]. - This **fibrous ring** anchors the tricuspid valve leaflets and marks the inferior aspect of the triangle [1]. *Coronary sinus* - The **coronary sinus ostium** (opening) forms another crucial boundary of **Koch's triangle** [1]. - It is located at the **inferior-posterior aspect** of the interatrial septum, opening into the right atrium [1]. *Tendon of todaro* - The **Tendon of Todaro** is a fibrous structure that forms the superior boundary of **Koch's triangle** [1]. - It extends from the **Eustachian valve** (of the inferior vena cava) towards the central fibrous body, playing a role in **AV nodal localization** [1].
Question 133: Which is the primary segment of the liver drained by the right hepatic vein?
- A. I
- B. II
- C. IV
- D. VII (Correct Answer)
Explanation: ***VII*** - The **right hepatic vein** drains the **posterior segment** of the right lobe, which includes segments **VI and VII**. Segment VII is particularly well-drained by this vein. [3] - Understanding hepatic venous drainage is crucial for **surgical planning** and interpreting imaging studies of the liver. [4] *I* - Segment I, the **caudate lobe**, is unique in its venous drainage, often by small veins directly into the **inferior vena cava (IVC)** or occasionally into the left and middle hepatic veins. [1] - It has a separate blood supply and drainage which differentiates it from other segments. [4] *II* - Segment II is part of the **left lateral segment** and is primarily drained by the **left hepatic vein**. - The left hepatic vein typically drains segments II and III. [2] *IV* - Segment IV, or the **quadrate lobe**, is primarily drained by the **middle hepatic vein**. - The middle hepatic vein also drains segment VIII and the anterior aspect of segment V.
Question 134: Where is the Bartholin gland situated?
- A. Superficial perineal pouch (Correct Answer)
- B. Deep perineal pouch
- C. Inguinal canal
- D. Ischiorectal fossa
Explanation: ***Superficial perineal pouch*** - The **Bartholin glands** are located posterolateral to the vaginal orifice within the boundaries of the **superficial perineal pouch** [1]. - They are covered by the **bulbospongiosus muscle** and their ducts open into the vestibule of the vagina [1]. *Deep perineal pouch* - This pouch contains structures like the **urethra**, part of the **vagina**, and the **deep transverse perineal muscle**, but not the Bartholin glands [2]. - It is located superior to the superficial perineal pouch and separated by the **perineal membrane**. *Inguinal canal* - The **inguinal canal** is a passage in the anterior abdominal wall that transmits the **round ligament of the uterus** in females and the **spermatic cord** in males. - It is anatomically distinct from the perineum and does not house the Bartholin glands. *Ischiorectal fossa* - The **ischiorectal fossae** are fat-filled spaces located lateral to the anal canal, inferior to the levator ani muscles. - They are known for their susceptibility to abscess formation but do not contain the Bartholin glands.
Question 135: What is the lower limit of the retropharyngeal space?
- A. Bifurcation of trachea (Correct Answer)
- B. 4th esophageal constriction
- C. C7
- D. None of the options
Explanation: Bifurcation of trachea - The retropharyngeal space extends inferiorly to approximately the level of T4-T5 vertebrae, corresponding to the bifurcation of the trachea and the superior mediastinum. - This space lies between the buccopharyngeal fascia (posterior to pharynx) and the alar layer of prevertebral fascia. - Clinically, infections or abscesses in this space can descend into the posterior mediastinum, making knowledge of this inferior extent crucial for surgical management. - Note: Some anatomical texts describe the space ending at T1-T2, but for clinical and surgical purposes, the functional inferior limit extends to the bifurcation of the trachea. C7 - While some texts describe the retropharyngeal space as terminating around C7 (level of the lower border of cricoid cartilage), this represents the narrower definition. - The clinical and surgical definition extends the space further inferiorly to allow for tracking of infections into the chest. - C7 alone does not represent the accepted lower limit for examination purposes. 4th esophageal constriction - The fourth esophageal constriction is not a standard anatomical landmark (esophagus has 3-4 constrictions depending on classification). - Esophageal constrictions are luminal narrowings within the esophagus itself and do not define the boundaries of the retropharyngeal space, which is a fascial space posterior to both pharynx and esophagus. None of the options - This is incorrect because bifurcation of the trachea is the recognized lower limit of the retropharyngeal space for clinical and examination purposes. - Understanding this anatomical boundary is essential for predicting the spread of deep neck space infections.
