Anatomy
1 questionsUpper Lid Retractors include
NEET-PG 2013 - Anatomy NEET-PG Practice Questions and MCQs
Question 991: Upper Lid Retractors include
- A. Muller muscle and superior rectus
- B. Levator palpebrae superioris and superior oblique
- C. Superior oblique and superior rectus
- D. Levator palpebrae superioris & Muller muscle (Correct Answer)
Explanation: ***Levator palpebrae superioris & Muller muscle*** - The **levator palpebrae superioris (LPS)** is the primary muscle responsible for lifting the upper eyelid. It is a striated muscle innervated by the oculomotor nerve (CN III). - **Müller's muscle** (also known as the superior tarsal muscle) is a smooth muscle that provides an additional, sustained lift to the upper eyelid. It is sympathetically innervated. *Muller muscle and superior rectus* - While **Müller's muscle** is an upper lid retractor, the **superior rectus** muscle primarily acts to elevate and adduct the eyeball, not the eyelid itself [1]. - The superior rectus muscle has only a minor, indirect role in upper eyelid elevation through its connection with the LPS aponeurosis. *Levator palpabrae superioris and superior oblique* - The **levator palpebrae superioris (LPS)** is a key upper lid retractor. - However, the **superior oblique** muscle is involved in depressing and intorting the eyeball [1], and has no direct role in upper eyelid retraction. *Superior oblique and superior rectus* - Neither the **superior oblique** nor the **superior rectus** muscles are primary upper lid retractors. - The superior oblique depresses and intorts the eye, while the superior rectus elevates and adducts the eye [1]. Both are extrinsic ocular muscles.
Internal Medicine
2 questionsDown-beat nystagmus is seen in lesion of ?
Down beat nystagmus is seen in?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 991: Down-beat nystagmus is seen in lesion of ?
- A. Cerebellum (Correct Answer)
- B. Basal ganglia
- C. Hippocampus
- D. Brainstem
Explanation: ***Cerebellum*** * **Down-beat nystagmus (DBN)** is most commonly associated with lesions in the **craniocervical junction** and **posterior fossa**, particularly affecting the **flocculonodular lobe** of the cerebellum. * The cerebellum plays a crucial role in maintaining **gaze stability** and coordinating eye movements; damage to specific cerebellar pathways can disrupt the vestibulo-ocular reflex, leading to DBN [1]. *Brainstem* * While the **brainstem** contains critical circuits for eye movements, lesions here typically result in other forms of nystagmus, such as **up-beat nystagmus** or **gaze-evoked nystagmus**, depending on the specific structures involved [1]. * Damage to brainstem nuclei or pathways controlling vertical gaze is usually indicated by different patterns of oculomotor dysfunction. *Basal ganglia* * Lesions in the **basal ganglia** are primarily associated with **movement disorders** like Parkinson's disease or Huntington's disease. * They do not typically cause primary nystagmus; any ocular abnormalities would generally be secondary to global motor control issues rather than direct involvement in oculomotor pathways. *Hippocampus* * The **hippocampus** is a key structure involved in **memory formation** and spatial navigation. * Lesions in the hippocampus cause **amnesia** and navigational deficits, but they are not directly involved in eye movement control or the generation of nystagmus.
Question 992: Down beat nystagmus is seen in?
