NEET-PG 2013 Practice Questions

Q: Downward and outward movement of eye is affected in injury of?

3rd nerve. The 3rd cranial nerve (oculomotor nerve) controls most extraocular muscles including the superior rectus, inferior rectus, medial rectus, and inferior oblique, as well as the levator palpebrae superioris. Injury to the 3rd nerve results in paralysis of these muscles, leaving only the lateral rectus (6th nerve) and superior oblique (4th nerve) functioning. This causes the classic "down and out" position of the eye at rest due to the unopposed action of these two muscles [1]. The eye is pulled downward by the superior oblique and outward by the lateral rectus [1]. Additional features include ptosis (drooping eyelid), dilated pupil, and diplopia (double vision) [1][2]. The patient loses the ability to move the eye upward, downward (via inferior rectus), and medially. Incorrect Option: 4th nerve - The 4th cranial nerve (trochlear nerve) innervates the superior oblique muscle. The superior oblique primarily causes depression (downward), intorsion, and abduction of the eye [1]. However, its action is most effective for downward and INWARD movement when the eye is adducted. - 4th nerve palsy results in vertical diplopia (especially when looking down and inward, like reading or descending stairs), hypertropia (upward deviation), and head tilt to the opposite side. This does NOT produce a "down and out" position. Incorrect Option: 5th nerve - The 5th cranial nerve (trigeminal nerve) provides sensory innervation to the face and motor innervation to the muscles of mastication. It has no role in eye movements. Incorrect Option: 6th nerve - The 6th cranial nerve (abducens nerve) innervates the lateral rectus muscle, responsible for abduction (outward movement) of the eye [1]. 6th nerve palsy causes inability to abduct the eye, resulting in esotropia (inward deviation) and horizontal diplopia.

Q: Which of the following does not contribute to the formation of the nasal septum?

Nasal bone. ***Nasal bone*** - The **nasal bones** form the bridge of the nose and are part of the external nasal skeleton, not the internal nasal septum. - They articulate with the frontal bone superiorly and the maxilla laterally, forming the **roof of the nasal cavity** anteriorly. *Septal cartilage* - The **septal cartilage**, or quadrangular cartilage, forms the anterior and inferior parts of the cartilaginous nasal septum. - It provides flexibility and support to the anterior nasal cavity. *Vomer* - The **vomer** is a thin, plowshare-shaped bone that forms the posteroinferior part of the bony nasal septum. - It articulates with the sphenoid, ethmoid, palatine, and maxillary bones. *Ethmoid* - The **perpendicular plate of the ethmoid bone** forms the superior part of the bony nasal septum. - It extends downward from the cribriform plate to meet the vomer and septal cartilage.

Q: What is the volume of blood loss associated with Class III hemorrhagic shock?

1500 - 2000 ml. ***1500 - 2000 ml*** - **Class III hemorrhagic shock** is characterized by a significant loss of blood volume, typically ranging from **30-40%** of total blood volume. - For an average adult, this translates to an estimated **1500-2000 ml** of blood loss, leading to marked physiological compromise. *750 - 1500 ml* - This range of blood loss corresponds to **Class II hemorrhagic shock**, where physiological changes are moderate, but compensatory mechanisms are still largely effective. - Patients in Class II shock typically present with **tachycardia** and a slight decrease in pulse pressure but generally normal blood pressure. *> 2000 ml* - A blood loss exceeding **2000 ml** (or >40% of total blood volume) is indicative of **Class IV hemorrhagic shock**, the most severe category. - This level of blood loss results in pronounced **hypotension**, severe tachycardia, and often requires immediate massive transfusion to prevent irreversible organ damage. *< 750 ml* - This range represents **Class I hemorrhagic shock**, which involves a minimal blood loss of up to 15% of total blood volume. - Patients in Class I shock typically show **minimal to no clinical signs of shock**, as compensatory mechanisms are highly effective in maintaining vital signs.

Q: A 25 year old female presents with generalized restriction of eye movement in all direction, intermittent ptosis, proximal muscle weakness and fatigability.Which is the MOST useful test in making the diagnosis?

Edrophonium test. ***Edrophonium test*** - The **Edrophonium test** (Tensilon test) is the **most useful** bedside diagnostic test for **myasthenia gravis**, providing immediate pharmacological confirmation within minutes. - In this patient with **generalized eye movement restriction**, **intermittent ptosis**, and **fatigable proximal weakness**, edrophonium administration will cause temporary but dramatic improvement by inhibiting **acetylcholinesterase** and increasing **acetylcholine** availability at the neuromuscular junction. *CPK* - **Creatine phosphokinase (CPK)** levels remain **normal** in myasthenia gravis as it's a **neuromuscular junction disorder**, not a primary muscle disease. - Elevated CPK indicates **muscle damage** seen in conditions like **myositis** or **muscular dystrophies**, which don't present with fatigable weakness. *EMG* - **Single-fiber EMG (SFEMG)** is the **most sensitive** electrophysiological test (95-99% sensitivity) for myasthenia gravis, showing increased **jitter** and **blocking**. - However, it's **less useful** than edrophonium for initial diagnosis as it requires specialized equipment, expertise, and doesn't provide immediate bedside confirmation like the pharmacological test. *Muscle biopsy* - **Muscle biopsy** shows **normal histology** in myasthenia gravis since the muscle fibers themselves are structurally intact. - This invasive procedure is reserved for primary **muscle disorders** like **inflammatory myopathies** or **dystrophies** that show characteristic pathological changes.

