Anatomy
1 questionsTraumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?
NEET-PG 2015 - Anatomy NEET-PG Practice Questions and MCQs
Question 981: Traumatic optic neuropathy due to closed head trauma commonly affects which part of the optic nerve?
- A. Optic canal (Correct Answer)
- B. Intraocular part
- C. Intracranial part
- D. Optic tract
Explanation: ***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.
Biochemistry
1 questionsWhich of these is not a part of extracellular matrix:
NEET-PG 2015 - Biochemistry NEET-PG Practice Questions and MCQs
Question 981: Which of these is not a part of extracellular matrix:
- A. Collagen
- B. Laminin
- C. Fibronectin
- D. Integrins (Correct Answer)
Explanation: ***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.
Dermatology
2 questionsAll of the following are part of the treatment of scabies except?
What do the Lines of Blaschko represent?
NEET-PG 2015 - Dermatology NEET-PG Practice Questions and MCQs
Question 981: All of the following are part of the treatment of scabies except?
- A. Topical Permethrin
- B. Oral antihistamines
- C. Oral ivermectin
- D. Long term oral steroids (Correct Answer)
Explanation: ***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.
Question 982: What do the Lines of Blaschko represent?
- A. Patterns along lymphatics
- B. Patterns along blood vessels
- C. Patterns along nerves
- D. Patterns of cell migration (Correct Answer)
Explanation: ***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.
Obstetrics and Gynecology
3 questionsWhat is the recommended dose of folic acid for a patient with a history of neural tube defect (NTD) in a previous pregnancy?
A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?
In which part of the fallopian tube is ectopic pregnancy most likely to survive longer?
NEET-PG 2015 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 981: What is the recommended dose of folic acid for a patient with a history of neural tube defect (NTD) in a previous pregnancy?
- A. 0.5 mg
- B. 1 mg
- C. 2 mg
- D. 4 mg (Correct Answer)
Explanation: ***4 mg*** - For women with a prior history of a **neural tube defect (NTD)-affected pregnancy**, a higher dose of **4 mg of folic acid daily** is recommended to significantly reduce the risk of recurrence. - This increased dosage is crucial for achieving adequate maternal folate levels to prevent NTDs, starting at least one month before conception and continuing through the first trimester. *0.5 mg* - This dose is lower than the standard recommendation for women without a history of NTDs and is insufficient for high-risk individuals. - Suboptimal folic acid levels can still lead to a higher risk of NTD recurrence in patients with a history of NTD-affected pregnancies. *1 mg* - While 1 mg is higher than the general recommendation, it is still insufficient for women with a **history of NTD in a previous pregnancy**. - Current guidelines suggest a significantly higher dose for secondary prevention due to altered folate metabolism or higher requirements in these individuals. *2 mg* - This dose is also lower than the **established recommendation for high-risk women** who have had a previous NTD-affected pregnancy. - It does not provide the optimal level of protection required to reduce the risk of recurrence effectively.
Question 982: A G2P1L1 female presents at 28 weeks of gestation with a 1:4 anti-D titre. What is the most appropriate management option?
- A. MCA Doppler (Correct Answer)
- B. Caesarean section
- C. Induction of labour
- D. Amniocentesis
Explanation: ***MCA Doppler*** - The presence of anti-D antibodies in a pregnant woman indicates **Rh isoimmunization**, which can lead to **hemolytic disease of the fetus and newborn (HDFN)**. - Even though a titre of **1:4 is below the critical threshold** (usually 1:16 or 1:32), any detectable anti-D titre at 28 weeks warrants **fetal surveillance** to detect early signs of fetal anemia. - **Middle cerebral artery (MCA) Doppler** is the **non-invasive gold standard** for detecting fetal anemia by measuring peak systolic velocity (PSV), which increases in anemic fetuses due to hyperdynamic circulation. - Serial MCA Doppler monitoring allows timely intervention if fetal anemia develops, avoiding unnecessary invasive procedures. *Caesarean section* - This is a mode of delivery and would only be considered if there were severe **fetal compromise** or other obstetric indications after proper monitoring and management. - At 28 weeks gestation with a low anti-D titre, immediate delivery is **not indicated** and would result in significant prematurity risks. *Induction of labour* - Induction of labour is a delivery method that would only be planned at term or for specific indications like severe fetal compromise unresponsive to other interventions. - At **28 weeks gestation**, the focus should be on **monitoring and prolonging pregnancy** while ensuring fetal wellbeing, not on delivery. *Amniocentesis* - Historically used to assess **bilirubin levels (ΔOD450)** in amniotic fluid as an indirect measure of fetal hemolysis, but it is an **invasive procedure** with risks (miscarriage ~1%, infection, worsening sensitization). - **MCA Doppler has largely replaced amniocentesis** for initial and serial assessment of fetal anemia due to its non-invasive nature, high sensitivity, and ability to be repeated safely.