Question 136: Maxillary bone does not articulate with:
- A. Frontal
- B. Lacrimal
- C. Sphenoid
- D. Ethmoid (Correct Answer)
Explanation: ***Ethmoid (Marked Correct - PYQ 2012)*** - This question reflects traditional teaching where the **maxilla-ethmoid articulation** was considered minimal or indirect. - In modern anatomy, the **maxilla DOES articulate with the ethmoid bone** via the uncinate process of the ethmoid and the medial wall of the maxillary sinus. - However, per the **NEET-PG 2012 answer key**, ethmoid was accepted as the correct answer, likely because this articulation is small and often not emphasized in basic anatomy teaching. - The maxilla has major articulations with: frontal, zygomatic, nasal, lacrimal, palatine, inferior nasal concha, vomer, and contralateral maxilla. *Sphenoid* - The **maxilla clearly articulates** with the **greater wing of the sphenoid bone** at the inferior orbital fissure. - This articulation is substantial and forms the posterolateral floor of the orbit. - The sphenoid-maxillary articulation contributes to the boundaries of the **pterygopalatine fossa**. *Frontal* - The **maxilla articulates extensively** with the **frontal bone** at the frontomaxillary suture. - This articulation forms the medial orbital rim and part of the anterior cranial floor interface. - This is one of the most prominent maxillary articulations. *Lacrimal* - The **maxilla articulates directly** with the **lacrimal bone**, forming the anterior part of the medial orbital wall. - Together they form the **lacrimal groove** which houses the lacrimal sac. - This articulation is essential for the nasolacrimal drainage pathway.
Question 137: The thyrocervical trunk is a branch of which part of subclavian artery?
- A. 1st part (Correct Answer)
- B. 2nd part
- C. 3rd part
- D. 4th part
Explanation: ***1st part*** - The **thyrocervical trunk** is one of the three primary branches arising from the **first part** of the subclavian artery. - The first part lies medial to the **anterior scalene muscle**. *2nd part* - The **second part** of the subclavian artery gives rise to the **costocervical trunk**. - This part lies posterior to the **anterior scalene muscle**. *3rd part* - The **third part** of the subclavian artery typically has no branches or may give off the **dorsal scapular artery**. - This part lies lateral to the **anterior scalene muscle**. *4th part* - This option is incorrect as the **subclavian artery has only three parts**, divided by their relationship to the anterior scalene muscle. - There is no anatomical fourth part of the subclavian artery.
Biochemistry
1 questionsIncreased uric acid levels are seen in which glycogen storage disease ?
NEET-PG 2012 - Biochemistry NEET-PG Practice Questions and MCQs
Question 131: Increased uric acid levels are seen in which glycogen storage disease ?