Q: In total parenteral nutrition, which of the following parameters is not routinely measured daily?

Liver function tests (LFTs). ***Liver function tests (LFTs)*** - **LFTs** are typically monitored periodically (e.g., weekly or bi-weekly) in patients on TPN, not daily, unless there are specific concerns about liver dysfunction [1]. - Daily monitoring is generally not required because changes in liver function due to TPN are usually insidious and not acutely life-threatening in hours. *Electrolyte* - **Electrolytes** (e.g., sodium, potassium, chloride) are crucial for cellular function and fluid balance [2]. They can fluctuate rapidly with TPN administration and patient's clinical status. - Daily measurement ensures prompt correction of imbalances to prevent serious complications like **cardiac arrhythmias** or neurological disturbances [2]. *Fluid intake and output* - **Fluid intake and output** are essential for assessing **hydration status** and preventing fluid overload or dehydration, which can change rapidly [2]. - Daily monitoring helps guide adjustments to fluid administration in TPN and other intravenous fluids. *Magnesium* - **Magnesium** is an important electrolyte involved in numerous enzymatic reactions and neuromuscular function, and its levels can be significantly affected by TPN [2]. - Daily or frequent monitoring is often necessary, especially in the initial phases of TPN or in patients with pre-existing deficiencies, to prevent complications such as **cardiac arrhythmias** or **weakness** [2].

Q: What is the condition characterized by a relative afferent pupillary defect?

Marcus Gunn pupil. ***Marcus Gunn pupil, a defect in the afferent pathway of the eye*** - A **Marcus Gunn pupil**, also known as a **relative afferent pupillary defect (RAPD)**, occurs due to a lesion or dysfunction in the **afferent (sensory) pathway** of one eye. - This results in an asymmetric response to light, where the pupil of the affected eye appears to dilate paradoxically when light is swung from the unaffected to the affected eye during the **swinging flashlight test**. *Efferent pathway defect* - An **efferent pathway defect** (e.g., in the oculomotor nerve, CN III) would cause a **fixed, dilated pupil** with impaired direct and consensual light reflexes, rather than an RAPD. - Such a defect would typically affect the motor response of the pupil, causing it to be unable to constrict. *Cerebral lesion* - While certain cerebral lesions can affect pupillary responses, a **relative afferent pupillary defect** specifically points to an issue in the direct sensory input from the retina to the brainstem. - Large **cerebral lesions** are more likely to cause other neurological signs or abnormalities in the motor control of the eye. *Total afferent pupillary defect* - A **total afferent pupillary defect**, often seen in **amaurotic pupil** (blind eye without light perception), would result in no direct or consensual light response in the affected eye. - In a RAPD, there is still some, albeit reduced, response to light, making it a **relative** defect rather than a total absence of afferent signaling.

Q: Schwalbe's ring is seen in which layer of the cornea?

Descemet's membrane. ***Descemet's membrane*** - Schwalbe's ring is a circular opacity representing the termination of **Descemet's membrane** at the periphery of the cornea, just anterior to the **trabecular meshwork**. - Its presence is a normal anatomical variant, but prominence can be associated with certain conditions like **posterior embryotoxon**. *Bowman's membrane* - This layer is found immediately beneath the **corneal epithelium** and does not extend to form Schwalbe's ring. - It is an acellular layer composed of collagen fibrils randomly arranged, offering resistance to infection and injury. *Stroma* - The stroma is the thickest layer of the cornea, composed primarily of **collagen lamellae** arranged in a highly organized manner. - It lies posterior to Bowman's membrane and anterior to Descemet's membrane, but its termination does not form Schwalbe's ring. *Substantia propria* - This is another name for the **corneal stroma**, which, as elaborated above, does not form Schwalbe's ring. - It comprises about 90% of the corneal thickness and provides the cornea's structural integrity and transparency.

Q: Which of the following is NOT a characteristic of caput succedaneum?