- A. Brain stem lesions
- B. Pontine hemorrhage and other conditions
- C. Labyrinthine damage and other conditions
- D. Arnold Chiari malformation and other conditions (Correct Answer)
Explanation: ***Arnold Chiari malformation and other conditions*** - Downbeat nystagmus is a characteristic finding in Arnold-Chiari malformations, especially **Chiari type 1**, due to compression of cerebellar structures. - Other conditions associated with downbeat nystagmus include **medullary lesions**, **magnesium deficiency**, and **lithium toxicity** [1]. *Brain stem lesions* - While brainstem lesions can cause various nystagmus types, **pure downbeat nystagmus** is less commonly the primary or most specific finding compared to cerebellar involvement [1]. - **Upbeat nystagmus** and other complex nystagmus patterns are more often associated with brainstem lesions like those in the tegmentum. *Pontine hemorrhage and other conditions* - Pontine hemorrhages are more commonly associated with **ocular bobbing**, **blink reflex abnormalities**, or **horizontal gaze palsies**, rather than downbeat nystagmus. - A pontine hemorrhage would typically present with more severe neurological deficits such as **coma** or **quadriparesis**, which are not directly associated with isolated nystagmus. *Labyrinthine damage and other conditions* - **Peripheral vestibular abnormalities** from labyrinthine damage typically cause **horizontal or torsional nystagmus**, often suppressed by visual fixation. - Downbeat nystagmus is a **central vestibular sign**, indicating a problem with central vestibular processing rather than the peripheral labyrinth [1].
Ophthalmology
6 questionsForced duction test is to find out?
In which condition is a positive forced duction test observed?
The earliest change noticed in hypertensive retinopathy is:
Hordeolum internum is?
In congenital dacryocystitis, the blockage occurs at?
Dacryocystorhinostomy involves?
NEET-PG 2013 - Ophthalmology NEET-PG Practice Questions and MCQs
Question 991: Forced duction test is to find out?
- A. Ocular muscle palsy
- B. Ocular muscle spasm
- C. Angle of deviation
- D. Mechanical restriction of eye movement (Correct Answer)
Explanation: ***Mechanical restriction of eye movement*** - The forced duction test is specifically designed to **detect mechanical restriction** that prevents free passive movement of the globe. - Performed under **topical anesthesia**, the examiner grasps the eye at the limbus with forceps and attempts to passively rotate it in the direction of limited motility. - A **positive test** (resistance to passive movement) indicates mechanical restriction from causes like **thyroid-associated orbitopathy, orbital floor fracture, entrapment, or fibrosis**. - This is the **primary clinical indication** for performing the test - to differentiate restrictive from paretic causes of strabismus. *Ocular muscle palsy* - In muscle palsy (paretic strabismus), the forced duction test is **negative** - the eye moves freely with passive movement. - The test helps **differentiate paretic from restrictive causes** of limited motility, but the test itself detects restriction, not palsy. - Free passive movement confirms that the limitation is due to muscle weakness rather than mechanical factors. *Ocular muscle spasm* - Active muscle spasm would not be detected by this test because it is performed **under topical or general anesthesia**, which eliminates active muscle contraction. - The test assesses **passive mechanical restriction**, not active muscle activity or spasm. - Spasm would be a neurogenic rather than mechanical cause and would show free passive movement on testing. *Angle of deviation* - The forced duction test does not measure the **degree or angle of deviation** in strabismus. - Tests like the **prism cover test** or **Hirschberg test** are used to quantify deviation. - The forced duction test provides qualitative information about the cause of limitation, not quantitative measurement of misalignment.
Question 992: In which condition is a positive forced duction test observed?
- A. Mechanical restriction of ocular movement (Correct Answer)
- B. Non-concomitant strabismus
- C. No condition
- D. Extraocular muscle paralysis
Explanation: ***Mechanical restriction of ocular movement*** - A **positive forced duction test** indicates a physical impediment to eye movement, meaning the eye cannot be passively moved beyond a certain point. - This test is crucial for differentiating between **muscle restriction** (e.g., thyroid eye disease, orbital floor fracture with muscle entrapment, post-surgical adhesions) and muscle weakness or paralysis. - When the examiner attempts to passively rotate the globe, there is **resistance** indicating mechanical tethering or restriction of the extraocular muscles. *Non-concomitant strabismus* - This refers to a squint where the magnitude of deviation varies with the direction of gaze. - While it can be caused by muscle restriction, non-concomitant strabismus itself is a **type of ocular misalignment**, not the specific finding of a forced duction test. - The forced duction test helps determine the **cause** of non-concomitant strabismus (mechanical vs. paralytic). *No condition* - This option is incorrect because a positive forced duction test specifically indicates mechanical obstruction or restriction in eye movement. - A positive result always points to an underlying pathological condition affecting ocular motility, not a normal finding. *Extraocular muscle paralysis* - In cases of **muscle paralysis**, the eye cannot move actively in the direction of the paralyzed muscle's action. - However, the **forced duction test would be negative** as the globe can be passively moved in all directions because there is no mechanical restriction. - This differentiates paralytic strabismus (negative test) from restrictive strabismus (positive test).
