NEET-PG 2015 Practice Questions

Q: Traumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?

Optic canal. ***Optic canal*** - The **optic nerve** is highly susceptible to injury within the **optic canal** due to its tight anatomical confines and the close proximity of the optic nerve to rigid bone. - Trauma to this region can lead to direct compression, shearing injury, or ischemia from damage to surrounding vasculature, resulting in significant visual impairment. *Intra ocular part* - The intraocular part of the optic nerve, including the **optic disc**, is typically protected by the globe and orbit against blunt trauma. - Direct intraocular trauma, such as a penetrating injury, would be required to significantly affect this segment, which is not usually the cause in closed head trauma. *Intracranial part* - The intracranial part of the optic nerve is relatively mobile within the cerebrospinal fluid and is less prone to direct compression or shearing forces from closed head trauma compared to the optic canal. - While it can be affected by diffuse axonal injury or mass effects within the cranium, it is not the most commonly affected segment for traumatic optic neuropathy in closed head injuries. *Optic tract* - The **optic tract** lies posterior to the optic chiasm and is part of the central nervous system pathways for vision, not the optic nerve itself. - Injuries to the optic tract are more likely to cause homonymous hemianopia rather than the profound unilateral vision loss characteristic of traumatic optic neuropathy, and are generally less vulnerable to direct mechanical trauma from closed head injury.

Q: What is the composition of soda lime?

4% NaOH, 80% Ca(OH)2, trace elements, 15% H2O. ***4% NaOH, 80% Ca(OH)2, trace elements, 15% H2O*** - **Soda lime** is primarily composed of **calcium hydroxide (Ca(OH)2)**, typically around 80%, which acts as the main absorbent. - It also contains **sodium hydroxide (NaOH)**, around 4%, which serves as an activator, along with approximately 15% **water (H2O)** to facilitate the reaction, and **trace elements** like potassium hydroxide. *4% NaOH, 90% Ca(OH)2, 1% KOH, 5% H2O* - This option shows a higher percentage of **calcium hydroxide (90%)** and a lower percentage of **water (5%)** than the standard composition. - The reduced water content might impair the efficiency of **carbon dioxide absorption**. *4% NaOH, 80% Ca(OH)2, 1% KOH, 15% H2O* - While the percentages of NaOH, Ca(OH)2, and H2O are closer to correct, this option specifically mentions **potassium hydroxide (KOH)** as a distinct component at 1%, rather than general trace elements. - The standard composition usually encompasses trace elements more broadly, and specific percentages for KOH are not always highlighted as a primary component. *15% NaOH, 80% Ca(OH)2, trace elements, 4% H2O* - This composition incorrectly suggests a significantly higher percentage of **sodium hydroxide (15%)** and a critically low percentage of **water (4%)**. - A higher NaOH concentration can increase the risk of **carbon monoxide formation** from halogenated anesthetics, and inadequate water reduces absorptive capacity.

Q: Which of these is not a part of extracellular matrix:

Integrins. ***Integrins*** - Integrins are **transmembrane receptors** on the cell surface that facilitate cell-extracellular matrix (ECM) adhesion and cell-cell adhesion. - They are part of the cell membrane, **not** an extracellular component. *Laminin* - **Laminin** is a major protein component of the **basal lamina**, a specialized extracellular matrix that underlies epithelial cells. - It plays a crucial role in cell adhesion, differentiation, and migration within the ECM. *Fibronectin* - **Fibronectin** is a large glycoprotein present in the **extracellular matrix** and in soluble form in blood plasma. - It mediates cell adhesion to the ECM by binding to integrins and various ECM components like collagen and proteoglycans. *Collagen* - **Collagen** is the most abundant protein in the human body and a primary structural component of the **extracellular matrix**. - It provides tensile strength and structural integrity to tissues like skin, bone, tendons, and cartilage.

Q: All of the following are part of the treatment of scabies except?

Long term oral steroids. ***Long term oral steroids*** - **Long-term oral steroids** are generally avoided in scabies treatment as they can **suppress the immune system**, potentially worsening the infestation. - While steroids might offer temporary relief from itching, they do not address the underlying parasitic cause and can lead to various **side effects** with prolonged use. *Topical Permethrin* - **Topical permethrin** 5% cream is a **first-line treatment** for scabies, highly effective against the *Sarcoptes scabiei* mite. - It is typically applied to the entire body from the neck down, left on for 8-14 hours, and then washed off. *Oral ivermectin* - **Oral ivermectin** is an alternative treatment, particularly useful for **crusted scabies**, widespread infestations, or in cases where topical treatments are difficult to administer. - It acts by disrupting the nervous system of the mites, leading to their death. *Oral antihistamines* - **Oral antihistamines** are used to manage the **intense pruritus** (itching) associated with scabies. - They do not kill the mites but provide symptomatic relief, improving patient comfort.