It does not disappear within 2-3 days. ***It does not disappear within 2-3 days*** - Caput succedaneum is a benign condition that typically resolves within **2 to 3 days** after birth as the edema is reabsorbed. - Therefore, a characteristic of caput succedaneum is that it *does* disappear relatively quickly, making the statement that it "does not disappear within 2-3 days" incorrect. *Crosses midline* - Caput succedaneum is a **diffuse swelling** that extends across the scalp and is **not limited by anatomical boundaries** like the midline of the skull. - This characteristic helps differentiate it from a **cephalohematoma**, which is typically confined to one side of the head. *Crosses the suture line* - The edema of caput succedaneum is in the **soft tissues superficial to the periosteum**, allowing it to **cross the suture lines** of the skull. - This is a key differentiating feature from a **cephalohematoma**, which is a subperiosteal hemorrhage and therefore confined by suture lines. *It is a diffuse edematous swelling of the soft tissues of the scalp* - This statement accurately describes caput succedaneum as a **collection of serosanguineous fluid** and **edema** in the most superficial layers of the scalp. - It results from pressure on the fetal scalp during labor, leading to **venous congestion** and extravasation of fluid.

Q: What is the treatment of choice for medullary carcinoma of the thyroid?

Total thyroidectomy. ***Total thyroidectomy*** - This is the **treatment of choice for medullary thyroid carcinoma (MTC)** due to its multifocal nature and high propensity for lymph node metastasis - **Complete surgical resection** (often with central compartment neck dissection) provides the best chance for cure by removing all thyroid tissue and involved lymph nodes - MTC arises from **parafollicular C cells** (calcitonin-producing cells) and frequently involves both lobes, making total thyroidectomy essential *Partial thyroidectomy* - This procedure removes only a portion of the thyroid gland, which is **insufficient for MTC** given its tendency for multifocality and bilateral involvement - Leaves residual thyroid tissue that could harbor undetected disease or develop future recurrences - Does not adequately address the aggressive nature of MTC *I-131 ablation* - **Radioactive iodine therapy** is effective for differentiated thyroid cancers (papillary and follicular) that take up iodine - MTC originates from **parafollicular C cells that do not concentrate iodine**, making I-131 ablation completely ineffective - This is a key distinguishing feature of MTC from other thyroid malignancies *Hemithyroidectomy* - This procedure removes only one thyroid lobe, which is **inadequate for MTC** - Risks leaving behind primary tumor in the contralateral lobe or occult bilateral disease - Fails to address the multifocal nature of MTC, particularly in hereditary cases (MEN 2A, MEN 2B, familial MTC)

Question 1

Downward and outward movement of eye is affected in injury of?

Accepted Answer

3rd nerve

Answer

4th nerve

Answer

5th nerve

Answer

6th nerve

Question 2

Which of the following does not contribute to the formation of the nasal septum?

Accepted Answer

Nasal bone

Answer

Vomer

Answer

Ethmoid

Answer

Septal cartilage

Question 3

Which of the following statements about laryngeal tuberculosis (TB) is true?

Accepted Answer

It presents with a mouse-nibbled appearance of the vocal cord.

Answer

It commonly involves the posterior 1/3 of the vocal cord.

Answer

It is more common in females.

Answer

It is a common form of tuberculosis.

Question 4

What is the volume of blood loss associated with Class III hemorrhagic shock?

Accepted Answer

1500 - 2000 ml

Answer

750 - 1500 ml

Answer

> 2000 ml

Answer

< 750 ml

Question 5

A 25 year old female presents with generalized restriction of eye movement in all direction, intermittent ptosis, proximal muscle weakness and fatigability.Which is the MOST useful test in making the diagnosis?

Accepted Answer

Edrophonium test

Answer

CPK

Answer

EMG

Answer

Muscle biopsy

Question 6

In total parenteral nutrition, which of the following parameters is not routinely measured daily?

Accepted Answer

Liver function tests (LFTs)

Answer

Electrolyte

Answer

Fluid intake and output

Answer

Magnesium

Question 7

What is the condition characterized by a relative afferent pupillary defect?

Accepted Answer

Marcus Gunn pupil

Answer

Efferent pathway defect

Answer

Cerebral lesion

Answer

Total afferent pupillary defect

Question 8

Schwalbe's ring is seen in which layer of the cornea?

Accepted Answer

Descemet's membrane

Answer

Bowman's membrane

Answer

Stroma

Answer

Substantia propria

Question 9

Which of the following is NOT a characteristic of caput succedaneum?

Accepted Answer

It does not disappear within 2-3 days

Answer

Crosses the suture line

Answer

Crosses midline

Answer

It is a diffuse edematous swelling of the soft tissues of the scalp

Question 10

What is the treatment of choice for medullary carcinoma of the thyroid?

Accepted Answer

Total thyroidectomy

Answer

I-131 ablation

Answer

Partial thyroidectomy

Answer

Hemithyroidectomy

NEET-PG 2013

Anatomy

ENT

Internal Medicine

Ophthalmology

Pediatrics

Surgery