Question 993: The earliest change noticed in hypertensive retinopathy is:
- A. Soft exudate
- B. Arteriolar spasm (Correct Answer)
- C. Venospasm
- D. Hard exudate
Explanation: ***Arteriolar spasm*** - **Arteriolar spasm** is the **earliest functional change** and is characterized by increased vascular tone in response to elevated blood pressure. - This spasm is a dynamic process and often leads to **narrowing of the retinal arterioles**, which can be observed during fundoscopic examination. *Soft exudate* - **Soft exudates**, also known as **cotton wool spots**, represent areas of **ischemic retinal nerve fiber layer** damage due to obstruction of precapillary arterioles. - These are typically seen in later stages of hypertensive retinopathy, indicating more significant vascular damage and ischemia. *Venospasm* - **Venospasm**, or narrowing of retinal veins, is **not a primary or early finding** in hypertensive retinopathy. - While venous changes like tortuosity can occur, arterial changes dominate the early pathogenesis. *Hard exudate* - **Hard exudates** are yellow-white deposits of **lipid and protein** that leak from damaged capillaries, often indicative of chronic retinal edema and incompetent blood-retinal barrier. - These usually appear in **more advanced stages** of hypertensive retinopathy and are not considered the earliest change.
Question 994: Hordeolum internum is?
- A. Chronic infection of Zeis gland
- B. Acute infection of Moll gland
- C. Acute infection of Zeis gland
- D. Acute infection of Meibomian gland (Correct Answer)
Explanation: ***Acute infection of Meibomian gland*** - A **hordeolum internum** is an acute, purulent infection of the **Meibomian glands**, which are sebaceous glands located within the tarsal plate of the eyelid. - The infection primarily manifests on the **inner surface of the eyelid** due to the gland's location, causing localized inflammation and pain. *Acute infection of Zeis gland* - An acute infection of a **Zeis gland** (a sebaceous gland connected to an eyelash follicle) is known as a **hordeolum externum**, or external stye. - Unlike a hordeolum internum, a **hordeolum externum** usually points externally at the lid margin. *Acute infection of Moll gland* - An acute infection of a **Moll gland** (apocrine sweat glands located near the lid margin) is also a type of **hordeolum externum**. - While it's an acute infection of an eyelid gland, it is not specifically referred to as a **hordeolum internum**. *Chronic infection of Zeis gland* - A chronic infection of a **Zeis gland** is not a typical designation for eyelid lesions; chronic inflammatory processes of sebaceous glands often lead to conditions like a **chalazion**, though chalazia are more commonly associated with Meibomian glands. - This option incorrectly identifies the gland for a hordeolum internum and specifies **chronic infection**, whereas a hordeolum is inherently **acute**.
Question 995: In congenital dacryocystitis, the blockage occurs at?
