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: 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 is not considered a contraindication for undergoing an MRI?

Ryle's tube. ***Ryle's tube*** - A **Ryle's tube** is a form of nasogastric tube made of radiopaque plastic, which is entirely **MRI-safe** and does not interact with magnetic fields. - It is made from inert materials that are **non-ferromagnetic**, posing no risk during an MRI scan. *Cardiac pacemaker* - **Cardiac pacemakers** contain metallic components that can malfunction, demagnetize, or migrate due to the strong magnetic fields and radiofrequency pulses of an MRI. - This can lead to **arrhythmias**, **pacemaker failure**, or **heating of leads**, posing a significant risk to the patient. *Cochlear implant* - **Cochlear implants** contain strong magnets and electronic components that can be damaged or displaced by the MRI's magnetic field. - This can cause **pain**, **implant damage**, or **hearing loss** for the patient. *Metallic splinter in eye* - A **metallic splinter in the eye** is a severe contraindication because the strong magnetic field can cause the metal fragment to move. - This movement can lead to **tissue damage**, **hemorrhage**, or **blindness** if it dislodges in the delicate structures of the eye.

Q: All are done to minimize radiation exposure to the patient under fluoroscopy, except which of the following?

Increasing fluoroscopic time. ***Increasing fluoroscopic time*** - **Increasing fluoroscopic time** directly leads to a greater cumulative dose of radiation received by the patient. - This action goes against the principle of **ALARA (As Low As Reasonably Achievable)** for radiation safety. *Decreasing fluoroscopic time* - **Decreasing fluoroscopic time** reduces the total duration of X-ray exposure, thereby minimizing the radiation dose to the patient. - This is a fundamental practice in radiation protection. *Using low dose of radiation* - Employing **low-dose radiation protocols** means using the minimum amount of radiation necessary to obtain diagnostic images. - This directly reduces the patient's exposure while maintaining image quality for diagnosis. *Decrease in field of view* - A **decrease in the field of view** (collimation) restricts the X-ray beam to only the area of interest, limiting irradiation of surrounding healthy tissues. - This targeted approach significantly reduces the overall radiation dose to the patient.

Q: Substance used for PET scan is

18F-FDG. ***18F-FDG*** - **18F-FDG (Fluorodeoxyglucose)** is a glucose analog labeled with a **positron-emitting radioisotope**, fluorine-18 (18F). - It is the most commonly used radiotracer in PET scans, as it accumulates in cells with high metabolic activity, particularly **cancer cells** and activated brain cells. *Gadolinium* - **Gadolinium** is a paramagnetic contrast agent primarily used in **MRI scans** to enhance the visualization of blood vessels and abnormal tissues. - It does not emit positrons and is therefore not suitable for PET imaging. *Gastrografin* - **Gastrografin** is an oral, water-soluble contrast agent containing **iodine**, typically used in **X-rays** and **CT scans** of the gastrointestinal tract. - It is not a radioactive tracer and has no application in PET imaging. *Iodine* - **Iodine** in various forms can be used as a contrast agent in **X-rays** and **CT scans**, or as a radioactive isotope (e.g., **I-131**) for **thyroid imaging** and treatment. - While some isotopes of iodine are radioactive, they are not typically used for PET imaging, which relies on positron emission.

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

Which of these is not a part of extracellular matrix:

Accepted Answer

Integrins

Answer

Collagen

Answer

Laminin

Answer

Fibronectin

Question 3

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 4

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 5

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 6

Which of the following is not considered a contraindication for undergoing an MRI?

Accepted Answer

Ryle's tube

Answer

Cardiac pacemaker

Answer

Cochlear implant

Answer

Metallic splinter in eye

Question 7

All are done to minimize radiation exposure to the patient under fluoroscopy, except which of the following?

Accepted Answer

Increasing fluoroscopic time

Answer

Decreasing fluoroscopic time

Answer

Using low dose of radiation

Answer

Decrease in field of view

Question 8

Substance used for PET scan is

Accepted Answer

18F-FDG

Answer

Gadolinium

Answer

Gastrografin

Answer

Iodine

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

Biochemistry

Dermatology

Obstetrics and Gynecology

Radiology

Surgery