Q: What do the Lines of Blaschko represent?

Patterns of cell migration. ***Patterns of cell migration*** - The **Lines of Blaschko** are invisible patterns in the skin reflecting the **movement and proliferation of cells** during embryonic development. - They become apparent in certain genetic conditions or mosaics when affected cells form streaks or swirls following these lines. *Patterns along lymphatics* - **Lymphatic patterns** refer to the distribution of the lymphatic system, which drains interstitial fluid and immune cells. - Skin conditions involving lymphatics often present as **lymphedema** or **lymphangitis**, which do not typically follow Blaschko's lines. *Patterns along blood vessels* - **Vascular patterns** describe the distribution of blood vessels in the skin, which can be affected in conditions like **livedo reticularis** or **vasculitis**. - These are distinct from Blaschko's lines, which are embryological in origin and not directly related to vascular anatomy. *Patterns along nerves* - **Nerve patterns** in the skin, such as **dermatomes**, correspond to the sensory innervation supplied by spinal nerves. - While some skin conditions can follow dermatomal distributions (e.g., **herpes zoster**), these are distinct from the embryological migration patterns represented by Blaschko's lines.

Q: Which of the following conditions is most commonly associated with cauda equina syndrome?

Herniated disc. ***Herniated disc*** - A **large central disc herniation**, especially at the L4-L5 or L5-S1 level, often compresses multiple nerve roots of the **cauda equina** [1]. - This compression leads to the characteristic symptoms of **saddle anesthesia**, **bowel/bladder dysfunction**, and **bilateral leg weakness**. *Trauma* - While **severe trauma** to the lumbar spine (e.g., fractures, dislocations) can cause cauda equina syndrome, it is a less common cause than disc herniation [1]. - Trauma typically involves an acute, high-energy injury, distinct from the more gradual onset seen with disc pathology. *Tumor* - **Spinal tumors**, both primary and metastatic, can compress the cauda equina, but they are relatively rare compared to disc herniations [1]. - Tumor-related cauda equina syndrome often presents with more insidious symptom progression and may include systemic symptoms or a history of malignancy. *Spinal stenosis* - **Spinal stenosis** can cause compression of nerve roots, typically leading to neurogenic claudication. - While severe stenosis can contribute to cauda equina symptoms, it generally involves diffuse narrowing over multiple levels and is less likely to cause acute, severe cauda equina syndrome than a single, large disc herniation.

Q: Suxamethonium primarily acts on which type of receptors?

Nicotinic acetylcholine receptors. ***Nicotinic acetylcholine receptors*** - **Suxamethonium** is a depolarizing muscle relaxant that acts as an **agonist at nicotinic acetylcholine receptors** at the neuromuscular junction. - This initial activation leads to muscle fasciculations followed by prolonged depolarization, causing **flaccid paralysis**. *Potassium channels* - While some drugs may affect potassium channels to alter neuronal excitability, suxamethonium's primary mechanism of action is not on these channels. - Blocking potassium channels is characteristic of drugs like **certain antiarrhythmics** or **sulfonylureas**. *Calcium channels* - **Calcium channels** play a role in muscle contraction, but they are not the primary target of suxamethonium. - Drugs like **dihydropyridines** (e.g., nifedipine) target calcium channels for their antihypertensive effects. *Chloride channels* - Chloride channels are involved in maintaining resting membrane potential and inhibitory neurotransmission. - Drugs such as **benzodiazepines** indirectly enhance GABA-mediated chloride influx, which is distinct from suxamethonium's action.

Q: Which of the following neck dissections is considered the most conservative?