- A. Type I (Von Gierke's disease) (Correct Answer)
- B. Type II (Pompe disease)
- C. Type IV (Andersen disease)
- D. Type III (Cori disease)
Explanation: ***Type I (Von Gierke's disease)*** - In **Von Gierke's disease**, the deficiency of **glucose-6-phosphatase** leads to accumulation of glucose-6-phosphate in hepatocytes. - **Hyperuricemia** occurs due to: 1. **Increased purine degradation** - Metabolic stress leads to accelerated ATP breakdown and increased uric acid production 2. **Decreased renal excretion** - Lactic acidosis (from G6P → pyruvate → lactate) competitively inhibits uric acid secretion in renal tubules 3. **Enhanced purine synthesis** - Increased availability of ribose-5-phosphate from pentose phosphate pathway - Classic triad: **Hepatomegaly, hypoglycemia, and lactic acidosis with hyperuricemia** *Type II (Pompe disease)* - Caused by a deficiency of **acid alpha-glucosidase** (acid maltase), leading to glycogen accumulation in **lysosomes**. - Primarily affects the **heart**, **muscles**, and **liver**, but does not cause hyperuricemia. *Type IV (Andersen disease)* - Results from a deficiency of **glycogen branching enzyme**, leading to the formation of abnormal glycogen with long, unbranched chains. - Primarily affects the **liver** and **spleen**, causing cirrhosis and hepatic failure, but not hyperuricemia. *Type III (Cori disease)* - Caused by a deficiency of **glycogen debranching enzyme** (amylo-1,6-glucosidase), leading to abnormal accumulation of glycogen with short outer branches. - Presents with hepatomegaly, hypoglycemia, and muscle weakness, but **hyperuricemia is not a characteristic feature**.
Internal Medicine
1 questionsWhich of the following is the most characteristic symptom of obstruction of the inferior vena cava?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 131: Which of the following is the most characteristic symptom of obstruction of the inferior vena cava?
- A. Paraumblical dilatation (Correct Answer)
- B. Thoraco-epigastric dilatation
- C. Haemorrhoides
- D. Oesophageal varices
Explanation: ***Paraumbilical dilatation*** - Obstruction of the **inferior vena cava (IVC)** leads to collateral circulation through superficial veins, especially around the umbilicus, causing **paraumbilical dilatation** (caput medusae). - This collateral flow bypasses the obstructed IVC to return blood to the superior vena cava system. *Thoraco-epigastric dilatation* - This pattern of collateral circulation is more characteristic of **superior vena cava (SVC) obstruction**, where blood from the upper body needs to bypass the SVC. - The dilated veins would typically be seen on the chest and upper abdomen, draining towards the femoral veins. *Oesophageal varices* - **Oesophageal varices** are typically caused by **portal hypertension** [1], often secondary to liver cirrhosis, not directly by IVC obstruction. - They represent portosystemic collateral veins, diverging from the portal system to the systemic circulation [1]. *Haemorrhoids* - **Haemorrhoids** are dilated veins in the anal canal, most commonly caused by **straining** during defecation or conditions that increase intra-abdominal pressure [2]. - While they can be a sign of portal hypertension [1], **IVC obstruction** is not their primary or most characteristic cause.
Physiology
1 questionsNeurotransmitter involved in nigrostriatal pathway is?
NEET-PG 2012 - Physiology NEET-PG Practice Questions and MCQs
Question 131: Neurotransmitter involved in nigrostriatal pathway is?
- A. Acetylcholine
- B. Serotonin
- C. Dopamine (Correct Answer)
- D. Norepinephrine
Explanation: ***Dopamine*** - The **nigrostriatal pathway** is a major dopaminergic pathway in the brain, originating in the **substantia nigra pars compacta** and projecting to the striatum. - It is crucial for the control of voluntary movement, and its degeneration is a hallmark of **Parkinson's disease**. *Serotonin* - Serotonin (5-HT) is primarily involved in mood, sleep, appetite, and cognition, and is not the primary neurotransmitter of the **nigrostriatal pathway**. - Serotonergic pathways originate in the **raphe nuclei** and project widely throughout the brain. *Acetylcholine* - Acetylcholine is a key neurotransmitter in the periphery (neuromuscular junction, autonomic nervous system) and in the central nervous system, involved in learning and memory. - Cholinergic neurons in the **basal forebrain** project to the cortex and hippocampus, but acetylcholine is not the neurotransmitter of the **nigrostriatal pathway**. *Norepinephrine* - Norepinephrine (noradrenaline) is involved in arousal, attention, and the fight-or-flight response, with pathways originating in the **locus coeruleus**. - While it plays a role in modulating motor circuits, it is not the main neurotransmitter of the **nigrostriatal pathway**.