- A. Nasolacrimal duct (Correct Answer)
- B. Punctum
- C. Lacrimal canaliculi
- D. Lacrimal sac
Explanation: ***Nasolacrimal duct*** - **Congenital dacryocystitis** is primarily caused by an obstruction in the **nasolacrimal duct**, specifically at the **valve of Hasner** at its distal end near the inferior meatus. - This blockage prevents the proper drainage of tears into the nasal cavity, leading to tear overflow (epiphora), mucoid discharge, and potential secondary infection. - Present in approximately **5-6% of newborns**, with most cases resolving spontaneously by 12 months of age. *Punctum* - Congenital **punctal agenesis** is rare and not the typical site of obstruction in congenital dacryocystitis. - The puncta are usually patent in this condition. *Lacrimal canaliculi* - Obstruction of the **lacrimal canaliculi** is uncommon in congenital cases. - Canalicular obstruction is more often acquired (trauma, infection, medications). *Lacrimal sac* - The **lacrimal sac** itself is not the site of primary obstruction in congenital dacryocystitis. - The sac may become distended due to downstream obstruction at the nasolacrimal duct.
Question 996: Dacryocystorhinostomy involves?
- A. Opening the terminal blocked end of the nasolacrimal duct
- B. Complete excision of the lacrimal sac
- C. Insertion of a drainage tube in the lacrimal sac
- D. Connecting the lacrimal sac to the nose by opening the medial wall (Correct Answer)
Explanation: ***Connecting the lacrimal sac to the nose by opening the medial wall*** - A **dacryocystorhinostomy (DCR)** is a surgical procedure to create a new drainage pathway between the **lacrimal sac** and the **nasal cavity**. - This bypasses an obstruction in the **nasolacrimal duct**, allowing tears to drain properly into the nose. *Opening the terminal blocked end of the nasolacrimal duct* - This describes a **dacryocystoplasty** or an attempt to probe the existing duct, which is a less invasive procedure than a DCR and often insufficient for complete obstruction. - While it aims to restore tear flow, it specifically addresses the terminal end rather than creating a new anastomosis. *Complete excision of the lacrimal sac* - This procedure is known as a **dacryocystectomy**, which is typically performed for tumors or chronic infections of the lacrimal sac that cannot be resolved otherwise. - It results in permanent dry eye and does not aim to restore tear drainage but rather to remove the problematic sac. *Insertion of a drainage tube in the lacrimal sac* - This describes **intubation** of the lacrimal drainage system, often using silicone tubes, which is usually a temporary measure to keep the duct patent after a procedure or for partial obstructions. - It is not the definitive surgical creation of a new permanent pathway, as achieved with a DCR.
Surgery
1 questionsAt which anatomical location is the opening created in dacryocystorhinostomy?
NEET-PG 2013 - Surgery NEET-PG Practice Questions and MCQs
Question 991: At which anatomical location is the opening created in dacryocystorhinostomy?
- A. Middle meatus (Correct Answer)
- B. Superior meatus
- C. Sphenoethmoidal recess
- D. Inferior meatus
Explanation: ***Middle meatus*** - In **dacryocystorhinostomy (DCR)**, the anastomosis is created between the **lacrimal sac** and the nasal cavity at the level of the **middle meatus**. - The lacrimal sac is located **lateral to the middle turbinate**, making this the anatomically appropriate site for creating the surgical opening. - This placement allows direct drainage of tears from the lacrimal sac into the nasal cavity, **bypassing the obstructed nasolacrimal duct**. - The **middle meatus** provides optimal access and physiological tear drainage. *Inferior meatus* - The **nasolacrimal duct** naturally drains into the **inferior meatus** under normal anatomy. - However, DCR is performed to **bypass** an obstructed nasolacrimal duct, so the anastomosis is created more **superiorly** at the lacrimal sac level. - The inferior meatus is **below** the level of the lacrimal sac and would not provide direct access to it. *Superior meatus* - The **superior meatus** is located above the superior turbinate and receives drainage from the **posterior ethmoidal sinuses**. - This location is **too superior** for DCR and does not correspond to the anatomical position of the lacrimal sac. *Sphenoethmoidal recess* - The **sphenoethmoidal recess** is the most superior and posterior area, receiving drainage from the **sphenoid sinus**. - This location is far too **superior and posterior** to be used for lacrimal drainage surgery.