Question 983: In which part of the fallopian tube is ectopic pregnancy most likely to survive longer?
- A. Isthmus
- B. Ampulla
- C. Cornua
- D. Interstitial (Correct Answer)
Explanation: ***Interstitial*** - An **interstitial (intramural) pregnancy** occurs in the portion of the fallopian tube that passes through the muscular wall of the uterus, known as the **cornua**. This position allows for a larger and more distensible space, potentially accommodating the pregnancy for a longer duration before rupture. - The surrounding **myometrial tissue** can provide a temporary blood supply and structural support, leading to later presentation (often up to 12-16 weeks) and often more significant hemorrhage upon rupture due to the rich vascularization of the uterine wall. - Interstitial pregnancies account for approximately 2-4% of all ectopic pregnancies but have a higher mortality rate due to massive hemorrhage when rupture occurs. *Isthmus* - The **isthmus** is the narrowest part of the fallopian tube, making it less accommodating for an ectopic pregnancy. - Pregnancies here tend to rupture earlier (typically by 6-8 weeks) due to limited space and thinner muscular walls. - Accounts for approximately 12% of tubal ectopic pregnancies. *Ampulla* - The **ampulla** is the most common site for ectopic pregnancies (approximately 70-80%), but pregnancies here typically rupture earlier than interstitial ones (usually by 8-12 weeks). - While wider than the isthmus, it lacks the substantial myometrial support of the interstitial portion. - The ampullary wall is thin and distensible but cannot sustain pregnancy as long as the interstitial portion. *Cornua* - While the interstitial part of the tube is located within the uterine wall (cornua), \"cornua\" itself refers to the upper angles of the uterus where the fallopian tubes enter. - The term **\"cornual pregnancy\"** is sometimes used interchangeably with **\"interstitial pregnancy,\"** though some authorities distinguish between them based on precise location. - Without the specific context of \"interstitial,\" this option is less precise in identifying the segment of the fallopian tube associated with prolonged survival.
Physiology
1 questionsAntimullerian hormone is secreted by ?
NEET-PG 2015 - Physiology NEET-PG Practice Questions and MCQs
Question 981: Antimullerian hormone is secreted by ?
- A. Theca cells
- B. Leydig cells
- C. Both Sertoli cells and granulosa cells (Correct Answer)
- D. None of the above
Explanation: ***Both Sertoli cells and granulosa cells*** - **Antimullerian hormone (AMH)** is produced by **Sertoli cells in males** and **granulosa cells in females** - In **males**: Sertoli cells secrete AMH during fetal development to cause **regression of Müllerian ducts** (which would otherwise develop into uterus, fallopian tubes, and upper vagina) - In **females**: Granulosa cells of developing ovarian follicles secrete AMH, which serves as a **marker of ovarian reserve** and inhibits excessive follicle recruitment - This is the only option that correctly identifies both cell types that produce AMH *Theca cells* - Theca cells are found in ovarian follicles and produce **androgens** (androstenedione and testosterone), not AMH - These androgens are converted to estrogens by granulosa cells via aromatase enzyme - Theca cells do not produce antimullerian hormone *Leydig cells* - Leydig cells are located in the **testes** and produce **testosterone** - They do not produce antimullerian hormone - Only Sertoli cells (not Leydig cells) produce AMH in males *None of the above* - This is incorrect because AMH is indeed produced by specific cell types: **Sertoli cells in males** and **granulosa cells in females**
Surgery
2 questionsWhich of the following neck dissections is considered the most conservative?
Supraomohyoid dissection is a type of?
NEET-PG 2015 - Surgery NEET-PG Practice Questions and MCQs
Question 981: Which of the following neck dissections is considered the most conservative?
- A. Supraomohyoid neck dissection (Correct Answer)
- B. Radical neck dissection
- C. Modified radical neck dissection
- D. All options are conservative.
Explanation: ***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.
Question 982: Supraomohyoid dissection is a type of?
- A. Selective neck dissection (Correct Answer)
- B. Modified radical neck dissection
- C. Radical neck dissection
- D. Posterolateral dissection
Explanation: ***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.