Supraomohyoid neck dissection. ***Supraomohyoid neck dissection*** - This dissection is highly **selective**, removing only lymph nodes from **levels I, II, and III**, which are the most superficial and anterior groups in the neck. - It preserves the **internal jugular vein**, spinal accessory nerve, and sternocleidomastoid muscle, minimizing functional and cosmetic morbidity. *Radical neck dissection* - This is the **most extensive** neck dissection, involving the removal of all lymph node levels (I-V), the **internal jugular vein**, the **spinal accessory nerve**, and the **sternocleidomastoid muscle**. - It is reserved for advanced cancers with extensive nodal involvement due to its significant associated morbidity and functional deficits. *Modified radical neck dissection* - This dissection removes lymph nodes in levels I-V but **spares at least one non-lymphatic structure**, such as the spinal accessory nerve, internal jugular vein, or sternocleidomastoid muscle. - While less radical than a full radical neck dissection, it is still more extensive than a supraomohyoid dissection as it targets a broader range of lymph node levels. *All options are conservative.* - This statement is incorrect because **radical neck dissection** is by definition the most extensive and least conservative surgical approach to neck nodal disease. - The different types of neck dissections represent a spectrum of extensiveness, with supraomohyoid being the most selective and conservative.

Q: Supraomohyoid dissection is a type of?

Selective neck dissection. ***Selective neck dissection*** - **Supraomohyoid dissection** specifically refers to a type of selective neck dissection, characterized by the removal of lymph node levels **I, II, and III**. - This procedure is commonly performed for early-stage oral cavity cancers due to their typical lymphatic spread patterns. *Modified radical neck dissection* - This dissection preserves one or more **non-lymphatic structures** (e.g., sternocleidomastoid muscle, internal jugular vein, spinal accessory nerve) that are typically removed in a radical neck dissection. - It involves a broader range of lymph node levels (typically **I-V**) compared to a supraomohyoid dissection. *Radical neck dissection* - This is a more extensive procedure involving the removal of all lymph node groups (levels **I-V**), along with the **sternocleidomastoid muscle**, **internal jugular vein**, and **spinal accessory nerve**. - It is reserved for advanced neck disease due to its significant morbidity. *Posterolateral dissection* - **Posterolateral neck dissection** is a term not commonly used within the standard classification of neck dissections (radical, modified radical, selective). - Lymphatic dissection is typically categorized based on anatomical levels rather than a general directional term like posterolateral.

Question 1

Traumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?

Accepted Answer

Optic canal

Answer

Intraocular part

Answer

Intracranial part

Answer

Optic tract

Question 2

What is the composition of soda lime?

Accepted Answer

4% NaOH, 80% Ca(OH)2, trace elements, 15% H2O

Answer

4% NaOH, 90% Ca(OH)2, 1% KOH, 5% H2O

Answer

15% NaOH, 80% Ca(OH)2, trace elements, 4% H2O

Answer

4% NaOH, 80% Ca(OH)2, 1% KOH, 15% H2O

Question 3

Which of these is not a part of extracellular matrix:

Accepted Answer

Integrins

Answer

Collagen

Answer

Laminin

Answer

Fibronectin

Question 4

All of the following are part of the treatment of scabies except?

Accepted Answer

Long term oral steroids

Answer

Topical Permethrin

Answer

Oral antihistamines

Answer

Oral ivermectin

Question 5

What do the Lines of Blaschko represent?

Accepted Answer

Patterns of cell migration

Answer

Patterns along lymphatics

Answer

Patterns along blood vessels

Answer

Patterns along nerves

Question 6

In which part of the fallopian tube is ectopic pregnancy most likely to survive longer?

Accepted Answer

Interstitial

Answer

Isthmus

Answer

Ampulla

Answer

Cornua

Question 7

Which of the following conditions is most commonly associated with cauda equina syndrome?

Accepted Answer

Herniated disc

Answer

Trauma

Answer

Tumor

Answer

Spinal stenosis

Question 8

Suxamethonium primarily acts on which type of receptors?

Accepted Answer

Nicotinic acetylcholine receptors

Answer

Potassium channels

Answer

Calcium channels

Answer

Chloride channels

Question 9

Which of the following neck dissections is considered the most conservative?

Accepted Answer

Supraomohyoid neck dissection

Answer

Radical neck dissection

Answer

Modified radical neck dissection

Answer

All options are conservative.

Question 10

Supraomohyoid dissection is a type of?

Accepted Answer

Selective neck dissection

Answer

Modified radical neck dissection

Answer

Radical neck dissection

Answer

Posterolateral dissection

NEET-PG 2015

Anatomy

Anesthesiology

Biochemistry

Dermatology

Obstetrics and Gynecology

Orthopaedics

Pharmacology

Surgery